AAON LZ Series chillers Installation, Operation, & Maintenance
The AAON LZ Series chillers are designed for outdoor use and offer energy-efficient cooling solutions for a variety of applications. These chillers feature staged or variable-speed R-410A scroll compressors, high-efficiency air-cooled microchannel condenser coils, and a range of accessories to meet your specific needs.
advertisement
LZ Series
Chillers and Outdoor Mechanical Rooms
Installation, Operation,
WARNING
FIRE OR EXPLOSION HAZARD
Failure to follow safety warnings exactly could result in serious injury, death or property damage.
Be sure to read and understand the installation, operation and service instructions in this manual.
Improper installation, adjustment, alteration, service or maintenance can cause serious injury, death or property damage.
A copy of this IOM should be kept with the unit.
& Maintenance
WARNING
Do not store gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance.
WHAT TO DO IF YOU SMELL GAS
Do not try to light any appliance.
Do not touch any electrical switch.
Do not use any phone in your building.
Leave the building immediately.
Immediately call you gas supplier from a phone remote from the building. Follow the gas supplier’s instructions.
If you cannot reach your gas supplier call the fire department.
Startup and service must be performed by a Factory Trained
Service Technician.
Table of Contents
3
4
Index of Tables and Figures
Tables:
Table 1 - Service Clearances ......................................................................................................... 25
Table 2 - Unit Gas Pipe Information, Feature B4 = A-J ............................................................... 31
Table 3 - Unit Gas Pipe Information, Feature B4 = K-N.............................................................. 32
Table 4 - Air-Cooled Condenser Fan Pitch ................................................................................... 44
Table 5 - Evaporative-Cooled Condenser Fan Pitch ..................................................................... 44
Table 6 - Condenser Fan Pin Location (Bushing Mount) ............................................................. 46
Table 7 - Condenser Fan Pin Location (Rotation Direction) ........................................................ 46
Table 8 - Fan Assembly Bushing Torque Specifications.............................................................. 47
Table 9 - Filter Drier Maximum Pressure Drop ............................................................................ 49
Table 10 - Acceptable Refrigeration Circuit Values ..................................................................... 50
Table 11 - R-134a Refrigerant Temperature-Pressure Chart ........................................................ 51
Table 12 - R-410A Refrigerant Temperature-Pressure Chart ....................................................... 52
Table 13 - Recirculating Water Quality Guidelines ..................................................................... 63
Figures:
Figure 1 - Backflow Preventer ...................................................................................................... 23
Figure 2 - Pressure Relief Valve ................................................................................................... 24
Figure 3 - Curb Mounting with Dimensions ................................................................................. 26
Figure 4 - Curb End Detail............................................................................................................ 26
Figure 5 - Steel Mounting Rail with Dimensions ......................................................................... 26
Figure 6 - Concrete Pad Mounting with Dimensions ................................................................... 27
Figure 7 - Lifting Points ................................................................................................................ 27
Figure 8 - LZ Series Example Lifting Detail ................................................................................ 28
Figure 9 - Water Pipe Flashing Installation .................................................................................. 29
Figure 10 - Sidewall Vent Shipping Cover Removal ................................................................... 32
Figure 11 - Sidewall Vent Plate Installation ................................................................................. 32
Figure 12 - Typical Air Intake Piping ........................................................................................... 33
Figure 13 - Typical Flue Vent Piping ........................................................................................... 33
Figure 14 - Sidewall Vent Base .................................................................................................... 34
Figure 15 - Sidewall Vent Cap...................................................................................................... 34
Figure 16 - Roof Air Intake and Vent Piping Shipping Covers .................................................... 34
Figure 17 - Typical Vertical Air Intake Piping ............................................................................. 35
Figure 18 - Correct Joint Connection............................................................................................ 36
Figure 19 - Incorrect Joint Connection ......................................................................................... 36
Figure 20 - Typical Vertical Vent Piping ..................................................................................... 37
5
Figure 21 - Vertical Termination of Air Intake and Vent Piping ................................................. 37
Figure 22 - Evaporative-Cooled Condenser Section Layout ........................................................ 42
Figure 23 - Fan with the HUB on the top and RET on the bottom. .............................................. 45
Figure 24 - Bushing Mount Location............................................................................................ 45
Figure 25 - RET with Pin in Groove 4 .......................................................................................... 45
Figure 26 - Fan HUB and RET Castings ...................................................................................... 45
Figure 27 - Pitch Insert ................................................................................................................. 46
Figure 28 - Replaceable Core Filter Driers ................................................................................... 48
Figure 29 - Proper Unit Location .................................................................................................. 57
Figure 30 - Improper Unit Locations ............................................................................................ 57
Figure 31 - Water Makeup Valve ................................................................................................. 60
V45100 · Rev. A · 150715
6
AAON LZ Series Features and Options Introduction
Energy Efficiency
• Staged or Variable Speed R-410A Scroll
Compressors
• Oil-Free Magnetic Bearing R-134a
Turbocor Centrifugal Compressors
• High Efficiency Air-Cooled
Microchannel Condenser Coils
• AAON Evaporative-Cooled Condenser
• VFD Controlled Pumping Packages
• VFD Controlled Condenser Fans
• 98% Thermal Efficiency Boilers
• Waterside Economizers
• Factory Installed EXVs
Outdoor Mechanical Room
• Chilled Water Applications up to 540 tons
• Hot Water Applications up to 6,000
MBH
• Lighted Walk-In Service Vestibule
• Factory Engineered Primary or
Primary/Secondary Pumping Packages
• Factory Installed Three Chemical Water
Treatment
• Factory Installed Compression Tank
• Brazed Plate or Shell and Tube
Evaporators
• Factory Installed Option Boxes for Field
Installed Accessories
Safety
• Phase and Brownout Protection
• Single Point Non-Fused Disconnect
Power Switch
• Factory Installed Refrigerant Leak
Detector
• Water Piping Air Separator
• Waterside Thermometer and Pressure
Gauge
Installation and Maintenance
• Double Wall Rigid Polyurethane Foam
Injected Panel Construction
• Lighted Walk-In Service Vestibule
• Access Doors with Full Length Stainless
Steel Piano Hinges
• Zinc Cast Lockable Handles
• Factory Installed Convenience Outlet
• Service Vestibule Heating and Cooling
• Motorized Service Vestibule Fresh Air
• Controls Diagnostics
• Touchscreen Computer Controls
Interface
• Evaporative-Cooled Condenser De-
Superheater
• Evaporative-Cooled Condenser Sump
Heaters
• Liquid Line Sight Glass
• Compressor Isolation Valves
• Auto Glycol Feeder
• Color-Coded Wiring Diagrams
System Integration
• Complete System with AAON Chilled
Water Air Handling Units
• BMS Connectivity
• Grooved End Water Piping Connections
• Custom Color Paint Options
Environmentally Friendly
• R-410A or R-134a Refrigerant
Extended Life
• Optional 5 Year Compressor Warranty
• Condenser Coil Guards
• 2,500 Hour Salt Spray Tested Exterior
Corrosion Protection
• 6,000 Hour Salt Spray Tested Polymer
E-Coated Condenser Coils
7
Safety
Attention should be paid to the following statements:
NOTE - Notes are intended to clarify the unit installation, operation and maintenance.
