Vilter PLC Twin Screw Compressor Operation manual
The Vilter Twin Screw Compressor PLC is a control system designed for use with Vilter Twin Screw Compressors. It provides a user-friendly interface for monitoring and controlling the compressor, and includes features such as auto start-stop, capacity slide control, and various safety features.
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Twin Screw Compressor PLC
Operation manual
Important Message
READ CAREFULLY BEFORE INSTALLING AND STARTING YOUR COMPRESSOR.
The following instructions have been prepared to assist in installation, operation and removal of Vilter Twin Screw
Compressors. Following these instructions will result in a long life of the compressor with satisfactory operation.
The entire manual should be reviewed before attempting to install, operate, service or repair the compressor.
A compressor is a positive displacement machine. It is designed to compress gas. The compressor must not be subjected to liquid carry over. Care must be exercised in properly designing and maintaining the system to prevent conditions that could lead to liquid carry over. Vilter Manufacturing is not responsible for the system or the controls needed to prevent liquid carry over and as such Vilter Manufacturing cannot warrant equipment damaged by improperly protected or operating systems.
Vilter Twin Screw Compressor components are thoroughly inspected at the factory. However, damage can occur in shipment. For this reason, the equipment should be thoroughly inspected upon arrival. Any damage noted should be reported immediately to the Transportation Company. This way, an authorized agent can examine the unit, determine the extent of damage and take necessary steps to rectify the claim with no serious or costly delays. At the same time, the local Vilter representative or the home office should be notified of any claim made.
All inquires should include the Vilter sales order number, compressor serial and model number. These can be found on the compressor name plate on the compressor.
All requests for information, services or parts should be directed to:
Vilter Manufacturing LLC
Customer Service Department
P.O. Box 8904
5555 South Packard Ave
Cudahy, WI 53110-8904 USA
Telephone: 1-414-744-0111
Fax:1-414-744-3483
E-mail: [email protected]
Equipment Identification Numbers:
Vilter Order Number: _______________________Compressor Serial Number: _________________
Vilter Order Number: _______________________Compressor Serial Number: _________________
Vilter Order Number: _______________________Compressor Serial Number: _________________
Vilter Order Number: _______________________Compressor Serial Number: _________________
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
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Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Table of Contents
Section Title Section Number
Important Message................................................................................................................................i
Section 1 • General Information
How To Use This Manual .........................................................................................................................1-1
Glossary of Terms ...................................................................................................................................1-2
Hardware Components ..........................................................................................................................1-6
Wiring Requirements .............................................................................................................................1-9
VFD Installation Recommendations .......................................................................................................1-10
Section 2 • Operation Descriptions
Overview ...............................................................................................................................................2-1
Operational Descriptions and Diagrams .................................................................................................2-2
Starting of the Compressor/Permissives.....................................................................................2-2
Compressor Start-up Sequence ..................................................................................................2-3
Start-Stop
Anti-Recycle ..............................................................................................................................2-4
Capacity Slide Control ................................................................................................................2-4
Operating .......................................................................................................................2-8
Load Limits and Forced Unloading..............................................................................................2-8
VFD Capacity Control .................................................................................................................2-10
Safeties ......................................................................................................................................2-10
Emergency
Heaters
Suction Oil Injection Solenoid ....................................................................................................2-11
Suction-Discharge Equalizing Solenoid ......................................................................................2-11
Oil Drain Solenoid ......................................................................................................................2-11
2-Way Oil Mixing Valve ..............................................................................................................2-12
Air Cooled Oil Cooler (VFD Type) ................................................................................................2-13
Oil Cooler Temperatures ............................................................................................................2-13
Oil Cooler Standby Heater ..........................................................................................................2-13
Air Cooled Aftercooler (VFD Type) ..............................................................................................2-14
Air Cooled Condenser (VFD Type)...............................................................................................2-15
Evaporative Condenser (VFD Type) ............................................................................................2-15
Air Cooled Oil Cooler (Step Type) ...............................................................................................2-16
Air Cooled Aftercooler (Step Type) .............................................................................................2-17
Air Cooled Condenser (Step Type) ..............................................................................................2-17
Water Cooled Gas Aftercooler ....................................................................................................2-18
Water Cooled Condenser ...........................................................................................................2-19
Liquid Injection Valve .................................................................................................................2-20
VPLUS Liquid Injection Pump .....................................................................................................2-21
Discharge Recycle Valve .............................................................................................................2-22
Economizer .............................................................................................................2-23
Hotgas Bypass Solenoid .............................................................................................................2-23
Venturi Oil Recovery ..................................................................................................................2-23
Gas ............................................................................................................................2-23
Building Enclosure Devices .........................................................................................................2-24
Twin Screw Compressor PLC Operation Manual •Vilter/Emerson • 35391CN
TOC - 1
Table of Contents
Section Title Section Number
Section 3 • Overview Screens
Compressor and System Overview Screens ............................................................................................3-1
Gas Compressor Unit Overview Screen Example 1
VRSG-3700 Compressor Unit for Natural Gas with Air Cooled VFD Type Oil Cooler .....................3-2
Refrigeration Compressor Unit Overview Screen Example 1
VRSH-2700 Compressor Unit for Ammonia with Liquid Injection Oil Cooling and Economizer ....3-5
Section 4 • HMI Navigation
HMI Navigation - Main Menu Screen .......................................................................................................4-1
HMI Security ..........................................................................................................................................4-8
Default .................................................................................................................................................4-8
OP1, OP2, OP3, OP4, OP5 (Operators) ...................................................................................................4-8
Super (Supervisor) .................................................................................................................................4-8
Logging In ..............................................................................................................................................4-8
Section 5 • Configuration - Supervisor Level
Configuration Screen - Supervisor (SUPER) Level ....................................................................................5-1
Date and Time ...........................................................................................................................5-2
Remote
Control
.....................................................................................................................5-2
Process Variable Source .............................................................................................................5-3
Auto
............................................................................................................................5-3
Select Setpoint 1/2 ....................................................................................................................5-3
Start-Stop
Motor
Scheduled Maintenance Timer ...................................................................................................5-3
Inlet/Outlet Scrubber Pump A/B .................................................................................................5-3
Change
PanelView
......................................................................................................................5-3
...........................................................................................................5-4
Initial Running Data ...................................................................................................................5-4
Device ............................................................................................................................5-4
Back to Menu .............................................................................................................................5-4
Editing Device Names ............................................................................................................................5-5
Devices and Vessels ...................................................................................................................5-5
........................................................................................................................5-6
Alarm and Trip ...........................................................................................................................5-7
Section 6 • Instrument Calibration
Calibration Main Screen .........................................................................................................................6-1
Pressure Calibration Screen ....................................................................................................................6-2
Calibrate Pressure Instrument ....................................................................................................6-3
Calibrate Transducer to a Known Pressure ..................................................................................6-3
Temperature Calibration Screen .............................................................................................................6-4
Calibrate Temperature Instrument .............................................................................................6-4
Other Analog Calibration Screen ............................................................................................................6-5
Calibrate an Additional Instrument ............................................................................................6-5
TOC - 2
Twin Screw Compressor PLC Operation Manual •Vilter/Emerson • 35391CN
Table of Contents
Section Title Section Number
Slide Calibration Screen .........................................................................................................................6-6
Calibrate Slide Valve - Linear Position Indicator (LPI) ...................................................................6-8
Linear Position Indicator Operation & Calibration .......................................................................6-9
Section 7 • Compressor Control Setpoints
Setpoints and Control Screens ...............................................................................................................7-1
Changing ...................................................................................................................7-1
Compressor Control Setpoints ...............................................................................................................7-2
Compressor Control Setpoints Screen 1 - Suction Pressure .....................................................................7-2
Suction Pressure Control ............................................................................................................7-2
Capacity Slide Valve ...................................................................................................................7-3
Auto .........................................................................................................................7-3
Main Motor VFD .........................................................................................................................7-3
Compressor Control Setpoints Screen 1 - Suction Pressure .....................................................................7-2
Process Temperature Control .....................................................................................................7-2
Capacity Slide Valve ...................................................................................................................7-3
Auto
Main Motor VFD .........................................................................................................................7-4
Compressor Control Setpoints Screen 1 - Discharge Pressure .................................................................7-5
Discharge Pressure Control ........................................................................................................7-5
Capacity Slide Valve ...................................................................................................................7-5
Auto
Main Motor VFD .........................................................................................................................7-6
Compressor Control Setpoints Screen 2 .................................................................................................7-7
Anti-Recycle
Start .....................................................................................................................................7-7
Shut
Oil Separator Heaters .................................................................................................................7-8
Load
Main Motor FLA .........................................................................................................................7-8
Compressor Control Setpoints Screen 3 .................................................................................................7-8
Supplemental False Start Protection ..........................................................................................7-8
Venturi Oil Recovery ..................................................................................................................7-9
Hotgas ...........................................................................................................................7-9
................................................................................................................................7-9
Enclosure ...................................................................................................................7-9
Oil Flow Control .........................................................................................................................7-9
Periodic Slide Valve Exercise .......................................................................................................7-10
Section 8 • Alarm and Trip Setpoints
Alarm and Trip Setpoints ........................................................................................................................8-1
Alarm and Trip Setpoints Screen 1 ..........................................................................................................8-1
Twin Screw Compressor PLC Operation Manual •Vilter/Emerson • 35391CN
TOC - 3
Table of Contents
Section Title
Section 9 • Step and PID Device Control Screens
Section Number
Oil Mixing Valve Screen ..........................................................................................................................9-1
Oil Mixing Valve Setpoints ..........................................................................................................9-1
Oil Cooler (VFD Type) Setpoints .................................................................................................9-2
Oil Cooler (Step Type) Setpoints .................................................................................................9-3
Aftercooler Screens ................................................................................................................................9-4
Aftercooler (VFD Type) Setpoints ...............................................................................................9-4
Aftercooler (Step Type) Setpoints ..............................................................................................9-5
Water Cooled Aftercooler Setpoints ...........................................................................................9-6
Condenser Screens ................................................................................................................................9-7
Condenser (Step Type) Setpoints ...............................................................................................9-7
Condenser (VFD Type) Setpoints ................................................................................................9-8
Water Cooled Condenser Setpoints ............................................................................................9-9
Liquid Injection Valve Screen ..................................................................................................................9-10
Liquid Injection Valve Setpoints .................................................................................................9-10
Liquid Injection (VPLUS Pump) Setpoints ...................................................................................9-11
Discharge Recycle Valve Screen ..............................................................................................................9-12
Discharge Recycle Valve Setpoints .............................................................................................9-12
Start Menu Popup Screen .......................................................................................................................9-13
Section 10 • Diagnostic Screens
IO/Comms Diagnostics Screen ...............................................................................................................10-1
Comms Diagnostics and I/O Status ............................................................................................10-1
Event List Screen ....................................................................................................................................10-2
Diagnostics Forced Outputs Screen ........................................................................................................10-3
Captured Data at Shutdown Screen .......................................................................................................10-4
Initial Baseline Running Data Screen .......................................................................................................10-5
Section 11 • Alarms, Trips, Status Information
Alarms and Trips ....................................................................................................................................11-1
Alarm Listing ..........................................................................................................................................11-2
Trip Listing .............................................................................................................................................11-9
Status Messages and Compressor State Indicator ...................................................................................11-16
Troubleshooting ....................................................................................................................................11-20
If the Compressor Will Not Start.................................................................................................11-20
If Control Power Will Not Turn On ..............................................................................................11-20
Section 12 • Central Controller Communications
Communication with a Central Controller/DCS ......................................................................................12-1
VPN ................................................................................................................................12-1
Setting Up Communications ......................................................................................................12-1
Watchdog
Data that can be Read from the Compressor PLC ....................................................................................12-1
Live Instrument Data .................................................................................................................12-1
Alarm and Trip Data ...............................................................................................................................12-8
Status Data ............................................................................................................................................12-16
States of Discrete I/O .............................................................................................................................12-20
TOC - 4
Twin Screw Compressor PLC Operation Manual •Vilter/Emerson • 35391CN
Table of Contents
Section Title Section Number
Section 12 • Central Controller Communications (Continued)
Compressor State Indicator ....................................................................................................................12-25
Sending Commands to Compressor PLC (Ethernet IP Version) ................................................................12-25
Watchdog
Discrete Compressor Commands ...............................................................................................12-26
Twin Screw Compressor PLC Operation Manual •Vilter/Emerson • 35391CN
TOC - 5
List of Tables and Figures
Table/Figure Section
Tables
Table 6-1. Connections - Visual and by Analogue Output (4-20 mA) .......................................................6-8
Table 6-2. Connections - Visual and by Digital 24V Output on Min & Max Load .......................................6-9
Table 11-1. Alarm Listing ........................................................................................................................11-2
Table 11-2. Trip Listing ...........................................................................................................................11-9
Table 11-3. Status Listing .......................................................................................................................11-16
Table 12-1. Engineered Units Value Interpretation (INT_OUT[x]) ...........................................................12-2
Table 12-2. Live Instrument Data ............................................................................................................12-2
Table 12-3. Alarm Data ...........................................................................................................................12-8
Table 12-4. Trip Data ..............................................................................................................................12-12
Table 12-5. Status Data ..........................................................................................................................12-16
Table 12-6. Discrete Input States ............................................................................................................12-20
Table 12-7. Discrete Output States .........................................................................................................12-22
Table 12-8. State Indicator .....................................................................................................................12-25
Table 12-9. Mode Indicator ....................................................................................................................12-25
Table 12-10. Compressor Command (Real) ............................................................................................12-26
Table 12-11. Compressor Command (Double Integer) ............................................................................12-26
Figures
Figure 2-1. Compressor Startup Sequence Diagram ...............................................................................2-3
Figure 2-2. Capacity Slide Control Diagram (Example) ............................................................................2-5
Figure 2-3. Operational Diagram - Capacity Slide, Discharge Pressure (Example) ....................................2-6
Figure 2-4. Operational Diagram - Capacity Slide, Suction
Pressure per Process Temperature (Example) .......................................................................2-7
Figure 2-5. Operational Diagram - Load Limits / Forced Unloading (Example) .........................................2-9
Figure 2-6. Control Panel Master Power and Emergency Stop Electrical Circuit .......................................2-11
Figure 2-7. Operational Diagram - 2-Way Oil Mixing Valve ......................................................................2-12
Figure 2-8. Operational Diagram - Air Cooled Oil Cooler (VFD Type) .......................................................2-13
Figure 2-9. Operational Diagram - Air Cooled Aftercooler (VFD Type) .....................................................2-14
Figure 2-10. Operational Diagram - Air Cooled Condenser (VFD Type) ....................................................2-15
Figure 2-11. Operational Diagram - All Air Cooled Oil Coolers (Step Type)...............................................2-16
Figure 2-12. Operational Diagram - Air Cooled Condenser ......................................................................2-17
Figure 2-13. Operational Diagram - Water Cooled Gas Aftercooler .........................................................2-18
Figure 2-14. Operational Diagram - Water-Cooled Condenser ................................................................2-19
Figure 2-15. Operational Diagram - Liquid Injection Valve ......................................................................2-20
Figure 2-16. Operational Diagram - VPLUS .............................................................................................2-21
Figure 2-17. Operational Diagram - Discharge Recycle Valve ..................................................................2-22
Figure 3-1. Basic Compressor Unit Screen ..............................................................................................3-1
Figure 3-2. Example 1 - Gas Compressor Unit Overview Screen,
VRSG-3700 Compressor Unit for Natural Gas with Air Cooled VFD Type Oil Cooler ................3-2
Figure 3-3. Example 2 - Refrigeration Compressor Unit Overview Screen,
VRSH-2700 Compressor Unit for Ammonia with Liquid Injection Oil Cooling & Economizer ..3-5
Figure 4-1. Main Menu Screen ................................................................................................................4-1
Figure 4-2. Screen Navigation Map .........................................................................................................4-2
Figure 4-3. Login Screen .........................................................................................................................4-8
Figure 4-4. Login Screen Keyboard .........................................................................................................4-9
TOC - 6
Twin Screw Compressor PLC Operation Manual •Vilter/Emerson • 35391CN
List of Tables and Figures
Figure 5-1. Configuration Screen - Supervisor Level ................................................................................5-1
Figure 5-2. Set Date/Time Pop-Up Screen - Supervisor Level ...................................................................5-2
Figure 5-3. Change Password Pop-Up Screen - Supervisor Level ..............................................................5-3
Figure 5-4. Define Device Names - Devices and Vessels (Supervisor Level) ..............................................5-5
Figure 5-5. Define Device Names - Instrumentation (Supervisor Level) ...................................................5-6
Figure 5-6. Define Device Names - Alarm and Trip 1 (Supervisor Level) ...................................................5-7
Figure 6-1. Instrument Calibration Overview Screen ..............................................................................6-1
Figure 6-2. Pressure Calibration Screen - 1 of 3 .......................................................................................6-2
Figure 6-3. Pressure Calibration Screen - 3 of 3 .......................................................................................6-3
Figure 6-4. Temperature Calibration Screen ...........................................................................................6-4
Figure 6-5. Other Analog Calibration Screen ..........................................................................................6-5
Figure 6-6. Slide Calibration Screen (Not in Calibration Mode) ................................................................6-6
Figure 6-7. Slide Calibration Screen (In Calibration Mode) ......................................................................6-7
Figure 6-8. Linear Position Indicator (LPI) ...............................................................................................6-8
Figure 6-9. Linear Position Indicator (LPI) with Cover Removed ...............................................................6-10
Figure 7-1. Numeric Entry Pop-up Screen ...............................................................................................7-1
Figure 7-2. Compressor Control Screen - 1 of 3 (Suction Pressure) ..........................................................7-2
Figure 7-3. Compressor Control Screen - 1 of 3 (Process Temperature) ...................................................7-4
Figure 7-4. Compressor Control Screen (Discharge Pressure) - 1 of 3 ......................................................7-5
Figure 7-5. Compressor Control Screen - 2 of 3 .......................................................................................7-7
Figure 7-6. Compressor Control Screen - 3 of 3 (All Options Shown) .......................................................7-9
Figure 8-1. Alarm and Trip Setpoints Screen - 1 of 2 ................................................................................8-1
Figure 8-2. Alarm and Trip Setpoints Screen - 2 of 2 ................................................................................8-2
Figure 9-1. Oil Mixing Valve Screen ........................................................................................................9-1
Figure 9-2. Oil Cooler Valve (VFD Type) Screen .......................................................................................9-2
Figure 9-3. Oil Cooler Valve (Step Type) Screen .......................................................................................9-3
Figure 9-4. Aftercooler (VFD Type) Screen ..............................................................................................9-4
Figure 9-5. Aftercooler (Step Type) Screen .............................................................................................9-5
Figure 9-6. Water Cooled Aftercooler Screen ..........................................................................................9-6
Figure 9-7. Condenser (Step Type) Screen ..............................................................................................9-7
Figure 9-8. Condenser (VFD Type) Screen ...............................................................................................9-8
Figure 9-9. Water Cooled Condenser Screen ...........................................................................................9-9
Figure 9-10. Liquid Injection Valve Screen ..............................................................................................9-10
Figure 9-11. Liquid Injection (VPLUS Pump) Screen ................................................................................9-11
Figure 9-12. Discharge Recycle Valve Screen ..........................................................................................9-12
Figure 9-13. Start Menu .........................................................................................................................9-13
Figure 10-1. IO/Comms Diagnostics Screen ...........................................................................................10-1
Figure 10-2. Event List Screen .................................................................................................................10-2
Figure 10-3. Diagnostics Forced Output Screen ......................................................................................10-3
Figure 10-4. Captured Data at Shutdown Screen ....................................................................................10-4
Figure 10-5. Initial Baseline Running Data Screen ...................................................................................10-5
Figure 11-1. Alarm/Trip/Status Bars (Main Menu Screen) ........................................................................11-1
Figure 11-2. Alarm Popup Screen ...........................................................................................................11-1
Figure 11-3. Alarm/Trip/Status Bars (Main Menu Screen) ........................................................................11-16
Twin Screw Compressor PLC Operation Manual •Vilter/Emerson • 35391CN
TOC - 7
Blank / TOC
Twin Screw Compressor PLC Operation Manual •Vilter/Emerson • 35391CN
Section 1 • General Information
HOW TO USE THIS MANUAL
This manual contains instructions for the PLC. It has been divided into 12 sections:
Section 1: General Information
Section 2: Sequence of Operation
Section 3: Overview Screens
Section 4: HMI Navigation
Section 5: Confi guration - Supervisor Level
Section 6: Instrument Calibration
Section 7: Compressor Control Setpoints
Section 8: Alarms and Trips Setpoints
Section 9: Step and PID Device Control Screens
Section 10: Diagnostics Screens
Section 11: Alarms, Trips, Status Information and
Troubleshooting
Section 12: Communications with a Central
Controller/DCS
ADDITIONAL IMPORTANT NOTES
• Installation, operation and maintenance instructions can be found in the associated gas compressor unit manual.
• Due to continuing changes and unit updates, always refer to the Vilter.com website to make sure you have the latest manual.
• Any suggestions of manual improvements can be made to Vilter Manufacturing at the contact information on page i.
It is highly recommended that the manual be reviewed prior to servicing system parts.
Figures and tables are included to illustrate key concepts.
Safety precautions are shown throughout the manual.
They are defi ned as the following:
NOTICE - Notice statements are shown when there are important information that shall be followed. Not following such notices may result in void of warranty, serious fi nes, serious injury and/or death.
WARNING - Warning statements are shown when there are hazardous situations, if not avoided, will result in serious injury and/or death.
CAUTION - Caution statements are shown when there are potentially hazardous situations, if not avoided, will result in damage to equipment.
NOTE - Notes are shown when there are additional information pertaining to the instructions explained.
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
1 – 1
Section 1 • General Information
Glossary of Terms
2-Way Oil Mixing Valve
Motorized valve mounted on the compressor unit that directs hot oil to the oil cooler when needed.
Aftercooler Heat Exchanger
Used to cool discharge gas from the compressor.
Aftercooler Outlet Temperature
Temperature of gas measured at the outlet of the
Aftercooler.
Alarm Warning
Annunciated by the compressor PLC that an operational or process condition is abnormal. When active, alarms will be displayed but will not shut down the compressor.
Bearing Temperature
Temperature of the bearings of the compressor main motor measured by an RTD.
Building Enclosure
Insulated enclosure or container the compressor and some ancillary equipment can be mounted in as a package.
Capacity Slide Valve
Internal mechanism in the compressor that controls compressor loading and unloading.
Capacity Hydraulic Slide Valve with Double Acting
Solenoid Valve
Oil pressure with double acting solenoid valves is used to control the capacity slide valve.
Chiller
Heat Exchanger where liquid refrigerant boils off cooling a process fl uid (liquid or gas, ex. natural gas, glycol, water)
Compressor Differential Calculated
Discharge Pressure minus Suction Pressure. Monitored to ensure compressor is equalized before starting.
Condenser
Heat exchanger that removes heat from superheated refrigerant vapor and converts it to a liquid.
Condensing Pressure:
Pressure of refrigerant vapor measured at the condenser.
Differential Pressure
The difference between two pressures.
Discharge Recycle Control Pressure
Pressure of discharge gas measured at the Discharge
Recycle Valve. Used to control the Discharge Recycle
Valve.
Discharge Recycle Valve
Motorized or Air Actuated Valve that recycles discharge gas back to the suction side of the compressor.
Discharge Pressure
Pressure of the refrigerant or gas measured at the outlet of the compressor.
Discharge Temperature
Temperature of the refrigerant or gas measured at the outlet of the compressor.
Economizer
Intermediate pressure between suction and discharge of the compressor, typically used to subcool liquid refrigerant to increase cooling capacity of the compressor. A solenoid valve controlled by the compressor PLC enables the economizer to function.
EPCS
EPCS stands for “Emergency Pressure Control System.”
Used where required on refrigeration applications to relieve high discharge pressure back to suction to prevent activating a relief valve. Consists of a solenoid valve and two pressure transmitters, one on the discharge (high) side and one on the suction (low) side. When the discharge (high) side pressure reaches 90% of relief valve setting, the solenoid will open and relieve high pressure discharge gas back to suction (low) side. When either pressure transmitter reaches 90% of their respective high or low side relief valve settings, the compressor will shut down.
Ethernet IP
Communication protocol used to communicate to the compressor PLC.
Gas Equalizing Solenoid
Solenoid Valve that opens at compressor stop to equalize suction and discharge pressures.
1 – 2
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 1 • General Information
HMI
HMI stands for “Human-Machine Interface.” The compressor HMI is a touchscreen terminal mounted in the door of the compressor control enclosure.
Hotgas Bypass
Self-regulated valve which provides a “false load” by recycling discharge gas to suction in refrigeration applications. Used to prevent the compressor from shutting down during low load conditions. A solenoid valve controlled by the compressor PLC enables the Hotgas
Bypass valve to function.
Inlet Scrubber
Vessel located on the inlet side of gas compressor or gas chiller to remove moisture and contaminants.
Inlet Scrubber Inlet Pressure
Pressure of gas measured at the inlet of the inlet scrubber.
Inlet Scrubber Outlet Pressure
Pressure of gas measured at the outlet of the inlet scrubber.
Inlet Scrubber Pressure Drop
Pressure differential between inlet and outlet of the inlet scrubber. Calculated: Scrubber Inlet Pressure minus
Scrubber Outlet Pressure.
Liquid Injection
Method of oil cooling where liquid refrigerant is metered into the compressor by a motorized or air actuated valve.
Liquid Refrigerant Temperature
Temperature of the liquid refrigerant measured in the chiller, also known as the evaporation temperature.
Main Motor
AC induction motor that is coupled to and drives the compressor.
Net Oil Pressure
Calculated: Oil Filter Out Pressure minus Discharge
Pressure. Monitored while compressor is running to ensure adequate lubrication.
Oil Circuit Pressure Drop
Calculated: Discharge Pressure minus Oil Filter Outlet
(Manifold) Pressure.
Oil Cooler
Heat Exchanger where hot oil from the compressor is cooled.
Oil Cooler Inlet Temperature
Temperature of compressor oil measured at the inlet of the oil cooler.
Oil Cooler Outlet Temperature
Temperature of compressor oil measured at the outlet of the oil cooler.
Oil Filter Differential Calculated
Oil Filter Outlet (Manifold) Pressure minus Oil Filter Inlet
Pressure. Monitored while compressor is running to determine condition of oil fi lter(s).
Oil Filter Inlet Pressure
Pressure of the compressor oil measured at the inlet of the oil fi lter(s).
Oil Filter Outlet (Manifold) Pressure
Pressure of the compressor oil measured between the oil fi lter(s) and the compressor.
Oil Injection Temperature
Temperature of the compressor oil going into the compressor.
Oil Separator
Vessel the compressor discharges into that separates oil from gas or refrigerant.
Oil Separator Gas Outlet Temperature
Temperature of the gas or refrigerant measured at the outlet of the oil separator vessel.
Oil Separator Outlet Pressure
Pressure of discharge gas or refrigerant measured at the outlet of the oil separator.
Oil Separator Pressure Drop Calculated
Discharge Pressure minus Oil Separator Outlet Pressure.
Monitored to determine condition of coalescing elements inside the oil separator vessel.
Outlet Scrubber
Vessel located on the outlet side of gas compressor or gas chiller to remove moisture, oil, and/or contaminants.
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
1 – 3
Section 1 • General Information
Outlet Scrubber Inlet Pressure
Pressure of gas measured at the inlet of the outlet scrubber.
Outlet Scrubber Outlet Pressure
Pressure of gas measured at the outlet of the outlet scrubber.
Outlet Scrubber Pressure Drop
Pressure differential between inlet and outlet of the outlet scrubber. Calculated: Scrubber Inlet Pressure minus
Scrubber Outlet Pressure.
PID Controller
PID stands for “Proportional Integral Derivative.” A PID controller manipulates a control variable (example: valve position or fan/pump speed) to maintain a process variable (example: process temperature or pressure) at a desired value (setpoint). The controller is driven by mathematical calculations that tell the control variable how to react to changes in the process variable.
PLC
PLC stands for “Programmable Logic Controller.” The
Compressor PLC is an industrial computer that controls the compressor unit or Package.
Prelube Oil Pressure
Calculated: Oil Filter Out Pressure minus Discharge
Pressure. Monitored at compressor start to ensure adequate lubrication.
Pressure Ratio
The ratio of compressor discharge pressure to suction pressure.
Pressure Ratio Calculated
(Discharge Pressure) / (Suction Pressure)
Pressure Transducer or Transmitter
Device that measures pressure and transmits the pressure reading as a 4-20mA signal. This 4-20mA signal is read by the PLC and displayed as a pressure.
Process Temperature
Temperature of the process fl uid (liquid or gas, ex. natural gas, glycol, water) measured at the process outlet of the chiller.
Rotor Feed Oil Pressure
Pressure of the Non-Pumped side of the oil circuit feeding oil to the screw (on machines that have an oil circuit with a non-pumped section).
RTD
RTD stands for “Resistance Temperature Detector.”
RTDs use electrical resistance to measure temperature.
This resistance is read by the PLC and displayed as a temperature.
Separator Oil Temperature
Temperature of the compressor oil in the bottom of the oil separator vessel.
Suction Oil Injection
Method of providing additional lubrication to large frame compressors at compressor start.
Suction Pressure
Pressure of the refrigerant or gas measured at the inlet of the compressor.
Suction Temperature
Temperature of the refrigerant or gas measured at the inlet of the compressor.
Surge Drum or Suction Accumulator
Vessel where additional liquid refrigerant may accumulate to prevent liquid from getting into the compressor.
Temperature Transmitter
Device that measures temperature and transmits the temperature reading as a 4-20mA signal. This 4-20mA signal is read by the PLC and displayed as a temperature.
Trip
Compressor shutdown due to an abnormal process or operational condition.
Venturi Oil Recovery
Method of recovering compressor oil from the chiller using solenoid valves on a cycle timer.
VFD
VFD stands for “Variable Frequency Drive.” A VFD is a motor control device that can vary the speed of an AC induction motor.
1 – 4
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 1 • General Information
V-PLUS
V-PLUS stands for “Vilter Pumped Liquid Unitary
System.” It is a method of oil cooling where liquid refrigerant is pumped into the discharge line or housing by a variable speed pump.
VPN
VPN stands for “Virtual Private Network.” A VPN connection allows remote access to the compressor PLC.
Winding Temperature
Internal winding temperature of the compressor main motor measured by an RTD.
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
1 – 5
Section 1 • General Information
Hardware Components - PLC Exterior
Each Compact Logix PLC may differ, but below are typical components that can found in each PLC. For specifi c PLC layout, refer to supplied electrical drawings.
1 - HMI Cover
2 - Enclosure Door
3 - Door Latch
4 - Main Enclosure
5 - HMI (Panel View Plus 6)
6 - Master Power
7 - Compressor Control Reset Button
8 - Emergency Stop Button
1 2
3
4
5
6
7
8
3
1 – 6
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 1 • General Information
Hardware Components - Enclosure Door Interior
3 8 7 6 5 2
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
1 – 7
Section 1 • General Information
Hardware Components - Main Enclosure Interior
10 - Terminal Blocks (AC Connections)
11 - Fuses
12 - Relays
13 - DC Power Supplies
14 - Ethernet Switch, 5 Port RJ45
15 - Panel Heater & Mounting (Not Shown, Field Installed)
16 - Modules
10 11 12 13
17 - Compact Logix Power Supply
18 - Compact Logix Processor with Ethernet, and
Memory Card
19 - Terminal Blocks (DC Low Voltage Connections)
20 - Terminal Blocks (Customer Connections)
21 - Terminal Blocks (Main Power Connections)
11 14
1 – 8
21 20 19 18 16 17 16 15
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 1 • General Information
Wiring Requirements
• Incoming power enters on the left bottom wall of the
PLC control enclosure. Route these conductors in the space between the sub-panel and inside wall of the enclosure.
• DC control, analog and communications or network wiring enters on the right bottom wall of the PLC control enclosure.
• Wiring external to the panel per NEC (NFPA 70), ANSI
12.12.01 and UL-598A.