CAUTION - Caution statements are given to prevent actions that may result in equipment damage, property damage, or personal injury.
WARNING - Warning statements are given to prevent actions that could result in equipment damage, property damage, personal injury or death.
DANGER - Danger statements are given to prevent actions that will result in equipment damage, property damage, severe personal injury or death.
WARNING
ELECTRIC SHOCK, FIRE OR
EXPLOSION HAZARD
Failure to follow safety warnings exactly could result in dangerous operation, serious injury, death or property damage.
Improper servicing could result in dangerous operation, serious injury, death, or property damage.
Before servicing, disconnect all electrical power to the unit. More than one disconnect may be provided.
When servicing controls, label all wires prior to disconnecting.
Reconnect wires correctly.
Verify proper operation after servicing. Secure all doors with key-lock or nut and bolt.
WARNING
QUALIFIED INSTALLER
Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury or loss of life. Startup and service must be performed by a
Factory Trained Service Technician.
A copy of this IOM should be kept with the unit.
CAUTION
WHAT TO DO IF YOU SMELL GAS
Do not try to turn on unit.
Shut off main gas supply.
Do not touch any electric switch.
Do not use any phone in the building.
Never test for gas leaks with an open flame.
Use a gas detection soap solution and check all gas connections and shut off valves.
8
WARNING
FIRE, EXPLOSION OR CARBON
MONOXIDE POISONING HAZARD
Failure to replace proper controls could result in fire, explosion or carbon monoxide poisoning. Failure to follow safety warnings exactly could result in serious injury, death or property damage. Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this appliance.
WARNING
Electric shock hazard. Before servicing, shut off all electrical power to the unit, including remote disconnects, to avoid shock hazard or injury from rotating parts. Follow proper Lockout-Tagout procedures.
WARNING
During installation, testing, servicing, and troubleshooting of the equipment it may be necessary to work with live electrical components. Only a qualified licensed electrician or individual properly trained in handling live electrical components shall perform these tasks.
Standard NFPA-70E, an OSHA regulation requiring an Arc Flash
Boundary to be field established and marked for identification of where appropriate Personal Protective
Equipment (PPE) be worn, should be followed.
WARNING
GROUNDING REQUIRED
All field installed wiring must be completed by qualified personnel.
Field installed wiring must comply with NEC/CEC, local and state electrical code requirements. Failure to follow code requirements could result in serious injury or death.
Provide proper unit ground in accordance with these code requirements.
WARNING
VARIABLE FREQUENCY DRIVES
Do not leave VFDs unattended in hand mode or manual bypass.
Damage to personnel or equipment can occur if left unattended. When in hand mode or manual bypass mode
VFDs will not respond to controls or alarms.
CAUTION
Electric motor over-current protection and overload protection may be a function of the Variable Frequency
Drive to which the motors are wired.
Never defeat the VFD motor overload feature. The overload ampere setting must not exceed 115% of the electric motors FLA rating as shown on the motor nameplate.
9
WARNING
UNIT HANDLING
To prevent injury or death lifting equipment capacity shall exceed unit weight by an adequate safety factor.
Always test-lift unit not more than 24 inches high to verify proper center of gravity lift point to avoid unit damage, injury or death.
WARNING
Always use a pressure regulator, valves and gauges to control incoming pressures when pressure testing a system. Excessive pressure may cause line ruptures, equipment damage or an explosion which may result in injury or death.
CAUTION
Door compartments containing hazardous voltage or rotating parts are equipped with door latches to allow locks. Door latches are shipped with nut and bolts requiring tooled access. If you do not replace the shipping hardware with a pad lock always re-install the nut & bolt after closing the door.
WARNING
Do not use oxygen, acetylene or air in place of refrigerant and dry nitrogen for leak testing. A violent explosion may result causing injury or death.
10
CAUTION
PVC (Polyvinyl Chloride) and CPVC
(Chlorinated Polyvinyl Chloride) are vulnerable to attack by certain chemicals. Polyolester (POE) oils that are used in R-410A and other refrigerant systems will cause stress cracking of PVC or CPVC piping, even if only present in trace amounts.
This will result in complete piping system failure.
WARNING
COMPRESSOR CYCLING
3 MINUTE MINIMUM OFF TIME
To prevent motor overheating compressors must cycle off for a minimum of 3 minutes.
3 MINUTE MINIMUM ON TIME
To maintain the proper oil level compressors must cycle on for a minimum of 3 minutes.
The cycle rate must not exceed 6 starts per hour.
CAUTION
To prevent damage to the unit, do not use acidic chemical coil cleaners. Do not use alkaline chemical coil cleaners with a pH value greater than
8.5, after mixing, without first using an aluminum corrosion inhibitor in the cleaning solution.
CAUTION
Polyolester (POE) and Polyvinylether
(PVE) oils are two types of lubricants used with R-410A and R134a refrigeration systems. Refer to the compressor label for the proper compressor lubricant type.
CAUTION
Do not clean DX refrigerant coils with hot water or steam. The use of hot water or steam on refrigerant coils will cause high pressure inside the coil tubing and damage to the coil.
CAUTION
Rotation must be checked on ALL
MOTORS AND COMPRESSORS of
3 phase units at startup by a qualified service technician. Scroll compressors are directional and can be damaged if rotated in the wrong direction. Compressor rotation must be checked using suction and discharge gauges. Fan motor rotation should be checked for proper operation. Alterations should only be made at the unit power connection.
WARNING
Some chemical coil cleaning compounds are caustic or toxic. Use these substances only in accordance with the manufacturer
’s usage instructions. Failure to follow instructions may result in equipment damage, injury or death.
1. Startup and service must be performed by a Factory Trained Service
Technician.
2. The unit is for outdoor use only. See
General Information section for more information.
3. Use only with type of the gas approved for the boiler. Refer to the boiler rating plate.
4. Provide adequate combustion ventilation air to the boiler.
5. Every unit has a unique equipment nameplate with electrical, operational, and unit clearance specifications.
Always refer to the unit nameplate for ratings unique to the model you have purchased.
6. READ THE ENTIRE INSTALLATION,
OPERATION AND MAINTENANCE
MANUAL. OTHER IMPORTANT
SAFETY PRECAUTIONS ARE
PROVIDED THROUGHOUT THIS
MANUAL.
7. Keep this manual and all literature safeguarded near or on the unit.
11
LZ Series Feature String Nomenclature
Model Options : Unit Feature Options
LZ A - 140 - C - 0 - 3 - F A C 0 E
-
0 0 0 0 : E 0 - 0 0 0 0 - 0 0 0 0 - 0 0 0 0 - 0 0 - 0 0 0
0 - 0 E 0 0 - 0 0 C 0 0 - 0 J 0 0 0 - 0 0 0 0 0 - 0 0 0 0 0 0 - 0 0 0 0 0 - 0 0 D B
LZ Series Feature String Nomenclature
MODEL OPTIONS
Series and Generation
LZ
Major Revision
A
Unit Size
Air-Cooled
045 = 45 ton Capacity
055 = 55 ton Capacity
060 = 60 ton Capacity
Evaporative-Cooled
053 = 53 ton Capacity
061 = 61 ton Capacity
069 = 69 ton Capacity
075 = 75 ton Capacity
090 = 90 ton Capacity
078 = 78 ton Capacity
090 = 90 ton Capacity
095 = 95 ton Capacity 106 = 106 ton Capacity
105 = 105 ton Capacity 120 = 120 ton Capacity
120 = 120 ton Capacity 121 = 121 ton Capacity
140 = 140 ton Capacity 134 = 134 ton Capacity
170 = 170 ton Capacity 150 = 150 ton Capacity
181 = 181 ton Capacity 161 = 161 ton Capacity
200 = 200 ton Capacity 180 = 180 ton Capacity
181 = 181 ton Capacity
193 = 193 ton Capacity
239 = 239 ton Capacity
240 = 240 ton Capacity
274 = 274 ton Capacity
300 = 300 ton Capacity
356 = 356 ton Capacity
360 = 360 ton Capacity
401 = 401 ton Capacity
441 = 441 ton Capacity
450 = 450 ton Capacity
478 = 478 ton Capacity
540 = 540 ton Capacity
Series - Scroll Compressor
Air-Cooled Evaporative-Cooled
A = 45-60 ton units
B = 75 ton unit
C = 95-140 ton units
A = 53-69 ton units
B = 78 ton unit
C = 106-161 ton units
D = 175-200 ton units D = 193-239 ton units
E = 274-319 ton units
F = 356-401 ton units
G = 441-478 ton units
12
Series - Turbocor Compressor
Air-Cooled Evaporative-Cooled
H = 90-120 ton units H = 90-120 ton units
K = 181 ton unit J = 150-180 ton units
K = 181 ton unit
L = 240 ton unit
M = 300-360 ton units
N = 450-540 ton units
Minor Revision
0
Voltage
2 = 230V/3Φ/60Hz
3 = 460V/3Φ/60Hz
4 = 575V/3Φ/60Hz
8 = 208V/3Φ/60Hz
A1: Compressor Style
F = R-410A Tandem VFD Compatible Scroll
Compressor
H = R-134a Turbocor Centrifugal Compressor
J = R-134a Turbocor Centrifugal Compressor with
Economizer
A2: Condenser Style
A = Air-Cooled Microchannel Condenser
H = Evaporative-Cooled Condenser
A3: Evaporator Configuration
A = Brazed Plate
B = Oversized Brazed Plate
C = Shell & Tube
D = Oversized Shell & Tube
A4: Coating
0 = Standard
E = Polymer E-Coated Condenser Coil
A5: Staging
0 = Staged On/Off Compressors
E = All Circuits Variable Capacity Compressors
G = Half Circuits Variable Capacity Compressors
LZ Series Feature String Nomenclature
Model Options : Unit Feature Options
LZ A - 140 - C - 0 - 3 - F A C 0 E
-
0 0 0 0 : E 0 - 0 0
0 0 - 0 0 0 0 - 0 0 0 0 - 0 0 - 0 0 0
0 - 0 E 0 0 - 0 0 C 0 0 - 0 J 0 0 0 - 0 0 0 0 0 - 0 0 0 0 0 0 - 0 0 0 0 0 - 0 0 D B
B1: Type
0 = No Boilers
B2: Boiler Quantity
0 = No Boilers
B3: Type and Pipe Size
0 = No Boilers
B4: Boiler Capacity
0 = No Boilers
UNIT FEATURE OPTIONS
1: Unit Orientation
E = Walk-in Vestibule Left Access Left Water
Connections
F = Walk-in Vestibule Left Access Right Water
Connections
G = Walk-in Vestibule Left Access Bottom Water
Connections
J = Walk-in Vestibule Right Access Left Water
Connections
K = Walk-in Vestibule Right Access Right Water
Connections
L = Walk-in Vestibule Right Access Bottom Water
Connections
2: Pumping Style
0 = No Pumps
A = Const. Primary Pumping System Small Pipe Size
B = Const. Primary Pumping System Large Pipe Size
C = Var. Primary Pumping System Small Pipe Size
D = Var. Primary Pumping System Large Pipe Size
E = Primary/Secondary Pumping System Small Pipe
Size
F = Primary/Secondary Pumping System Large Pipe
Size
3A: Building Pump Configuration
0 = No Building Pumps
A = 1 Pump + High Eff Motor
B = 1 Dual Pump + High Eff Motors
C = 2 Single Pumps + High Eff Motors
D = 1 Pump + VFD + High Eff Motor
E = 1 Dual Pump + 2 VFD's + High Eff Motors
F = 2 Single Pumps + 2 VFD’s + High Eff Motors
K = 1 Pump + Field Installed VFD + High Eff Motor
L = 1 Dual Pump + 2 Field Installed VFD's + High
Eff Motors
M = 2 Single Pumps + 2 Field Installed VFD’s +
High Eff Motors
3B: Building Pump Series and RPM
0 = No Building Pumps
A = 4360 (1,200 nominal rpm)
B = 4360 (1,800 nominal rpm)
C = 4360 (3,600 nominal rpm)
D = 4380 (1,200 nominal rpm)
E = 4380 (1,800 nominal rpm)
F = 4380 (3,600 nominal rpm)
G = 4300 (1,200 nominal rpm)
H = 4300 (1,800 nominal rpm)
J = 4300 (3,600 nominal rpm)
K = 4382 (1,200 nominal rpm)
L = 4382 (1,800 nominal rpm)
M = 4382 (3,600 nominal rpm)
N = 4302 (1,200 nominal rpm)
P = 4302 (1,800 nominal rpm)
Q = 4302 (3,600 nominal rpm)
13
LZ Series Feature String Nomenclature
Model Options : Unit Feature Options
LZ A - 140 - C - 0 - 3 - F A C 0 E
-
0 0 0 0 : E 0 - 0 0
0 0 - 0 0
0 0 - 0 0 0 0 - 0 0 - 0 0 0
0 - 0 E 0 0 - 0 0 C 0 0 - 0 J 0 0 0 - 0 0 0 0 0 - 0 0 0 0 0 0 - 0 0 0 0 0 - 0 0 D B
3C: Pump Size
0 = No Building Pumps
A = 1.5B
B = 2B
C = 2D
D = 3D
E = 1.5x1.5x6
F = 2x2x6
G = 3x3x6
H = 4x4x6
J = 6x6x6
K = 1.5x1.5x8
L = 2x2x8
M = 3x3x8
N = 4x4x8
P = 5x5x8
Q = 6x6x8
R = 8x8x8
S = 2x2x10
T = 3x3x10
U = 4x4x10
V = 6x6x10
W = 8x8x10
Y = 4x4x11.5
Z = 5x5x11.5
1 = 6x6x11.5
2 = 8x8x11.5
3 = 4x4x13
4 = 6x6x13
5 = 8x8x13
3D: Building Pump Motor Size
0 = No Building Pumps