• Panel construction and wiring per UL-508A for all panels and ANSI 12.12.01 and UL-698A for hazardous locations.
• Electrical transmission, control, and alarm wiring shall be stranded copper no smaller than #14 AWG.
Use JIC color code, unless otherwise noted.
• All control circuits from a source outside of this panel are to be #14 AWG Orange.
• All control circuit neutrals from a source outside of this panel are to be no smaller than #14 AWG White/
Orange Tracer.
• All analog inputs are to be connected with shielded cable. Shield terminated at panel side and isolated at device side.
• All shielding is to be grounded at a single point on the chassis.
• Analog wiring must be run separate from AC wiring and kept separate within the enclosure.
• All analog signal wiring shall be grounded at one end only. Ground shield of signal cables.
• Use alpha P/N 2423C, 3 Cond, 18 AWG, shielded or approved equal.
• Only one customer network cable to switch.
• Unused defi ned as having a previous assignment.
Spare defi ned as no previous assignment.
• Where applicable, remove jumper between connections if used.
• All power circuits from a source outside of this panel are to be no smaller than #12 AWG Orange.
• All power circuit neutrals from a source outside of this panel are to be no smaller than #12 AWG White/
Orange Tracer.
• All equipment grounds must be Green/Yellow. For ground conductors larger than #6 AWG, apply Green/
Yellow heat shrink or color conductor with marker at both ends.
• All power sources for heating devices shall be supplied by others.
• Designated for a trip function (i.e. limit trip, sequence shutdown, etc.). Recommended hard wire connection.
• Use alpha P/N 2422C, 2 Cond, 18 AWG, shielded or approved equal.
• Category 6 Ethernet cable is recommended for all of our equipment.
SEPARATION OF INTRINSICALLY SAFE CIRCUITS (IF
USED)
The intrinsically safe wiring enters on the bottom-left wall of the PLC control enclosure.
To reduce the possibility of interconnection, additional requirements exist for the separation of intrinsically safe and non-intrinsically safe circuits. Exceptions to this rule may be found in NEC Section 504-30(A)(1) and (2).
Separation by distance:
• The distance between intrinsically safe fi eld wiring terminals and non-intrinsically safe fi eld wiring terminals shall be a minimum 8 inches.
• The distance between intrinsically safe fi eld wiring terminals and non-intrinsically safe fi eld circuits shall be a minimum 5 inches.
• The distance between intrinsically safe fi eld wiring terminals and non-intrinsically safe fi eld circuits and wiring shall be a minimum 5 inches.
• The distance between intrinsically safe fi eld wiring terminals and non-intrinsically safe internal wiring shall be a minimum 2 inches.
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
1 – 9
Section 1 • General Information
VFD Installation Recommendations
• All wiring to and from the Variable Frequency Drive
(VFD) starter shall conform to the National Fire
Protetcion Association 70 (NFPA-70), local codes and the manufacturer’s guidelines and specifi cations.
• Thoroughly read the manufacturer’s VFD installation and instruction manuals.
• In the event of a code and manufacturer recommendation confl ict, always use the more stringent standard.
• Only use an inverter duty rated motor built to NEMA
MG1 PART 30 & 31.
• Always used copper conductors to feed the VFD starter and motor. Use cable with thermoset insulation such as XLPE or XHHW-2 from the VFD to motor.
• It is preferred to use VFD cable, service wire company or equal, between the VFD and the motor per manufacturer’s instructions.
• It is preferred to use continuous metal conduit to the
VFD starter to the motor.
• If non-metallic conduit is used, VFD cable must be used.
• If using VFD cable in metal conduit, the metal conduit must be insulated at the motor, so that the metal conduit is not a continuous run.
• Always use fl exible metallic liquid-tight conduit to feed the motor from metallic conduit.
• Grounding conductor must run from the VFD ground terminals directly to the motor conduit box. Always use proper grounding techniques (Star Method) and sized according to the NFPA 70 NEC.
• Always use bonding bushings on all conduit ends,
• Always use bonding bushings on all conduit ends, with proper size braided copper cable bonded to the starter panel.
• All grounding and bonding conductors and lugs must terminate on bare metal and not to painted surfaces.
• Always use a minimum of 3% impedance line reactor such as MTE or equal.
• Where the cables to the motor are longer than 50’, always use a load reactor (customer must provide
Vilter with cable lengths from feeder to starter and from starter to motor).
• Where the cables to the motor are longer than 500’, always use a DV/DT load fi lter (customer must provide Vilter with cable lengths from feeder to starter and from starter to motor).
• Where the cables to the motor are longer than 1000’, always use a sine fi lter (customer must provide Vilter with cable lengths from feeder to starter and from starter to motor).
• Line and load conductors must be separated, as much as the starter cabinet will allow, and cannot be in the same conduit or cable chase.
• By no means shall power and control cables run in parallel - cables must be separated, as much as the starter cabinet will allow, and cannot be in the same conduit or cable chase.
• For analog signals, use twisted shielded control cable rated for 600V.
• When a generator is feeding a VFD starter, use a 5% line reactor.
• Some countries require RFI/EMI fi lters -- please consult country codes and standards.
• As an insurance policy against motor shaft currents, use a split ring bearing protection ring on the motor shaft with the non-load bearing insulated.
1 – 10
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 2 • Operational Descriptions
Overview
The following are standard equipment on all compressor units or packages that can be controlled or monitored:
• Suction Pressure – Pressure of the gas measured at the inlet of the compressor.
• Discharge Pressure – Pressure of the gas at the outlet of the compressor. Measured at the oil separator.
• Oil Filter Inlet Pressure – Pressure of oil measured at the inlet of the oil fi lter(s).
• Oil Manifold Pressure (Oil Filter Out) – Pressure of oil measured after the oil fi lter(s).
• Prelube Oil Pressure (at compressor start, Oil Filter
Out Pressure minus Discharge Pressure)
• Net Oil Pressure (when compressor is running, Oil
Filter Out Pressure minus Discharge Pressure)
• Suction Temperature – Temperature of the gas measured at the inlet of the compressor.
• Discharge Temperature – Temperature of the gas and oil mixture at the outlet of the compressor
• Separator Oil Temperature – Temperature of the oil in the oil separator vessel.
• Oil Injection Temperature – Temperature of the oil as it goes into the compressor.
• Capacity Slide Valve Position - % Travel of the capacity slide valves.
• Main Motor Amperage – Current draw by the main motor.
• Separator Oil Heaters
• Compressor Main Motor
• Oil Pump (Full Time)
• Selectable groups of setpoints for varying operating conditions
The following are additional software controls available that are native to all compressor units controlled by the compressor PLC:
• Monitoring of Instrument Data, Alarms, Trips, and
Machine Status by DCS/Central Controller
• Compressor Capacity control setpoint from DCS/
Central Controller
• Control of Compressor Loading/Unloading from
DCS/Central Controller
• Capacity control on External Pressure Transducer data from DCS/Central Controller
• Auto Start/Stop based on process pressure or temperature
• Control of Local/Remote from DCS/Central Controller
• Setpoint Group Selectable from DCS/Central
Controller
• Remote Starting and Stopping of the Compressor
• The following are optional compressor unit-specifi c items that can be controlled or monitored:
• Compressor Main Motor VFD Control
• Main Motor Winding Temperatures
• Main Motor Bearing Temperatures
• Motor Vibration (up to 2 sensors)
• Compressor Vibration (up to 2 sensors)
• Oil Separator Level Switch
• Suction Oil Injection Solenoid Valve
• Suction-Discharge Equalizing Solenoid Valve
• Oil Drain Solenoid Valve
• Oil Separator Outlet Pressure, to calculate pressure drop across coalescing elements of oil separator
• 2-Way Oil Mixing Valve
• Air Cooled Oil Cooler (Step or VFD Type)
• Oil Cooler Inlet/Outlet Temperatures
• Oil Cooler Standby Heater
The following are optional compressor unit and package items that can be controlled or monitored, specifi c to refrigeration applications:
• Air Cooled Condenser (Step Type or VFD Type)
• Evaporative Air Cooled Condenser
• Water Cooled Condenser
• Oil Injection Control Valve
• Liquid Injection Oil Cooling
• VPLUS Liquid Oil Cooling
• Economizer Port Solenoid Valves (single or dual)
• Hotgas Bypass Solenoid
• Venturi Oil Recovery
• Liquid Refrigerant Temperature – Temperature of the liquid refrigerant in the chiller.
• Process Temperature – Temperature of the process fl uid leaving the chiller
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
2 – 1
Section 2 • Operational Descriptions
The following are optional compressor unit and package items that can be controlled or monitored, specifi c to gas compression applications:
• Up to 2 Aftercoolers
• Air Cooled Step Type
• Air Cooled VFD Type
• Water Cooled
• Inlet Scrubber
• Pressure Drop across vessel
• Condensate Drain
• Low/High Level Safety Switches
• Outlet Scrubber
• Pressure Drop across vessel
• Condensate Drain
• Low/High Level Safety Switches
• Discharge Recycle Valve
• Building Enclosure Devices
• Space Heaters
• Roof Exhaust Fans
• Methane %LEL Detector
• Oil Separator Gas Outlet Temperature – Temperature of the gas measured at the discharge of the oil separator. Used to monitor the temperature of the gas relative to dew point. If the compressor is warm and this temperature is too low, the controller will generate an alarm.
• Oil Separator Gas Outlet Pressure – Pressure of the gas measured at the discharge of the oil separator.
Used to monitor the pressure drop across the coalescing elements of the oil separator. When pressure drop is too high, the controller will generate an alarm.
• Reheater Vessel and shell/tube side Temperatures –
Temperature of the gas measured at the discharge of both the shell and tube sides of the reheater vessel.
• Periodic Slide Valve Exercising
Operational Descriptions and
Diagrams
STARTING OF THE COMPRESSOR/PERMISSIVES
To run the compressor, it must me started from the
“Start Menu” screen on the control panel HMI. Pressing
“Unit Start” in the “Start Menu” screen will initiate a start if all permissives to initiate a start are met. To initiate a start, the following conditions must be met:
• Control Power is ON (Emergency Stop button is not pressed, Master Control Relay is energized or activated by remote device, indicated by pilot light on front of panel)
• No Active Trips
When a start is initiated, the compressor will start if all permissives to run the compressor are met. If all permissives to run the compressor are not met, the control will wait in a “standby” mode until all conditions to run are satisfi ed. Any condition that the control is waiting on is annunciated on the overview and menu screens and logged in the Event List. To begin the compressor startup sequence, the following conditions must be met:
• Control Power is ON (Emergency Stop button is not pressed and Master Control Relay is energized, indicated by pilot light on front of panel)
• No Active Trips
• Compressor start has been initiated by pressing “Unit
Start” in the “Start Menu” screen.
• Remote Permissive input is ON
• Soft run permissive from the DCS/Central Controller is ON (if control by communications selected)
• Anti-Recycle Timer is not active
• Suction – Discharge is equalized to within a settable differential
• Auto Start control is calling for the compressor to start, if Auto Start/Stop is Enabled.
If a start is initiated at the compressor, the machine state indicator will indicate “Standby” and the condition the compressor is waiting on will be annunciated on the overview and menu screens.
2 – 2
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 2 • Operational Descriptions
COMPRESSOR STARTUP SEQUENCE
PERMISSIVES MET &
UNIT STARTED
IDLE
MOVE CAPACITY SLIDES
HOME
CAPACITY SLIDE POSITION < 5% TRAVEL
COMPRESSOR STOP
TRIP
AUTO CYCLE OFF
STORE (MANIFOLD MINUS DISCHARGE)
PRELUBE DIFFERENTIAL PRESSURE
ADD 1 TO PRELUBE PUMP
START COUNTER. WAIT 5
SECONDS BETWEEN EACH
PUMP START
TRIP
PRELUBE
PUMP START
COUNTER = 3
START OIL PUMP
PRELUBE NOT
SATISFIED AFTER OIL
PUMP RUNS FOR 10
SECONDS (SETTABLE)
PRELUBE PRESSURE
(MANIFOLD
DIFFERENTIAL
PRESSURE) SATISFIED
FOR 3 SECONDS
START COMPRESSOR
PRELUBE PRESSURE NOT
SATISFIED FOR 3 SECONDS
TRIP
PRELUBE PRESSURE
SATISFIED FOR 10 SECONDS
COMPRESSOR WARM-UP
OIL PUMP ON
50 SECONDS DELAY BEFORE CAPACITY
SLIDE VALVES GO TO AUTO
COMPRESSOR RUNNING
MODULATE CAPACITY SLIDE
Figure 2-1. Compressor Startup Sequence Diagram
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
2 – 3
Section 2 • Operational Descriptions
AUTO START-STOP
When enabled, the Auto Start-Stop feature will allow the compressor to cycle on and off based on the controlled pressure or temperature. The Anti-Recycle timer still applies when Auto Start-Stop is enabled. Additional variables that factor in to Auto Start-Stop are described below:
• Auto Start Pressure/Temperature: Pressure or
Temperature at which the control will start the compressor.
• Auto Start Delay: Amount of time that the Auto Start
Pressure/Temperature must be met before the compressor is commanded to start.
• Auto Stop Pressure/Temperature: Pressure or
Temperature at which the control will stop the compressor.
• Auto Stop Delay: Amount of time that the Auto Stop
Pressure/Temperature must be met with the capacity slide at or below “Minimum Slide Position” before the compressor is commanded to stop.
• Minimum Slide Position: Position the capacity slide must be at or below before the compressor is commanded to stop.
When Auto Start-Stop control is enabled, it will function as follows:
• When Auto Start Pressure/Temperature is met for the
Auto Start Delay Time, the compressor will be commanded to start.
• When the Auto Stop Pressure/Temperature is met and the capacity slide has decreased to the Minimum
Slide Position for the Auto Stop Delay time, the compressor will be commanded to stop.
ANTI-RECYCLE
After the compressor main motor stops, it is not allowed to re-start again for a settable time. This is to protect the compressor from damage by allowing oil to drain from it before the next start. If the Anti-Recycle timer is active, a banner will appear on the overview and menu screens that shows the remaining time. If a start is initiated, the compressor state indicator will indicate “Standby” until the Anti-Recycle timer is done. If all other permissives are met, the compressor will re-start.
2 – 4
CAPACITY SLIDE CONTROL
Reference examples, Figures 2-2, 2-3 and 2-4
While the compressor is running, the controller will automatically adjust the position of the compressor capacity slide valve to hold the desired pressure or temperature. Three control methods are available:
• Discharge Pressure Control: Compressor loads to increase discharge Pressure to desired setpoint
• Suction Pressure Control: Compressor loads to lower suction pressure to desired setpoint
• Process Temperature Control: Compressor Loads to lower process temp to desired setpoint. An instrument to monitor the Process Temperature is required.
The capacity slide control of the PLC operates by periodically calculating an adjustment to the capacity slide position based on where the selected process variable is in relation to the target setpoint. When the process pressure or temperature is far away from the setpoint, capacity slide position is adjusted by the defi ned maximum.
As the control pressure or temperature gets closer to setpoint, smaller adjustments are made to the capacity slide position. All of the variables that factor in to this calculation are described below:
• Target pressure or Temperature – the desired suction pressure, discharge pressure, or process temperature that the machine will try to maintain.
• Upper Proportional Deadband – Range above Target pressure or Temperature where no capacity slide adjustment will be made.
• Lower Proportional Deadband – Range below Target pressure or Temperature where no capacity slide adjustment will be made.
• Upper Proportional Band – Range above Target pressure or Temperature where adjustments to capacity slide position are made proportional to the difference between Target pressure or Temperature and
Actual. Outside this range, the adjustment made will be the set maximum.
• Lower Proportional Band - Range below Target pressure or Temperature where adjustments to capacity slide position are made proportional to the difference between Target pressure or Temperature and
Actual. Outside this range, the adjustment made will be the set maximum.
• Load Interval Time – Cycle time for calculating capacity slide position adjustment when the controller is calling for the machine to increase capacity slide position. Where the Load Interval Time is T1, the control will make an adjustment calculation every T1 seconds.
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 2 • Operational Descriptions
• Unload Interval Time – Cycle time for calculating capacity slide position adjustment when the controller is calling for the machine to decrease capacity slide position. Where the Load Interval Time is T2, the control will make an adjustment calculation every T2 seconds.
• Max Load Adjustment per Interval – Maximum position adjustment that can be made when the control is calling for the machine to increase capacity slide position. Where the Maximum Load Adjustment is
A1, the capacity slide position will increase by A1% every cycle of the Load Interval Timer when outside the bandwidth range. When inside the bandwidth range, the capacity slide position adjustment will be a percentage of A1.
• Max Unload Adjustment per Interval – Maximum position adjustment that can be made when the control is calling for the machine to decrease capacity slide position. Where the Maximum Unload Adjustment is A2, the capacity slide position will increase by A2% every cycle of the Unload Interval Timer when outside the bandwidth range. When inside the bandwidth range, the capacity slide position adjustment will be a percentage of A2.
When the compressor is stopped, the capacity slide will return to its minimum position.
SUCTION PRESSURE & PROCESS TEMPERATURE
*EVERY CYCLE OF INTERVAL TEMPERATURE, MAX LOAD
ADJUSTMENT IS MADE (CAP INCREASE)
60 PSIG
UPPER PROPORTIONAL BAND
(10 PSID)
*EVERY CYCLE OF INTERVAL TIMER, CAPACITY COMMAND WILL
INCREASE BY CALCULATED AMOUNT, PROPORTIONAL TO ERROR
51 PSIG
UPPER PROPORTIONAL DEADBAND
1 PSID (NO ADJUSTMENT)
TARGET (50 PSIG)
LOWER PROPORTIONAL DEADBAND
LOWER PROPORTIONAL BAND
(5 PSID)
1 PSID (NO ADJUSTMENT)
49 PSIG
*EVERY CYCLE OF INTERVAL TIMER, CAPACITY COMMAND WILL
DECREASE BY CALCULATED AMOUNT, PROPORTIONAL TO ERROR
45 PSIG
*EVERY CYCLE OF INTERVAL TIMER, MAX UNLOAD
ADJUSTMENT IS MADE (CAPACITY DECREASE)
DISCHARGE PRESSURE
*EVERY CYCLE, UNLOAD BY MAX UNLOAD ADJUSTMENT
105 PSIG
UPPER BANDWIDTH
5 PSID
*EVERY CYCLE OF INTERVAL TIMER, MAKE
PROPORTIONAL ADJUSTMENT (CAPACITY DECREASE)
UPPER PROPORTIONAL DEADBAND
LOWER PROPORTIONAL DEADBAND
2 PSID (NO ADJUSTMENT)
2 PSID (NO ADJUSTMENT)
102 PSIG
TARGET (100 PSIG)
98 PSIG
LOWER BANDWIDTH
10 PSID
*EVERY CYCLE OF INTERVAL TIMER, MAKE
PROPORTIONAL ADJUSTMENT (CAPACITY INCREASE)
90 PSIG
*EVERY CYCLE, LOAD BY MAX LOAD ADJUSTMENT
Figure 2-2. Capacity Slide Control Diagram (Example)
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
2 – 5
Section 2 • Operational Descriptions
+UPPER PROPORTIONAL BAND
+UPPER PROPORTIONAL DEADBAND
TARGET
-LOWER PROPORTIONAL DEADBAND
-LOWER PROPORTIONAL BAND
ACTUAL
PRESSURE
COMMANDED CAPACITY
SLIDE VALVE POSITION
MAX LOAD PER
INTERVAL (%)
MAX LOAD PER
INTERVAL (%)
LOAD INTERVAL
CYCLE TIME
(SECONDS)
UNLOAD INTERVAL
CYCLE TIME
(SECONDS)
Figure 2-3. Operational Diagram - Capacity Slide, Discharge Pressure (Example)
2 – 6
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 2 • Operational Descriptions
TARGET
DISCHARGE
PRESSURE
CAPCITY
SLIDE
100
50
MOTOR
SPEED
0
START
10 SECOND
DELAY (FIXED)
Figure 2-4. Operational Diagram - Capacity Slide, Suction
Pressure per Process Temperature (Example)
10 SECOND
DELAY (FIXED)
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
2 – 7
Section 2 • Operational Descriptions
OPERATING MODES
The loading and unloading of the compressor can be confi gured to operate in several ways, depending on the needs of the site. This mode selection is made at the
“Start Menu” screen. There are four basic modes, described below:
• Local-Auto: The compressor will adjust the position of the capacity slide automatically using the control’s capacity control algorithm. The target pressure or temperature setpoint is set on the compressor’s local HMI.
• Local-Manual: The operator is in control of the capacity slide from the local HMI. When in Local-Manual mode, the operator controls the capacity slide position using increase/decrease pushbuttons on the compressor overview screen.
• Remote-Auto: The compressor will adjust the position of the capacity slide automatically using the control’s capacity control algorithm. The target pressure or temperature setpoint is defi ned by the
DCS/Central Controller via communications. (NOTE:
Control by Communications must be enabled to use this mode.)
• Remote-Manual: The capacity slide position is controlled by a DCS or Central Controller. There are four selectable methods of using Remote-Manual Control, settable from the HMI’s confi guration screen.
• Caphold-Ethernet: Capacity slide valve position commands are given by the central controller/
DCS via communications. (NOTE: Control by
Communications must be enabled to use this method.)
Caphold-4-20mA Hardwired: Capacity slide valve position commands are given by the central controller/DCS via a 4-20mA analog signal.
The scaling is 4mA = 0% Capacity Slide Position,
20mA = 100% capacity slide position. Control by
Communications does not need to be enabled to use this method.
• Discrete Load/Unload – Ethernet: Capacity slide valve increase and decrease commands are given by the central controller/DCS via communications. (NOTE: Control by Communications must be enabled to use this method.)
• Discrete Load/Unload – Hardwired: Capacity slide valve increase and decrease commands are given by the central controller/DCS via discrete hardwired inputs. Control by communications does not need to be enabled to use this method.
In any of the above modes, all local safeties and load limits still apply and will override external commands.
For safety reasons, remote mode is only enabled under certain conditions. If these conditions are not met, the machine will revert to local mode. To be able to enter remote mode, the one of the following must be true:
• Auto Mode Selected, Control By Communications
Enabled.
• Manual Mode Selected, Remote Manual Control
Source is Hardwired
• Manual Mode Selected, Control by Communications
Enabled
In the event that the communications link between the compressor PLC and the central controller/DCS is lost, the action taken is selectable from the Confi guration screen. The machine will Trip or revert to Local mode and continue to run depending on the selection.
The compressor PLC can be remotely commanded to
Local or Remote Mode if Control by Communications is enabled.
NOTE
If a main motor VFD is being used for capacity control, only discrete commands may be used in Remote-
Manual Control.
LOAD LIMITS AND FORCED UNLOADING
Reference example, Figure 2-5
To protect the compressor and process, the controller will inhibit the compressor from loading or force it to unload if certain variables get outside of set ranges. Three load limiting variables are continuously monitored:
• Low Suction Pressure
• High Discharge Pressure
• High Main Motor Amps
There are independent Load Limit Setpoints specifi c to
“Setpoint 1” and “Setpoint 2” setpoint groups, allowing load limits to be specifi c to unique operating conditions. For each of the three variables, three setpoints are active:
• Inhibit Loading: when this setpoint is reached, the compressor will not be allowed to continue loading.
• Unload at: when this setpoint is reached, the capacity slide will move in the decrease direction continuously (forced unload) until the “Unload To” setpoint is reached.
• Unload To: this is the setpoint at which the capacity slide will stop unloading from a forced unload condition.
2 – 8
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 2 • Operational Descriptions
When a load limit or forced unload condition is active it will be annunciated in the status banner on the overview and menu HMI screens, and will also be logged in the event list.
LOW SUCTION PRESSURE
INHIBIT
LOAD
A
FORCE
UNLOAD TO
FORCE
UNLOAD AT
D
C
B
(A) CAPACITY SLIDE WILL NOT INCREASE
(B & C) CAPACITY SLIDE WILL DECREASE UNTIL PRESSURE REACHES “C”
(D) CAPACITY SLIDE MAY INCREASE
FORCE
UNLOAD AT
FORCE
UNLOAD TO
HIGH DISCHARGE PRESSURE OR AMPS
B
C
INHIBIT
LOAD
A
D
(A) CAPACITY SLIDE WILL NOT INCREASE
(B & C) FORCED UNLOAD UNTIL DISCHARGE PRESSURE/AMPS REACHES “C”
(D) CAPACITY SLIDE ALLOWED TO INCREASE
Figure 2-5. Operational Diagram - Load Limits / Forced Unloading (Example)
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
2 – 9
Section 2 • Operational Descriptions
VFD CAPACITY CONTROL
When a VFD is used on the compressor main motor to control capacity, it works in conjunction with the capacity slide valve to maintain the Target pressure or
Temperature. At start, the compressor main motor will run at 50% speed until the capacity slide reaches its maximum position. At this point, the VFD will begin adjusting the speed of the main motor to maintain the target pressure or temperature. The speed adjustments made by the controller follow the same algorithm as the capacity slide. Additional variables that factor into the operation of a main motor VFD are described below:
• Max Speed Increase per Interval – Maximum motor speed adjustment that can be made when the control is calling for the machine to increase motor speed. Where the Maximum Speed Increase is S the main motor will speed up by S
1
1
,
% every cycle of the Load Interval Timer when outside the bandwidth range. When inside the bandwidth range, the motor speed adjustment will be a percentage of S
1
.
• Max Speed Decrease per Interval – Maximum motor speed adjustment that can be made when the control is calling for the machine to decrease motor speed. Where the Maximum Speed Decrease is S the main motor will slow down by S
2
2
,
% every cycle of the Unload Interval Timer when outside the bandwidth range. When inside the bandwidth range, motor speed adjustment will be a percentage of S
2
.
EMERGENCY STOP
Reference Figure 2-6
The Emergency Stop circuit in the compressor control panel energizes the Master Control Relay, which provides power to PLC outputs that control heaters, motor starters, valves, etc. The Master Control Relay may be energized by pressing the “Control Power On” illuminated pushbutton on the door of the compressor control panel. When the Master Control Relay is energized, the “Control Power On” pushbutton will illuminate. The following conditions must be satisfi ed to energize the
Master Control Relay:
• Emergency Stop pushbutton on the door of the compressor control panel must be pulled out.
• Any additional Emergency stops or safety devices tied in to the Emergency Stop circuit must be reset.
• The compressor PLC must be booted up and operational.
• The 24-volt DC power supplies in the compressor control panel must be powered up and OK.
OIL HEATERS
Immersion Heaters in the oil separator are controlled by the compressor PLC to maintain warm oil. The heaters cycle on and off to maintain a desired separator oil temperature range.
SAFETIES
The compressor controller continuously monitors operational and process data and annunciates an alarm and/ or stops the machine if any condition becomes abnormal. Two levels of safeties exist when an abnormal condition is detected.
• Alarm: If active, alarms are annunciated on the compressor HMI. When activated, a popup screen showing the date and time of the alarm and alarm message will appear. Alarms are also logged in the Event List.
An alarm serves only as a warning to the operator; if an alarm is active the machine is still allowed to run.
• Trip: If active, trips will shut the machine down or not allow the compressor to start. Trips are annunciated on the compressor HMI. When activated, a popup screen showing the date and time of the trip and trip message will appear. Trips are also logged in the
Event List.
The “Alarm Reset” pushbutton on the overview screen will reset any active alarms or trips if the abnormal condition has been removed.
For a comprehensive list of alarms and trips and possible causes, see the troubleshooting guide in this manual.
2 – 10
SUCTION-DISCHARGE EQUALIZING SOLENOID
If installed, the equalizing solenoid opens for a settable time on compressor stop to equalize pressure between suction and discharge of the compressor.
OIL DRAIN SOLENOID
If installed, the oil drain solenoid valve opens for a settable time on compressor stop to allow oil to drain from the compressor. It also opens during the prelube retry wait periods in the prelube sequence.
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 2 • Operational Descriptions
Figure 2-6. Control Panel Master Power and Emergency Stop Electrical Circuit
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
2 – 11
Section 2 • Operational Descriptions
PID CONTROLS (1 OF 2)
OIL MIXING
VALVE
M
HOT OIL FROM
OIL SEPARATOR
OIL COOLER
VALVE POSITION
(100% OPEN)
TARGET
OIL
INJECTION
OIL FLOW
COOL OIL FROM
OIL COOLER
TEMPERATURE
MACHINE STARTS
VALVE POSITION (% OPEN)
Figure 2-7. Operational Diagram - 2-Way Oil Mixing Valve
2-WAY OIL MIXING VALVE
Reference Figure 2-7
If installed, the 2-way oil mixing valve modulates to control compressor Oil Injection Temperature. The valve is installed in the compressor oil circuit such that when it closes, it forces more oil through the cooler. The valve position is adjusted to mix the correct amount of hot oil from the oil separator and cool oil coming back from the oil cooler.
A PID controller determines the valve position command to maintain Oil Injection Temperature. On rising temperature the controller will command the valve to close; on falling temperature the controller will command the valve to open.
• When the compressor is stopped, the 2-way mixing valve is commanded to 100% open.
• When running, the valve will remain open until Oil
Injection Temperature begins to rise, and then begin to close.
2 – 12
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 2 • Operational Descriptions
TE
TARGET
OUTPUT
TEMPERATURE
START
TEMPERATURE
OIL COOLER
MINIMUM FAN
SPEED
TEMPERATURE (OIL COOLER
OUTLET TEMPERATURE)
FAN SPEED
Figure 2-8. Operational Diagram - Air Cooled Oil Cooler (VFD Type)
AIR COOLED OIL COOLER (VFD TYPE)
Reference Figure 2-8
If installed, the VFD type air cooled oil cooler is a heat exchanger that uses one or more fans running on a VFD to control the oil temperature at its outlet.
A PID controller adjusts the speed of the fan(s) to control the temperature at the outlet of the oil cooler. When the temperature of the oil at the outlet of the cooler exceeds the desired temperature plus a deadband, the fan(s) will increase speed to add more cooling. When outlet temperature drops below the desired temperature minus a deadband, the fan(s) will decrease speed.
• When the compressor is stopped, the oil cooler fan(s) will stop.
• When the compressor is running and the oil cooler outlet temperature rises above the “Oil Cooler
Start” temperature set in the “VFD Type Oil Cooler
Setpoints” screen, the fan(s) will start at a settable minimum speed.
• When the compressor is running and the oil cooler outlet temperature is above the deadband, the PID controller will increase fan speed.
• When the compressor is running and the oil cooler outlet temperature is below the deadband, the PID controller will decrease fan speed.
OIL COOLER TEMPERATURES
It is possible to monitor Oil Cooler Inlet Temperature, and monitor Oil Cooler Outlet Temperature if an oil cooler is not being controlled.
OIL COOLER STANDBY HEATER
If installed, a heater within the remote oil cooler is controlled by the compressor PLC to maintain warm oil. The heater cycles on and off to maintain a desired oil cooler outlet temperature range. Setpoints to control the Oil
Cooler Standby Heater are on the “Oil Cooler Control
Setpoints (Step or VFD Type)” Screen.
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
2 – 13
Section 2 • Operational Descriptions
TE
AFTERCOOLER
TARGET
OUTPUT
TEMPERATURE
START
TEMPERATURE
AFTERCOOLER OUTLET
TEMPERATURE
FAN SPEED
MINIMUM FAN
SPEED
Figure 2-9. Operational Diagram - Air Cooled Aftercooler (VFD Type)
AIR COOLED AFTERCOOLER (VFD TYPE)
Reference Figure 2-9
If installed, the VFD type air cooled aftercooler is a heat exchanger that uses one or more fans running on a
VFD to remove heat from the gas discharged from the compressor. The VFD speeds up or slows down the fan motor to control the amount of cooling done by the aftercooler.
A PID controller adjusts the speed of the fan(s) to maintain the outlet gas temperature of the aftercooler. When the aftercooler outlet temperature exceeds the desired temperature plus a deadband, the fan(s) will increase speed to add more cooling. When aftercooler outlet temperature drops below the desired temperature minus a deadband, the fan(s) will decrease speed.