A = 0.5 hp
B = 0.75 hp
C = 1 hp
D = 1.5 hp
E = 2 hp
F = 3 hp
G = 5 hp
H = 7.5 hp
J = 10 hp
K = 15 hp
L = 20 hp
M = 25 hp
N = 30 hp
14
P = 40 hp
Q = 50 hp
R = 60 hp
S = 75 hp
4A: Recirculating Pump Configuration
0 = No Recirculating Pumps
A = 1 Pump + High Eff Motor
B = 1 Dual Pump + High Eff Motors
C = 2 Single Pumps + High Eff Motors
4B: Recirculation Pump Series & RPM
0 = No Recirculating Pumps
A = 4360 (1,200 nominal rpm)
B = 4360 (1,800 nominal rpm)
C = 4360 (3,600 nominal rpm)
D = 4380 (1,200 nominal rpm)
E = 4380 (1,800 nominal rpm)
F = 4380 (3,600 nominal rpm)
G = 4300 (1,200 nominal rpm)
H = 4300 (1,800 nominal rpm)
J = 4300 (3,600 nominal rpm)
K = 4382 (1,200 nominal rpm)
L = 4382 (1,800 nominal rpm)
M = 4382 (3,600 nominal rpm)
N = 4302 (1,200 nominal rpm)
P = 4302 (1,800 nominal rpm)
Q = 4302 (3,600 nominal rpm)
LZ Series Feature String Nomenclature
Model Options : Unit Feature Options
LZ A - 140 - C - 0 - 3 - F A C 0 E
-
0 0 0 0 : E 0 - 0 0 0 0 - 0 0
0 0 - 0 0 0 0 - 0 0 - 0 0
0
0 - 0 E 0 0 - 0 0 C 0 0 - 0 J 0 0 0 - 0 0 0 0 0 - 0 0 0 0 0 0 - 0 0 0 0 0 - 0 0 D B
4C: Recirculating Pump Size
0 = No Recirculating Pumps
A = 1.5B
B = 2B
C = 2D
D = 3D
E = 1.5x1.5x6
F = 2x2x6
G = 3x3x6
H = 4x4x6
J = 6x6x6
K = 1.5x1.5x8
L = 2x2x8
M = 3x3x8
N = 4x4x8
P = 5x5x8
Q = 6x6x8
R = 8x8x8
S = 2x2x10
T = 3x3x10
U = 4x4x10
V = 6x6x10
W = 8x8x10
Y = 4x4x11.5
Z = 5x5x11.5
1 = 6x6x11.5
2 = 8x8x11.5
3 = 4x4x13
4 = 6x6x13
5 = 8x8x13
4D: Recirculating Pump Motor Size
0 = No Recirculating Pumps
A = 0.5 hp
B = 0.75 hp
C = 1 hp
D = 1.5 hp
E = 2 hp
F = 3 hp
G = 5 hp
H = 7.5 hp
J = 10 hp
K = 15 hp
L = 20 hp
M = 25 hp
N = 30 hp
P = 40 hp
Q = 50 hp
R = 60 hp
S = 75 hp
5A: Boiler Building Pump Configuration
0 = No Boiler Pumps
5B: Boiler Building Pump Series & RPM
0 = No Boiler Pumps
5C: Boiler Building Pump Size
0 = No Boiler Pumps
5D: Boiler Building Pump Motor Size
0 = No Boiler Pumps
6: Refrigeration Options
0 = None
A = Hot gas bypass on non-variable capacity compressor circuits
B = Hot gas bypass on all circuits
7: Refrigeration Accessories
0 = Standard
A = Sight Glass
B = Compressor Isolation Valves
C = Option A + B
8A: Unit Disconnect Type
0 = Standard Single Point Power Block
A = Single Point Power Non-fused Disconnect
8B: Disconnect 1 Size
0 = Power Block
N = 100 amps
R = 150 amps
U = 225 amps
Z = 400 amps
3 = 600 amps
5 = 800 amps
7 = 1200 amps
15
LZ Series Feature String Nomenclature
Model Options : Unit Feature Options
LZ A - 140 - C - 0 - 3 - F A C 0 E
-
0 0 0 0 : E 0 - 0 0 0 0 - 0 0 0 0 - 0 0 0 0 - 0 0 - 0 0
0
0 - 0 E 0 0 - 0 0 C 0 0 - 0 J
0 0 0 - 0 0 0 0 0 - 0 0 0 0 0 0 - 0 0 0 0 0 - 0 0 D B
8C: Blank
0 = Standard
9: Accessories
0 = None
B = Phase & Brown Out Protection
10A: Unit Control Sequence
0 = Standard AAON Controls
10B: Unit Control Supplier
E = MCS Controls
10C: Control Supplier Options
0 = None
A = Touchscreen Computer Interface
C = Modem
G = Option A + C
10D: BMS Connection & Diagnostics
0 = None
A = BACnet IP
B = BACnet MSTP
C = Modbus IP
D = Modbus RTU
E = LonTalk
H = No BMS Connection with Diagnostics
J = BACnet IP with Diagnostics
K = BACnet MSTP with Diagnostics
L = Modbus IP with Diagnostics
M = Modbus RTU with Diagnostics
N = LonTalk with Diagnostics
11: Cabinet Options
0 = None
B = Access Door Windows
12: Vestibule Accessories
0 = None
A = Refrigerant Leak Detector
B = Motorized Service Vestibule Fresh Air
C = Vestibule Heating (Electric)
D = Vestibule Cooling (Fan/Coil)
F = Option A + B
G = Option A + C
16
H = Option A + D
K = Option B + C
L = Option B + D
N = Option C + D
R = Option A + B + C
S = Option A + B + D
U = Option A + C + D
Y = Option B + C + D
3 = Option A + B + C + D
13: Maintenance Accessories
0 = None
A = 115VAC Convenience Outlet Factory Wired
B = 115VAC Convenience Outlet Field Wired
C = Service Lights
F = Option A + C
J = Option B + C
14: Option Boxes
0 = None
A = 2 ft Option Box
B = 4 ft Option Box
C = 6 ft Option Box
D = 8 ft Option Box
F = 10 ft Option Box
G = 12 ft Option Box
15: Code Options
0 = Standard ETL U.S.A. Listing
A = Chicago Code
B = ETL U.S.A. + Canada Listing
16: Shipping Splits
0 = One Piece Unit
A = Two Piece Unit
17: Air-Cooled Condenser Accessories
0 = None (No Air-Cooled Condenser)
H = Cond Coil Guards + 3Φ Condenser Fan Motor +
Fan Cycling (25
°F)
J = Cond Coil Guards + 3Φ Condenser Fan Motor +
VFD Condenser Fan Head Pressure Control (0
°F)
LZ Series Feature String Nomenclature
Model Options : Unit Feature Options
LZ A - 140 - C - 0 - 3 - F A C 0 E
-
0 0 0 0 : E 0 - 0 0 0 0 - 0 0
0 0 - 0 0 0 0 - 0 0 - 0 0
0
0 - 0 E 0 0 - 0 0 C 0 0 - 0 J 0 0 0 - 0 0 0 0 0 - 0 0 0 0 0 0 - 0 0 0 0 0 - 0 0 D B
18: Evaporative-Cooled Condenser Accessories
0 = None (No Evaporative-Condenser)
A = No Sump Heat
B = Sump Heaters
19: Blank
0 = None
20: Blank
0 = None
21: Chiller Compression Tank
0 = None
A = AX-15V
B = AX-20V
C = AX-40V
D = AX-60V
E = AX-80V
F = AX-100V
G = AX-120V
H = AX-180V
J = AX-200V
K = AX-240V
L = AX-260V
M = AX-280V
22: Boiler Compression Tank
0 = None
23: Blank
0 = Standard
24: Chiller Accessories 1
0 = None
A = Glycol chiller
B = Air Separator
C = Thermometers & Pressure Gauges
D = Chemical Pot Feeder
E = Auto Glycol Feeder
F = Option A + B
G = Option A + C
H = Option A + D
J = Option A + E
K = Option B + C
L = Option B + D
M = Option B + E
N = Option C + D
P = Option C + E
Q = Option D + E
R = Option A + B + C
S = Option A + B + D
T = Option A + B + E
U = Option A + C + D
V = Option A + C + E
W = Option A + D + E
Y = Option B + C + D
Z = Option B + C + E
1 = Option B + D + E
2 = Option C + D + E
3 = Option A + B + C + D
4 = Option A + B + C + E
5 = Option A + B + D + E
6 = Option A + C + D + E
7 = Option B + C + D + E
8 = Option A + B + C + D + E
25: Blank
0 = Standard
26A: Blank
0 = Standard
26B: Blank
0 = Standard
26C: Blank
0 = Standard
26D: Blank
0 = Standard
26E: Blank
0 = Standard
26F: Blank
0 = Standard
27: Blank
0 = Standard
17
LZ Series Feature String Nomenclature
Model Options : Unit Feature Options
LZ A - 140 - C - 0 - 3 - F A C 0 E
-
0 0 0 0 : E 0 - 0 0 0 0 - 0 0 0 0 - 0 0 0 0 - 0 0 - 0 0 0
0 - 0 E 0 0 - 0 0 C 0 0 - 0 J 0 0 0 - 0 0 0 0 0 - 0 0 0 0 0 0 - 0
0 0 0 0 - 0 0 D B
28: Blank
0 = Standard
29: Blank
0 = Standard
30: Blank
0 = Standard
31: Blank
0 = Standard
32: Blank
0 = Standard
33: Warranty
0 = Standard Warranty
D = Compressor Warranty Years 2-5
18
34: Cabinet Material
D = Galvanized Cabinet 6” Base Rail + Double Slope
Roof
H = Galvanized Cabinet 8” Base Rail + Double Slope
Roof
35: Paint & Special Pricing Authorizations
B = Premium AAON Gray Paint Exterior
E = Premium AAON Gray Paint Exterior + Shrink
Wrap
X = Special Pricing Authorization + Premium AAON
Gray Paint Exterior
1 = Option X + Shrink Wrap
4 = Special Pricing Authorization + Special Exterior
Paint Color
7 = Option 4 + Shrink Wrap
General Information
AAON LZ Series chiller outdoor mechanical rooms are complete selfcontained liquid chilling units. They are assembled, wired, charged, and run-tested.
Models are available for air-cooled and evaporative-cooled applications. Chiller primary pumping packages, primary/secondary pumping packages, and boilers with pumping package are available as optional features.
WARNING
Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury or loss of life. Startup and service must be performed by a
Factory Trained Service Technician.
WARNING
RISK OF ELECTRICAL SHOCK
Electrical raceways are located in the upper wall sections of the unit. DO
NOT CUT OR DRILL into the wall sections of the unit that are within 12 inches of the roofline.
Codes and Ordinances
LZ Series units have been tested and certified, by TL, in accordance with UL
Safety Standard 1995/CSA C22.2 No. 236.
System should be sized in accordance with the American Society of Heating,
Refrigeration and Air Conditioning
Engineers Handbook.
Installation of LZ Series units must conform to the ICC standards of the International
Mechanical Code, the International Building
Code, and local building, plumbing and waste water codes. All appliances must be electrically grounded in accordance with local codes, or in the absence of local codes, the current National Electric Code,
ANSI/NFPA 70 or the current Canadian
Electrical Code CSA C22.1.
CAUTION
The Clean Air Act of 1990 bans the intentional venting of refrigerant as of
July 1, 1992. Approved methods of recovery, recycling, or reclaiming must be followed.
WARNING
Coils and sheet metal surfaces present sharp edges and care must be taken when working with equipment.
WARNING
Failure to observe the following instructions will result in premature failure of your system and possible voiding of the warranty.
Receiving Unit
When received, the unit should be checked for damage that might have occurred in transit. If damage is found it should be noted on the carrier’s Freight Bill. A request for inspection by carrier’s agent should be made in writing at once. Nameplate should be checked to ensure the correct model sizes
19
and voltages have been received to match the job requirements.
Storage
If installation will not occur immediately following delivery, store equipment in a dry protected area away from construction traffic and in the proper orientation as marked on the packaging with all internal packaging in place. Leave all internal packaging in place and secure all looseshipped items.
Outdoor Mechanical Room
WARNING
COMPRESSOR CYCLING
3 MINUTE MINIMUM OFF TIME
To prevent motor overheating compressors must cycle off for a minimum of 3 minutes.
3 MINUTE MINIMUM ON TIME
To maintain the proper oil level compressors must cycle on for a minimum of 3 minutes.
The cycle rate must not exceed 6 starts per hour.
Failure to observe the following instructions will result in premature failure of your system, and possible voiding of the warranty.
CAUTION
Before unit operation, the main power switch must be turned on for at least
24 hours for units equipped with crankcase heaters.
Never turn off the main power supply to the unit, except for complete shutdown. When power is cut off from the unit, any compressors equipped with crankcase heaters cannot prevent refrigerant migration.
This means the compressor will cool down, and liquid refrigerant may accumulate in the compressor. The compressor is designed to pump refrigerant gas and damage may occur when power is restored if liquid enters the compressor.