• When the compressor is stopped, the aftercooler fan(s) will stop.
• When the compressor is running and the gas aftercooler outlet temperature rises above the “Start
Aftercooler At” set in the “VFD Type Aftercooler
Setpoints” screen, the fan(s) will start at a settable minimum speed.
• When the compressor is running and the aftercooler outlet temperature is above the deadband, the PID controller will increase fan speed.
• When the compressor is running and the aftercooler outlet temperature is below the deadband, the PID controller will decrease fan speed.
2 – 14
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 2 • Operational Descriptions
PT
CONDENSER
TARGET
OUTPUT
PRESSURE
START
PRESSURE
CONDENSING PRESSURE
FAN SPEED
MINIMUM FAN
SPEED
Figure 2-10. Operational Diagram - Air Cooled Condenser (VFD Type)
AIR COOLED CONDENSER (VFD TYPE)
Reference Figure 2-10
If installed, the VFD type air cooled condenser is a heat exchanger that uses one or more fans running on a VFD to condense refrigerant vapor into a liquid. The VFD speeds up or slows down the fan motor to control the amount of cooling done by the condenser.
A PID controller adjusts the speed of the fan(s) to control condensing pressure. When the condensing pressure exceeds the desired pressure plus a deadband, the fan(s) will increase speed to add more cooling. When condensing pressure drops below the desired temperature minus a deadband, the fan(s) will decrease speed.
• When the compressor is stopped, the condenser fan(s) will stop.
• When the compressor is running and the oil cooler outlet temperature rises above the “Condenser Start
Pressure” set in the “VFD Type Condenser Setpoints” screen, the fan(s) will start at a settable minimum speed.
• When the compressor is running and the condensing pressure is above the deadband, the PID controller will increase fan speed.
• When the compressor is running and the condensing pressure is below the deadband, the PID controller will decrease fan speed.
EVAPORATIVE CONDENSER
If installed, an evaporative condenser incorporates a water circulating pump that mists water over the condenser to provide additional cooling.
• When using with step-type condensers, the pump can be added or removed from the step sequence as if it were another fan. The pump will start when the steps that it is enabled are active.
• When using with VFD-type condensers, the pump can be enabled or disabled by a selection on the condenser control setpoints screen. When enabled, the pump starts at the same time as the fan.
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2 – 15
Section 2 • Operational Descriptions
TE
OIL COOLER
TARGET
START
TEMPERATURE OR
PRESSURE
STEP #
FANS TURNING ON FANS TURNING OFF
TEMPERATURE OR
PRESSURE
1 STEP ADDED
EVERY CYCLE OF
CYCLE TIMER
TARGET
DEADBAND
DEADBAND
NO STEPS ADDED
OR REMOVED
1 STEP REMOVED
EVERY CYCLE OF
CYCLE TIMER
STEP #
Figure 2-11. Operational Diagram - All Air Cooled Oil Coolers (Step Type)
AIR COOLED OIL COOLER (STEP TYPE)
Reference Figure 2-11
If installed, the step type air cooled oil cooler is a heat exchanger that uses multiple fans to control the oil temperature at its outlet.
The controller starts and stops fans in a sequence to control the temperature at the outlet of the oil cooler. When the temperature of the oil at the outlet of the cooler
2 – 16
exceeds the desired temperature plus a deadband, fans will be turned on after a time delay to add more cooling.
When outlet temperature drops below the desired temperature minus a deadband, fans will be turned off after a time delay.
• When the compressor is stopped, all oil cooler fans are turned off.
• When the compressor is running and the oil cooler
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 2 • Operational Descriptions outlet temperature rises above the “Oil Cooler Start” temperature set in the “Step Type Oil Cooler
Setpoints” screen, the fi rst fan (or group of fans) will start.
• When the compressor is running and the oil cooler outlet temperature is above the deadband, a fan (or group of fans) will start each time through the “Step
Dwell Time.”
• When the compressor is running and the oil cooler outlet temperature is below the deadband, a fan (or group of fans) will stop each time through the “Step
Dwell Time.”
• Once started, the fi rst fan or group of fans will remain running until the compressor stops.
AIR COOLED AFTERCOOLER (STEP TYPE)
Reference Figure 2-11
If installed, the step type air cooled aftercooler is a heat exchanger that uses multiple fans to remove heat from the gas discharged from the compressor. The number of fans that run is determined by the gas temperature at the outlet of the aftercooler.
The controller starts and stops fans in a sequence to control the gas temperature at the outlet of the aftercooler. When the aftercooler outlet temperature exceeds the desired temperature plus a deadband, fans will be turned on after a time delay to add more cooling. When aftercooler outlet temperature drops below the desired temperature minus a deadband, fans will be turned off after a time delay.
• When the compressor is stopped, all aftercooler fans are turned off.
• When the compressor is running and the aftercooler outlet temperature rises above the “Start Aftercooler
At” temperature set in the “Step Type Aftercooler
Setpoints” screen, the fi rst fan (or group of fans) will start.
• When the compressor is running and the aftercooler outlet temperature is above the deadband, a fan (or group of fans) will start each time through the “Step
Dwell Time.”
• When the compressor is running and the aftercooler outlet temperature is below the deadband, a fan (or group of fans) will stop each time through the “Step
Dwell Time.”
• Once started, the fi rst fan or group of fans will remain running until the compressor stops.
AIR COOLED CONDENSER (STEP TYPE)
Reference Figure 2-12 and 2-11 for curves
If installed, the step type air cooled condenser is a heat exchanger that uses multiple fans to condense refrigerant vapor to a liquid. The number of fans that run is determined by the refrigerant pressure at the condenser.
The controller starts and stops fans in a sequence to control the condensing pressure. When the condensing pressure exceeds the desired pressure plus a deadband, fans will be turned on after a time delay to add more cooling. When condensing pressure drops below the desired pressure minus a deadband, fans will be turned off after a time delay.
• When the compressor is stopped, all condenser fans are turned off.
• When the compressor is running and the oil cooler outlet temperature rises above the “Condenser Start” pressure set in the “Step Type Condenser Setpoints” screen, the fi rst fan (or group of fans) will start.
• When the compressor is running and the condensing pressure is above the deadband, a fan (or group of fans) will start each time through the “Step Dwell
Time.”
• When the compressor is running and the condensing pressure is below the deadband, a fan (or group of fans) will stop each time through the “Step Dwell
Time.”
• Once started, the fi rst fan or group of fans will remain running until the compressor stops.
PT
CONDENSER
Figure 2-12. Operational Diagram - Air Cooled Condenser
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
2 – 17
Section 2 • Operational Descriptions
Figure 2-13. Operational Diagram - Water Cooled Gas Aftercooler
WATER COOLED GAS AFTERCOOLER
Reference Figure 2-13
If installed, the water-cooled gas aftercooler is a heat exchanger that uses a modulating valve to control cooling water fl ow to remove heat from the gas discharged by the compressor. The valve position is adjusted to control the amount of cooling done by the aftercooler.
A PID controller adjusts the opening degree of the modulating valve to maintain a desired temperature at the outlet of the gas aftercooler. When the aftercooler outlet temperature exceeds the desired pressure plus a deadband, the valve will open further to add more cooling. When aftercooler outlet temperature drops below the desired temperature minus a deadband, the valve will begin to close.
• When the compressor is stopped, the valve will be commanded to 0% open (full close).
• When the compressor is running and the condensing pressure rises above the “Open Valve At” setpoint in the “Water Cooled Aftercooler Setpoints” screen, the valve will open to a settable minimum position.
2 – 18
• When the compressor is running and the aftercooler outlet temperature is above the deadband, the PID controller will increase the valve opening degree.
• When the compressor is running and the aftercooler outlet temperature is below the deadband, the PID controller will decrease the valve opening degree.
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 2 • Operational Descriptions
Figure 2-14. Operational Diagram - Water Cooled Condenser
WATER COOLED CONDENSER
Reference Figure 2-14
If installed, the water-cooled condenser is a heat exchanger that uses a modulating valve to control cooling water fl ow to condense refrigerant vapor into a liquid.
The valve position is adjusted to control the amount of cooling done by the condenser.
A PID controller adjusts the opening degree of the modulating valve to control condensing pressure. When the condensing pressure exceeds the desired pressure plus a deadband, the valve will open further to add more cooling. When condensing pressure drops below the desired temperature minus a deadband, the valve will begin to close.
• When the compressor is stopped, the valve will be commanded to 0% open (full close).
• When the compressor is running and the condensing pressure rises above the “Condenser Start Pressure” set in the “Water Cooled Condenser Setpoints” screen, the valve will open to a settable minimum position.
• When the compressor is running and the condensing pressure is above the deadband, the PID controller will increase the valve opening degree.
• When the compressor is running and the condensing pressure is below the deadband, the PID controller will decrease valve opening degree.
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
2 – 19
Section 2 • Operational Descriptions
LIQUID
REFRIGERANT
LIQUID INJECTION
VALVES
M S
SUCTION
COMPRESSOR
TE
TARGET
OUTPUT
PRESSURE
START
PRESSURE
DISCHARGE TEMPERATURE
VALVE POSITION
MINIMUM VALVE
POSITION
Figure 2-15. Operational Diagram - Liquid Injection Valve
LIQUID INJECTION VALVE
Reference Figure 2-15
If installed, liquid injection is a method of oil cooling where liquid refrigerant is injected into a port on the compressor. A modulating valve regulates the amount of liquid allowed into the compressor to control the amount of cooling done by liquid injection.
A PID controller adjusts the opening degree of the modulating valve to control compressor discharge temperature (temperature of the gas and oil mixture leaving the compressor). When the discharge temperature exceeds the desired temperature plus a deadband, the valve will open further to add more cooling. When discharge temperature drops below the desired temperature minus a deadband, the valve will begin to close.
• When the compressor is stopped, the valve will be commanded to 0% open (full closed).
• When the compressor is running, the discharge temperature rises above the “Open Valve Above” setpoint and Separator Oil Temperature rises above “Oil
Separator Override Temp” in the “Liquid Injection
Valve Setpoints” screen, the valve will open to a settable minimum position.
• When the compressor is running and the discharge temperature is above the deadband, the PID controller will increase the valve opening degree.
• When the compressor is running and the discharge temperature is below the deadband, the PID controller will decrease valve opening degree.
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Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 2 • Operational Descriptions
SUCTION
VPLUS
S
COMPRESSOR
TE
LIQUID
REFRIGERANT
TARGET
OUTPUT
TEMPERATURE
START
TEMPERATURE
DISCHARGE TEMPERATURE
PUMP SPEED
MINIMUM PUMP
SPEED
Figure 2-16. Operational Diagram - VPLUS
VPLUS LIQUID INJECTION PUMP
Reference Figure 2-16
If installed, VPLUS liquid injection is a method of oil cooling where liquid refrigerant is pumped through a nozzle in the discharge housing of the compressor. A variable speed pump regulates the amount of liquid pumped into the compressor to control the amount of cooling.
A PID controller adjusts the speed of the VPLUS pump to control compressor discharge temperature (temperature of the gas and oil mixture leaving the compressor).
When the discharge temperature exceeds the desired temperature plus a deadband, the pump will increase speed to add more cooling. When discharge temperature drops below the desired temperature minus a deadband, the pump will decrease speed.
• When the compressor is stopped, the pump is stopped.
• When the compressor is running, the discharge temperature rises above the “Start Pump At” setpoint and Separator Oil Temperature rises above
“Oil Separator Override Temp” in the “VPLUS Pump
Setpoints” screen, the pump will start at a settable minimum speed.
• When the compressor is running and the discharge temperature is above the deadband, the PID controller will increase the pump speed.
• When the compressor is running and the discharge temperature is below the deadband, the PID controller will decrease the pump speed.
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
2 – 21
Section 2 • Operational Descriptions
DISCHARGE
RECYCLE
SETTING
COMPRESSOR
CONTROL
TARGET
DISCHARGE
PRESSURE
100
DISCHARGE
RECYCLE VALVE
POSITION (% OPEN)
0
Figure 2-17. Operational Diagram - Discharge Recycle Valve
DISCHARGE RECYCLE VALVE
Reference Figure 2-17
NOTE
Discharge recycle valve must be controlled by others when multiple compressors are connected to a common header.
If installed, the discharge recycle valve is a motorized or air actuated valve that recycles discharge gas back to the suction of the compressor. The valve acts as a regulator, opening to maintain the set pressure in the discharge line.
A PID controller adjusts the opening degree of the valve to maintain a desired pressure on the high pressure side of the valve. When the recycle control pressure exceeds the desired pressure plus a deadband, the valve will start to open to recycle high pressure gas back to suction.
2 – 22
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 2 • Operational Descriptions
ECONOMIZER SOLENOID(S)
If installed, an economizer is a heat exchanger that operates at an intermediate pressure, above suction pressure but below discharge pressure. Up to two solenoids control when the economizer becomes part of the refrigeration process.
The compressor controller opens and closes the economizer port solenoid valves based on ON and OFF capacity slide position setpoints. The economizer solenoid is typically energized when capacity slide valve position is above a settable value.
• When the compressor is stopped, economizer solenoid valves are closed.
• When the compressor is running, the economizer port solenoid will open when capacity slide position is greater than the “ON Above” Setpoint in the
Compressor Control Setpoints Screens.
• When the compressor is running, the economizer port solenoid will close when capacity slide position is less than the “OFF Below” Setpoint in the Compressor
Control Setpoints Screens.
HOTGAS BYPASS SOLENOID
If installed, the hotgas bypass solenoid valve enables a regulator that circulates discharge “hotgas” back to suction to simulate a load on the compressor by raising the suction pressure. It is typically enabled on low load conditions to prevent the compressor from shutting down on low suction pressure.
The compressor controller opens and closes the hotgas bypass solenoid valve based on ON and OFF capacity slide position setpoints. The hotgas bypass solenoid is typically energized when capacity slide position is below a settable value.
• When the compressor is stopped, the hotgas bypass solenoid is closed.
• When the compressor is running, the hotgas bypass solenoid will open when capacity slide position is less than the “ON Below” Setpoint in the Compressor
Control Setpoints Screens.
• When the compressor is running, the economizer port solenoid will close when capacity slide position is less than the “OFF Below” Setpoint in the Compressor
Control Setpoints Screens.
VENTURI OIL RECOVERY
If installed, the venturi oil recovery system uses a group of solenoid valves that function together to return any oil that has accumulated in the chiller back to the compressor. When the solenoid valves are energized, discharge hotgas passes through a venturi to draw out any oil that may have accumulated in the chiller. Venturi
Oil Recovery is typically used in Freon or Propane applications where the oil is less dense than the liquid refrigerant and tends to fl oat on top.
Oil recovery is activated by a level switch that senses low oil level in the oil separator. When activated, the venturi oil recovery solenoids will cycle on and off by a settable cycle timer. ON time and OFF time are settable in the
“Compressor Control Setpoints” screens.
GAS SCRUBBERS
A gas scrubber (or knockout drum) is a vessel with a demister pad or coalescing elements installed to remove moisture and other contaminants from the gas stream.
Gas scrubbers may be installed on the suction side or discharge side of a gas compressor (if an aftercooler is used, the scrubber is installed downstream of the aftercooler), or on the inlet or outlet side of a gas chiller. A condensate pump or solenoid valve drains accumulated moisture from the vessel.
Gas scrubbers include the following devices:
• Pressure transducers on the inlet and outlet of the vessel – used to measure pressure drop across the demister pad or coalescing elements to help determine when to clean or replace.
• Level switches to monitor the condensate level:
• LSH (High Level) – when liquid level reaches the
LSH level switch, an alarm is annunciated on the compressor HMI.
• LSHH (High High Level) – when liquid level reaches the LSHH level switch, an alarm or trip is annunciated on the compressor HMI. The alarm or trip action is confi gurable depending on the site and location of the vessel. If trip action is selected, the compressor will shut down if the LSHH is activated. Typically the purpose of the LSHH is to alarm or shut down the compressor to prevent bringing liquid into the compressor suction.
• LSLL (Low Low Level) – when liquid level drops below the LSLL level switch, an alarm or trip is annunciated on the compressor HMI. The alarm or trip action is confi gurable depending on the site and location of the vessel. If trip action is selected, the compressor will shut down if the LSLL is activated.
Typically the purpose of the LSLL is to detect if the liquid seal is lost to prevent introducing gas into the condensate drain system.
• Condensate Drain System:
• A drain pump or solenoid valve will turn on when the liquid level in the scrubber reaches the “Cutin”
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
2 – 23
Section 2 • Operational Descriptions level switch.
• The drain pump or solenoid valve will turn off when the liquid level in the scrubber drops to the
“Cutout” level switch.
• Dual pumps may be used. Selection of Pump A or
B is made in the Confi guration screen.
BUILDING ENCLOSURE DEVICES
If the compressor unit is mounted inside a building enclosure, the following are monitored/controlled:
• Space Heater – maintains a desired temperature range inside the enclosure. Space Heater ON and
OFF setpoints are in the compressor control setpoint screens.
• Exhaust Fans – maintains a desired temperature range inside the enclosure. Exhaust Fan ON and OFF setpoints are in the compressor control setpoint screens. If the methane detector %LEL reaches alarm level, the exhaust fans will also turn on until the alarm is cleared.
• Methane Detector – monitors the %LEL of the air inside the enclosure. Generates an alarm and trip.
Alarm and trip setpoints are settable in the Alarm and
Trip Setpoints screen.
• Smoke Detector – If triggered by smoke within the enclosure, will shut down the compressor and trip the compressor emergency stop.
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Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 3 • Overview Screens
Compressor and System Overview Screens
The Compressor and system overview screens shows compressor status, confi guration, any active alarms or trips, and live process data. The compressor and/or process are displayed in a format similar to a P&I Diagram with live process data shown on the screen.
From the compressor and system overview screens, all other screens are accessed by pressing the “Main Menu” go to screen button in the lower right of the screen. The system overview display is accessed from the compressor overview screen and vice-versa, if a system overview screen is displayed.
The following are some examples of different compressor and package confi gurations and how they are displayed on the HMI.
Figure 3-1. Basic Compressor Unit Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
3 – 1
Section 3 • Overview Screens
Example 1 - Gas Compressor Unit Overview Screen
VRSG-3700 Compressor Unit for Natural Gas with Air Cooled VFD Type Oil Cooler
Figure 3-2. Example 1 - Gas Compressor Unit Overview Screen,
VRSG-3700 Compressor Unit for Natural Gas with Air Cooled VFD Type Oil Cooler
3 – 2
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 3 • Overview Screens
Example 2 - Refrigeration Compressor Unit Overview Screen
VRSH-2700 Compressor Unit for Ammonia with Liquid Injection Oil Cooling and Economizer
Figure 3-3. Example 2 - Refrigeration Compressor Unit Overview Screen,
VRSH-2700 Compressor Unit for Ammonia with Liquid Injection Oil Cooling and Economizer
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
3 – 3
3 – 4 / Blank
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 4 • HMI Navigation
HMI Navigation
HMI screens are accessed by using the navigation buttons on each screen. When the HMI boots up, the compressor overview screen is displayed by default. The HMI
Screens are divided into groups, all of which are accessible from the Menu Screen.
Figure 4-1. Main Menu Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
4 – 1
Section 4 • HMI Navigation
The Menu Screen allows the user to view basic compressor confi guration, status, active alarms and trips, as well as navigate to confi guration, control, calibration, and diagnostics screens.
An electronic copy of the compressor PLC manual is accessed from the Menu Screen.
Main
Menu
Compressor
Overview
Compressor
Animation
(1)
Gas Chiller
Reheat
Overview
(1)
Gas Chiller
Overview
(1)
Natural Gas
Overview
(1)
Natural Gas
Reheat
Overview
(1)
Refrigeration
Overview
Start
Menu
(1) Overview Screen is selected in
“Configuration Ͳ Authorized Users ONLY”.
Only the selected overview screen is visible.
Figure 4-2. Screen Navigation Map - Main Screens (1 of 7)
4 – 2
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 4 • HMI Navigation
Main
Menu
(SP)
Compressor
Control Ͳ 1 of 3
(Suction Pressure)
Compressor
Control Ͳ 2 of 3
Compressor
Control Ͳ 3 of 3
(PT)
Compressor
Control Ͳ 1 of 3
(Process Temperature)
(DP)
Compressor
Control Ͳ 1 of 3
(Discharge Pressure)
(SP) Visible when in Suction Pressure Mode only.
(PT) Visible when in Process Temperature Mode only.
(DP) Visible when in Discharge Pressure Mode only.
Alarm and Trip
Setpoints Ͳ 1 of 2
Alarm and Trip
Setpoints Ͳ 2 of 2
Figure 4-2. Screen Navigation Map - Compressor Control, Alarm and Trip (2 of 7)
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
4 – 3
Section 4 • HMI Navigation
Main
Menu
Instrument Cal.
Ͳ Overview
Pressure
Calibration Ͳ 1 of 3
(SUPER to Edit)
Pressure
Calibration Ͳ 2 of 3
(SUPER to Edit)
Pressure
Calibration Ͳ 3 of 3
(SUPER to Edit)
Temperature
Calibration Ͳ 1 of 3
(SUPER to Edit)
Temperature
Calibration Ͳ 2 of 3
(SUPER to Edit)
Temperature
Calibration Ͳ 3 of 3
(SUPER to Edit)
Slide
Calibration
(SUPER to Edit)
Other Analog
Device Calibration
(SUPER to Edit)
Volume Slide
Details
Figure 4-2. Screen Navigation Map - Instrument Calibration (3 of 7)
4 – 4
Main
Menu
5 Minute Trend Data
Page 1
Pressures & Temp
24 Hour Trend Data
Page 1
Pressures & Temp
24 Hour Trend Data
Page 2 ͲͲ Motor Amps,
Cap. Pos., Vol. Pos.
2 Hour Trend Data
Page 1
Pressures & Temp
5 Day Trend Data
Page 1
Pressures & Temp
5 Day Trend Data Page
2 ͲͲ Motor Amps, Cap.
Pos., Vol. Pos.
5 Minute Trend Data
Page 2 ͲͲ Motor Amps,
Cap. Pos., Vol. Pos.
2 Hour Trend Data
Page 2 ͲͲ Motor Amps,
Cap. Pos., Vol. Pos.
Figure 4-2. Screen Navigation Map - Trending (4 of 7)
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 4 • HMI Navigation
Main
Menu
After Cooler 1
(Step Type)
(1)
After Cooler 1
(VFD Type)
(1)
After Cooler 1
(Water Cooled)
(1)
After Cooler 2
(Step Type)
(1)
After Cooler 2
(VFD Type)
(1)
After Cooler 2
(Water Cooled)
(1)
(1) Visibility dependant on After Cooler Selections
Figure 4-2. Screen Navigation Map - Aftercoolers (5 of 7)
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
4 – 5
Section 4 • HMI Navigation
Main
Menu
Goto
Configure Mode
(SUPER)
Shutdown
(SUPER)
Diagnostic Force
Outputs Ͳ Authorized
Users ONLY
(SUPER)
Diagnostic Force
Outputs Ͳ Authorized
Users ONLY
(SUPER)
Initial Baseline Running
Data (1 of 2)
Initial Baseline Running
Data (2 of 2)
Set Date and Time
Configuration Ͳ
Authorized Users ONLY
(SUPER)
Define Device Names Ͳ
Instrumentation
(SUPER)
Define Device Names Ͳ
Devices and Vessels
(SUPER)
Define Device Names Ͳ
Alarm and Trip – 1
(SUPER)
Define Device Names Ͳ
Alarm and Trip Ͳ 2
(SUPER)
Figure 4-2. Screen Navigation Map - Confi guration, Device Names and Initial Baseline (6 of 7)
4 – 6
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 4 • HMI Navigation
Main
Menu
Condenser
(Water Cooled)
Condenser
(Step Type)
Condenser
(VFD Type)
Oil Mixing
Valve
Oil Cooler
(Step Type)
Oil Cooler
(VFD Type)
Comms
Diagnostics
Event List
(### Ͳ ###)
Captured Data at
Shutdown (1 of 2)
Captured Data at
Shutdown (2 of 2)
Discharge
Recycle Valve
Liquid Injection
Valve
Liquid Injection
Ͳ VPLUS Pump
Figure 4-2. Screen Navigation Map - Condenser, Oil Mixing or Cooler, Liquid Injection, Misc.
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
4 – 7
Section 4 • HMI Navigation
HMI Security
Some items and screens on the HMI require a login to be viewed or changed.
Login accounts are described below, each with its default password and level of access.
DEFAULT
• This is the user account that is active when the HMI boots up or the user logs out of another user account.
• Permissions:
• May start and stop the machine
• May change Remote-Local and Auto-Manual modes
May view setpoints, calibration data, and diagnostics
SUPER
• This user account is intended for site supervisors, managers, and superintendents.
• Default Password: 1
• Permissions
• May start and stop the machine
• May change Remote-Local and Auto-Manual modes
• May Operate the machine in Manual mode
May view setpoints, calibration data, and diagnostics
• May change setpoints
• May force Discrete and Analog outputs on the PLC
• May make changes to machine confi guration selections
OP1, OP2, OP3, OP4, OP5
• These user accounts are intended for operators.
• Default Password: 1
• Permissions
• May start and stop the machine
• May change Remote-Local and Auto-Manual modes
• May Operate the machine in Manual mode
May view setpoints, calibration data, and diagnostics
• May change setpoints
LOGGING IN
To log on, press the “Log On” button. The “Log On” button is located in the Upper-Right corner of most screens, and in the lower right corner of the menu screen. The login pop-up screen will appear, see Figure 4-3.
Enter User Name and password using the pop-up keyboard, see Figure 4-4.
It is recommended to log out when fi nished. Every login is recorded in the compressor control’s event list. After
10 minutes of inactivity, the HMI will automatically log out the current user.
4 – 8
Figure 4-3. Login Pop-up Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 4 • HMI Navigation
Figure 4-4. Login Screen Keyboard
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
4 – 9
4 – 10 / Blank
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 5 • Configuration - Supervisor Level
Confi guration Screen - Supervisor Level
NOTE
Some screens may have inverted colors for ease of readability.
Most of the confi guration that is specifi c to the compressor or package is completed at the factory and not accessible to the user. The options that may be confi gured by the user are included on this screen. To change option selections, press on the list selector and use the up, down, and enter buttons on the lower side of the screen.
Figure 5-1. Confi guration Screen - All Options Shown (Supervisor Level)
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
5 – 1
Section 5 • Configuration - Supervisor Level
DATE AND TIME
Allows the Real Time Clock in the PLC to be set. Pressing
“Set Date and Time” will bring up the “Set Date and
Time” pop-up screen.
• Date and Time must be set in 24-hour format.
• Pressing “Set Date and Time” will set the PLC time clock.
• The HMI time clock will automatically synchronize to the PLC time clock.
Figure 5-2. Set Date/Time Pop-Up Screen - Supervisor Level
REMOTE OPERATION
For the compressor control to accept commands from a
DCS or Central Controller, Control by Communications must be enabled. For more details on remote operation, see Section 8, Communication with DCS/Central
Controller.
• Control by Communications
• If enabled, allows a central controller/DCS to send commands to the compressor PLC
• If disabled, allows a central controller/DCS to read data only.
• Communications Watchdog and Communication
Fault Action
• The settable watchdog time defi nes the amount of time a loss in communications can be detected before triggering a communication fault
Action Taken on Communication Fault is selectable:
• Alarm and Revert to local mode – The compressor controller will generate an alarm, and change the mode to local-auto. The machine will continue to run (if running) in local mode.
•
5 – 2
• Trip Machine – Communication Fault will shut the machine down.
• Remote Manual Control Source – Defi nes how the capacity slide will be operated in remote Manual mode.
Caphold-Ethernet: Caphold values are sent to compressor via Ethernet IP. The capacity slide will go to the desired value. (Control By
Communications must be enabled)
• Caphold-4-20mA hardwired: command signal sent to compressor via 4-20mA input, scaled
0-100%.
• Discrete Load/Unload - Ethernet. Turning on a bit will cause the compressor to increase or decrease
Capacity. (Control By Communications must be enabled)
Discrete Load/Unload – Hardwired: Discrete
Increase and Decrease commands via Physical
Inputs.
• If a VFD is selected, only discrete increase and decrease commands are supported. The compressor program will handle the transitioning of increasing/decreasing capacity slide to increasing/ decreasing drive speed.
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 5 • Configuration - Supervisor Level
PROCESS VARIABLE SOURCE
Defi nes the pressure data used to control the capacity slide.
• Local Hard-Wired Transducer – capacity slide and auto start/stop is controlled by the suction/discharge pressure transducer mounted on the compressor unit or package.
• Common/Remote – capacity slide and auto start/ stop is controlled by suction/discharge header pressure data from a DCS/Central Controller. On loss of communications, the compressor control will either shut down the compressor or revert to the local transducer based on the “Communication Fault
Action” setting.
CONTROL MODE
Defi nes the pressure or temperature the compressor will try to maintain. See Section 2 “Operational
Descriptions” for more information on the functionality of each control mode.
SELECT SETPOINT 1 / 2
Determines which group of setpoints is active – used when a machine could be run in 2 unique sets of operating conditions, ex. High/low stage swing compressor.
MOTOR RTDs
Selects if Motor Winding and Bearing Temperatures are being monitored by the controller.
SCHEDULED MAINTENANCE TIMER
Optional function that can be set up to display maintenance reminders after a settable amount of runtime. When the accumulated runtime reaches the set
“Maintenance Interval” time, a status message will appear on the overview and menu screens indicating the text entered in the “Message” fi eld.
INLET / OUTLET SCRUBBER PUMP A / B
If the inlet and/or outlet scrubbers include dual condensate pumps, this selection determines which pump is active.
CHANGE PASSWORD
Pressing the “Change Password” button opens the
“Change Password” pop-up screen, see Figure 5-3 To change a password on an account, the user must be logged in under that account.
AUTO START-STOP
Enables or Disables the auto start-stop function. See
Section 2 “Operational Descriptions” for more information on the functionality of the auto start-stop function.
Figure 5-3. Change Password Pop-Up Screen - Supervisor Level
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
5 – 3
Section 5 • Configuration - Supervisor Level
PANELVIEW CONFIGURATION
Pressing the “Panelview Confi guration” button closes the compressor control application running on the HMI and opens the Factory Talk View ME Station confi guration screens.
INITIAL RUNNING DATA
Pressing the “Initial Running Data” Button opens the
Initial Running Data Screen which shows baseline data logged when the compressor was new. See Section 10
“Diagnostics Screens” for more information.
DEVICE NAMES
Pressing the “Device Names” button navigates to the
Defi ne Device Names screens. See “Defi ne Device
Names” later in this section for more information.
BACK TO MENU
Pressing the “Back to Menu” button navigates back to the main menu screen.
5 – 4
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 5 • Configuration - Supervisor Level
Editing Device Names
The “Device Names” group of screens allows a user logged in as “SUPER” to edit names shown on the screen identifying compressor unit and package equipment, instrumentation, and alarm and trip designations. To edit the text fi elds in this group of screens, press on the string input button and use the popup keyboard to edit the text.
Typically, the device names entered in this group of screens are the designations for each device, instrument, or alarm that relate it back to the P&ID diagram.
The “Device Names” group of screens is divided into three sections, see Figure 5-3.
DEVICES AND VESSELS
In Figure 5-4, this screen allows the user to edit device names shown on the screen for devices, vessels, and equipment installed on the compressor unit or package.
The user may navigate to other screens within the
“Defi ne Device Names” group by using the navigation buttons on the right side of the screen.
Figure 5-4. Defi ne Device Names - Devices and Vessels (Supervisor Level)
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
5 – 5
Section 5 • Configuration - Supervisor Level
INSTRUMENTATION
In Figure 5-5, this screen allows the user to edit device names shown on the screen for instrumentation installed on the compressor unit or package.
Figure 5-5. Defi ne Device Names - Instrumentation (Supervisor Level)
5 – 6
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 5 • Configuration - Supervisor Level
ALARM AND TRIP
In Figure 5-6, this screen allows the user to edit the alarm and trip designation text that appears in the alarm and trip banners, alarm pop-up screen, and event list.