CAUTION
Rotation must be checked on all
MOTORS AND COMPRESSORS of three phase units. All motors, to include and not be limited to pump motors and condenser fan motors, should all be checked by a qualified service technician at startup and any wiring alteration should only be made at the unit power connection.
CAUTION
Scroll compressors are directional and will be damaged by operation in the wrong direction. High pressure switches on compressors have been disconnected after factory testing.
Rotation should be checked by a qualified service technician at startup using suction and discharge pressure gauges and any wiring alteration should be made at the unit power connection.
Always control the system from the building management system, or control panel, never at the main power supply (except for emergency or for complete shutdown of the system).
20
Scroll compressors must be on a minimum of 3 minutes and off for a minimum of 3 minutes. The cycle rate must be no more than 6 starts per hour.
The chiller is furnished with a flow switch installed on the outlet of each heat exchanger. This sensor must not be bypassed since it provides a signal to the unit controller that water flow is present in the heat exchanger and the unit can operate without the danger of freezing the liquid.
Compressor life will be seriously shortened by reduced lubrication, and the pumping of excessive amounts of liquid oil and refrigerant.
Wiring Diagrams
A complete set of unit specific wiring diagrams in both ladder and point-to-point form are laminated in plastic and located inside the control vestibule.
CAUTION
FIELD WIRED CONNECTIONS
Some units may require field wired connections. Refer to the wiring diagrams contained within the unit to identify any components or controls requiring additional wiring in the field before placing the unit into service.
All additional field wiring should be performed by a Factory Trained
Service Technician.
General Maintenance
When the initial startup is made and on a periodic schedule during operation, it is necessary to perform routine service checks on the performance of the chiller and boiler.
This includes reading and recording suction pressures and checking for normal subcooling and superheat. See the evaporativecooled condenser and air-cooled condenser sections in this manual for specific details.
Chiller Primary Pumping
Primary pumping uses a single pump to move water (or glycol) through the chiller evaporator and back to the building. This pumping package provides a constant or variable flow of water to the building. The pump is activated whenever the chiller is given a run signal.
Water enters the unit through the return water piping, and then travels through an air separator to remove any air that is entrapped in the water. Following this, the water flows through a suction guide with an integral strainer. The end of the suction guide is removable for strainer access. The strainer assembly is composed of two parts, the operational strainer and the startup strainer,
(located inside the operational strainer) which is to be removed 24 hours after startup.
The pump is installed after the suction guide, and before a combination valve (Flo-
Trex). This combination valve acts as an isolation valve, check valve, and flow balancing valve. The evaporator is placed after the combination valve in the water circuit, with a flow switch installed at its inlet and outlet. This pressure switch closes when the velocity is above .7 feet per second. The closing flow switch signals the control system to indicate flow through the heat exchanger and allow cooling to activate as required to maintain the setpoint. The water exiting the chiller evaporator leaves the unit through the water out connection.
Chiller Primary/Secondary Pumping
Primary/secondary pumping option provides variable flow to the system. It consists of a constant flow pump for the chiller heat exchanger and a variable flow pump for the
21
building. The controls package senses differential pressure across the pump with pressure transducers installed at the suction and discharge, and varies the speed of the pump using a VFD in order to maintain a given differential pressure across the pump.
The primary/secondary pumping package is essentially composed of two piping loops coupled together. The primary loop has a constant flow rate in order to keep the chiller heat exchanger from freezing, and the secondary, variable flow loop, provides water to the building. The two loops are coupled via a water line that compensates for excess flow in either loop. As the flow in the secondary loop decreases below the flow in the primary loop, excess flow bypasses the building loop and circulates through the bypass water line. On the other hand, as the flow in the secondary loop increases above the flow in the primary loop, excess flow bypasses the chiller and circulates through the bypass water line.
The secondary pump has its own suction guide, combination valve, and isolation valve, similar to the primary pump, with the addition of an air separator to remove any air that is entrapped in the water.
Condensing Boilers
AAON LZ chillers are available with factory installed condensing boilers. All boiler systems will include either fixed or variable speed building pumps. All boiler building pumps will be supplied with a suction guide with a strainer and triple duty valve. The suction guide contains both an operational strainer and a startup strainer. The startup strainer should be removed 24 hours after startup. The triple duty valve functions as an isolation valve, check valve, and flow balancing valve.
The condensing boilers will be a water tube design or a fire tube design. In a water-tube boiler, the water flows through tubes with the combustion products heating from the outside. These boilers require a constant water flow and will be provided with a primary pump for each heat exchanger.
Some boilers have two heat exchangers and will have two primary pumps. The primary pump is controlled by the boiler and will only come on when it has a call for heat.
Water-tube boilers are provided with flow switches, which must make before the boiler can operate.
In fire-tube boilers water flows through a tank, with the combustion products inside tubes. These boilers are capable of significant water flow turn-down and do not require individual primary pumps. A control valve, operate by the boiler controls, is provided with each boiler. A water flow switch is not required with fire-tube boilers.
A low-level cutoff switch is used which will prevent the boiler from operating when there is not a sufficient water level present. Upon initial startup, the boiler may have to be cycled several times to generate an adequate water level.
Makeup Water
A city make up water connection is provided to replace water that is lost from the system.
Glycol units require a glycol feeder
(optional factory installed or field installed) to replace fluid that is lost in the system.
Water should not be directly added to glycol applications as this would dilute the glycol concentration and thereby increase the freezing temperature of the fluid.
The makeup water connection is provided with a backflow preventer that has isolation valves on the inlet and outlet for service.
22
Figure 1 shows the pressure drop versus
flow rate for the backflow preventer.
Figure 1 - Backflow Preventer
There is a pressure-reducing valve after the backflow preventer. This valve reduces the city water pressure to maintain the operating pressure of the system. This valve is adjustable from 10-35 psig with a factory setting of 30 psig. The system pressure varies with the height of the system. The pressure-reducing valve setting should be set so that the pressure at the high point in the system is high enough to vent air from the system (usually 4 psig). There should be air vents at all parts in the system where air could be trapped. If the pressure is not high enough throughout the system, flashing could occur in the piping or the pump could cavitate. There is an isolation valve on the inlet and outlet of the pressure-reducing valve for service.
The pressure reducing valve fills the system at a reduced rate. There is a bypass around the pressure reducing valve for the initial fill of the system to increase the initial fill speed. After the initial system fill, this valve should be closed.
Compression Tank
As the water temperature in the system increases, the volume that water displaces increases. In order to compensate for these expansion forces, a compression or expansion tank must be used. The factory installed tank option includes a prepressurized diaphragm compression tank that is preset for 12 psig.
The factory pre-charge pressure may need to be field adjusted. The tank must be precharged to system design fill pressure before placing into operation. Remove the pipe plug covering the valve enclosure. Check and adjust the charge pressure by adding or releasing air.
If the system has been filled, the tank must be isolated from the system and the tank emptied before charging. This ensures that all fluid has exited the diaphragm area and proper charging will occur.
If the pre-charge adjustment is necessary, oil and water free compressed air or nitrogen gas may be used. Check the pre-charge using an accurate pressure gauge at the charging valve and adjust as required. Check air valve for leakage. If evident, replace the
Schrader valve core. Do not depend on the valve cap to seal the leak. After making sure the air charge is correct, replace the pipe plug over the charging valve for protection.
Purge air from system before placing tank into operation. All models have system water contained behind the diaphragm.
It is recommended that the pre-charge be checked annually to ensure proper system protection and long life for the vessel.
Pressure Relief Valve
Required pressure relief valve is installed in
the unit. This valve is set at 125 psig. Figure
2 shows inlet pressure versus capacity for
this pressure relief valve. See appendix for additional information.
23
Figure 2 - Pressure Relief Valve
Automatic Air Vent
There is an automatic air vent installed at the high point of the system inside the pumping package compartment. The air vent valve must be in the proper position for operation.
Ensure that the small vent cap is loosened two turns from the closed position, allowing air to be vented from the system. It is advisable to leave the cap on to prevent impurities from entering the valve. See appendix for additional information.
Dual Pumps
When redundant pumping is required, factory installed dual pumps or two single pumps can be ordered. A dual pump is a pump with two independent motors and impellors in a single casing. This dual pump has a swing split-flapper valve in the discharge port to prevent liquid recirculation when only one pump is operating. Isolation valves in the casing allow one pump to be isolated and removed for service while the other pump is still operating.
When redundant pumping is required with high flow rates, two independent pumps may be installed in parallel. Each pump will have its own suction guide/strainer, combination valve, and isolation valves.
The controls package will activate the pump when the unit is given a run command. If the controls do not recognize flow in 60 seconds
(factory default), the second pump will be activated and an alarm signal will be generated. If the second pump does not activate, the cooling will be locked out. See
Appendix - Water Piping Component
Information for additional information.
Pressure Gauges and Thermometers
Pressure gauges and thermometers are available as a factory installed option.
Thermometers are installed on the inlet and outlet of the unit. One pressure gauge is installed at each pump. This pressure gauge is connected in three places to the water piping before the suction guide/strainer, after the suction guide and before the pump, and after the pump. There is also a valve at each of these points to isolate the pressure.
To measure the pressure at any given point, open the valve at that point and close the other two valves. One gauge is used so that the calibration of the pressure gauge is irrelevant in the calculation of the differential pressure.
Pipe Insulation
The water piping and components on units with pumping packages are not insulated at the factory. Insulation should be installed on the water piping after the system has been checked for leaks.
24
Installation
Outdoor Mechanical Room Placement
The AAON LZ Series is designed for outdoor applications and can be mounted at ground level or on a rooftop. It must be placed on a level and solid foundation that has been prepared to support its weight.
The placement relative to the building air intakes and other structures must be carefully selected. Be sure to observe the dimensions that are on the rating plate of the chiller for operational and service clearances.
Table 1 - Service Clearances
Location
Unit Size
45-540 tons
Left
Right
Compressor End
Chiller HXC End
96”
72”
Top Unobstructed
Condenser coils and fans must be free of any obstructions in order to start and operate properly with a correct amount of airflow.
For proper unit operation, the immediate area around condenser(s) must remain free of debris that may be drawn in and obstruct airflow in the condensing section.
Consideration must be given to obstruction caused by snow accumulation when placing the unit.
Curb and Steel Mount Installation
Make openings in the roof decking large enough to allow for water piping, electrical, and gas penetrations and workspace only.
Do not make openings larger than necessary.
Set the curb to coincide with the openings.
Make sure curb is level.
Unit specific curb drawing is included with job submittal. See SMACNA Architectural
Sheet Metal Manual for curb installation details.
CAUTION
All roofing work should be performed by competent roofing contractors to avoid any possible leakage.
When installed at ground level, a one-piece concrete slab should be used with footings that extend below the frost line. Care must also be taken to protect the coil and fins from damage due to vandalism or other causes.
If unit is elevated a field supplied catwalk is recommended to allow access to unit service doors.
This unit ships with a curb gasket that is
1¼” wide and 1½” tall. It is recommended that this or another similar gasket be used between the curb and the unit to reduce vibration transmission from the unit to the building.
25
Figure 3 - Curb Mounting with Dimensions
Figure 4 - Curb End Detail
26
Figure 5 - Steel Mounting Rail with Dimensions
Figure 6 - Concrete Pad Mounting with Dimensions
Lifting and Handling
If cables or chains are used to hoist the unit they must be the same length and care should be taken to prevent damage to the
cabinet. See Figure 8 for additional
information.
Before lifting unit, be sure that all shipping material has been removed from unit. Secure hooks and cables at all lifting points/ lugs provided on the unit.
Hoist unit to a point directly above the curb or mounting rail. Be sure that the gasket
Figure 7 - Lifting Points material has been applied to the curb or mounting rail.
Carefully lower and align unit with utility openings. Lower the unit until the unit skirt fits around the curb. Make sure the unit is properly seated on the curb and is level.
Do not push, pull or lift the unit from anything other than its base.
27
28
Figure 8 - LZ Series Example Lifting Detail
Lifting slot locations are unit specific.
Unit must be rigged at all marked lifting points.
Water Connection
Remove the shipping cover from the water connection cutout in the post. Connect the supply and return water lines. The standard water connection is grooved end pipe. The connection size is listed on the unit rating sheet along with the designed volumetric flow rate. The maximum operating pressure for AAON LZ Series unit is 125 psi. Install the flashing provided by AAON according
to the steps in Figure 9. Finished water
connection will be water tight.
WARNING
The chiller must be operated only with liquid flowing through the evaporators.
WARNING
Boilers must be operated only with liquid flowing through the boiler.
CAUTION
PVC (Polyvinyl Chloride) and CPVC
(Chlorinated Polyvinyl Chloride) are vulnerable to attack by certain chemicals. Polyolester (POE) oils used with R-410A and other refrigerants, even in trace amounts, in a PVC or CPVC piping system will result in stress cracking of the piping and fittings. This will result in complete piping system failure.
CAUTION
Installing Contractor is responsible for proper sealing of the water piping and electrical entries into the unit
Failure to seal the entries may result in damage to the unit and property.
Figure 9 - Water Pipe Flashing Installation
29
Boiler Gas Connection
Before making gas connection, make sure the boiler is being supplied with the type of fuel shown on the boiler nameplate.
Table 2 and Table 3 show the gas
connection size and type (NPT or flanged) provided along with the required inlet gas pressure for the unit. Refer to feature B on the LZ Series unit feature string to determine which line of the table to use. For example, a unit with feature B = A3CC will have a 2” NPT gas connection and require an inlet gas pressure in the range of 6-14”
W.C.