In addition, messages for 5 user-defi ned alarms and trips may be defi ned on this screen.
Figure 5-6. Defi ne Device Names - Alarm and Trip 1 (Supervisor Level) (1 of 2)
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
5 – 7
Section 5 • Configuration - Supervisor Level
Figure 5-6. Defi ne Device Names - Alarm and Trip 2 (Supervisor Level) (2 of 2)
5 – 8
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 6 • Instrument Calibration
Calibration Main Screen
NOTE
Some screens may have inverted colors for ease of readability.
Pressing the “Instrument Calibration” navigation button on the menu screen opens the instrument calibration group of screens. This group of screens allows the user to view and edit calibration data for specifi c instruments installed on the compressor unit or package.
From the main menu, pressing the “Instrument
Calibration” button navigates to the calibration overview screen, see Figure 6-1. The calibration overview screen shows information related to all instruments installed on the compressor unit or package, including their raw values, base units (used internally in the program) and as displayed. Calibration of specifi c instruments is accessed using the navigation buttons on the right side of the screen.
Figure 6-1. Instrument Calibration Overview Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
6 – 1
Section 6 • Instrument Calibration
Pressure Calibration Screen
In Figure 6-2, the temperature calibration group of screens allows the user to change the pressure units displayed on the screen as well as calibrate pressure instruments.
Pressure units are specifi c to individual pressure instruments. Changing the pressure display units for a transducer also converts all pressure setpoints related to that transducer to the new selected units.
The following pressure units are available for display:
• PSIG (Pounds/square inch gage)
• PSIA (Pounds/square inch absolute)
• kPa[A] (Kilopascals absolute)
• kPa[G] (Kilopascals gage)
• kg/cm2[A] (Kilograms/square centimeter absolute)
• kg/cm2[G] (Kilograms/square centimeter gage)
• inHg (inches of mercury) – Vacuum is shown in inHg, positive pressure is shown in PSIG
• inWC (gage)
• Bar[A] (absolute)
• Bar[G] (gage)
• Torr[A] (absolute)
• Torr[G] (gage)
6 – 2
Figure 6-2. Pressure Calibration Screen - 1 of 3
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 6 • Instrument Calibration
CALIBRATE PRESSURE INSTRUMENT
To calibrate a pressure instrument, proceed with the following steps:
1. Select the units that the transducer is calibrated in. For example, for a transducer calibrated 0-200
PSIA, the transducer units selected shall be ‘PSIA.’
For a transducer calibrated -30inHg to 30PSIG, the transducer units selected shall be “inHg.”
2. Select the units that the pressure will be displayed in on the HMI.
3. Enter the raw mA range (typically 4-20mA)
4. Enter the Span of the instrument. For a 0-200 PSIA transducer, Enter “0” for XDCR Min and “200” for
XDCR Max.
CALIBRATE TRANSDUCER TO A KNOWN PRESSURE
There are two options when calibrating a transducer to a known pressure.
NOTE
Differential pressures does not require calibration, but the differential pressure display units can be selected.
OPTION 1
1. Open the pressure transducer to a known pressure.
2. Adjust the Offset value until the “Displayed” value is equal to the known pressure.
OPTION 2
1. Open the pressure transducer to a known pressure.
2. Enter the known pressure (in transducer units) into
“Target Value.” The controller will calculate an offset based on the known pressure that was entered.
Figure 6-3. Pressure Calibration Screen - 3 of 3
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
6 – 3
Section 6 • Instrument Calibration
Temperature Calibration Screen
The temperature calibration group of screens allows the user to change the temperature units displayed on the screen as well as calibrate temperature instruments.
Four Temperature units are available for display:
• Fahrenheit
• Celsius or Centigrade
• Kelvin (Absolute Celsius temperature scale)
• Rankine (Absolute Fahrenheit temperature scale)
CALIBRATE TEMPERATURE INSTRUMENTS
There two types of temperature instruments that can be calibrated, RTDs and temperature transmitters.
To calibrate an RTD, proceed with the following steps.
NOTE
Typically, RTDs are very accurate and do not require calibration.
1. Expose the RTD to a known temperature (such as a slurry of crushed ice and water).
2. Enter an offset so the displayed temperature is equal to the known temperature.
Temperature units can be changed by touching on the list selector in any temperature calibration screen and using the up, down, and enter buttons. Changing the temperature display units also converts all temperature setpoints to the new selected units.
To calibrate a temperature transmitter, proceed with the following steps.
1. Enter the raw mA range (typically 4-20mA).
2. Enter the span of the transmitter in degrees
Fahrenheit. For a 32-392 Fahrenheit transmitter,
Enter “32” for XDCR Min and “392” for XDCR Max.
6 – 4
Figure 6-4. Temperature Calibration Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 6 • Instrument Calibration
Other Analog Device Calibration
The Other Analog Device Calibration Screen allows the user to calibrate additional 4-20mA input devices.
4-20mA devices that can be calibrated:
• Main Motor Amperage
• Main Motor VFD Speed
• Compressor and Motor Vibration Sensors
• Methane Detector
CALIBRATE AN ADDITIONAL INSTRUMENT
To calibrate an additional instrument, proceed with the following steps.
1. Enter the raw mA range (typically 4-20mA).
2. Enter the Span of the transmitter.
3. Enter minimum scale value in “XDCR Min” and full scale value for “XDCR Max.”
Figure 6-5. Other Analog Calibration Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
6 – 5
Section 6 • Instrument Calibration
Slide Calibration Screen
The slide calibration screen allows the user to calibrate the capacity slide valve.
Slide Calibration Overview:
• Must be logged in as “SUPER” to calibrate slides.
• Press “Enter Slide Calibration” To Activate Slide
Calibration Mode, see Figure 6-7. (Machine MUST be stopped to enter slide calibration mode. Machine will not be allowed to start if slide calibration is active.)
• Use up/down pushbuttons to move the capacity slide valve.
• Enter minimum and maximum raw values in numerical entry fi elds.
The capacity slide valve should be calibrated when one or more of these have occurred:
• Compressor unit starting up for the fi rst time.
• Slide valve does not unload below 5% or doesn’t move.
6 – 6
Figure 6-6. Slide Calibration Screen (Not in Calibration Mode)
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 6 • Instrument Calibration
Figure 6-7. Slide Calibration Screen (In Calibration Mode)
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
6 – 7
Section 6 • Instrument Calibration
CALIBRATE CAPACITY SLIDE VALVE - LINEAR
POSITION INDICATOR (LPI)
General:
An electronic device called a Linear Potentiometer gives an indication of the position of the slide valve which can be used by the compressor control system.
The Linear Position Indicator (LPI) is an electronic contact-less displacement sensor inserted into a sensor well which allows the LPI to be removed from compressor without loss of oil or gas from the compressor.
The LPI has several usable options built into one device.
The slide valve position can be indicated in three different ways:
• Visual Light emitting diodes (LED)
• Visual and by an analogue output 4-20mA
• Visual and by a digital 24 V DC signal output on minimum and maximum slide valve position
NOTE
The compressor can only be allowed to start with the slide valve in the minimum load position. Therefore a signal from the minimum load electronic position switch is always required or if the 4 – 20 mA signal is being used, then a 4 mA signal is required
Visual and by an Analogue Output (4-20mA):
Reference Table 6-1
The minimum load position is given by the 4 mA output and the maximum load position is given by the 20 mA output. (White Wire)
Part load positions are indicated by intermediate values between 4 and 20 mA.
The LED’s on the indicator also give a visual indication of part load operation. It should be noted that part load slide valve position is not a direct indication of actual compressor capacity at part load. Use of the 4 – 20 mA signal is common for many control systems and may be used on its own, if required, for all control functions for single and multiple compressor installations, subject to a suitable control system.
Visual:
It is always possible to see the position of the slide valve, see Figure 6-8.
At minimum load a yellow LED is illuminated at the lowest light on the left of the LPI.
At maximum load a blue LED is illuminated at the lowest light on the right of the LPI.
At part load only some of the LED are illuminated, eg, At
50% load only half of the LED will be illuminated.
6 – 8
Figure 6-8. Linear Position Indicator (LPI)
Table 6-1. Connections - Visual and by Analogue Output (4-20mA)
Wiring Plug Connections Function
1 = Brown
2 = White
3 = Blue
Supply Voltage + 24V DC
Output Signal 4-20 mA
Common – 0 VDC
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 6 • Instrument Calibration
Visual and by a Digital 24V Output on Minimum and Maximum Load:
Reference Table 6-2
There is also another option that can be used to control and get the minimum signal for start-up.
This option works the same as the mechanical microswitches but instead uses the electronic switches incorporated in the LPI unit. These electronic switches give a
24 V DC output.
A digital output is given on the Minimum and Maximum position of the slide valve and an interposing relay, which must be incorporated in the control panel in place of each mechanical micro-switch, is activated by the digital signal completing the control circuit signal. This interposing relay must have contacts with suitable ratings. The interposing relay replaces the original switch function.
The LED’s only give a visual indication of the slide valve position.
If the slide valve is in the minimum position and the LED for minimum is illuminated, there will be a digital output on the green/yellow wire.
If the slide valve is in the maximum position and all the
LED’s are illuminated, there will be a digital output on the black wire.
Existing installations equipped with the mechanical micro-switches can use this option.
Choose the best way for giving a start signal and connect the wires according to the table.
LINEAR POSITION INDICATOR OPERATION &
CALIBRATION
All compressors with variable Vi are despatched from
Howden Compressors facility with Vi set at 2.2 and the
LPI calibrated to suit Vi 2.2.
When the Slide Valve is in the unloaded position, the
10% minimum load LED should be illuminated.
To check that the LPI indicates maximum load when the slide valve is in the fully loaded position, ie all LED’s are illuminated, the following checks should be made.
Move the slide valve to 100% (by using the oil pump or if the system is shut down, use a manual oil pump or air pressure). By pressurizing the outboard side of the actuator piston the slide valve will be moved to the fully loaded position. The LPI should indicate 100% by illuminating all LED’s. If this is not the case repeat the calibration procedure.
Table 6-2. Connections - Visual and by Digital 24V Output on Min & Max Load
Wiring Plug Connections Function
1 = Brown
3 = Blue
4 = Black
5 = Green/Yellow
Supply Voltage + 24V DC
Common - 0 VDC
Digital Output Max. Load
Digital Output Min. Load
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
6 – 9
Section 6 • Instrument Calibration
Linear Position Indicator (LPI) Calibration
Procedure
NOTE
If Vi is changed, LPI must be re-calibrated.
The Minimum Load position gives a 4mA output and the Maximum Load gives a 20mA output.
1. Move slide valve to Minimum Load position.
2. Remove calibration button cover.
3. Connect power supply to LPI, 24v DC max.
4. With slide valve in Minimum Load position, push calibration button once. Red LED will light, after 15-
20 seconds light will turn to “Flashing Red”.
5. Move slide valve to Full/Maximum Load position.
6. With slide valve in Full/Maximum Load position, push calibration button once, Red LED will light for 15 seconds and then go off. Green LED will now light.
7. Calibration is now complete and sensor should now red maximum or 100% capacity.
8. Refi t button cover.
Figure 6-9. Linear Position Indicator (LPI) with Cover Removed
6 – 10
Figure 6-10. Linear Position Indicator (LPI) Wiring Diagram
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 7 • Compressor Control Setpoints
Setpoints and Control Screens
The setpoint and control screens relate to the operation and control of the compressor. Process and operational setpoints for the compressor and other equipment are adjustable within this group of screens.
CHANGING SETPOINTS
To change setpoints within the setpoint and control screens, the user must be logged in. Setpoints that may be adjusted by the logged in user appear as a white button that shows the current value of the setpoint.
Setpoints that may not be adjusted by the logged in user
(or if no user is logged in) appear as text only and cannot be changed.
Pressing on a numeric entry opens the numeric entry pop-up screen, see Figure 7-1.
• In Figure 7-1, the Suction Pressure Control screen, the current value of the setpoint is highlighted by a green box.
• In Figure 7-1, the numeric entry pop-up screen, the range of values above the numerical buttons is the acceptable range that can be entered. If a value outside this range is entered the HMI will not accept it.
• To enter a new setpoint, use the numerical keypad and enter key.
• To close the numerical input pop-up screen without changing the setpoint, push the “ESC” key.
Acceptable Range
Current Setpoint Value
Figure 7-1. Numeric Entry Pop-up Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
7 – 1
Section 7 • Compressor Control Setpoints
Compressor Control Setpoints
NOTE
Screens may have inverted colors for ease of readability.
Compressor control setpoints can be controlled by suction pressure, process temperature or discharge pressure. Depending on which control scheme is chosen, compressor control screen 1 of 3 will display that chosen option.
Compressor Control Setpoints Screen 1 - Suction Pressure
The Compressor Control Setpoints page 1 (Suction
Pressure) screen appears when navigating to
“Compressor Control Setpoints” from the menu screen when Suction Pressure control is selected. Setpoints for desired suction pressure, capacity slide valve control, auto start-stop, and main motor VFD are settable within this screen. For more information and operational descriptions, see section 2 “Operational Descriptions.”
SUCTION PRESSURE CONTROL
• Target Suction Pressure: This is the desired suction pressure the compressor will try to maintain.
• Upper and Lower Deadband: This is a range of pressures above and below the Target Suction Pressure.
Within this range, no capacity slide position adjustments will be made.
The following groups of setpoints are settable. If multiple groups of setpoints are being used, the active group of setpoints is designated by the “Setpoint 1” or
“Setpoint 2” text being shown in green. Auto Start/Stop and Main Motor VFD Setpoints will appear if selected.
• Upper and Lower Proportional Band: This is a range of pressures above and below the Target Suction
Pressure. Within this range, the controller will make proportionally smaller adjustments to capacity slide position.
7 – 2
Figure 7-2. Compressor Control Screen - 1 of 3 (Suction Pressure)
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 7 • Compressor Control Setpoints
CAPACITY SLIDE VALVE
• Load/Unload Interval time: This is the cycle time between making capacity slide position adjustments.
• Max Load/Unload Adjustment per interval: This is the maximum amount the capacity position command may be adjusted by every time through the Load/
Unload Cycle timer.
• Auto Stop Delay: Amount of time Auto Stop pressure must be met before the compressor will be commanded to stop.
• Minimum Slide Position: Slide position must be below this setpoint (indicating the compressor is fully unloaded) before the compressor will be commanded to stop.
AUTO START/STOP
• Auto Start Pressure: When suction pressure is above this setpoint for the Auto Start Delay Time, the compressor will be commanded to start.
• Auto Stop Pressure: When suction pressure is below this setpoint and capacity slide position is below
Minimum Slide Position for the Auto Stop Delay time, the compressor will be commanded to stop.
• Auto Start Delay: Amount of time Auto Start pressure must be met before the compressor will be commanded to start.
MAIN MOTOR VFD
• Max Speed Increase/Decrease per interval: This is the maximum amount the main motor speed command may be adjusted by every time through the Load/
Unload Cycle timer.
• Forced Unload Rate: If a forced unload condition exists and the main motor is running above 50% speed, this is the rate it will decelerate until it reaches 50% speed and the capacity slide begins unloading.
Compressor Control Setpoints Screen 1 - Process Temperature
The Compressor Control Setpoints page 1 (Process
Temperature) screen appears when navigating to
“Compressor Control Setpoints” from the menu screen when Process Temperature control is selected.
Setpoints for desired process temperature, capacity slide valve control, auto start-stop, and main motor VFD are settable within this screen. For more information and operational descriptions, see section 2 “Operational
Descriptions.”
The following groups of setpoints are settable. If multiple groups of setpoints are being used, the active group of setpoints is designated by the “Setpoint 1” or
“Setpoint 2” text being shown in green. Auto Start/Stop and Main Motor VFD Setpoints will appear if selected.
PROCESS TEMPERATURE CONTROL
• Target Process Temperature: This is the desired process temperature the compressor will try to maintain.
• Upper and Lower Deadband: This is a range of temperatures above and below the Target Process
Temperature. Within this range, no capacity slide position adjustments will be made.
• Upper and Lower Proportional Band: This is a range of temperatures above and below the Target Process
Temperature. Within this range, the controller will make proportionally smaller adjustments to capacity slide position.
CAPACITY SLIDE VALVE
• Load/Unload Interval time: This is the cycle time between making capacity slide position adjustments.
• Max Load/Unload Adjustment per interval: This is the maximum amount the capacity position command may be adjusted by every time through the Load/
Unload Cycle timer.
AUTO START/STOP
• Auto Start Temperature: When process temperature is above this setpoint for the Auto Start Delay Time, the compressor will be commanded to start.
• Auto Stop Temperature: When process temperature is below this setpoint and capacity slide position is below Minimum Slide Position for the Auto Stop
Delay time, the compressor will be commanded to stop.
• Auto Start Delay: Amount of time Auto Start temperature must be met before the compressor will be commanded to start.
• Auto Stop Delay: Amount of time Auto Stop temperature must be met before the compressor will be commanded to stop.
• Minimum Slide Position: Slide position must be below this setpoint (indicating the compressor is fully unloaded) before the compressor will be commanded to stop.
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
7 – 3
Section 7 • Compressor Control Setpoints
MAIN MOTOR VFD
• Max Speed Increase/Decrease per interval: This is the maximum amount the main motor speed command may be adjusted by every time through the Load/
Unload Cycle timer.
Forced Unload Rate: If a forced unload condition exists and the main motor is running above 50% speed, this is the rate it will decelerate until it reaches 50% speed and the capacity slide begins unloading.
7 – 4
Figure 7-3. Compressor Control Screen - 1 of 3 (Process Temperature)
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 7 • Compressor Control Setpoints
Compressor Control Setpoints Screen 1 - Discharge Pressure
The Compressor Control Setpoints page 1 (Discharge
Pressure) screen appears when navigating to
“Compressor Control Setpoints” from the menu screen when Discharge Pressure control is selected. Setpoints for desired discharge pressure, capacity slide valve control, auto start-stop, and main motor VFD are settable within this screen. For more information and operational descriptions, see section 2 “Operational Descriptions.”
The following groups of setpoints are settable. If multiple groups of setpoints are being used, the active group of setpoints is designated by the “Setpoint 1” or
“Setpoint 2” text being shown in green. Auto Start/Stop and Main Motor VFD Setpoints will appear if selected.
DISCHARGE PRESSURE CONTROL
• Target Discharge Pressure: This is the desired discharge pressure the compressor will try to maintain.
• Upper and Lower Deadband: This is a range of pressures above and below the Target Discharge
Pressure. Within this range, no capacity slide position adjustments will be made.
• Upper and Lower Proportional Band: This is a range of pressures above and below the Target Discharge
Pressure. Within this range, the controller will make proportionally smaller adjustments to capacity slide position.
CAPACITY SLIDE VALVE
• Load/Unload Interval time: This is the cycle time between making capacity slide position adjustments.
• Max Load/Unload Adjustment per interval: This is the maximum amount the capacity position command may be adjusted by every time through the Load/
Unload Cycle timer.
Figure 7-4. Compressor Control Screen - 1 of 3 (Discharge Pressure)
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
7 – 5
Section 7 • Compressor Control Setpoints
AUTO START/STOP
• Auto Start Pressure: When discharge pressure is above this setpoint for the Auto Start Delay Time, the compressor will be commanded to start.
• Auto Stop Pressure: When discharge pressure is below this setpoint and capacity slide position is below
Minimum Slide Position for the Auto Stop Delay time, the compressor will be commanded to stop.
• Auto Start Delay: Amount of time Auto Start pressure must be met before the compressor will be commanded to start.
• Auto Stop Delay: Amount of time Auto Stop pressure must be met before the compressor will be commanded to stop.
• Minimum Slide Position: Slide position must be below this setpoint (indicating the compressor is fully unloaded) before the compressor will be commanded to stop.
MAIN MOTOR VFD
• Max Speed Increase/Decrease per interval: This is the maximum amount the main motor speed command may be adjusted by every time through the Load/
Unload Cycle timer.
• Forced Unload Rate: If a forced unload condition exists and the main motor is running above 50% speed, this is the rate it will decelerate until it reaches 50% speed and the capacity slide begins unloading.
7 – 6
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 7 • Compressor Control Setpoints
Compressor Control Setpoints Screen 2
ANTI-RECYCLE
• Anti-Recycle Time: Defi nes the minimum amount of time after the compressor stops before it is allowed to start again.
START UP
• The “Start Up” Group of setpoints defi nes parameters for the compressor start sequence. For more information on the compressor start sequence, see
Section 2 Operational Descriptions.
• Maximum Comp. Differential to Start: Compressor
Discharge-Suction Pressures must be equalized to within this setpoint to start the compressor.
• Minimum Prelube Pressure: Prelube pressure that must be achieved by the oil pump before the compressor is allowed to start.
• Prelube Time Before Motor Start: Amount of time that minimum prelube pressure must be maintained before compressor is allowed to start.
• Prelube Retry Wait Time: Amount of wait time before oil pump restarts if prelube oil pressure is not achieved.
• Prelube Time After Motor Start: Amount of time that minimum prelube pressure must be maintained after compressor main motor starts.
• Warmup Time: Amount of warmup time the compressor will run with the oil pump on and capacity slide valve at minimum position before it will start loading.
• Suction Oil Injection ON time at start: Amount of time the suction oil injection solenoid will be energized after the start of the main motor, if installed.
SHUT DOWN
• Suction-Discharge Equalizing Solenoid ON Time (at
Stop): Amount of time the equalizing line solenoid
Figure 7-5. Compressor Control Screen - 2 of 3
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
7 – 7
Section 7 • Compressor Control Setpoints will be energized after the compressor main motor stops, if installed.
• Oil Drain Solenoid ON Time (at Stop): Amount of time the oil drain solenoid will be energized after the compressor main motor stops, if installed.
OIL SEPARATOR HEATERS
• Defi nes separator oil temperature setpoints to control the oil separator heaters.
LOAD LIMITS
For more information on load limits and forced unloading, see Section 2 Operational Descriptions.
• Low Suction Pressure Inhibit Loading: compressor will not be allowed to load if Suction Pressure falls below this setpoint.
• Low Suction Pressure Unload At: Compressor will begin continuously unloading if Suction Pressure falls below this setpoint.
• Low Suction Pressure Unload To: If forced unloading is active, the compressor will unload continuously until Suction Pressure reaches this setpoint.
• High Discharge Pressure Inhibit Loading: compressor will not be allowed to load if Discharge Pressure rises above this setpoint.
• High Discharge Pressure Unload At: Compressor will begin continuously unloading if Discharge Pressure rises above this setpoint.
• High Discharge Pressure Unload To: If forced unloading is active, the compressor will unload continuously until Discharge Pressure reaches this setpoint.
• High Motor Amps Inhibit Loading: compressor will not be allowed to load if Main Motor Amperage rises above this setpoint.
• High Motor Amps Unload At: Compressor will begin continuously unloading if Main Motor Amperage rises above this setpoint.
• High Motor Amps Unload To: If forced unloading is active, the compressor will unload continuously until
Main Motor Amperage reaches this setpoint.
MAIN MOTOR FLA
• This is a convenience calculation to aid in setting motor amps load limit setpoints.
Compressor Control Setpoints Screen 3
SUPPLEMENTAL FALSE START PROTECTION
• Provided to operate a safety device to de-energize power to the main motor in the event of a False
Start of the Main Motor
VENTURI OIL RECOVERY
• Cycle Time: Defi nes the ON and OFF time for the venturi oil recovery solenoids, if installed.
HOTGAS BYPASS
• ON/OFF Capacity Slide Position: Defi nes the capacity slide valve positions the hotgas bypass solenoid will turn ON below and OFF above, if installed.
ECONOMIZER
• Port 1: Defi nes the capacity slide valve positions the economizer port 1 solenoid(s) will turn ON above and OFF below, if installed.
• Port 2: Defi nes the capacity slide valve positions the economizer solenoid(s) will turn ON above and OFF below, if installed.
ENCLOSURE SETPOINTS
• Enclosure Heater: Defi nes Enclosure Temperature setpoints to control the enclosure space heaters.
Enclosure Roof Vents: Defi nes Enclosure
Temperature setpoints to control the enclosure roof vents/exhaust fans.
OIL FLOW CONTROL
• Oil Flow Control Start Temp (Oil Injection): Defi nes the oil injection temperature at which the oil fl ow control valve will modulate. Below this temperature the valve will remain 100% open.
7 – 8
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 7 • Compressor Control Setpoints
PERIODIC SLIDE VALVE EXERCISE
Cycle Time: Defi nes the amount of time of slide valve non-movement to activate the periodic slide valve exercise function, if enabled.
Figure 7-6. Compressor Control Screen - 3 of 3 (All Options Shown)
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
7 – 9
7 – 10 / Blank
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 8 • Alarm and Trip Setpoints
Alarm and Trip Setpoints
NOTE
Screens may have inverted colors for ease of readability.
The compressor controller continuously monitors operational and process data and annunciates an alarm and/ or shuts the compressor down if any condition becomes abnormal. The alarm and trip points for some of the operational and process data are adjustable by the user in the alarm and trip setpoints screens. The alarm and trip setpoints are interlocked such that a low alarm may not be set lower than a low trip, and a high trip may not be set below a high alarm.
Actual values of the specifi c operational and process data is shown in the column in the middle of the screen.
Setpoints are only shown for applicable alarm and trip points. When alarms or trips are specifi c to “Setpoint 1” or “Setpoint 2” setpoint groups, the alarm or trip point will only be active when the associated setpoint group is active.
Alarm and Trip Setpoints Screen 1
• Suction Pressure Setpoint 1 and 2: Low Alarm and
Low Trip setpoints for compressor suction pressure.
• Discharge Pressure Setpoint 1 and 2: High Alarm and High Trip setpoints for compressor discharge pressure.
• Net Oil Pressure - Start: Low Alarm and Low Trip setpoints for net oil pressure (oil manifold pressure – suction pressure) during compressor warmup.
• Net Oil Pressure – Run: Low Alarm and Low Trip setpoints for net oil pressure (oil manifold pressure – suction pressure) after compressor warmup.
• Oil Filter Differential Pressure – Start: High Alarm and
High Trip setpoints for pressure drop across the oil fi lter(s) at compressor start.
• Oil Filter Differential Pressure – Run: High Alarm and
High Trip setpoints for pressure drop across the oil fi lter(s) after oil fi lter differential changeover timer expires
Figure 8-1. Alarm and Trip Setpoints Screen - 1 of 2
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
8 – 1
Section 8 • Alarm and Trip Setpoints
• Motor Winding Temperature: High Alarm and High
Trip setpoints for temperature of the main motor windings, if motor winding RTDs are installed.
• Motor Bearing Temperature: High Alarm and High
Trip setpoints for temperature of the main motor bearings, if motor bearing RTDs are installed.
• Process Temperature: Low Alarm, Low Trip, and High
Alarm setpoints for process temperature, if it is being controlled or monitored.
• Liquid Refrigerant Temperature: Low Alarm and Low
Trip for temperature of the liquid refrigerant in the chiller, if it is being monitored.
• Motor Amps: High Alarm and High Trip for main motor current.
• Oil Cooler Outlet Temperature: Low and High Alarms for temperature of the oil at the outlet of the oil cooler, if it is being controlled or monitored.
• Separator Oil Temp Changeover Time: Time after compressor starts when separator oil temperature alarm and trip transitions from start setpoints to run setpoints.
• Oil Filter Differential Changeover Time: Time after compressor starts when oil fi lter differential alarm and trip transitions from start setpoints to run setpoints.
• Main Motor FLA: Convenience calculation for setting main motor amperage alarms and trips.
8 – 2
Figure 8-2. Alarm and Trip Setpoints Screen - 2 of 2
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 9 • Step and PID Device Control Screens
Oil Mixing Valve Screen
OIL MIXING VALVE SETPOINTS
• Target Oil Injection Temp: Defi nes the desired temperature of oil entering the compressor. The mixing valve will adjust to maintain this temperature.
• Deadband: Range above and below setpoint where the controller will not make adjustments to valve position.
• PID Tuning: PID Calculations displayed to aid in tuning the PID loop.
• Loop Update Time: Defi nes the PID controller loop time. The PID calculation will update every cycle of the loop update timer.
• Proportional Gain (Kp): Defi nes the Proportional
Constant of the PID calculation.
• Integral Gain (Ki): Defi nes the Integral Constant of the PID calculation.
• Derivative Gain (Kd): Defi nes the Derivative Constant of the PID Calculation.
• Oil Mixing Valve Force: Allows the user to manually force the oil mixing valve to a settable position.
Activating the Oil Mixing Valve Force pushbutton will command the oil mixing valve to go to the set position, and will override calculations from the PID
Controller.
Figure 9-1. Oil Mixing Valve Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
9 – 1
Section 9 • Step and PID Device Control Screens
OIL COOLER (VFD TYPE) SETPOINTS
• Start Oil Cooler Above: Defi nes the temperature the oil cooler fans will come on at minimum speed.
• Target Oil Cooler Outlet Temperature: Defi nes the desired temperature of oil at the outlet of the oil cooler.
The oil cooler fan speed will adjust to maintain this temperature.
• Deadband: Range above and below setpoint where the controller will not make adjustments to fan speed.
• PID Tuning: PID Calculations displayed to aid in tuning the PID loop.
• Loop Update Time: Defi nes the PID controller loop time. The PID calculation will update every cycle of the loop update timer.
• Proportional Gain (Kp): Defi nes the Proportional
Constant of the PID calculation.
• Integral Gain (Ki): Defi nes the Integral Constant of the PID calculation.
• Derivative Gain (Kd): Defi nes the Derivative Constant of the PID Calculation.
• Minimum Speed: Defi nes the minimum oil cooler fan speed.
• Plenum Heater ON Temp: Defi nes the oil cooler outlet temperature at which the oil cooler plenum heater turns ON (if used).
• Plenum Heater OFF Temp: Defi nes the oil cooler outlet temperature at which the oil cooler plenum heater turns OFF (if used).
• Oil Cooler Fan VFD Force: Allows the user to manually force the oil cooler fan(s) to a settable speed.
Activating the Oil Cooler Fan VFD Force pushbutton will command the oil cooler fan(s) to go to the set speed, and will override calculations from the PID
Controller.
9 – 2
Figure 9-2. Oil Cooler (VFD Type) Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 9 • Step and PID Device Control Screens
OIL COOLER (STEP TYPE) SETPOINTS
• Start Oil Cooler Above: Defi nes the temperature the fi rst oil cooler step will come on.
• Target Oil Cooler Outlet Temperature: Defi nes the desired temperature of oil at the outlet of the oil cooler.
The controller will cycle fans on and off to maintain this temperature.
• Deadband: Range above and below setpoint where the controller will not add or remove any steps.
• Step Dwell Time: Amount of time Oil Cooler Outlet
Temperature must be outside the deadband to add or remove a step.
• Plenum Heater ON Temp: Defi nes the oil cooler outlet temperature at which the oil cooler plenum heater turns ON (if used).
• Plenum Heater OFF Temp: Defi nes the oil cooler outlet temperature at which the oil cooler plenum heater turns OFF (if used).
• Oil Cooler Fan Confi guration: Truth table that defi nes which fan outputs are turned on in each step.
Figure 9-3. Oil Cooler (Step Type) Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
9 – 3
Section 9 • Step and PID Device Control Screens
Aftercooler Screens
AFTERCOOLER (VFD TYPE) SETPOINTS
• Start Aftercooler Above: Defi nes the temperature the aftercooler fans will come on at minimum speed.
• Target Aftercooler Outlet Temperature: Defi nes the desired temperature of gas at the outlet of the aftercooler. The aftercooler fan speed will adjust to maintain this temperature.
• Deadband: Range above and below setpoint where the controller will not make adjustments to fan speed.
• PID Tuning: PID Calculations displayed to aid in tuning the PID loop.
• Loop Update Time: Defi nes the PID controller loop time. The PID calculation will update every cycle of the loop update timer.
• Proportional Gain (Kp): Defi nes the Proportional
Constant of the PID calculation.
• Integral Gain (Ki): Defi nes the Integral Constant of the PID calculation.
• Derivative Gain (Kd): Defi nes the Derivative Constant of the PID Calculation.
• Minimum Speed: Defi nes the minimum aftercooler fan speed.
• Aftercooler VFD Force: Allows the user to manually force the aftercooler fan(s) to a settable speed.
Activating the Aftercooler VFD Force pushbutton will command the aftercooler fan(s) to go to the set speed, and will override calculations from the PID
Controller
9 – 4
Figure 9-4. Aftercooler (VFD Type) Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 9 • Step and PID Device Control Screens
AFTERCOOLER (STEP TYPE) SETPOINTS
• Start Aftercooler Above: Defi nes the temperature the fi rst aftercooler step will come on.
• Target Aftercooler Outlet Temperature: Defi nes the desired temperature of gas at the outlet of the aftercooler. The controller will cycle fans on and off to maintain this temperature.
• Deadband: Range above and below setpoint where the controller will not add or remove any steps.
• Step Dwell Time: Amount of time Aftercooler Outlet
Temperature must be outside the deadband to add or remove a step.
• Aftercooler Fan Confi guration: Truth table that defi nes which fan outputs are turned on in each step.
Figure 9-5. Aftercooler (Step Type) Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
9 – 5
Section 9 • Step and PID Device Control Screens
WATER COOLED AFTERCOOLER SETPOINTS
• Open Valve Above: Defi nes the temperature the aftercooler water supply valve will open to minimum position.
• Target Aftercooler Outlet Temperature: Defi nes the desired temperature of gas at the outlet of the aftercooler. The aftercooler water supply valve position will adjust to maintain this temperature.
• Deadband: Range above and below setpoint where the controller will not make adjustments to water supply valve position.
• PID Tuning: PID Calculations displayed to aid in tuning the PID loop.
• Loop Update Time: Defi nes the PID controller loop time. The PID calculation will update every cycle of the loop update timer.
• Proportional Gain (Kp): Defi nes the Proportional
Constant of the PID calculation.
• Integral Gain (Ki): Defi nes the Integral Constant of the PID calculation.
• Derivative Gain (Kd): Defi nes the Derivative Constant of the PID Calculation.
• Minimum Valve Open: Defi nes the minimum water supply valve position.
• Aftercooler Valve Force: Allows the user to manually force the aftercooler water supply valve to a settable position. Activating the Aftercooler Valve Force pushbutton will command the aftercooler water supply valve to go to the set position, and will override calculations from the PID Controller.
9 – 6
Figure 9-6. Water Cooled Aftercooler Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 9 • Step and PID Device Control Screens
Condenser Screens
CONDENSER (STEP TYPE) SETPOINTS
• Start Condenser Above: Defi nes the pressure the fi rst condenser step will come on.
• Target Condensing Pressure: Defi nes the desired pressure of gas at the condenser. The controller will cycle fans on and off to maintain this temperature.
• Deadband: Range above and below setpoint where the controller will not add or remove any steps.
• Step Dwell Time: Amount of time Condensing pressure must be outside the deadband to add or remove a step.
• Condenser Fan Confi guration: Truth table that defi nes which fan outputs are turned on in each step.
If a condenser pump is installed, the truth table also defi nes which steps the pump output is turned on.
Figure 9-7. Condenser (Step Type) Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
9 – 7
Section 9 • Step and PID Device Control Screens
CONDENSER (VFD TYPE) SETPOINTS
• Start Condenser Above: Defi nes the temperature the condenser fans will come on at minimum speed.
• Target Condensing Pressure: Defi nes the desired pressure of gas at the condenser. The condenser fan speed will adjust to maintain this pressure.
• Deadband: Range above and below setpoint where the controller will not make adjustments to fan speed.
• PID Tuning: PID Calculations displayed to aid in tuning the PID loop.
• Loop Update Time: Defi nes the PID controller loop time. The PID calculation will update every cycle of the loop update timer.
• Proportional Gain (Kp): Defi nes the Proportional
Constant of the PID calculation.
• Integral Gain (Ki): Defi nes the Integral Constant of the PID calculation.
• Derivative Gain (Kd): Defi nes the Derivative Constant of the PID Calculation.
• Minimum Speed: Defi nes the minimum condenser fan speed.
• Condenser VFD Force: Allows the user to manually force the condenser fan(s) to a settable speed.
Activating the Condenser VFD Force pushbutton will command the condenser fan(s) to go to the set speed, and will override calculations from the PID
Controller.
• Condenser Pump Enable: If installed, this selector defi nes if the condenser pump will be commanded to run when the condenser fan VFD starts.
9 – 8
Figure 9-8. Condenser (VFD Type) Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 9 • Step and PID Device Control Screens
WATER COOLED CONDENSER SETPOINTS
• Open Valve Above: Defi nes the pressure at which the aftercooler water supply valve will open to minimum position.
• Target Condensing Pressure: Defi nes the desired pressure of gas at the condenser. The condenser water supply valve position will adjust to maintain this pressure.
• Deadband: Range above and below setpoint where the controller will not make adjustments to water supply valve positon.
• PID Tuning: PID Calculations displayed to aid in tuning the PID loop.
• Loop Update Time: Defi nes the PID controller loop time. The PID calculation will update every cycle of the loop update timer.
• Proportional Gain (Kp): Defi nes the Proportional
Constant of the PID calculation.
• Integral Gain (Ki): Defi nes the Integral Constant of the PID calculation.
• Derivative Gain (Kd): Defi nes the Derivative Constant of the PID Calculation.
• Minimum Valve Open: Defi nes the minimum water supply valve position.
• Condenser Valve Force: Allows the user to manually force the condenser water supply valve to a settable position. Activating the Condenser Valve Force pushbutton will command the condenser water supply valve to go to the set position, and will override calculations from the PID Controller.
Figure 9-9. Water Cooled Condenser Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
9 – 9
Section 9 • Step and PID Device Control Screens
Liquid Injection Valve Screens
LIQUID INJECTION VALVE SETPOINTS
• Open Valve Above: Defi nes the temperature at which the liquid injection valve will open to minimum position.
• Target Discharge Temperature: Defi nes the desired temperature of gas and oil discharging from the compressor. The liquid injection valve position will adjust to maintain this temperature.
• Deadband: Range above and below setpoint where the controller will not make adjustments to the liquid injection valve position.
• Oil Separator Override Temperature: Separator Oil
Temperature must be above this temperature for the liquid injection to operate.
• PID Tuning: PID Calculations displayed to aid in tuning the PID loop.
• Loop Update Time: Defi nes the PID controller loop time. The PID calculation will update every cycle of the loop update timer.
• Proportional Gain (Kp): Defi nes the Proportional
Constant of the PID calculation.
• Integral Gain (Ki): Defi nes the Integral Constant of the PID calculation.
• Derivative Gain (Kd): Defi nes the Derivative Constant of the PID Calculation.
• Minimum Valve Open: Defi nes the minimum liquid injection valve position.
• Liquid Injection Valve Force: Allows the user to manually force the liquid injection valve to a settable position. Activating the Liquid Injection Valve Force pushbutton will command the liquid injection valve to go to the set position, and will override calculations from the PID Controller.
9 – 10
Figure 9-10. Liquid Injection Valve Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 9 • Step and PID Device Control Screens
LIQUID INJECTION (VPLUS PUMP) SETPOINTS
• Start Pump At: Defi nes the temperature at which the
VPLUS pump will start at its minimum speed.
• Target Discharge Temperature: Defi nes the desired temperature of gas and oil discharging from the compressor. The VPLUS pump will adjust speed to maintain this temperature.
• Deadband: Range above and below setpoint where the controller will not make adjustments to the
VPLUS pump speed.
• Oil Separator Override Temperature: Separator Oil
Temperature must be above this temperature for the
VPLUS pump to operate.
• PID Tuning: PID Calculations displayed to aid in tuning the PID loop.
• Loop Update Time: Defi nes the PID controller loop time. The PID calculation will update every cycle of the loop update timer.
• Proportional Gain (Kp): Defi nes the Proportional
Constant of the PID calculation.
• Integral Gain (Ki): Defi nes the Integral Constant of the PID calculation.
• Derivative Gain (Kd): Defi nes the Derivative Constant of the PID Calculation.
• Minimum Pump Speed: Defi nes the minimum speed of the VPLUS pump.
• VPLUS Pump Force: Allows the user to manually force the VPLUS pump to a settable speed. Activating the
VPLUS Pump Force pushbutton will command the
VPLUS pump to go to the set speed, and will override calculations from the PID Controller.
Figure 9-11. Liquid Injection (VPLUS Pump) Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
9 – 11
Section 9 • Step and PID Device Control Screens
Discharge Recycle Valve Screen
DISCHARGE RECYCLE VALVE SETPOINTS
• Target Recycle Control Pressure: Defi nes the pressure at which the discharge recycle valve will begin to open.
• Deadband: Range above and below setpoint where the controller will not make adjustments to the recycle valve position.
• PID Tuning: PID Calculations displayed to aid in tuning the PID loop.
• Loop Update Time: Defi nes the PID controller loop time. The PID calculation will update every cycle of the loop update timer.
• Proportional Gain (Kp): Defi nes the Proportional
Constant of the PID calculation.
• Integral Gain (Ki): Defi nes the Integral Constant of the PID calculation.
• Derivative Gain (Kd): Defi nes the Derivative Constant of the PID Calculation.
• Discharge Recycle Valve Force: Allows the user to manually force the discharge recycle valve to a settable position. Activating the Discharge Recycle Valve
Force pushbutton will command the discharge recycle valve to go to the set position, and will override calculations from the PID Controller.
9 – 12
Figure 9-12. Discharge Recycle Valve Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 9 • Step and PID Device Control Screens
Start Menu Popup Screen
Pressing “Start Menu” on the compressor or system overview screen will open the “Start Menu” popup screen. The “Start Menu” screen allows the user to change operating modes and start the compressor.
• Remote: Pressing the remote pushbutton puts the compressor loading control in remote mode. The remote mode pushbutton will only be visible if the confi guration is correct
• Local: Pressing the Local pushbutton puts the compressor loading control in local mode.
• Auto: Pressing the Auto pushbutton puts the compressor loading control in Auto mode.
• Manual: Pressing the Manual pushbutton puts the compressor loading control in Manual mode.
• Unit Start: Pressing the Unit Start pushbutton initiates a compressor start.
For more information on operating modes, see Section 2
Operational Descriptions.
Figure 9-13. Start Menu Popup Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
9 – 13
9 – 14 / Blank
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 10 • Diagnostic Screens
IO/Comms Diagnostics Screen
COMMS DIAGNOSTICS AND I/O STATUS
NOTE
Some screens may have inverted colors for ease of readability.
The IO/Comms Diagnostics Screen is divided into 3 sections.
• SYSTEM INFORMATION
• Shows basic information about the Compressor
PLC panel: Vilter sales order number, Software revision, IP addresses, hardware information, and fi rmware revisions of compressor PLC and HMI.
• BITS/REALS FROM DCS:
• Shows commands from a central controller or
DCS to verify communications setup with a central controller or DCS.
• LOCAL I/O STATUS
• Shows a graphic representation of the compressor PLC’s local I/O modules and the raw data specifi c to each channel.
• Use the following rules to interpret the data:
• Discrete inputs and outputs: Green = ON
• Analog Inputs (voltage): The number shown for a specifi c channel represents the voltage signal being read in millivolts. Ex: a value of
2500 indicates 2500 millivolts or 2.5 volts.
• Analog Inputs and outputs (4-20mA): The number shown for a specifi c channel represents the signal in .001 mA. Ex: a value of
4000 indicates 4.000 mA.
• RTD Inputs: The number shown for a specifi c channel represents the temperature reading in Fahrenheit times 10. Ex: a value of 730 indicates 73.0 degrees Fahrenheit.
Figure 10-1. IO/Comms Diagnostics Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
10 – 1
Section 10 • Diagnostic Screens
Event List Screen
The event list is a running log of alarm, trip, and status information. The event list shows the last 400 events logged by the compressor PLC, most recent is at the top of the screen. Each event is logged with a time and date stamp.
To scroll through past events, use the navigation buttons at the bottom of the screen.
10 – 2
Figure 10-2. Event List Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 10 • Diagnostic Screens
Diagnostics Forced Outputs Screen
The force outputs screen allows a user logged in as
“SUPER” to force discrete and analog outputs to verify operation of devices on the compressor unit or package.
Outputs that are available to force depend on the confi guration for a specifi c compressor machine or package.
• Pressing a force button forces ON the PLC output for that particular device. If there is an associated analog output (speed or position command) the keyed in value will be applied to that output. Pressing the force button again removes the force.
• Pressing “Clear all Forces” removes all active forces.
CAUTION
Do not overfi ll oil separator and suction header with oil. Wait at least 30 minutes prior to starting compressor. Failure to comply may result in damage to equipment.
Figure 10-3. Diagnostics Forced Output Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
10 – 3
Section 10 • Diagnostic Screens
Captured Data at Shutdown Screen
The captured data at shutdown screen shows process and operational data at the time the compressor shuts down. Data from the last 5 shutdowns are logged. Each shutdown is given a time and date stamp. The most recent shutdown is on the left.
10 – 4
Figure 10-4. Captured Data at Shutdown Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 10 • Diagnostic Screens
Initial Baseline Running Data Screen
The Initial Baseline Running Data screen shows data collected when the compressor is fi rst started up. Vilter
Service Technicians or Engineers only may log this data.
This is to give a reference point for comparing operational and process data to a baseline set of data collected when the compressor or package was new.
Figure 10-5. Initial Baseline Running Data Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
10 – 5
10 – 6 / Blank
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 11 • Alarms, Trips, Status Information & Troubleshooting
Alarms & Trips
Process and Operational data of the compressor unit is continuously monitored by the compressor PLC. If an abnormal condition is detected, an alarm or trip will be annunciated.
• Alarms
• Warns of an abnormal condition. Compressor may continue to run.
• Trips
• Compressor will shut down if active.
A scrolling display at the top of the overview and menu screens shows all active alarms and trips, see Figure
11-1.
Trips are shown in the red banner, alarms are shown in the yellow banner.
When a new alarm or trip is triggered, the alarm popup screen will appear showing the most recent alarm or trip, see Figure 11-2.
Figure 11-1. Alarm/Trip/Status Bars (Main Menu Screen)
Figure 11-2. Alarm/Trip Popup Screen
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
11 – 1
Section 11 • Alarms, Trips, Status Information & Troubleshooting
Alarm Listing
The following table shows all possible alarms and trips and possible causes. Some alarms and trips are application specifi c, and do not apply unless a specifi c option is selected.
To reset alarms or trips press the “Alarm Reset” Button on the overview screen. If the condition is cleared, the alarm will reset. If the condition is not cleared, the alarm will remain active.
Alarm Message
(A001) Alarm: (Unassigned)
(A002) Alarm: PLC to Central Comms
Faulted
(A003) Alarm: High Main Motor
Amps
(A004) Alarm: (Unassigned)
(A005) Alarm: (Unassigned)
(A006) Alarm: Low Separator Oil
Level
(A007) Alarm: Not Assigned
(A008) Alarm: Not Assigned
(A009) Alarm: Not Assigned
(A010) Alarm: Not Assigned
(A011) Alarm: Low Suction
Temperature
(A012) Alarm: High Discharge
Temperature
(A013) Alarm: Low Oil Separator
Temperature - Start
(A014) Alarm: Low Oil Separator
Temperature - Run
(A015) Alarm: Low Oil Injection
Temperature
(A016) Alarm: High Oil Injection
Temperature
Table 11-1. Alarm Listing
Cause(s)
Loss of Communication with DCS/
Central - Settable Communications
Watchdog Timer Expired. (Alarm and Revert to Local Selected on
Communication Failure.)
Main Motor Amps exceeds Motor
Amps High Alarm setpoint.
Oil Separator Level Switch has opened indicating drop in Separator
Oil Level. (Alarm action Selected)
Suction Temperature falls below
"Suction Temperature" Low Alarm
Setpoint.
Discharge Temperature exceeds
"Discharge Temperature" High Alarm
Setpoint.
Separator Oil Temperature is Below
"Separator Oil Temperature - Start"
Low Alarm Setpoint when compressor is off or Oil Separator Start-Run
Timer has not expired.
Separator Oil Temperature is
Below "Separator Oil Temperature
- Run" Low Alarm Setpoint After
Oil Separator Start-Run Timer has expired.
Oil Injection Temperature is Below
"Oil Injection Temperature" Low
Alarm Setpoint after compressor has completed pre-lube and warm up stages.
Oil Injection Temperature exceeds
"Oil Injection Temperature" High
Alarm Setpoint
Notes
Watchdog Active if Control by
Communications is selected
Active if Oil Separator Level Switch
Selected.
11 – 2
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 11 • Alarms, Trips, Status Information & Troubleshooting
Alarm Message
(A017) Alarm: Low Process
Temperature
(A018) Alarm: High Process
Temperature
(A019) Alarm: (Unassigned)
(A020) Alarm: Low Liquid Refrigerant
Temperature
(A021) Alarm: Low Suction Pressure
Stpt. 1
(A022) Alarm: Low Suction Pressure
Stpt. 2
(A023) Alarm: High Discharge
Pressure Stpt. 1
(A024) Alarm: High Discharge
Pressure Stpt. 2
(A025) Alarm: Low Net Oil Pressure
- Run
(A026) Alarm: Unassigned
(A027) Alarm: High Oil Filter
Differential - Start
(A028) Alarm: High Oil Filter
Differential - Run
Cause(s)
Process Temperature falls below
Process Temperature Low Alarm
Setpoint in Process Temperature control or if displaying Process
Temperature.
Process Temperature exceeds
Process Temperature High Alarm
Setpoint in Process Temperature control or if displaying Process
Temperature.
Liquid Refrigerant Temperature falls below Liquid Refrigerant
Temperature Low Alarm Setpoint if displaying Liquid Refrigerant
Temperature
Setpoint 1 is selected and Suction
Pressure falls below Suction Pressure
Low Alarm.
Setpoint 2 is selected and Suction
Pressure falls below Suction Pressure
Low Alarm.
Setpoint 1 is selected and Discharge
Pressure falls below Discharge
Pressure High Alarm.
Setpoint 2 is selected and Discharge
Pressure falls below Discharge
Pressure High Alarm.
Net Oil Pressure (Oil Manifold
Pressure - Suction Pressure) falls below Net Oil Pressure Low Alarm
Setpoint after prelube and warmup are complete.
Oil Filter Differential (Filter In
Pressure - Oil Manifold Pressure) exceeds Oil Filter Differential - Start
High Alarm Setpoint when compressor is running and before Oil Filter
Differential Start-Run Changeover
Timer expires.
Oil Filter Differential (Filter In
Pressure - Oil Manifold Pressure) exceeds Oil Filter Differential - Run
High Alarm Setpoint when compressor is running and after Oil Filter
Differential Start-Run Changeover
Timer expires.
Notes
Active if controlling or displaying
Process Temperature
Active if controlling or displaying
Process Temperature
Active if displaying Liquid Refrigerant
Temperature
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
11 – 3
Section 11 • Alarms, Trips, Status Information & Troubleshooting
Alarm Message
(A029) Alarm: Low Oil Pressure
- Start
(A030) Alarm: Low Rotor Feed Oil
Pressure
(A031) Alarm: Out of Range: Oil
Cooler Inlet Temp
(A032) Alarm: Out of Range: Oil
Cooler Outlet Temp
(A033) Alarm: Out of Range:
Condensing Pressure
(A034) Alarm: Out of Range:
Aftercooler 1 Outlet Temp
(A035) Alarm: Out of Range:
Aftercooler 2 Outlet Temp
(A036) Alarm: Out of Range: Inlet
Scrubber Inlet Pressure
(A037) Alarm: Out of Range: Inlet
Scrubber Outlet Pressure
(A038) Alarm: Out of Range: Outlet
Scrubber Inlet Pressure
(A039) Alarm: Out of Range: Outlet
Scrubber Outlet Pressure
Cause(s)
Net Oil Pressure (Oil Manifold
Pressure - Suction Pressure) falls below Net Oil Pressure Low Alarm
Setpoint after before Warmup is complete
Rotor Feed Oil Pressure falls below
Low Alarm Setpoint.
Oil Cooler Inlet Temperature
Instrument is Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA (if using a 4-20mA
Temperature Transmitter).
Oil Cooler Outlet Temperature
Instrument is Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA (if using a 4-20mA
Temperature Transmitter).
Condensing Pressure Instrument is
Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA.
Aftercooler 1 Out Temperature
Instrument is Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA (if using a 4-20mA
Temperature Transmitter).
Aftercooler 2 Out Temperature
Instrument is Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA (if using a 4-20mA
Temperature Transmitter).
Inlet Scrubber Inlet Pressure
Instrument is Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA.
Inlet Scrubber Outlet Pressure
Instrument is Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA.
Outlet Scrubber Inlet Pressure
Instrument is Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA.
Outlet Scrubber Outlet Pressure
Instrument is Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA.
Notes
On Twin Screw Applications with
Partially Pumped Oil Circuit.
Active if Displaying Oil Cooler Inlet
Temperature
Active if Controlling an Oil Cooler or Displaying Oil Cooler Outlet
Temperature
Active if Controlling a Condenser
Active if Controlling Aftercooler 1
Active if Controlling Aftercooler 2
Active if Inlet Scrubber is Present
Active if Inlet Scrubber is Present
Active if Outlet Scrubber is Present
Active if Outlet Scrubber is Present
11 – 4
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 11 • Alarms, Trips, Status Information & Troubleshooting
Alarm Message
(A040) Alarm: Out of Range:
Discharge Recycle Control Pressure
(A041) Alarm: Out of Range: Oil
Separator Outlet Pressure
(A042) Alarm: Unassigned
(A043) Alarm: Unassigned
(A044) Alarm: (Unassigned)
(A045) Alarm: (Unassigned)
(A046) Alarm: High Oil Separator
Pressure Drop
(A047) Alarm: Low Oil Separator
Outlet Temp (Dew Point)
(A048) Alarm: High Motor Phase A
Temperature
(A049) Alarm: High Motor Phase B
Temperature
(A050) Alarm: High Motor Phase C
Temperature
(A051) Alarm: Motor DE Bearing
Temperature
(A052) Alarm: Motor ODE Bearing
Temperature
(A053) Alarm: High Motor Vibration
- Sensor 1
(A054) Alarm: High Motor Vibration
- Sensor 2
(A055) Alarm: High Compressor
Vibration - Sensor 1
(A056) Alarm: High Compressor
Vibration - Sensor 2
(A057) Alarm: Inlet Scrubber High
Level
Cause(s)
Discharge Recycle Control Pressure
Instrument is Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA.
Oil Separator Outlet Pressure
Instrument is Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA.
Pressure Drop Across Oil Separator
Coalescing Elements is greater than
High Alarm Setpoint.
Temperature At Outlet of Oil
Separator is less than Low Alarm
Setpoint.
Phase A Motor Winding
Temperature exceeds Motor
Winding Temperature High Alarm
Setpoint
Phase B Motor Winding Temperature exceeds Motor Winding
Temperature High Alarm Setpoint
Phase C Motor Winding Temperature exceeds Motor Winding
Temperature High Alarm Setpoint
Drive End Motor Bearing
Temperature exceeds Motor Bearing
Temperature High Alarm Setpoint
Opposite Drive End Motor Bearing
Temperature exceeds Motor Bearing
Temperature High Alarm Setpoint
Motor Vibration exceeds Motor
Vibration High Alarm Setpoint
(Sensor 1)
Motor Vibration exceeds Motor
Vibration High Alarm Setpoint
(Sensor 2)
Compressor Vibration exceeds
Compressor Vibration High Alarm
Setpoint (Sensor 1)
Compressor Vibration exceeds
Compressor Vibration High Alarm
Setpoint (Sensor 2)
Inlet Scrubber High Liquid Level
Switch Activated
Notes
Active if Controlling Discharge
Recycle Valve
Active if Displaying Oil Separator
Outlet Pressure
When Monitoring Oil Separator
Outlet Pressure.
When Monitoring Oil Separator
Outlet Temperature.
Active if Displaying Motor Winding
Temperatures
Active if Displaying Motor Winding
Temperatures
Active if Displaying Motor Winding
Temperatures
Active if Displaying Motor Bearing
Temperatures
Active if Displaying Motor Bearing
Temperatures
Active if Displaying Motor Vibration
Sensor 1
Active if Displaying Motor Vibration
Sensor 2
Active if Displaying Compressor
Vibration Sensor 1
Active if Displaying Compressor
Vibration Sensor 2
Active if Vane Type Inlet Scrubber is
Present
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
11 – 5
Section 11 • Alarms, Trips, Status Information & Troubleshooting
Alarm Message
(A058) Alarm: Inlet Scrubber High
High Level
(A059) Alarm: Inlet Scrubber Low
Low Level
(A060) Alarm: Upper Inlet Scrubber
High Level
(A061) Alarm: Upper Inlet Scrubber
High High Level
(A062) Alarm: (Unassigned)
(A063) Alarm: Lower Inlet Scrubber
High Level
(A064) Alarm: Lower Inlet Scrubber
High High Level
(A065) Alarm: Inlet Scrubber High
Pressure Drop
(A066) Alarm: Inlet Scrubber
Condensate Pump Starter Fault
(A067) Alarm: Outlet Scrubber High
Level
(A068) Alarm: Outlet Scrubber High
High Level
(A069) Alarm: Outlet Scrubber Low
Low Level
(A070) Alarm: Upper Outlet
Scrubber High Level
(A071) Alarm: Upper Outlet
Scrubber High High Level
(A072) Alarm: (Unassigned)
(A073) Alarm: Lower Outlet
Scrubber High Level
(A074) Alarm: Lower Outlet
Scrubber High High Level
(A075) Alarm: Outlet Scrubber High
Pressure Drop
(A076) Alarm: Outlet Scrubber
Condensate Pump Starter Fault
(A077) Alarm: (Unassigned)
(A078) Alarm: (Unassigned)
Cause(s)
Inlet Scrubber High High Liquid Level
Switch Activated (Selected Action =
ALARM)
Inlet Scribber Low Low Level Switch
Activated (Selected Action =
ALARM)
Inlet Scrubber Upper Section High
Level Switch Activated
Inlet Scrubber Upper Section
High High Level Switch Activated
(Selected Action = ALARM)
Inlet Scrubber Lower Section High
Level Switch Activated
Inlet Scrubber Lower Section High
High Level Switch Activated
Pressure Drop across Inlet Scrubber is greater than High Alarm Setpoint.
Inlet Scrubber Condensate Pump
Commanded to run, run confi rmation not received.
Outlet Scrubber High Liquid Level
Switch Activated
Outlet Scrubber High High Liquid
Level Switch Activated (Selected
Action = ALARM)
Outlet Scribber Low Low Level
Switch Activated (Selected Action =
ALARM)
Outlet Scrubber Upper Section High
Level Switch Activated
Outlet Scrubber Upper Section
High High Level Switch Activated
(Selected Action = ALARM)
Outlet Scrubber Lower Section High
Level Switch Activated
Outlet Scrubber Lower Section High
High Level Switch Activated
Pressure Drop Across Outlet
Scrubber is greater than High Alarm
Setpoint.
Outlet Scrubber Condensate Pump
Commanded to run, running confi rmation not received.
Notes
Active if Vane Type Inlet Scrubber is
Present
Active if Vane Type Inlet Scrubber is
Present
Active if Coalescing Type Inlet
Scrubber is Present
Active if Coalescing Type Inlet
Scrubber is Present
Active if Coalescing Type Inlet
Scrubber is Present
Active if Coalescing Type Inlet
Scrubber is Present
Active if Inlet Scrubber is Selected.
Active if Controlling a condensate
Pump on Inlet Scrubber
Active if Vane Type Outlet Scrubber is Present
Active if Vane Type Outlet Scrubber is Present
Active if Vane Type Outlet Scrubber is Present
Active if Coalescing Type Outlet
Scrubber is Present
Active if Coalescing Type Outlet
Scrubber is Present
Active if Coalescing Type Outlet
Scrubber is Present
Active if Coalescing Type Outlet
Scrubber is Present
Active if Outlet Scrubber is selected.
Active if Controlling a Condensate
Pump on Outlet Scrubber
11 – 6
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 11 • Alarms, Trips, Status Information & Troubleshooting
Alarm Message
(A079) Alarm:
(A080) Alarm:
(A081) Alarm:
(A082) Alarm:
(A083) Alarm:
(A084) Alarm: (Unassigned)
(A085) Alarm: (Unassigned)
(A086) Alarm: (Unassigned)
(A087) Alarm: (Unassigned)
(A088) Alarm: (Unassigned)
(A089) Alarm: Oil Cooler Fan VFD
Fault
(A090) Alarm: Oil Cooler Fan (Step
Type) Starter Fault
(A091) Alarm: (Unassigned)
(A092) Alarm: (Unassigned)
(A093) Alarm: Aftercooler 1 Fan VFD
Fault
(A094) Alarm: Aftercooler 1 Fan
(Step Type) Starter Fault
(A095) Alarm: Aftercooler 2 Fan VFD
Fault
(A096) Alarm: Aftercooler 2 Fan
(Step Type) Starter Fault
(A097) Alarm: Economizer High
Level
(A098) Alarm: Chiller High Level
(A099) Alarm: Air Cooled Condenser
Fan VFD Fault
(A100) Alarm: Air Cooled Condenser
(Step Type) Starter Fault
(A101) Alarm: Unassigned
(A102) Alarm: Unassigned
(A103) Alarm: (Unassigned)
(A104) Alarm: (Unassigned)
(A105) Alarm: (Unassigned)
Cause(s)
User defi ned Alarm 1
User Defi ned Alarm 2
User Defi ned Alarm 3
User defi ned Alarm 4
User defi ned Alarm 5
Fault Contact open on Oil Cooler
VFD
Oil Cooler Fan commanded to start, running confi rmation not received.
Fault Contact open on Aftercooler 1
VFD
Aftercooler 1 Fan commanded to start, running confi rmation not received.
Fault Contact open on Aftercooler 2
VFD
Aftercooler 2 Fan commanded to start, running confi rmation not received.
Economizer High Liquid Level Switch
Activated
Chiller High Liquid Level Switch
Activated
Fault Contact open on Condenser
VFD
Condenser Fan commanded to start, run confi rmation not received.
Notes
Message Defi ned in "Device Names"
Screens
Message Defi ned in "Device Names"
Screens
Message Defi ned in "Device Names"
Screens
Message Defi ned in "Device Names"
Screens
Message Defi ned in "Device Names"
Screens
If controlling a VFD Type Oil Cooler
If controlling a Step Type Oil Cooler
If controlling a VFD Type
Aftercooler 1
If controlling a Step Type
Aftercooler 1
If controlling a VFD Type
Aftercooler 2
If controlling a Step Type
Aftercooler 2
If monitoring the liquid level in economizer vessel
If monitoring the liquid level in chiller vessel
If controlling a VFD Type Condenser
If controlling a Step Type Condenser
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
11 – 7
Section 11 • Alarms, Trips, Status Information & Troubleshooting
Alarm Message
(A106) Alarm: High Methane Gas
%LEL
(A107) Alarm: (Unassigned)
(A108) Alarm: Low Oil Cooler Out
Temperature
(A109) Alarm: High Oil Cooler Out
Temperature
(A110) Alarm: High Enclosure
Temperature
(A111) Alarm: (Unassigned)
(A112) Alarm: (Unassigned)
(A113) Alarm: (Unassigned)
(A114) Alarm: (Unassigned)
(A115) Alarm: (Unassigned)
(A116) Alarm: (Unassigned)
(A117) Alarm: (Unassigned)
(A118) Alarm: (Unassigned)
(A119) Alarm: (Unassigned)
(A120) Alarm: (Unassigned)
(A121) Alarm: (Unassigned)
(A122) Alarm: (Unassigned)
(A123) Alarm: (Unassigned)
(A124) Alarm: (Unassigned)
(A125) Alarm: (Unassigned)
(A126) Alarm: (Unassigned)
(A127) Alarm: (Unassigned)
Cause(s)
Methane Concentration in Building
Exceeds Methane Gas %LEL High
Alarm Setpoint.
Oil Cooler Outlet Temperature falls below Oil Cooler Outlet Temperature
- Low Alarm Setpoint
Oil Cooler Outlet Temperature exceeds Oil Cooler Outlet Temperature
- High Alarm Setpoint
Temperature inside Enclosure exceeds Enclosure Temperature - High
Setpoint
Notes
If compressor is in an enclosure
If controlling an oil cooler or displaying Oil Cooler Outlet Temperature
If controlling an oil cooler or displaying Oil Cooler Outlet Temperature
If compressor is in an enclosure
11 – 8
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 11 • Alarms, Trips, Status Information & Troubleshooting
Trip Listing
Trip Message
Table 11-2. Trip Listing
Cause(s) Notes
(T001) Trip: MCR Not Energized/E-
Stop Active
(T002) Trip: PLC to Central Comms
Faulted
Emergency Stop Button on PLC panel Pressed, Loss of Power
Loss of Communication with DCS/
Central - Settable Communications
Watchdog Timer Expired. (Action on
Comm Failure = Trip)
(T003) Trip: High Main Motor Amps Main Motor Amps exceeds Motor
Amps High Trip setpoint.
(T004) Setpoint out of Range - See
Menu Screen
(T005) Trip: False Start Detected Controller detected main motor running when not commanded.
Check main motor starter.
(T006) Trip: Low Separator Oil Level Oil Separator Level Switch has opened indicating drop in Separator
Oil Level. (Trip action Selected)
(T007) Trip: Faulted I/O Module
Connection or Module Type
(T008) Trip: Main Motor Starter Fault
(T009) Trip: Main Motor Feedback
Fault/Overload
(T010) Trip: Supplemental Shutdown
Active
Supplemental Shutdown output is turned on and Emergency Stop is activated by the controller.
(T011) Trip: Low Suction
Temperature
(T012) Trip: High Discharge
Temperature
(T013) Trip: Low Oil Separator
Temperature - Start
(T014) Trip: Low Oil Separator
Temperature - Run
Suction Temperature falls below
"Suction Temperature" Low Trip
Setpoint.
Discharge Temperature exceeds
"Discharge Temperature" High Trip
Setpoint.
Separator Oil Temperature is Below
"Separator Oil Temperature - Start"
Low Trip Setpoint when compressor is off or Oil Separator Start-Run
Timer has not expired.
Separator Oil Temperature is Below
"Separator Oil Temperature - Run"
Low Trip Setpoint After Oil Separator
Start-Run Timer has expired.
Watchdog Active if Control by
Communications is selected
Active if Oil Separator Level Switch
Selected.
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
11 – 9
Section 11 • Alarms, Trips, Status Information & Troubleshooting
Trip Message
(T015) Trip: Low Oil Injection
Temperature
(T016) Trip: High Oil Injection
Temperature
(T017) Trip: Low Process
Temperature
(T018) Trip: (Unassigned)
(T019) Trip: (Unassigned)
(T020) Trip: Low Liquid Refrigerant
Temperature
(T021) Trip: Low Suction Pressure
Stpt. 1
(T022) Trip: Low Suction Pressure
Stpt. 2
(T023) Trip: High Discharge Pressure
Stpt. 1
(T024) Trip: High Discharge Pressure
Stpt. 2
(T025) Trip: Low Net Oil Pressure
- Run
(T026) Trip: Failed To Reach Prelube
Pressure - Start Sequence Aborted
(T027) Trip: High Oil Filter
Differential - Start
Cause(s)
Oil Injection Temperature is Below
"Oil Injection Temperature" Low Trip
Setpoint after compressor has completed pre-lube and warm up stages.
Oil Injection Temperature exceeds
"Oil Injection Temperature" High Trip
Setpoint
Process Temperature falls below
Process Temperature Low Trip
Setpoint in Process Temperature control or if displaying Process
Temperature.
Liquid Refrigerant Temperature falls below Liquid Refrigerant
Temperature Low Trip Setpoint if displaying Liquid Refrigerant
Temperature
Setpoint 1 is selected and Suction
Pressure falls below Suction Pressure
Low Trip Setpoint.
Setpoint 2 is selected and Suction
Pressure falls below Suction Pressure
Low Trip Setpoint.
Setpoint 1 is selected and Discharge
Pressure falls below Discharge
Pressure High Trip Setpoint.
Setpoint 2 is selected and Discharge
Pressure falls below Discharge
Pressure High Trip Setpoint.
Net Oil Pressure (Oil Manifold
Pressure - Suction Pressure) falls below Net Oil Pressure Low Trip
Setpoint after prelube and warmup are complete.
Failed to maintain required prelube pressure for required time during start-up.
Oil Filter Differential (Filter In
Pressure - Oil Manifold Pressure) exceeds Oil Filter Differential - Start
High Trip Setpoint when compressor is running and before Oil Filter
Differential Start-Run Changeover
Timer expires.
Notes
Active if controlling or displaying
Process Temperature
Active if displaying Liquid Refrigerant
Temperature
11 – 10
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 11 • Alarms, Trips, Status Information & Troubleshooting
Trip Message
(T028) Trip: High Oil Filter
Differential - Run
Cause(s)
Oil Filter Differential (Filter In
Pressure - Oil Manifold Pressure) exceeds Oil Filter Differential - Run
High Trip Setpoint when compressor is running and after Oil Filter
Differential Start-Run Changeover
Timer expires.
(T029) Trip: Low Oil Pressure - Start Net Oil Pressure (Oil Manifold
Pressure - Suction Pressure) falls below Net Oil Pressure Low Trip
Setpoint after before Warmup is complete
(T030) Trip: Low Rotor Feed Oil
Pressure
Rotor Feed Oil Pressure is below Low
Trip Setpoint.
(T031) Trip: Out of Range: Suction Pr Suction Pressure Instrument is
Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA
(T032) Trip: Out of Range: Discharge
Pr
Discharge Pressure Instrument is
Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA
(T033) Trip: Out of Range: Manifold
Pr
Oil Manifold Pressure Instrument is
Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA.
(T034) Trip: Out of Range: Filter Inlet
Pr
(T035) Trip: Out of Range: Suction
Temp
(T036) Trip: Out of Range: Discharge
Temp
(T037) Trip: Out of Range: Oil Sep
Temp
(T038) Trip: Out of Range: Oil
Injection Temp
Oil Filter Inlet Pressure Instrument is Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA
Suction Temperature Instrument is
Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA (if using a 4-20mA Temperature
Transmitter).
Discharge Temperature Instrument is Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA (if using a 4-20mA Temperature
Transmitter).
Separator Oil Temperature
Instrument is Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA (if using a 4-20mA
Temperature Transmitter).
Oil Injection Temperature
Instrument is Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA (if using a 4-20mA
Temperature Transmitter).
Notes
Used on Twin Screw Machines with
Partially Pumped Oil Circuit.
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
11 – 11
Section 11 • Alarms, Trips, Status Information & Troubleshooting
Trip Message
(T039) Trip: Out of Range: Main
Motor Amps
(T040) Trip: Out of Range: Capacity
Slide Position
(T041) Unassigned
(T042) Trip: Out of Range: Process
Temp
(T043) Trip: Out of Range: Motor
RTD Phase A
(T044) Trip: Out of Range: Motor
RTD Phase B
(T045) Trip: Out of Range: Motor
RTD Phase C
(T046) Trip: Out of Range: Motor
RTD ODE
(T047) Trip: Out of Range: Motor
RTD DE
(T048) Trip: High Motor Phase A
Temperature
(T049) Trip: High Motor Phase B
Temperature
(T050) Trip: High Motor Phase C
Temperature
(T051) Trip: High Motor DE Bearing
Temperature
(T052) Trip: High Motor ODE Bearing
Temperature
(T053) Trip: High Motor Vibration -
Sensor 1
Cause(s)
Main Motor Current Transmitter is
Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA.
Capacity Slide Cable is Disconnected or Raw value is less than 0 mV or
Greater than 5200 mV.
Notes
Process Temperature Instrument is
Disconnected or Raw value is less than 3.5 mA or Greater than 20.5 mA (if using a 4-20mA Temperature
Transmitter).
Winding RTD is disconnected or faulty
Winding RTD is disconnected or faulty
Winding RTD is disconnected or faulty
Bearing RTD is disconnected or faulty
Bearing RTD is disconnected or faulty
Phase A Motor Winding Temperature exceeds Motor Winding
Temperature High Trip Setpoint
Phase B Motor Winding Temperature exceeds Motor Winding
Temperature High Trip Setpoint
Phase C Motor Winding Temperature exceeds Motor Winding
Temperature High Trip Setpoint
Drive End Motor Bearing
Temperature exceeds Motor Bearing
Temperature High Trip Setpoint
Opposite Drive End Motor Bearing
Temperature exceeds Motor Bearing
Temperature High Trip Setpoint
Motor Vibration exceeds Motor
Vibration High Trip Setpoint (Sensor
1)
Active if Displaying Motor Winding
Temperatures
Active if Displaying Motor Winding
Temperatures
Active if Displaying Motor Winding
Temperatures
Active if Displaying Motor Bearing
Temperatures
Active if Displaying Motor Bearing
Temperatures
Active if Displaying Motor Vibration
Sensor 1
11 – 12
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 11 • Alarms, Trips, Status Information & Troubleshooting
Trip Message
(T054) Trip: High Motor Vibration -
Sensor 2
(T055) Trip: High Compressor
Vibration - Sensor 1
(T056) Trip: High Compressor
Vibration - Sensor 2
(T057) Trip: (Unassigned)
(T058) Trip: Inlet Scrubber High High
Level
(T059) Trip: Inlet Scrubber Low Low
Level
(T060) Trip: (Unassigned)
(T061) Trip: Upper Inlet Scrubber
High High Level
(T062) Trip: (Unassigned)
(T063) Trip: (Unassigned)
(T064) Trip: Lower Inlet Scrubber
High High Level
(T065) Trip: (Unassigned)
(T066) Trip: (Unassigned)
(T067) Trip: (Unassigned)
(T068) Trip: Outlet Scrubber High
High Level
(T069) Trip: Outlet Scrubber Low
Low Level
(T070) Trip: (Unassigned)
(T071) Trip: Upper Outlet Scrubber
High High Level
(T072) Trip: (Unassigned)
(T073) Trip: (Unassigned)
(T074) Trip: Lower Outlet Scrubber
High High Level
(T075) Trip: (Unassigned)
(T076) Trip: (Unassigned)
(T077) Trip: (Unassigned)
Cause(s)
Motor Vibration exceeds Motor
Vibration High Trip Setpoint (Sensor
2)
Compressor Vibration exceeds
Compressor Vibration High Trip
Setpoint (Sensor 1)
Compressor Vibration exceeds
Compressor Vibration High Trip
Setpoint (Sensor 2)
Inlet Scrubber High High Liquid Level
Switch Activated (Selected Action =
TRIP)
Inlet Scrubber Low Low Level Switch
Activated (Selected Action = TRIP)
Inlet Scrubber Upper Section
High High Level Switch Activated
(Selected Action = TRIP)
Inlet Scrubber Lower Section
High High Level Switch Activated
(Selected Action = Trip)
Outlet Scrubber High High Liquid
Level Switch Activated (Selected
Action = TRIP)
Outlet Scribber Low Low Level
Switch Activated (Selected Action =
TRIP)
Outlet Scrubber Upper Section
High High Level Switch Activated
(Selected Action = TRIP)
Outlet Scrubber Lower Section
High High Level Switch Activated
(Seelcted Action = TRIP)
Notes
Active if Displaying Motor Vibration
Sensor 2
Active if Displaying Compressor
Vibration Sensor 1
Active if Displaying Compressor
Vibration Sensor 2
Active if Vane Type Inlet Scrubber is
Present
Active if Vane Type Inlet Scrubber is
Present
Active if Coalescing Type Inlet
Scrubber is Present
Active if Coalescing Type Inlet
Scrubber is Present
Active if Vane Type Outlet Scrubber is Present
Active if Vane Type Outlet Scrubber is Present
Active if Coalescing Type Outlet
Scrubber is Present
Active if Coalescing Type Outlet
Scrubber is Present
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
11 – 13
Section 11 • Alarms, Trips, Status Information & Troubleshooting
Trip Message
(T078) Trip: (Unassigned)
(T079) Trip:
(T080) Trip:
(T081) Trip:
(T082) Trip:
(T083) Trip:
Cause(s)
User defi ned Trip 1
User Defi ned Trip 2
User Defi ned Trip 3
User defi ned Trip 4
User defi ned Trip 5
(T084) Trip: (Unassigned)
(T085) Trip: (Unassigned)
(T086) Trip: (Unassigned)
(T087) Trip: (Unassigned)
(T088) Trip: (Unassigned)
(T089) Trip: (Unassigned)
(T090) Trip: (Unassigned)
(T091) Trip: (Unassigned)
(T092) Trip: (Unassigned)
(T093) Trip: (Unassigned)
(T094) Trip: (Unassigned)
(T095) Trip: (Unassigned)
(T096) Trip: (Unassigned)
(T097) Trip: (Unassigned)
(T098) Trip: Chiller High Level Liquid Level in Chiller Vessel has tripped the high level switch.
(T099) Trip: (Unassigned)
(T100) Trip: (Unassigned)
(T101) Trip: EPCS Safety Active
- Low/Suction
(T102) Trip: EPCS Safety Active
- High/Discharge
Low Side/Suction Pressure Exceeds
EPCS Low Side Relief Setpoint
High Side/Discharge Pressure
Exceeds EPCS High Side Relief
Setpoint
(T103) Trip: (Unassigned)
(T104) Trip: (Unassigned)
(T105) Trip: (Unassigned)
(T106) Trip: High Methane Gas %LEL Methane Concentration in Building
Exceeds Methane Gas %LEL High Trip
Setpoint.
(T107) Trip: (Unassigned)
Notes
Message Defi ned in "Device Names"
Screens
Message Defi ned in "Device Names"
Screens
Message Defi ned in "Device Names"
Screens
Message Defi ned in "Device Names"
Screens
Message Defi ned in "Device Names"
Screens
Active if EPCS Safety Selected.
Active if EPCS Safety Selected.
If compressor is in an enclosure
11 – 14
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 11 • Alarms, Trips, Status Information & Troubleshooting
Trip Message Cause(s)
(T108) Trip: Smoke Detector Tripped Smoke Detector Trip Contact opened, detected smoke in compressor enclosure
(T109) Trip: (Unassigned)
(T110) Trip: High Enclosure
Temperature
(T111) Trip: Out of Range: 4-20 mA
Caphold Target
(T112) Trip: Out of Range: Building
Temperature
(T113) Trip: Out of Range: Methane
Detector
(T114) Trip: Out of Range: EPCS Low
Pressure
(T115) Trip: Out of Range: EPCS High
Pressure
(T116) Trip: Out of Range: Motor
Vibration 1
(T117) Trip: Out of Range: Motor
Vibration 2
(T118) Trip: Out of Range:
Compressor Vibration 1
(T119) Trip: Out of Range:
Compressor Vibration 2
(T120) Trip: Out of Range: Rotor
Feed Oil Pressure
(T121) Trip: (Unassigned)
(T122) Trip: (Unassigned)
(T123) Trip: (Unassigned)
(T124) Trip: (Unassigned)
(T125) Trip: (Unassigned)
(T126) Trip: (Unassigned)
(T127) Trip: (Unassigned)
(T128) Trip: (Unassigned)
Temperature inside Enclosure exceeds Enclosure Temperature - High
Trip Setpoint
4-20mA Caphold Input is
Disconnected or Raw Value is less than 3.5 mA or greater than 20 mA
Building Temperature RTD Input is
Disconnected or Raw Value is less than 3.5 mA or greater than 20 mA
(If using 4-20mA Transmitter)
Methane Detector is Disconnected or Raw Value is less than 3.5 mA or greater than 20 mA
Low Side EPCS Relief Instrument is
Disconnected or Raw Value is less than 3.5 mA or greater than 20 mA
High Side EPCS Relief Instrument is
Disconnected or Raw Value is less than 3.5 mA or greater than 20 mA
Motor Vibration 1 Instrument is
Disconnected or Raw Value is less than 3.5 mA or greater than 20 mA
Motor Vibration 2 Instrument is
Disconnected or Raw Value is less than 3.5 mA or greater than 20 mA
Compressor Vibration 1 Instrument is Disconnected or Raw Value is less than 3.5 mA or greater than 20 mA
Compressor Vibration 2 Instrument is Disconnected or Raw Value is less than 3.5 mA or greater than 20 mA
Rotor Feed Oil Pressure Instrument is Disconnected or Raw Value is less than 3.5 mA or greater than 20 mA
Notes
If compressor is in an enclosure
If compressor is in an enclosure
If remote manual mode active and
4-20mA caphold selected as Remote
Manual Source
If compressor is in an enclosure
If compressor is in an enclosure
Active if EPCS Safety Selected.
Active if EPCS Safety Selected.
If Motor Vibration Sensor 1 is installed
If Motor Vibration Sensor 2 is installed
If Compressor Vibration Sensor 1 is installed
If Compressor Vibration Sensor 2 is installed
On Twin Screw Machines with
Partially Pumped Oil Circuit.
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
11 – 15
Section 11 • Alarms, Trips, Status Information & Troubleshooting
Status Messages and Compressor State Indicator
Status messages are used to indicate compressor status information to the user. Status messages are used to inform the user of any of the following conditions.
• Anti-Recycle Timer is active
• Compressor is in standby mode and is waiting for one or more conditions to be met
• State of the Compressor Startup Sequence
• Load Limits and Forced Unloading
• Slide Calibration is active
• Compressor PLC has automatically reverted to Local-Auto mode on loss of communications with central controller or DCS (if this function is enabled)
• A user is logged in
• An output is forced
• Scheduled Maintenance is due (if this function is enabled)
• Slide valve exercising is active (if this function is enabled)
Status messages are shown in a green scrolling banner at the top of the overview and menu screens.
Figure 11-3. Alarm/Trip/Status Bars (Main Menu Screen)
Table 11-3. Status Listing
Status Message
(S001) Status: Compressor Stopped
(S002) Status: Compressor Started
(S003) Status: NOT USED
(S004) Status: True Anti-Recycle Active: Remaining:
XX:XX
(S005) Status: NOT USED
(S006) Status: Waiting to Start: Discharge-Suction Not
Equalized
Notes
Displayed in the Event List only
Displayed in the Event List only
Shows remaining anti-recycle time
(S007) Status: Waiting to Start: Remote Run Permissive
Input
(S008) Status: Waiting to Start: Soft Run Permissive from
DCS/Central
(S009) Status: Auto Cycle Stop - Suction Pressure
(S010) Status: Auto Cycle Stop - Process Temperature
11 – 16
Compressor PLC is waiting for compressor Discharge-
Suction to be equalized to within a settable differential before the compressor will start.
Compressor PLC is waiting for a contact closure on the remote run permissive input before the compressor will start
Compressor PLC is waiting for a run command from the central controller or DCS (if control by communications is enabled)
Auto Start-Stop function is enabled and "Stop" Pressure has been reached.
Auto Start-Stop function is enabled and "Stop"
Temperature has been reached.
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 11 • Alarms, Trips, Status Information & Troubleshooting
Status Message
(S011) Status: Auto Cycle Stop - Discharge Pressure
Notes
Auto Start-Stop function is enabled and "Stop" Pressure has been reached.
(S012) Status: Compressor Prelube
(S013) Status: Compressor Prelube Failed, Retry in XX
Seconds
(S014) Status: Oil Pump Transition
(S015) Status: Compressor Warmup - Hold at Minimum
Capacity Slide Position
Shows remaining time until the compressor prelube cycle will re-start
Shows remaining warmup time until compressor will begin loading.
(S016) Status: Loading Inhibited: Low Suction Pressure
(S017) Status: Loading Inhibited: High Discharge Pressure
(S018) Status: Loading Inhibited: High Motor Amps
(S019) Status: Forced Unload: Low Suction Pressure
(S020) Status: Forced Unload: High Discharge Pressure
(S021) Status: Forced Unload: High Motor Amps
(S022) Status: Slide Valve Calibration Active
(S023) Status: Comms Faulted, Reverted to Local Mode If "Control by Communications" is enabled and "Alarm and Revert to Local" is selected as the communications fault action.
(S024) Status: User SUPER Logged In
(S025) Status: User OP1 Logged In
(S025) Status: User OP2 Logged In
(S025) Status: User OP3 Logged In
(S025) Status: User OP4 Logged In
(S025) Status: User OP5 Logged In
(S030) Status: Main Motor FORCED ON
(S031) Status: NOT USED
(S032) Status: Oil Pump FORCED ON
(S033) Status: Oil Cooler VFD FORCED ON
(S034) Status: Oil Cooler Fan 1 FORCED ON
(S035) Status: Oil Cooler Fan 2 FORCED ON
(S036) Status: Oil Cooler Fan 3 FORCED ON
(S037) Status: Oil Cooler Fan 4 FORCED ON
(S038) Status: Oil Cooler Fan 5 FORCED ON
(S039) Status: Oil Cooler Fan 6 FORCED ON
(S040) Status: Oil Cooler Fan 7 FORCED ON
(S041) Status: Oil Cooler Fan 8 FORCED ON
(S042) Status: Oil Cooler Fan 9 FORCED ON
(S043) Status: Oil Cooler Fan 10 FORCED ON
(S044) Status: Aftercooler 1 VFD FORCED ON
(S045) Status: Aftercooler 1 Fan 1 FORCED ON
(S046) Status: Aftercooler 1 Fan 2 FORCED ON
(S047) Status: Aftercooler 1 Fan 3 FORCED ON
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
11 – 17
Section 11 • Alarms, Trips, Status Information & Troubleshooting
Status Message
(S048) Status: Aftercooler 1 Fan 4 FORCED ON
(S049) Status: Aftercooler 1 Fan 5 FORCED ON
(S050) Status: Aftercooler 1 Fan 6 FORCED ON
(S051) Status: Aftercooler 1 Fan 7 FORCED ON
(S052) Status: Aftercooler 1 Fan 8 FORCED ON
(S053) Status: Aftercooler 1 Fan 9 FORCED ON
(S054) Status: Aftercooler 1 Fan 10 FORCED ON
(S055) Status: Aftercooler 2 VFD FORCED ON
(S056) Status: Aftercooler 2 Fan 1 FORCED ON
(S057) Status: Aftercooler 2 Fan 2 FORCED ON
(S058) Status: Aftercooler 2 Fan 3 FORCED ON
(S059) Status: Aftercooler 2 Fan 4 FORCED ON
(S060) Status: Aftercooler 2 Fan 5 FORCED ON
(S061) Status: Aftercooler 2 Fan 6 FORCED ON
(S062) Status: Aftercooler 2 Fan 7 FORCED ON
(S063) Status: Aftercooler 2 Fan 8 FORCED ON
(S064) Status: Aftercooler 2 Fan 9 FORCED ON
(S065) Status: Aftercooler 2 Fan 10 FORCED ON
(S066) Status: Condenser Fan VFD FORCED ON
(S067) Status: Condenser Fan 1 FORCED ON
(S068) Status: Condenser Fan 2 FORCED ON
(S069) Status: Condenser Fan 3 FORCED ON
(S070) Status: Condenser Fan 4 FORCED ON
(S071) Status: Condenser Fan 5 FORCED ON
(S072) Status: Condenser Fan 6 FORCED ON
(S073) Status: Condenser Fan 7 FORCED ON
(S074) Status: Condenser Fan 8 FORCED ON
(S075) Status: Condenser Fan 9 FORCED ON
(S076) Status: Condenser Fan 10 FORCED ON
(S077) Status: Condenser Water Valve FORCED ON
(S078) Status: VPLUS Pump FORCED ON
(S079) Status: Liquid Injection Valve Air SOV FORCED ON
(S080) Status: Discharge Recycle Air SOV FORCED ON
(S081) Status: Oil Mixing Valve FORCED ON
(S082) Status: Oil Injection Valve FORCED ON
(S083) Status: Alarm Indication FORCED ON
(S084) Status: Trip Indication FORCED ON
(S085) Status: Oil Separator Heaters FORCED ON
(S086) Status: Suction Oil SOV FORCED ON
(S087) Status: Gas EQ SOV FORCED ON
(S088) Status: Economizer SOV FORCED ON
11 – 18
Notes
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 11 • Alarms, Trips, Status Information & Troubleshooting
Status Message
(S089) Status: Hotgas SOV FORCED ON
(S090) Status: Venturi Oil Recovery SOVs FORCED ON
(S091) Status: Inlet Scrubber Drain Pump/SOV FORCED
ON
(S092) Status: Inlet Scrubber Backup SOV FORCED ON
(S093) Status: Outlet Scrubber Drain Pump/SOV FORCED
ON
(S094) Status: Outlet Scrubber Backup SOV FORCED ON
(S095) Status: Enclosure Vent Fans FORCED ON
(S096) Status: Enclosure Heaters FORCED ON
(S097) Status: Evap Condenser Pump FORCED ON
(S098) Status: EPCS Low Side SOV FORCED ON
(S099) Status: EPCS High Side SOV FORCED ON
Notes
(S100) Status: Oil Cooler STBY Heaters FORCED ON
(S101) Status: Alarm Horn FORCED ON
(S102) Status: Stacklight - Amber FORCED ON
(S103) Status: Stacklight - Red FORCED ON
(S104) Status: INLET SCRUBBER - PUMP 2 FORCED ON
(S105) Status: OUTLET SCRUBBER - PUMP 2 FORCED ON
(S106) Status: OIL DRAIN SV FORCED ON
(S107) Status: Economizer Port 2 FORCED ON
(S108) Status: Shunt Trip FORCED ON
(S109) Status: User MGR Logged In
(S110) Status: Setpoint 1 Active
(S111) Status: Setpoint 2 Active
(S112) Status: Scheduled Maintenance Due
(S113) Status: Aftercooler 1 Valve Forced
(S114) Status: Aftercooler 2 Valve Forced
(S115) Status: Capacity Slide Exercise Active
Displayed in the Event List only
Displayed in the Event List only
The message entered in the settable maintenance timer dialog will appear in the status banner and event list
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
11 – 19
Section 11 • Alarms, Trips, Status Information & Troubleshooting
Troubleshooting
IF THE COMPRESSOR WILL NOT START
In order to initiate a start at the compressor, make sure all permissives to initiate a start are met.
To initiate a start, the following conditions must be met:
• Control Power is ON (Emergency Stop button is not pressed and Master Control Relay is energized, indicated by pilot light on front of panel)
• No Active Trips
If a start has been initiated and the compressor has not started, it is in standby mode. When in standby mode, the status banner will indicate the condition that is preventing the compressor from starting.
IF CONTROL POWER WILL NOT TURN ON
If unable to turn on control power/reset an emergency stop, check the following conditions:
To energize the Master Control Relay, the following conditions must be met:
• Compressor PLC Panel must be supplied with 120VAC power.
• “Master Power” Selector Switch must be ON
• Local Emergency Stop pushbutton (mounted on PLC enclosure door) must be pulled out.
• DC power supplies must be powered up and functional, “DC OK” Relay must be energized.
• Compact logix processor must be powered up and functional, “PLC OK” Output must be ON.
• Optional/External Emergency Stop Devices are not tripped.
11 – 20
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 12 • Communications with a Central Controller/DCS
Communication with a Central
Controller/DCS
It is possible for a central controller/DCS to read live data and other information from the compressor PLC as well as send commands to the compressor PLC. The following section outlines the PLC addresses that are used for interface between the Compressor PLC and central controller/DCS.
VPN ACCESS
VPN access allows Vilter engineers and technicians connect remotely to the compressor PLC for greater ease of support and troubleshooting. If possible, it is recommended that VPN access be provided.
To allow VPN access to a compressor PLC, the following are required:
• A physical Ethernet Connection from the compressor
PLC to the site control network
• IP address, Subnet Mask, and Gateway address must be defi ned for each compressor PLC and HMI on the site control network
• A VPN server linked to the site control network
• VPN server login information
Central Controller/DCS. It is only necessary to write watchdog logic when the Central Controller/DCS is sending commands to the compressor PLC. If reading data only, the Watchdog timer is not used.
The watchdog timer works by “passing a bit” back and forth between the Compressor PLC and central controller/DCS. If the compressor PLC sees the bit in the same state for a settable watchdog time, the communications are faulted. The Communication fault action is selectable between “Alarm and Revert to Local Mode” or “Trip
Machine.” If “Alarm and Revert to Local Mode” is selected, the compressor will continue to run if running. If
“Trip Machine” is selected, the compressor will trip and shut down. The settable watchdog time and communications fault action are selected on the Confi guration
Screen.
The watchdog bits that are used are:
• Compressor to Central/DCS: BOOL_OUT[0].0
• Central/DCS to Compressor: BOOL_IN[0].0
When the Compressor PLC sees BOOL_IN[0].0 OFF it will turn BOOL_OUT[0].0 ON. To maintain the handshake, the Central Controller/DCS shall Turn BOOL_IN[0].0 ON when it sees BOOL_OUT[0].0 ON.
SETTING UP COMMUNICATIONS
The compressor PLC communicates using the Ethernet
IP protocol. Communication to other devices compatible with Ehternet IP is as simple as setting up CIP message instructions and does not require any additional hardware other than that required for the physical connection.
Interface Data in the compressor PLC is organized into arrays for simple access of data. For example, all live instrument data is arranged into a single block 200 elements long. To get all of the data, only one message would need to be confi gured to read an array of registers, Data type REAL, Length of 200. See the communication tables below for specifi cs.
NOTE
Setting up communications using a protocol other than Ethernet IP is possible (Example Modbus RTU or Modbus TCP), but additional hardware, software, programming, and setup are required.
Data that can be Read from the
Compressor PLC
LIVE INSTRUMENT DATA
Tags “REAL_OUT[0]” through “REAL_OUT[99]” present the live data values as they appear on the HMI screen in the selected engineering units. The Tags “REAL_
OUT[100]” through “REAL_OUT[199]” present all live data values in base units, which are PSIA for pressures and Degrees Fahrenheit for Temperatures. For data other than Pressures and Temperatures, the engineering units are fi xed and not selectable, and will appear the same in
“REAL_OUT[0]” through “REAL_OUT[99]” as they will in
“REAL_OUT[100]” through “REAL_OUT[199].” The engineering units selected are presented in the tags “INT_
OUT[0]” through “INT_OUT[99].”
WATCHDOG TIMER
A watchdog timer is used to monitor the status of the communication link between the compressor PLC and
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
12 – 1
Section 12 • Communications with a Central Controller/DCS
Pressure Units
PSIG
PSIA (PSID) kPa[A] (kPa[D]) kPa[G] kg/cm^2[A] (kg/cm^2[D]) kg/cm^2[G] inHg (vac) PSIG (pressure) inWC
Bar[A] (Bar[D])
Bar[G]
Torr[A] (Torr[D])
Torr[G]
Table 12-1. Engineered Units Value Interpretation (INT_OUT[x])
INT_OUT[x] Value
4
15
6
16
7
17
12
3
13
0
1
2
Temperature Units
Degrees Fahrenheit
Degrees Celsius
Kelvin
Degrees Rankine
INT_OUT[x] Value
2
3
0
1
REAL_OUT[1]
REAL_OUT[2]
REAL_OUT[3]
REAL_OUT[4]
REAL_OUT[5]
REAL_OUT[6]
REAL_OUT[7]
REAL_OUT[8]
REAL_OUT[9]
REAL_OUT[10]
REAL_OUT[11]
REAL_OUT[12]
REAL_OUT[13]
REAL_OUT[14]
REAL_OUT[15]
REAL_OUT[16]
REAL_OUT[17]
REAL_OUT[18]
REAL_OUT[19]
Table 12-2. Live Instrument Data
Live Instrument Data: "REAL_OUT" (Data Type = REAL, Length = 200)
Interface Tag Description Units
REAL_OUT[0] Suction Temperature INT_OUT[0]
Discharge Temperature
Oil Separator Temp
Oil Injection Temp
Oil Separator Outlet Temp
Suction Pressure
Discharge Pressure
Filter In Pressure
Filter Out Pressure
Oil Separator Out Pressure
Oil Separator Pressure Drop
Filter Differential Pressure
Net Oil Pressure
Oil Circuit Pressure Drop
Main Motor Amps
INT_OUT[1]
INT_OUT[2]
INT_OUT[3]
INT_OUT[4]
INT_OUT[5]
INT_OUT[6]
INT_OUT[7]
INT_OUT[8]
INT_OUT[9]
INT_OUT[10]
INT_OUT[11]
INT_OUT[12]
INT_OUT[13]
INT_OUT[14]
INT_OUT[15]
Amps
Capacity Slide Position
Oil Mixing Valve Commanded Postion
% Position
% Position
12 – 2
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 12 • Communications with a Central Controller/DCS
Interface Tag
REAL_OUT[20]
REAL_OUT[39]
REAL_OUT[40]
REAL_OUT[41]
REAL_OUT[42]
REAL_OUT[43]
REAL_OUT[44]
REAL_OUT[45]
REAL_OUT[46]
REAL_OUT[47]
REAL_OUT[48]
REAL_OUT[49]
REAL_OUT[50]
REAL_OUT[51]
REAL_OUT[52]
REAL_OUT[53]
REAL_OUT[54]
REAL_OUT[21]
REAL_OUT[22]
REAL_OUT[23]
REAL_OUT[24]
REAL_OUT[25]
REAL_OUT[26]
REAL_OUT[27]
REAL_OUT[28]
REAL_OUT[29]
REAL_OUT[30]
REAL_OUT[31]
REAL_OUT[32]
REAL_OUT[33]
REAL_OUT[34]
REAL_OUT[35]
REAL_OUT[36]
REAL_OUT[37]
REAL_OUT[38]
REAL_OUT[55]
REAL_OUT[56]
REAL_OUT[57]
REAL_OUT[58]
REAL_OUT[59]
REAL_OUT[60]
Description
Phase A Winding Temp
Phase B Winding Temp
Phase C Winding Temp
ODE Bearing Temp
DE Bearing Temp
Motor Vibration 1
Motor Vibration 2
Compressor Vibration 1
Compressor Vibration 2
Compressor VFD Commanded Speed
Compressor VFD Actual Speed
Process Temp
Liquid Refrigerant Temp
Liquid Injection Commanded Postion
VPLUS Commanded Speed
Oil Cooler Inlet Temp
Oil Cooler Outlet Temp
Oil Cooler Fan Commanded Speed
Aftercooler 1 Outlet Temp
Aftercooler 2 Outlet Temp
Aftercooler 1 VFD Speed
Aftercooler 2 VFD Speed
Discharge Recycle Control Pressure
Discharge Recycle Commanded Postion
Condensing Pressure
Condenser VFD Speed
Inlet Scrubber Inlet Pressure
Inlet Scrubber Outlet Pressure
Inlet Scrubber Pressure Drop
Outlet Scrubber Inlet Pressure
Outlet Scrubber Outlet Pressure
Outlet Scrubber Pressure Drop
Building Temperature
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
INT_OUT[20]
Units
% Speed
INT_OUT[40]
INT_OUT[41]
INT_OUT[42]
% Speed
% Speed
INT_OUT[45]
INT_OUT[46]
% Position
INT_OUT[48]
INT_OUT[49]
INT_OUT[50]
% Speed
INT_OUT[52]
INT_OUT[53]
INT_OUT[54]
INT_OUT[21]
INT_OUT[22]
INT_OUT[23]
INT_OUT[24] in/sec in/sec in/sec in/sec
% Speed
% Speed
INT_OUT[31]
INT_OUT[32]
INT_OUT[33]
% Position
% Speed
INT_OUT[36]
INT_OUT[37]
INT_OUT[38]
INT_OUT[55]
INT_OUT[56]
INT_OUT[57]
INT_OUT[58]
INT_OUT[59]
INT_OUT[60]
12 – 3
Section 12 • Communications with a Central Controller/DCS
Interface Tag
REAL_OUT[61]
REAL_OUT[62]
REAL_OUT[63]
REAL_OUT[64]
REAL_OUT[65]
REAL_OUT[66]
REAL_OUT[84]
REAL_OUT[85]
REAL_OUT[86]
REAL_OUT[87]
REAL_OUT[88]
REAL_OUT[89]
REAL_OUT[90]
REAL_OUT[91]
REAL_OUT[92]
REAL_OUT[93]
REAL_OUT[94]
REAL_OUT[95]
REAL_OUT[96]
REAL_OUT[97]
REAL_OUT[98]
REAL_OUT[99]
REAL_OUT[100]
REAL_OUT[101]
REAL_OUT[67]
REAL_OUT[68]
REAL_OUT[69]
REAL_OUT[70]
REAL_OUT[71]
REAL_OUT[72]
REAL_OUT[73]
REAL_OUT[74]
REAL_OUT[75]
REAL_OUT[76]
REAL_OUT[77]
REAL_OUT[78]
REAL_OUT[79]
REAL_OUT[80]
REAL_OUT[81]
REAL_OUT[82]
REAL_OUT[83]
12 – 4
Description
Methane Detector LEL
EPCS Low Side Pressure
EPCS High Side Pressure
Runtime Hours
Runtime Mins
Resettable Runtime Hours
Resettable Runtime Min
Current/Last Runtime Hours
Current/Last Runtime Min
Rotor Feed Oil Pressure
Rotor Feed Net Oil Pressure
Suction Temperature
Discharge Temperature
% LEL
INT_OUT[62]
INT_OUT[63]
Units
INT_OUT[64]
INT_OUT[65]
INT_OUT[66]
INT_OUT[84]
INT_OUT[85]
INT_OUT[86]
INT_OUT[87]
INT_OUT[88]
INT_OUT[89]
INT_OUT[90]
INT_OUT[91]
INT_OUT[92]
INT_OUT[93]
INT_OUT[94]
INT_OUT[95]
INT_OUT[96]
INT_OUT[97]
INT_OUT[98]
INT_OUT[99]
DEGF
DEGF
INT_OUT[67]
INT_OUT[68]
INT_OUT[69]
Hours
Minutes
Hours
Minutes
Hours
Minutes
INT_OUT[76]
INT_OUT[77]
INT_OUT[78]
INT_OUT[79]
INT_OUT[80]
INT_OUT[81]
INT_OUT[82]
INT_OUT[83]
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 12 • Communications with a Central Controller/DCS
Interface Tag
REAL_OUT[102]
REAL_OUT[121]
REAL_OUT[122]
REAL_OUT[123]
REAL_OUT[124]
REAL_OUT[125]
REAL_OUT[126]
REAL_OUT[127]
REAL_OUT[128]
REAL_OUT[129]
REAL_OUT[130]
REAL_OUT[131]
REAL_OUT[132]
REAL_OUT[133]
REAL_OUT[134]
REAL_OUT[135]
REAL_OUT[136]
REAL_OUT[137]
REAL_OUT[138]
REAL_OUT[139]
REAL_OUT[140]
REAL_OUT[141]
REAL_OUT[142]
REAL_OUT[103]
REAL_OUT[104]
REAL_OUT[105]
REAL_OUT[106]
REAL_OUT[107]
REAL_OUT[108]
REAL_OUT[109]
REAL_OUT[110]
REAL_OUT[111]
REAL_OUT[112]
REAL_OUT[113]
REAL_OUT[114]
REAL_OUT[115]
REAL_OUT[116]
REAL_OUT[117]
REAL_OUT[118]
REAL_OUT[119]
REAL_OUT[120]
Description
Oil Separator Temp
Oil Injection Temp
Oil Separator Outlet Temp
Suction Pressure
Discharge Pressure
Filter In Pressure
Filter Out Pressure
Oil Separator Out Pressure
Oil Separator Pressure Drop
Filter Differential Pressure
Net Oil Pressure
Oil Circuit Pressure Drop
Main Motor Amps
Capacity Slide Position
Oil Mixing Valve Commanded Postion
Phase A Winding Temp
Phase B Winding Temp
Phase C Winding Temp
ODE Bearing Temp
DE Bearing Temp
Motor Vibration 1
Motor Vibration 2
Compressor Vibration 1
Compressor Vibration 2
Compressor VFD Commanded Speed
Compressor VFD Actual Speed
Process Temp
Liquid Refrigerant Temp
Liquid Injection Commanded Postion
VPLUS Commanded Speed
Oil Cooler Inlet Temp
Oil Cooler Outlet Temp
Oil Cooler Fan Commanded Speed
Aftercooler 1 Outlet Temp
Aftercooler 2 Outlet Temp
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
DEGF
DEGF
DEGF
PSIA
PSIA
PSIA
PSIA
PSIA
PSID
PSID
PSID
PSID
Amps
Units
% Position
% Position
DEGF
DEGF
DEGF
DEGF
DEGF in/sec in/sec in/sec in/sec
% Speed (100%=60Hz)
% Speed (100%=60Hz)
DEGF
DEGF
% Position
% Speed
DEGF
DEGF
% Speed (100%=60Hz)
DEGF
DEGF
12 – 5
Section 12 • Communications with a Central Controller/DCS
Interface Tag
REAL_OUT[143]
REAL_OUT[162]
REAL_OUT[163]
REAL_OUT[164]
REAL_OUT[165]
REAL_OUT[166]
REAL_OUT[167]
REAL_OUT[168]
REAL_OUT[169]
REAL_OUT[170]
REAL_OUT[171]
REAL_OUT[172]
REAL_OUT[173]
REAL_OUT[174]
REAL_OUT[175]
REAL_OUT[176]
REAL_OUT[177]
REAL_OUT[178]
REAL_OUT[144]
REAL_OUT[145]
REAL_OUT[146]
REAL_OUT[147]
REAL_OUT[148]
REAL_OUT[149]
REAL_OUT[150]
REAL_OUT[151]
REAL_OUT[152]
REAL_OUT[153]
REAL_OUT[154]
REAL_OUT[155]
REAL_OUT[156]
REAL_OUT[157]
REAL_OUT[158]
REAL_OUT[159]
REAL_OUT[160]
REAL_OUT[161]
REAL_OUT[179]
REAL_OUT[180]
REAL_OUT[181]
REAL_OUT[182]
Description
Aftercooler 1 VFD Speed
Aftercooler 2 VFD Speed
Discharge Recycle Control Pressure
Discharge Recycle Commanded Postion
Condensing Pressure
Condenser VFD Speed
Inlet Scrubber Inlet Pressure
Inlet Scrubber Outlet Pressure
Inlet Scrubber Pressure Drop
Outlet Scrubber Inlet Pressure
Outlet Scrubber Outlet Pressure
Outlet Scrubber Pressure Drop
Building Temperature
Methane Detector LEL
EPCS Low Side Pressure
EPCS High Side Pressure
Runtime Hours
Runtime Mins
Resettable Runtime Hours
Resettable Runtime Min
Current/Last Runtime Hours
Current/Last Runtime Min
Rotor Feed Oil Pressure
Rotor Feed Net Oil Pressure
PSIA
% Speed (100%=60Hz)
PSIA
PSIA
PSIA
PSIA
PSIA
PSIA
DEGF
% LEL
PSID
PSID
Hours
Minutes
Hours
Minutes
Hours
Minutes
PSIA
PSID
Units
% Speed (100%=60Hz)
% Speed (100%=60Hz)
PSIA
% Position
12 – 6
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 12 • Communications with a Central Controller/DCS
Interface Tag
REAL_OUT[183]
REAL_OUT[184]
REAL_OUT[185]
REAL_OUT[186]
REAL_OUT[187]
REAL_OUT[188]
REAL_OUT[189]
REAL_OUT[190]
REAL_OUT[191]
REAL_OUT[192]
REAL_OUT[193]
REAL_OUT[194]
REAL_OUT[195]
REAL_OUT[196]
REAL_OUT[197]
REAL_OUT[198]
REAL_OUT[199]
Description Units
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
12 – 7
Section 12 • Communications with a Central Controller/DCS
Alarm and Trip Data
Alarm and Trip Data is presented in Double Integer Format. To interpret the Alarm and Trip data, it is necessary to address the specifi c bits of the Double Integer.
Interface Tag
BOOL_OUT[1].0
BOOL_OUT[1].1
BOOL_OUT[1].2
BOOL_OUT[1].3
BOOL_OUT[1].4
BOOL_OUT[1].5
BOOL_OUT[1].6
BOOL_OUT[1].7
BOOL_OUT[1].8
BOOL_OUT[1].9
BOOL_OUT[1].10
BOOL_OUT[1].11
BOOL_OUT[1].12
BOOL_OUT[1].13
BOOL_OUT[1].14
BOOL_OUT[1].15
BOOL_OUT[1].16
BOOL_OUT[1].17
BOOL_OUT[1].18
BOOL_OUT[1].19
BOOL_OUT[1].20
BOOL_OUT[1].21
BOOL_OUT[1].22
BOOL_OUT[1].23
BOOL_OUT[1].24
BOOL_OUT[1].25
BOOL_OUT[1].26
BOOL_OUT[1].27
BOOL_OUT[1].28
BOOL_OUT[1].29
BOOL_OUT[1].30
BOOL_OUT[1].31
BOOL_OUT[2].0
12 – 8
Table 12-3. Alarm Data
ALARMS AND TRIPS (Data Type = DINT)
Description
(A001) Alarm: (Unassigned)
(A002) Alarm: PLC to Central Comms Faulted
(A003) Alarm: High Main Motor Amps
(A004) Alarm: (Unassigned)
(A005) Alarm: (Unassigned)
(A006) Alarm: Low Separator Oil Level
(A007) Alarm: Not Assigned
(A008) Alarm: Not Assigned
(A009) Alarm: Not Assigned
(A010) Alarm: Not Assigned
(A011) Alarm: Low Suction Temperature
(A012) Alarm: High Discharge Temperature
(A013) Alarm: Low Oil Separator Temperature - Start
(A014) Alarm: Low Oil Separator Temperature - Run
(A015) Alarm: Low Oil Injection Temperature
(A016) Alarm: High Oil Injection Temperature
(A017) Alarm: Low Process Temperature
(A018) Alarm: High Process Temperature
(A019) Alarm: High Suction Temperature
(A020) Alarm: Low Liquid Refrigerant Temperature
(A021) Alarm: Low Suction Pressure Stpt. 1
(A022) Alarm: Low Suction Pressure Stpt. 2
(A023) Alarm: High Discharge Pressure Stpt. 1
(A024) Alarm: High Discharge Pressure Stpt. 2
(A025) Alarm: Low Net Oil Pressure - Run
(A026) Alarm: Unassigned
(A027) Alarm: High Oil Filter Differential - Start
(A028) Alarm: High Oil Filter Differential - Run
(A029) Alarm: Low Oil Pressure - Start
(A030) Alarm: (Unassigned)
(A031) Alarm: Out of Range: Oil Cooler Inlet Temp
(A032) Alarm: Out of Range: Oil Cooler Outlet Temp
(A033) Alarm: Out of Range: Condensing Pressure
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 12 • Communications with a Central Controller/DCS
Interface Tag
BOOL_OUT[2].1
BOOL_OUT[2].2
BOOL_OUT[2].3
BOOL_OUT[2].4
BOOL_OUT[2].5
BOOL_OUT[2].6
BOOL_OUT[2].7
BOOL_OUT[2].8
BOOL_OUT[2].9
BOOL_OUT[2].10
BOOL_OUT[2].11
BOOL_OUT[2].12
BOOL_OUT[2].13
BOOL_OUT[2].14
BOOL_OUT[2].15
BOOL_OUT[2].16
BOOL_OUT[2].17
BOOL_OUT[2].18
BOOL_OUT[2].19
BOOL_OUT[2].20
BOOL_OUT[2].21
BOOL_OUT[2].22
BOOL_OUT[2].23
BOOL_OUT[2].24
BOOL_OUT[2].25
BOOL_OUT[2].26
BOOL_OUT[2].27
BOOL_OUT[2].28
BOOL_OUT[2].29
BOOL_OUT[2].30
BOOL_OUT[2].31
BOOL_OUT[3].0
BOOL_OUT[3].1
BOOL_OUT[3].2
BOOL_OUT[3].3
BOOL_OUT[3].4
BOOL_OUT[3].5
BOOL_OUT[3].6
BOOL_OUT[3].7
BOOL_OUT[3].8
BOOL_OUT[3].9
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Description
(A034) Alarm: Out of Range: Aftercooler 1 Outlet Temp
(A035) Alarm: Out of Range: Aftercooler 2 Outlet Temp
(A036) Alarm: Out of Range: Inlet Scrubber Inlet Pressure
(A037) Alarm: Out of Range: Inlet Scrubber Outlet Pressure
(A038) Alarm: Out of Range: Outlet Scrubber Inlet Pressure
(A039) Alarm: Out of Range: Outlet Scrubber Outlet Pressure
(A040) Alarm: Out of Range: Discharge Recycle Control Pressure
(A041) Alarm: Out of Range: Oil Separator Outlet Pressure
(A042) Alarm: Unassigned
(A043) Alarm: Unassigned
(A044) Alarm: (Unassigned)
(A045) Alarm: (Unassigned)
(A046) Alarm: High Oil Separator Pressure Drop
(A047) Alarm: Low Oil Separator Outlet Temp (Dew Point)
(A048) Alarm: High Motor Phase A Temperature
(A049) Alarm: High Motor Phase B Temperature
(A050) Alarm: High Motor Phase C Temperature
(A051) Alarm: Motor DE Bearing Temperature
(A052) Alarm: Motor ODE Bearing Temperature
(A053) Alarm: High Motor Vibration - Sensor 1
(A054) Alarm: High Motor Vibration - Sensor 2
(A055) Alarm: High Compressor Vibration - Sensor 1
(A056) Alarm: High Compressor Vibration - Sensor 2
(A057) Alarm: Inlet Scrubber High Level
(A058) Alarm: Inlet Scrubber High High Level
(A059) Alarm: Inlet Scrubber Low Low Level
(A060) Alarm: Upper Inlet Scrubber High Level
(A061) Alarm: Upper Inlet Scrubber High High Level
(A062) Alarm: (Unassigned)
(A063) Alarm: Lower Inlet Scrubber High Level
(A064) Alarm: Lower Inlet Scrubber High High Level
(A065) Alarm: Inlet Scrubber High Pressure Drop
(A066) Alarm: Inlet Scrubber Condensate Pump Starter Fault
(A067) Alarm: Outlet Scrubber High Level
(A068) Alarm: Outlet Scrubber High High Level
(A069) Alarm: Outlet Scrubber Low Low Level
(A070) Alarm: Upper Outlet Scrubber High Level
(A071) Alarm: Upper Outlet Scrubber High High Level
(A072) Alarm: (Unassigned)
(A073) Alarm: Lower Outlet Scrubber High Level
(A074) Alarm: Lower Outlet Scrubber High High Level
12 – 9
Section 12 • Communications with a Central Controller/DCS
Interface Tag
BOOL_OUT[3].10
BOOL_OUT[3].29
BOOL_OUT[3].30
BOOL_OUT[3].31
BOOL_OUT[4].0
BOOL_OUT[4].1
BOOL_OUT[4].2
BOOL_OUT[4].3
BOOL_OUT[4].4
BOOL_OUT[4].5
BOOL_OUT[4].6
BOOL_OUT[4].7
BOOL_OUT[4].8
BOOL_OUT[4].9
BOOL_OUT[4].10
BOOL_OUT[4].11
BOOL_OUT[4].12
BOOL_OUT[4].13
BOOL_OUT[4].14
BOOL_OUT[4].15
BOOL_OUT[4].16
BOOL_OUT[4].17
BOOL_OUT[4].18
BOOL_OUT[3].11
BOOL_OUT[3].12
BOOL_OUT[3].13
BOOL_OUT[3].14
BOOL_OUT[3].15
BOOL_OUT[3].16
BOOL_OUT[3].17
BOOL_OUT[3].18
BOOL_OUT[3].19
BOOL_OUT[3].20
BOOL_OUT[3].21
BOOL_OUT[3].22
BOOL_OUT[3].23
BOOL_OUT[3].24
BOOL_OUT[3].25
BOOL_OUT[3].26
BOOL_OUT[3].27
BOOL_OUT[3].28
12 – 10
Description
(A075) Alarm: Outlet Scrubber High Pressure Drop
(A076) Alarm: Outlet Scrubber Condensate Pump Starter Fault
(A077) Alarm: (Unassigned)
(A078) Alarm: (Unassigned)
(A079) Alarm:
(A080) Alarm:
(A081) Alarm:
(A082) Alarm:
(A083) Alarm:
(A084) Alarm: (Unassigned)
(A085) Alarm: (Unassigned)
(A086) Alarm: (Unassigned)
(A087) Alarm: (Unassigned)
(A088) Alarm: (Unassigned)
(A089) Alarm: Oil Cooler Fan VFD Fault
(A090) Alarm: Oil Cooler Fan (Step Type) Starter Fault
(A091) Alarm: (Unassigned)
(A092) Alarm: (Unassigned)
(A093) Alarm: Aftercooler 1 Fan VFD Fault
(A094) Alarm: Aftercooler 1 Fan (Step Type) Starter Fault
(A095) Alarm: Aftercooler 2 Fan VFD Fault
(A096) Alarm: Aftercooler 2 Fan (Step Type) Starter Fault
(A097) Alarm: Economizer High Level
(A098) Alarm: Chiller High Level
(A099) Alarm: Air Cooled Condenser Fan VFD Fault
(A100) Alarm: Air Cooled Condenser (Step Type) Starter Fault
(A101) Alarm: Unassigned
(A102) Alarm: Unassigned
(A103) Alarm: (Unassigned)
(A104) Alarm: (Unassigned)
(A105) Alarm: (Unassigned)
(A106) Alarm: High Methane Gas %LEL
(A107) Alarm: (Unassigned)
(A108) Alarm: Low Oil Cooler Out Temperature
(A109) Alarm: High Oil Cooler Out Temperature
(A110) Alarm: High Enclosure Temperature
(A111) Alarm: (Unassigned)
(A112) Alarm: (Unassigned)
(A113) Alarm: (Unassigned)
(A114) Alarm: (Unassigned)
(A115) Alarm: (Unassigned)
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 12 • Communications with a Central Controller/DCS
Interface Tag
BOOL_OUT[4].19
BOOL_OUT[4].20
BOOL_OUT[4].21
BOOL_OUT[4].22
BOOL_OUT[4].23
BOOL_OUT[4].24
BOOL_OUT[4].25
BOOL_OUT[4].26
BOOL_OUT[4].27
BOOL_OUT[4].28
BOOL_OUT[4].29
BOOL_OUT[4].30
BOOL_OUT[4].31
(A116) Alarm: (Unassigned)
(A117) Alarm: (Unassigned)
(A118) Alarm: (Unassigned)
(A119) Alarm: (Unassigned)
(A120) Alarm: (Unassigned)
(A121) Alarm: (Unassigned)
(A122) Alarm: (Unassigned)
(A123) Alarm: (Unassigned)
(A124) Alarm: (Unassigned)
(A125) Alarm: (Unassigned)
(A126) Alarm: (Unassigned)
(A127) Alarm: (Unassigned)
Description
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
12 – 11
Interface Tag
BOOL_OUT[11].0
BOOL_OUT[11].19
BOOL_OUT[11].20
BOOL_OUT[11].21
BOOL_OUT[11].22
BOOL_OUT[11].23
BOOL_OUT[11].24
BOOL_OUT[11].25
BOOL_OUT[11].26
BOOL_OUT[11].27
BOOL_OUT[11].28
BOOL_OUT[11].29
BOOL_OUT[11].30
BOOL_OUT[11].31
BOOL_OUT[12].0
BOOL_OUT[12].1
BOOL_OUT[12].2
BOOL_OUT[12].3
BOOL_OUT[12].4
BOOL_OUT[12].5
BOOL_OUT[11].1
BOOL_OUT[11].2
BOOL_OUT[11].3
BOOL_OUT[11].4
BOOL_OUT[11].5
BOOL_OUT[11].6
BOOL_OUT[11].7
BOOL_OUT[11].8
BOOL_OUT[11].9
BOOL_OUT[11].10
BOOL_OUT[11].11
BOOL_OUT[11].12
BOOL_OUT[11].13
BOOL_OUT[11].14
BOOL_OUT[11].15
BOOL_OUT[11].16
BOOL_OUT[11].17
BOOL_OUT[11].18
Section 12 • Communications with a Central Controller/DCS
Table 12-4. Trip Data
TRIPS (Data Type = Double Integer)
Description
(T001) Trip: MCR Not Energized/E-Stop Active
(T002) Trip: PLC to Central Comms Faulted
(T003) Trip: High Main Motor Amps
(T004) Setpoint out of Range - See Menu Screen
(T005) Trip: False Start Detected
(T006) Trip: Low Separator Oil Level
(T007) Trip: Faulted I/O Module Connection or Module Type
(T008) Trip: Main Motor Starter Fault
(T009) Trip: Main Motor Feedback Fault/Overload
(T010) Trip: Supplemental Shutdown Active
(T011) Trip: Low Suction Temperature
(T012) Trip: High Discharge Temperature
(T013) Trip: Low Oil Separator Temperature - Start
(T014) Trip: Low Oil Separator Temperature - Run
(T015) Trip: Low Oil Injection Temperature
(T016) Trip: High Oil Injection Temperature
(T017) Trip: Low Process Temperature
(T018) Trip: (Unassigned)
(T019) Trip: High Suction Temperature
(T020) Trip: Low Liquid Refrigerant Temperature
(T021) Trip: Low Suction Pressure Stpt. 1
(T022) Trip: Low Suction Pressure Stpt. 2
(T023) Trip: High Discharge Pressure Stpt. 1
(T024) Trip: High Discharge Pressure Stpt. 2
(T025) Trip: Low Net Oil Pressure - Run
(T026) Trip: Failed To Reach Prelube Pressure - Start Sequence Aborted
(T027) Trip: High Oil Filter Differential - Start
(T028) Trip: High Oil Filter Differential - Run
(T029) Trip: Low Oil Pressure - Start
(T030) Trip: (Unassigned)
(T031) Trip: Out of Range: Suction Pr
(T032) Trip: Out of Range: Discharge Pr
(T033) Trip: Out of Range: Manifold Pr
(T034) Trip: Out of Range: Filter Inlet Pr
(T035) Trip: Out of Range: Suction Temp
(T036) Trip: Out of Range: Discharge Temp
(T037) Trip: Out of Range: Oil Sep Temp
(T038) Trip: Out of Range: Oil Injection Temp
12 – 12
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 12 • Communications with a Central Controller/DCS
Interface Tag
BOOL_OUT[12].6
BOOL_OUT[12].25
BOOL_OUT[12].26
BOOL_OUT[12].27
BOOL_OUT[12].28
BOOL_OUT[12].29
BOOL_OUT[12].30
BOOL_OUT[12].31
BOOL_OUT[13].0
BOOL_OUT[13].1
BOOL_OUT[13].2
BOOL_OUT[13].3
BOOL_OUT[13].4
BOOL_OUT[13].5
BOOL_OUT[13].6
BOOL_OUT[13].7
BOOL_OUT[13].8
BOOL_OUT[13].9
BOOL_OUT[13].10
BOOL_OUT[13].11
BOOL_OUT[13].12
BOOL_OUT[13].13
BOOL_OUT[13].14
BOOL_OUT[12].7
BOOL_OUT[12].8
BOOL_OUT[12].9
BOOL_OUT[12].10
BOOL_OUT[12].11
BOOL_OUT[12].12
BOOL_OUT[12].13
BOOL_OUT[12].14
BOOL_OUT[12].15
BOOL_OUT[12].16
BOOL_OUT[12].17
BOOL_OUT[12].18
BOOL_OUT[12].19
BOOL_OUT[12].20
BOOL_OUT[12].21
BOOL_OUT[12].22
BOOL_OUT[12].23
BOOL_OUT[12].24
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Description
(T039) Trip: Out of Range: Main Motor Amps
(T040) Trip: Out of Range: Capacity Slide Position
(T041) Trip: Out of Range: Volume Slide Position
(T042) Trip: Out of Range: Process Temp
(T043) Trip: Out of Range: Motor RTD Phase A
(T044) Trip: Out of Range: Motor RTD Phase B
(T045) Trip: Out of Range: Motor RTD Phase C
(T046) Trip: Out of Range: Motor RTD ODE
(T047) Trip: Out of Range: Motor RTD DE
(T048) Trip: High Motor Phase A Temperature
(T049) Trip: High Motor Phase B Temperature
(T050) Trip: High Motor Phase C Temperature
(T051) Trip: High Motor DE Bearing Temperature
(T052) Trip: High Motor ODE Bearing Temperature
(T053) Trip: High Motor Vibration - Sensor 1
(T054) Trip: High Motor Vibration - Sensor 2
(T055) Trip: High Compressor Vibration - Sensor 1
(T056) Trip: High Compressor Vibration - Sensor 2
(T057) Trip: (Unassigned)
(T058) Trip: Inlet Scrubber High High Level
(T059) Trip: Inlet Scrubber Low Low Level
(T060) Trip: (Unassigned)
(T061) Trip: Upper Inlet Scrubber High High Level
(T062) Trip: (Unassigned)
(T063) Trip: (Unassigned)
(T064) Trip: Lower Inlet Scrubber High High Level
(T065) Trip: (Unassigned)
(T066) Trip: (Unassigned)
(T067) Trip: (Unassigned)
(T068) Trip: Outlet Scrubber High High Level
(T069) Trip: Outlet Scrubber Low Low Level
(T070) Trip: (Unassigned)
(T071) Trip: Upper Outlet Scrubber High High Level
(T072) Trip: (Unassigned)
(T073) Trip: (Unassigned)
(T074) Trip: Lower Outlet Scrubber High High Level
(T075) Trip: (Unassigned)
(T076) Trip: (Unassigned)
(T077) Trip: (Unassigned)
(T078) Trip: (Unassigned)
(T079) Trip: User Defi ned Trip 1
12 – 13
Section 12 • Communications with a Central Controller/DCS
Interface Tag
BOOL_OUT[13].15
BOOL_OUT[14].2
BOOL_OUT[14].3
BOOL_OUT[14].4
BOOL_OUT[14].5
BOOL_OUT[14].6
BOOL_OUT[14].7
BOOL_OUT[14].8
BOOL_OUT[14].9
BOOL_OUT[14].10
BOOL_OUT[14].11
BOOL_OUT[14].12
BOOL_OUT[14].13
BOOL_OUT[14].14
BOOL_OUT[14].15
BOOL_OUT[14].16
BOOL_OUT[14].17
BOOL_OUT[14].18
BOOL_OUT[14].19
BOOL_OUT[14].20
BOOL_OUT[14].21
BOOL_OUT[14].22
BOOL_OUT[14].23
BOOL_OUT[13].16
BOOL_OUT[13].17
BOOL_OUT[13].18
BOOL_OUT[13].19
BOOL_OUT[13].20
BOOL_OUT[13].21
BOOL_OUT[13].22
BOOL_OUT[13].23
BOOL_OUT[13].24
BOOL_OUT[13].25
BOOL_OUT[13].26
BOOL_OUT[13].27
BOOL_OUT[13].28
BOOL_OUT[13].29
BOOL_OUT[13].30
BOOL_OUT[13].31
BOOL_OUT[14].0
BOOL_OUT[14].1
12 – 14
Description
(T080) Trip: User Defi ned Trip 2
(T081) Trip: User Defi ned Trip 3
(T082) Trip: User Defi ned Trip 4
(T083) Trip: User Defi ned Trip 5
(T084) Trip: (Unassigned)
(T085) Trip: (Unassigned)
(T086) Trip: (Unassigned)
(T087) Trip: (Unassigned)
(T088) Trip: (Unassigned)
(T089) Trip: (Unassigned)
(T090) Trip: (Unassigned)
(T091) Trip: (Unassigned)
(T092) Trip: (Unassigned)
(T093) Trip: (Unassigned)
(T094) Trip: (Unassigned)
(T095) Trip: (Unassigned)
(T096) Trip: (Unassigned)
(T097) Trip: (Unassigned)
(T098) Trip: Chiller High Level
(T099) Trip: (Unassigned)
(T100) Trip: (Unassigned)
(T101) Trip: EPCS Safety Active - Low/Suction
(T102) Trip: EPCS Safety Active - High/Discharge
(T103) Trip: (Unassigned)
(T104) Trip: (Unassigned)
(T105) Trip: (Unassigned)
(T106) Trip: High Methane Gas %LEL
(T107) Trip: (Unassigned)
(T108) Trip: Smoke Detector Tripped
(T109) Trip: (Unassigned)
(T110) Trip: High Enclosure Temperature
(T111) Trip: Out of Range: 4-20 mA Caphold Target
(T112) Trip: Out of Range: Building Temperature
(T113) Trip: Out of Range: Methane Detector
(T114) Trip: Out of Range: EPCS Low Pressure
(T115) Trip: Out of Range: EPCS High Pressure
(T116) Trip: Out of Range: Motor Vibration 1
(T117) Trip: Out of Range: Motor Vibration 2
(T118) Trip: Out of Range: Compressor Vibration 1
(T119) Trip: Out of Range: Compressor Vibration 2
(T120) Trip: (Unassigned)
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 12 • Communications with a Central Controller/DCS
Interface Tag
BOOL_OUT[14].24
BOOL_OUT[14].25
BOOL_OUT[14].26
BOOL_OUT[14].27
BOOL_OUT[14].28
BOOL_OUT[14].29
BOOL_OUT[14].30
BOOL_OUT[14].31
(T121) Trip: (Unassigned)
(T122) Trip: (Unassigned)
(T123) Trip: (Unassigned)
(T124) Trip: (Unassigned)
(T125) Trip: (Unassigned)
(T126) Trip: (Unassigned)
(T127) Trip: (Unassigned)
(T128) Trip: (Unassigned)
Description
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
12 – 15
Section 12 • Communications with a Central Controller/DCS
Status Data
Compressor Status Data is presented in Double Integer Format. To interpret the compressor status data, it is necessary to address the specifi c bits of the Double Integer.
Interface Tag
BOOL_OUT[21].0
BOOL_OUT[21].1
BOOL_OUT[21].2
BOOL_OUT[21].3
BOOL_OUT[21].4
BOOL_OUT[21].5
BOOL_OUT[21].6
BOOL_OUT[21].7
BOOL_OUT[21].8
BOOL_OUT[21].9
BOOL_OUT[21].10
BOOL_OUT[21].11
BOOL_OUT[21].12
BOOL_OUT[21].13
BOOL_OUT[21].14
BOOL_OUT[21].15
BOOL_OUT[21].16
BOOL_OUT[21].17
BOOL_OUT[21].18
BOOL_OUT[21].19
BOOL_OUT[21].20
BOOL_OUT[21].21
BOOL_OUT[21].22
BOOL_OUT[21].23
BOOL_OUT[21].24
BOOL_OUT[21].25
BOOL_OUT[21].26
BOOL_OUT[21].27
BOOL_OUT[21].28
BOOL_OUT[21].29
BOOL_OUT[21].30
BOOL_OUT[21].31
BOOL_OUT[22].0
Table 12-5. Status Data
STATUS (Data Type = DINT, Length = 10)
Description
(S001) Status: Compressor Stopped
(S002) Status: Compressor Started
(S003) Status: NOT USED
(S004) Status: True Anti-Recycle Active
(S005) Status: NOT USED
(S006) Status: Waiting to Start: Discharge-Suction Not Equalized
(S007) Status: Waiting to Start: Remote Run Permissive Input
(S008) Status: Waiting to Start: Soft Run Permissive from DCS/Central
(S009) Status: Auto Cycle Stop - Suction Pressure
(S010) Status: Auto Cycle Stop - Process Temperature
(S011) Status: Auto Cycle Stop - Discharge Pressure
(S012) Status: Compressor Prelube
(S013) Status: Compressor Prelube Failed
(S014) Status: Oil Pump Transition
(S015) Status: Compressor Warmup - Hold at Minimum Capacity Slide Position
(S016) Status: Loading Inhibited: Low Suction Pressure
(S017) Status: Loading Inhibited: High Discharge Pressure
(S018) Status: Loading Inhibited: High Motor Amps
(S019) Status: Forced Unload: Low Suction Pressure
(S020) Status: Forced Unload: High Discharge Pressure
(S021) Status: Forced Unload: High Motor Amps
(S022) Status: Slide Valve Calibration Active
(S023) Status: Comms Faulted, Reverted to Local Mode
(S024) Status: User SUPER Logged In
(S025) Status: User OP1 Logged In
(S026) Status: User OP2 Logged In
(S027) Status: User OP3 Logged In
(S028) Status: User OP4 Logged In
(S029) Status: User OP5 Logged In
(S030) Status: Main Motor FORCED ON
(S031) Status: NOT USED
(S032) Status: Oil Pump FORCED ON
(S033) Status: Oil Cooler VFD FORCED ON
12 – 16
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 12 • Communications with a Central Controller/DCS
Interface Tag
BOOL_OUT[22].1
BOOL_OUT[22].20
BOOL_OUT[22].21
BOOL_OUT[22].22
BOOL_OUT[22].23
BOOL_OUT[22].24
BOOL_OUT[22].25
BOOL_OUT[22].26
BOOL_OUT[22].27
BOOL_OUT[22].28
BOOL_OUT[22].29
BOOL_OUT[22].30
BOOL_OUT[22].31
BOOL_OUT[23].0
BOOL_OUT[23].1
BOOL_OUT[23].2
BOOL_OUT[23].3
BOOL_OUT[23].4
BOOL_OUT[23].5
BOOL_OUT[23].6
BOOL_OUT[23].7
BOOL_OUT[23].8
BOOL_OUT[23].9
BOOL_OUT[22].2
BOOL_OUT[22].3
BOOL_OUT[22].4
BOOL_OUT[22].5
BOOL_OUT[22].6
BOOL_OUT[22].7
BOOL_OUT[22].8
BOOL_OUT[22].9
BOOL_OUT[22].10
BOOL_OUT[22].11
BOOL_OUT[22].12
BOOL_OUT[22].13
BOOL_OUT[22].14
BOOL_OUT[22].15
BOOL_OUT[22].16
BOOL_OUT[22].17
BOOL_OUT[22].18
BOOL_OUT[22].19
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Description
(S034) Status: Oil Cooler Fan 1 FORCED ON
(S035) Status: Oil Cooler Fan 2 FORCED ON
(S036) Status: Oil Cooler Fan 3 FORCED ON
(S037) Status: Oil Cooler Fan 4 FORCED ON
(S038) Status: Oil Cooler Fan 5 FORCED ON
(S039) Status: Oil Cooler Fan 6 FORCED ON
(S040) Status: Oil Cooler Fan 7 FORCED ON
(S041) Status: Oil Cooler Fan 8 FORCED ON
(S042) Status: Oil Cooler Fan 9 FORCED ON
(S043) Status: Oil Cooler Fan 10 FORCED ON
(S044) Status: Aftercooler 1 VFD FORCED ON
(S045) Status: Aftercooler 1 Fan 1 FORCED ON
(S046) Status: Aftercooler 1 Fan 2 FORCED ON
(S047) Status: Aftercooler 1 Fan 3 FORCED ON
(S048) Status: Aftercooler 1 Fan 4 FORCED ON
(S049) Status: Aftercooler 1 Fan 5 FORCED ON
(S050) Status: Aftercooler 1 Fan 6 FORCED ON
(S051) Status: Aftercooler 1 Fan 7 FORCED ON
(S052) Status: Aftercooler 1 Fan 8 FORCED ON
(S053) Status: Aftercooler 1 Fan 9 FORCED ON
(S054) Status: Aftercooler 1 Fan 10 FORCED ON
(S055) Status: Aftercooler 2 VFD FORCED ON
(S056) Status: Aftercooler 2 Fan 1 FORCED ON
(S057) Status: Aftercooler 2 Fan 2 FORCED ON
(S058) Status: Aftercooler 2 Fan 3 FORCED ON
(S059) Status: Aftercooler 2 Fan 4 FORCED ON
(S060) Status: Aftercooler 2 Fan 5 FORCED ON
(S061) Status: Aftercooler 2 Fan 6 FORCED ON
(S062) Status: Aftercooler 2 Fan 7 FORCED ON
(S063) Status: Aftercooler 2 Fan 8 FORCED ON
(S064) Status: Aftercooler 2 Fan 9 FORCED ON
(S065) Status: Aftercooler 2 Fan 10 FORCED ON
(S066) Status: Condenser Fan VFD FORCED ON
(S067) Status: Condenser Fan 1 FORCED ON
(S068) Status: Condenser Fan 2 FORCED ON
(S069) Status: Condenser Fan 3 FORCED ON
(S070) Status: Condenser Fan 4 FORCED ON
(S071) Status: Condenser Fan 5 FORCED ON
(S072) Status: Condenser Fan 6 FORCED ON
(S073) Status: Condenser Fan 7 FORCED ON
(S074) Status: Condenser Fan 8 FORCED ON
12 – 17
Section 12 • Communications with a Central Controller/DCS
Interface Tag
BOOL_OUT[23].10
BOOL_OUT[23].29
BOOL_OUT[23].30
BOOL_OUT[23].31
BOOL_OUT[24].0
BOOL_OUT[24].1
BOOL_OUT[24].2
BOOL_OUT[24].3
BOOL_OUT[24].4
BOOL_OUT[24].5
BOOL_OUT[24].6
BOOL_OUT[24].7
BOOL_OUT[24].8
BOOL_OUT[24].9
BOOL_OUT[24].10
BOOL_OUT[24].11
BOOL_OUT[24].12
BOOL_OUT[24].13
BOOL_OUT[24].14
BOOL_OUT[24].15
BOOL_OUT[24].16
BOOL_OUT[24].17
BOOL_OUT[24].18
BOOL_OUT[23].11
BOOL_OUT[23].12
BOOL_OUT[23].13
BOOL_OUT[23].14
BOOL_OUT[23].15
BOOL_OUT[23].16
BOOL_OUT[23].17
BOOL_OUT[23].18
BOOL_OUT[23].19
BOOL_OUT[23].20
BOOL_OUT[23].21
BOOL_OUT[23].22
BOOL_OUT[23].23
BOOL_OUT[23].24
BOOL_OUT[23].25
BOOL_OUT[23].26
BOOL_OUT[23].27
BOOL_OUT[23].28
12 – 18
Description
(S075) Status: Condenser Fan 9 FORCED ON
(S076) Status: Condenser Fan 10 FORCED ON
(S077) Status: Condenser Water Valve FORCED ON
(S078) Status: VPLUS Pump FORCED ON
(S079) Status: Liquid Injection Valve Air SOV FORCED ON
(S080) Status: Discharge Recycle Air SOV FORCED ON
(S081) Status: Oil Mixing Valve FORCED ON
(S082) Status: Oil Injection Valve FORCED ON
(S083) Status: Alarm Indication FORCED ON
(S084) Status: Trip Indication FORCED ON
(S085) Status: Oil Separator Heaters FORCED ON
(S086) Status: Suction Oil SOV FORCED ON
(S087) Status: Gas EQ SOV FORCED ON
(S088) Status: Economizer SOV FORCED ON
(S089) Status: Hotgas SOV FORCED ON
(S090) Status: Venturi Oil Recovery SOVs FORCED ON
(S091) Status: Inlet Scrubber Drain Pump/SOV FORCED ON
(S092) Status: Inlet Scrubber Backup SOV FORCED ON
(S093) Status: Outlet Scrubber Drain Pump/SOV FORCED ON
(S094) Status: Outlet Scrubber Backup SOV FORCED ON
(S095) Status: Enclosure Vent Fans FORCED ON
(S096) Status: Enclosure Heaters FORCED ON
(S097) Status: Evap Condenser Pump FORCED ON
(S098) Status: NOT USED
(S099) Status: EPCS SOV FORCED ON
(S100) Status: Oil Cooler STBY Heaters FORCED ON
(S101) Status: Alarm Horn FORCED ON
(S102) Status: Stacklight - Amber FORCED ON
(S103) Status: Stacklight - Red FORCED ON
(S104) Status: INLET SCRUBBER - PUMP 2 FORCED ON
(S105) Status: OUTLET SCRUBBER - PUMP 2 FORCED ON
(S106) Status: OIL DRAIN SV FORCED ON
(S107) Status: Economizer Port 2 FORCED ON
(S108) Status: Supplemental Shutdown FORCED ON
(S109) Status: User MGR Logged In
(S110) Status: Setpoint 1 Active
(S111) Status: Setpoint 2 Active
(S112) Status: Maintenance Due
(S113) Status: Aftercooler 1 Valve Forced
(S114) Status: Aftercooler 2 Valve Forced
(S115) Status: Capacity Slide Exercise Active
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 12 • Communications with a Central Controller/DCS
Interface Tag
BOOL_OUT[24].19
BOOL_OUT[24].20
BOOL_OUT[24].21
BOOL_OUT[24].22
BOOL_OUT[24].23
BOOL_OUT[24].24
BOOL_OUT[24].25
Description
(S116) Status: Volume Slide Exercise Active
(S117) Status: Volume Slide In Manual Mode
NOT USED
(S119) Status: Compressor Ready
(S120) Status: NOT USED
(S121) Status: NOT USED
(S122) Status: NOT USED
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
12 – 19
Section 12 • Communications with a Central Controller/DCS
States of Discrete I/O
States of the Discrete Inputs and Outputs is presented in Double Integer Format. To interpret the IO State data, it is necessary to address the specifi c bits of the Double Integer.
Interface Tag
BOOL_OUT[31].0
BOOL_OUT[31].1
BOOL_OUT[31].2
BOOL_OUT[31].3
BOOL_OUT[31].4
BOOL_OUT[31].5
BOOL_OUT[31].6
BOOL_OUT[31].7
BOOL_OUT[31].8
BOOL_OUT[31].9
BOOL_OUT[31].10
BOOL_OUT[31].11
BOOL_OUT[31].12
BOOL_OUT[31].13
BOOL_OUT[31].14
BOOL_OUT[31].15
BOOL_OUT[31].16
BOOL_OUT[31].17
BOOL_OUT[31].18
BOOL_OUT[31].19
BOOL_OUT[31].20
BOOL_OUT[31].21
BOOL_OUT[31].22
BOOL_OUT[31].23
BOOL_OUT[31].24
BOOL_OUT[31].25
BOOL_OUT[31].26
BOOL_OUT[31].27
BOOL_OUT[31].28
BOOL_OUT[31].29
BOOL_OUT[31].30
BOOL_OUT[31].31
BOOL_OUT[32].0
12 – 20
Table 12-6. Discrete Input
Discrete Input States (Data Type = DINT)
Description
Aftercooler 1 Fan Aux Contact (Step Type)
Aftercooler 1 Fan Aux Contact (Step Type)
Aftercooler 1 Fan Aux Contact (Step Type)
Aftercooler 1 Fan Aux Contact (Step Type)
Aftercooler 1 Fan Aux Contact (Step Type)
Aftercooler 1 Fan Aux Contact (Step Type)
Aftercooler 1 Fan Aux Contact (Step Type)
Aftercooler 1 Fan Aux Contact (Step Type)
Aftercooler 1 Fan Aux Contact (Step Type)
Aftercooler 1 Fan Aux Contact (Step Type)
Aftercooler 1 VFD Faulted (VFD Type)
Aftercooler 1 VFD Running
Aftercooler 2 Fan Aux Contact (Step Type)
Aftercooler 2 Fan Aux Contact (Step Type)
Aftercooler 2 Fan Aux Contact (Step Type)
Aftercooler 2 Fan Aux Contact (Step Type)
Aftercooler 2 Fan Aux Contact (Step Type)
Aftercooler 2 Fan Aux Contact (Step Type)
Aftercooler 2 Fan Aux Contact (Step Type)
Aftercooler 2 Fan Aux Contact (Step Type)
Aftercooler 2 Fan Aux Contact (Step Type)
Aftercooler 2 Fan Aux Contact (Step Type)
Aftercooler 2 VFD Faulted (VFD Type)
Aftercooler 2 VFD Running
Chiller/Surge Drum High Level Alarm
Chiller/Surge Drum High Level Trip
Condenser Fan Aux Contact (Step Type)
Condenser Fan Aux Contact (Step Type)
Condenser Fan Aux Contact (Step Type)
Condenser Fan Aux Contact (Step Type)
Condenser Fan Aux Contact (Step Type)
Condenser Fan Aux Contact (Step Type)
Condenser Fan Aux Contact (Step Type)
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 12 • Communications with a Central Controller/DCS
Interface Tag
BOOL_OUT[32].1
BOOL_OUT[32].20
BOOL_OUT[32].21
BOOL_OUT[32].22
BOOL_OUT[32].23
BOOL_OUT[32].24
BOOL_OUT[32].25
BOOL_OUT[32].26
BOOL_OUT[32].27
BOOL_OUT[32].28
BOOL_OUT[32].29
BOOL_OUT[32].30
BOOL_OUT[32].31
BOOL_OUT[33].0
BOOL_OUT[33].1
BOOL_OUT[33].2
BOOL_OUT[33].3
BOOL_OUT[33].4
BOOL_OUT[33].5
BOOL_OUT[33].6
BOOL_OUT[33].7
BOOL_OUT[33].8
BOOL_OUT[33].9
BOOL_OUT[32].2
BOOL_OUT[32].3
BOOL_OUT[32].4
BOOL_OUT[32].5
BOOL_OUT[32].6
BOOL_OUT[32].7
BOOL_OUT[32].8
BOOL_OUT[32].9
BOOL_OUT[32].10
BOOL_OUT[32].11
BOOL_OUT[32].12
BOOL_OUT[32].13
BOOL_OUT[32].14
BOOL_OUT[32].15
BOOL_OUT[32].16
BOOL_OUT[32].17
BOOL_OUT[32].18
BOOL_OUT[32].19
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Description
Condenser Fan Aux Contact (Step Type)
Condenser Fan Aux Contact (Step Type)
Condenser Fan Aux Contact (Step Type)
Evap Condenser Pump Running
Condenser VFD Faulted (VFD Type)
Condenser VFD Running
E-stop OK and MCR energized
NOT USED
NOT USED
Inlet Scrubber Condensate Pump Aux Contact
Inlet Scrubber Condensate Pump Aux Contact
Lower Inlet Scrubber High Alarm (Coalescing)
Lower Inlet Scrubber High Trip (Coalescing)
Upper Inlet Scrubber High Alarm (Coalescing)
Upper Inlet Scrubber High Trip (Coalescing)
Inlet Scrubber Condensate Drain Cutin Switch
Inlet Scrubber Condensate Drain Cutout Switch
Inlet Scrubber High Alarm (Vane type)
Inlet Scrubber High Trip (Vane Type)
Inlet Scrubber Low Level (Vane Type)
Compressor Main Motor Aux Contact
Compressor Main Motor Fault
Main Motor Cooling Blower Running
Oil Cooler Fan Aux Contact (Step Type)
Oil Cooler Fan Aux Contact (Step Type)
Oil Cooler Fan Aux Contact (Step Type)
Oil Cooler Fan Aux Contact (Step Type)
Oil Cooler Fan Aux Contact (Step Type)
Oil Cooler Fan Aux Contact (Step Type)
Oil Cooler Fan Aux Contact (Step Type)
Oil Cooler Fan Aux Contact (Step Type)
Oil Cooler Fan Aux Contact (Step Type)
Oil Cooler Fan Aux Contact (Step Type)
Oil Cooler VFD Faulted (VFD Type)
Oil Cooler VFD Running
Oil Recovery Enable Switch
Oil Separator Low Level Switch
Outlet Scrubber Condensate Pump Aux Contact
Outlet Scrubber Condensate Pump Aux Contact
Lower Outlet Scrubber High Alarm (Coalescing)
Lower Outlet Scrubber High Trip (Coalescing)
12 – 21
Section 12 • Communications with a Central Controller/DCS
Interface Tag
BOOL_OUT[33].10
BOOL_OUT[33].11
BOOL_OUT[33].12
BOOL_OUT[33].13
BOOL_OUT[33].14
BOOL_OUT[33].15
BOOL_OUT[33].16
BOOL_OUT[33].17
BOOL_OUT[33].18
BOOL_OUT[33].19
BOOL_OUT[33].20
BOOL_OUT[33].21
BOOL_OUT[33].22
BOOL_OUT[33].23
BOOL_OUT[33].24
BOOL_OUT[33].25
BOOL_OUT[33].26
BOOL_OUT[33].27
BOOL_OUT[33].28
BOOL_OUT[33].29
BOOL_OUT[33].30
BOOL_OUT[33].31
Description
Upper Outlet Scrubber High Alarm (Coalescing)
Upper Outlet Scrubber High Trip (Coalescing)
Outlet Scrubber Condensate Drain Cutin Switch
Outlet Scrubber Condensate Drain Cutout Switch
Outlet Scrubber High Alarm (Vane type)
Outlet Scrubber High Trip (Vane Type)
Outlet Scrubber Low Level (Vane Type)
User Defi ned Alarm Input 1
User Defi ned Alarm Input 2
User Defi ned Alarm Input 3
User Defi ned Alarm Input 4
User Defi ned Alarm Input 5
Remote Manual Capacity Decrease Input
Remote Manual Capacity Increase Input
Remote Permissive hardwired input
User Defi ned Trip Input 1
User Defi ned Trip Input 2
User Defi ned Trip Input 3
User Defi ned Trip Input 4
User Defi ned Trip Input 5
Smoke Detector Input
Interface Tag
BOOL_OUT[36].0
BOOL_OUT[36].1
BOOL_OUT[36].2
BOOL_OUT[36].3
BOOL_OUT[36].4
BOOL_OUT[36].5
BOOL_OUT[36].6
BOOL_OUT[36].7
BOOL_OUT[36].8
BOOL_OUT[36].9
BOOL_OUT[36].10
BOOL_OUT[36].11
BOOL_OUT[36].12
BOOL_OUT[36].13
12 – 22
Table 12-7. Discrete Output
Discrete Output States (Data Type = DINT)
Description
Aftercooler 1 Fan Starter (Step Type)
Aftercooler 1 Fan Starter (Step Type)
Aftercooler 1 Fan Starter (Step Type)
Aftercooler 1 Fan Starter (Step Type)
Aftercooler 1 Fan Starter (Step Type)
Aftercooler 1 Fan Starter (Step Type)
Aftercooler 1 Fan Starter (Step Type)
Aftercooler 1 Fan Starter (Step Type)
Aftercooler 1 Fan Starter (Step Type)
Aftercooler 1 Fan Starter (Step Type)
Aftercooler 1 VFD Start Command
Aftercooler 2 Fan Starter (Step Type)
Aftercooler 2 Fan Starter (Step Type)
Aftercooler 2 Fan Starter (Step Type)
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 12 • Communications with a Central Controller/DCS
Interface Tag
BOOL_OUT[36].14
BOOL_OUT[36].15
BOOL_OUT[36].16
BOOL_OUT[36].17
BOOL_OUT[36].18
BOOL_OUT[36].19
BOOL_OUT[36].20
BOOL_OUT[36].21
BOOL_OUT[36].22
BOOL_OUT[36].23
BOOL_OUT[36].24
BOOL_OUT[36].25
BOOL_OUT[36].26
BOOL_OUT[36].27
BOOL_OUT[36].28
BOOL_OUT[36].29
BOOL_OUT[36].30
BOOL_OUT[36].31
BOOL_OUT[37].0
BOOL_OUT[37].1
BOOL_OUT[37].2
BOOL_OUT[37].3
BOOL_OUT[37].4
BOOL_OUT[37].5
BOOL_OUT[37].6
BOOL_OUT[37].7
BOOL_OUT[37].8
BOOL_OUT[37].9
BOOL_OUT[37].10
BOOL_OUT[37].11
BOOL_OUT[37].12
BOOL_OUT[37].13
BOOL_OUT[37].14
BOOL_OUT[37].15
BOOL_OUT[37].16
BOOL_OUT[37].17
BOOL_OUT[37].18
BOOL_OUT[37].19
BOOL_OUT[37].20
BOOL_OUT[37].21
BOOL_OUT[37].22
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Aftercooler 2 Fan Starter (Step Type)
Description
Aftercooler 2 Fan Starter (Step Type)
Aftercooler 2 Fan Starter (Step Type)
Aftercooler 2 Fan Starter (Step Type)
Aftercooler 2 Fan Starter (Step Type)
Aftercooler 2 Fan Starter (Step Type)
Aftercooler 2 Fan Starter (Step Type)
Aftercooler VFD Start Command
Alarm Indication (0=ALARM)
Enclosure Alarm Horn
Capacity Decrease Output
Capacity Increase Output
Water Cooled Condenser Air Solenoid
Condenser Fan Starter (Step Type)
Condenser Fan Starter (Step Type)
Condenser Fan Starter (Step Type)
Condenser Fan Starter (Step Type)
Condenser Fan Starter (Step Type)
Condenser Fan Starter (Step Type)
Condenser Fan Starter (Step Type)
Condenser Fan Starter (Step Type)
Condenser Fan Starter (Step Type)
Condenser Fan Starter (Step Type)
Condenser Pump Starter (If Step Type)
Condenser Pump Starter (If VFD Type)
Condenser VFD Start Command
Discharge Recycle Air Supply Solenoid
Economizer Port 1
Economizer Port 2
Enclosure Roof Vent Fans
Enclosure Heaters
EPCS High Side Relief Solenoid
N/A
Suction-Discharge Equalizing Solenoid
Hotgas Bypass Valve
Inlet Scrubber Backup Drain Solenoid
Inlet Scrubber Condensate Pump Starter
Inlet Scrubber Condensate Pump Starter (or SV)
Liquid Injection Air Supply Solenoid
NOT USED
NOT USED
12 – 23
Interface Tag
BOOL_OUT[37].23
BOOL_OUT[38].10
BOOL_OUT[38].11
BOOL_OUT[38].12
BOOL_OUT[38].13
BOOL_OUT[38].14
BOOL_OUT[38].15
BOOL_OUT[38].16
BOOL_OUT[38].17
BOOL_OUT[38].18
BOOL_OUT[38].19
BOOL_OUT[38].20
BOOL_OUT[38].21
BOOL_OUT[38].22
BOOL_OUT[38].23
BOOL_OUT[38].24
BOOL_OUT[38].25
BOOL_OUT[38].26
BOOL_OUT[38].27
BOOL_OUT[38].28
BOOL_OUT[38].29
BOOL_OUT[38].30
BOOL_OUT[38].31
BOOL_OUT[37].24
BOOL_OUT[37].25
BOOL_OUT[37].26
BOOL_OUT[37].27
BOOL_OUT[37].28
BOOL_OUT[37].29
BOOL_OUT[37].30
BOOL_OUT[37].31
BOOL_OUT[38].0
BOOL_OUT[38].1
BOOL_OUT[38].2
BOOL_OUT[38].3
BOOL_OUT[38].4
BOOL_OUT[38].5
BOOL_OUT[38].6
BOOL_OUT[38].7
BOOL_OUT[38].8
BOOL_OUT[38].9
12 – 24
Section 12 • Communications with a Central Controller/DCS
Description
Main Motor Start Command
Oil Cooler Fan Starter (Step Type)
Oil Cooler Fan Starter (Step Type)
Oil Cooler Fan Starter (Step Type)
Oil Cooler Fan Starter (Step Type)
Oil Cooler Fan Starter (Step Type)
Oil Cooler Fan Starter (Step Type)
Oil Cooler Fan Starter (Step Type)
Oil Cooler Fan Starter (Step Type)
Oil Cooler Fan Starter (Step Type)
Oil Cooler Fan Starter (Step Type)
Oil Cooler Standby Heater
Oil Cooler VFD Start Command
Oil Drain Solenoid
Oil Mix Valve Air Supply Solenoid
Oil Pump Starter
Oil Separator Heaters
Outlet Scrubber Backup Drain Solenoid
Outlet Scrubber Condensate Pump Starter
Outlet Scrubber Condensate Pump Starter (or SV)
N/A
Amber Stacklight
Red Stacklight
Suction Oil Injection Solenoid
Trip Indication (0=TRIP)
Venturi Oil Recovery Output
VPLUS Pump Start Command
PLC OK Relay (0=PLC triggered E-Stop)
Supplemental Shutdown Output
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
Section 12 • Communications with a Central Controller/DCS
Compressor State and Mode Indicator
The state of the compressor state indicator shown on the compressor and system overview screens can be monitored.
Table 12-8. State Indicator
State Indicator (Data Type = DINT, Length = 1)
Tag Description
COMP_STATE_IND Compressor State Indicator
State
0
Stopped
Description
1
2
3
Standby
Moving Slides to Minimum Position
Pre-lube
4
Pre-lube - Compressor Starting
5
6
Compressor Warm-up
Running
Table 12-9. Mode Indicator
Mode Indicator (Data Type = DINT, Length = 1)
Tag Description
MODE_IND Compressor State Indicator
State
1 Local-Auto
Description
2
3
4
Local-Manual
Remote-Auto
Remote-Manual
Sending Commands to Compressor PLC (Ethernet IP Version)
To send commands to the Compressor PLC, Control by Communications must be enabled from the Confi guration screen and the watchdog must show that communications between the Compressor PLC and Central Controller/DCS are not faulted. On a communication fault, the commands from the Central controller will stay in their last state/value in the compressor PLC.
WATCHDOG BITS
NOTE
When PLC Sees BOOL_IN[0].0 OFF it will turn BOOL_OUT[0].0 ON. DCS Shall Turn BOOL_
IN[0].0 ON when it sees BOOL_OUT[0].0 ON to maintain the handshake.
TO DCS: BOOL_OUT[0].0
FROM: BOOL_IN[0].0
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
12 – 25
Section 12 • Communications with a Central Controller/DCS
Table 12-10. Compressor Command (Real)
Compressor Commands: “REAL_IN” (Data Type = REAL)
Interface Tag Description
REAL_IN[0] Remote Discharge Pressure Setpoint
REAL_IN[1]
Remote Process Temp Setpoint
REAL_IN[2]
Remote Suction Pressure Setpoint
REAL_IN[3]
REAL_IN[4]
REAL_IN[5]
Common Discharge Header Pressure From DCS
Common Suction Header Pressure From DCS
Capacity Slide Position Command From DCS
Units
PSIA
PSIA
PSIA
PSIA
PSIA
% Position
DISCRETE COMPRESSOR COMMANDS
Discrete Compressor commands are presented in
Double Integer Format. To send discrete commands, it is necessary to address the specifi c bits of the Double
Integer.
If Control by communications is enabled from the
Confi guration Screen, the soft run command (BOOL_
IN[1].5) must be held HIGH in addition to the remote permissive physical input.
Interface Tag
BOOL_IN[1].0
BOOL_IN[1].1
BOOL_IN[1].2
BOOL_IN[1].3
BOOL_IN[1].4
BOOL_IN[1].5
BOOL_IN[1].6
BOOL_IN[1].7
BOOL_IN[1].8
BOOL_IN[1].9
BOOL_IN[1].10
BOOL_IN[1].11
BOOL_IN[1].12
BOOL_IN[1].13
BOOL_IN[1].14
BOOL_IN[1].15
Table 12-11. Compressor Command (Double Integer)
Write Data: “BOOL_IN” (Data Type = DINT)
Description
Soft Capacity Decrease Command from DCS
Soft Capacity increase Command from DCS
Local Mode Command from DCS
Remote Mode Command from DCS
Reset Alarms from DCS
Soft Run Command from DCS
Command to Switch to Setpoint 1
Command to Switch to Setpoint 2
12 – 26
Twin Screw Compressor PLC Operation Manual • Vilter/Emerson • 35391CN
35391CN Rev. 0 (3/14) Emerson and Vilter are trademarks of Emerson Electric Co. or one of its affi liated companies. © 2014 Emerson Climate Technologies, Inc. All rights reserved. Printed in the USA.

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Key features
- Auto start-stop
- Capacity slide control
- Load limits and forced unloading
- VFD capacity control
- Safety features
- HMI navigation
- Configuration options
- Instrument calibration
- Alarm and trip setpoints
- Diagnostics screens