Use only pipe sealing compound that is compatible with propane gases on all threaded connections. Apply sparingly only to the male threads of the pipe joints so that the pipe sealing compound does not block any gas flow.
WARNING
Failure to apply sealing compound as detailed can result in property damage, personal injury, or death.
Before being placed in operation, the boiler and all gas piping connections must be checked for leaks. The boiler must be disconnected from the gas supply piping system during any pressure testing of the system at pressures in excess of .5 psig (14”
W.C.). The boiler must be isolated from the gas supply piping system by closing the manual shutoff valve during any pressure testing of the system at pressures equal to or less than .5 psig (14” W.C.).
Some leak test solutions, including soap and water, may cause corrosion. These solutions should be rinsed off with water after testing.
WARNING
DO NOT use matches, candles, open flames, or other ignition sources to check for gas leaks. Use only approved leak detection methods.
Failure to comply with this warning can result in property damage, personal injury, or death.
Boiler Air Intake / Vent Piping
Each boiler requires the installation of air intake and vent piping. This piping has been removed for shipping purposes. All piping must be reinstalled according to the instructions provided in this section prior to boiler operation.
All boilers must be vented and supplied with combustion and ventilation air as described in this section and in the Lochinvar
Installation & Operation Manual included with the boiler. Ensure the vent and air piping and combustion air supply comply with instructions regarding vent system, air system, and combustion air quality.
Inspect finished vent and air intake piping thoroughly to ensure all are airtight and comply with the instructions provided and with all requirements of applicable codes.
WARNING
Failure to provide a properly installed vent and air system can result in property damage, personal injury, or death.
30
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
B1
Table 2 - Unit Gas Pipe Information, Feature B4 = A-J
Heating Feature Boiler
B2 B3 B4 Size Qty
Input
Capacity
(CFH)
Inlet Gas
Pressure
1 C or D A
2 C or D A
3 C or D A
4 C or D A
1 C or D B
2 C or D B
3 C or D B
4 C or D B
KBN400
KBN501
1
2
3
4
1
2
3
4
Gas Header
Pipe
Size
400 6-14” W.C. 1
Conn.
Type
800 6-14” W.C. 1 1/2 NPT
1,200
1,600
500
1,000
1,500
2,000
6-14” W.C.
6-14” W.C.
6-14” W.C.
6-14” W.C.
6-14” W.C.
6-14” W.C.
2
2
1 1/2
1 1/2
2
2
NPT
NPT
NPT
NPT
NPT
NPT
NPT
1 C or D C
2 C or D C
3 C or D C
4 C or D C
1 C or D D
2 C or D D
3 C or D D
4 C or D D
1 C or D F
2 C or D F
3 C or D F
4 C or D F
KBN601
KBN701
KBN801
1
2
3
4
1
2
3
4
1
2
3
4
600
2,400
6-14” W.C.
2-5 psi
1 1/2
1,200 6-14” W.C. 2
1,800 6-14” W.C. 2
2
NPT
NPT
NPT
NPT
700 6-14” W.C. 1 1/2 NPT
1,400 6-14” W.C. 2
2,100 2-5 psi 2
2,800 2-5 psi 2
NPT
NPT
NPT
800 6-14” W.C. 1 1/2 NPT
1,600 6-14” W.C. 2 NPT
2,400
3,200
2-5 psi
2-5 psi
2
2
NPT
NPT
1 C or D G
2 C or D G
3 C or D G
4 C or D G
1 C or D H
2 C or D H
3 C or D H
4 C or D H
1 C or D J
2 C or D J
3 C or D J
4 C or D J
SBN1000
SBN1300
SBN1500
1
2
3
4
1
2
3
4
1
2
3
4
1,000 6-14” W.C. 1 1/2 NPT
2,000 2-5 psi 2 NPT
3,000
4,000
2-5 psi
2-5 psi
2
2
NPT
NPT
1,300 6-14” W.C. 2
2,600
3,900
5,400
2-5 psi
2-5 psi
2-5 psi
2
2
2
NPT
NPT
NPT
NPT
1,500 6-14” W.C. 2
3,000 2-5 psi 2
4,500
6,000
2-5 psi
2-5 psi
2
2
NPT
NPT
NPT
NPT
31
A
A
A
A
A
A
A
A
B1
A
A
A
A
Table 3 - Unit Gas Pipe Information, Feature B4 = K-N
Heating Feature Boiler
B2 B3 B4 Size Qty
Input
Capacity
(CFH)
Inlet Gas
Pressure
1 C or D K
2 C or D K
3 C or D K
4 C or D K
1 C or D L
2 C or D L
3 C or D L
4 C or D L
FBN2000
FBN2500
1
2
3
4
1
2
3
4
Gas Header
Pipe
Size
Conn.
Type
2,000 2-5 psi 1 1/2 NPT
4,000 2-5 psi
6,000
8,000
2,500
5,000
7,500
10,000
2-5 psi
2-5 psi
2-5 psi
2-5 psi
2-5 psi
2-5 psi
2
2
3
1 1/2
2
3
3
NPT
NPT
Flange
NPT
NPT
Flange
Flange
1 C or D M
2 C or D M
3 C or D M
4 C or D M
FBN3000
A
A
A
A
1 C or D N
2 C or D N
3 C or D N
4 C or D N
FBN3500
Sidewall Direct Boiler Venting
For units with Lochinvar Knight XL and
SYNC boilers (feature B4 = A, B, C, D, E,
F, G, H, or K), the air intake and vent piping runs from each boiler through the sidewall of the unit into the supplied sidewall vent termination.
1. On the sidewall above the boiler access door, remove the shipping cover and attach the sidewall vent plate shipped with the unit.
1
2
3
4
1
2
3
4
3,000 2-5 psi
6,000 2-5 psi
9,000 2-5 psi
12,000 2-5 psi
3,500 2-5 psi
7,000 2-5 psi
10,500 2-5 psi
14,000 2-5 psi
1 1/2
2
3
3
2
3
3
3
NPT
NPT
Flange
Flange
NPT
Flange
Flange
Flange
Figure 11 - Sidewall Vent Plate Installation
2. Attach air intake piping to the air inlet connector on the boiler at one end and run through the sidewall of the unit at the other end. All air intake pipes and fittings are
PVC.
Figure 10 - Sidewall Vent Shipping Cover
Removal
WARNING
Use only primer and cement approved for use with PVC
(ANSI/ASTM D2564).
32
Figure 12 - Typical Air Intake Piping
Figure 13 - Typical Flue Vent Piping
33
3. Attach vent piping to the flue pipe adapter on the boiler at one end and run through the sidewall of the unit at the other end. All
Vent pipes and fittings are CPVC. Vent piping must be pitched at a minimum of 1/4 inch per foot back to the boiler.
WARNING
Use only primer and cement approved for use with CPVC
(ANSI/ASTM F493).
4. Install the vent and air intake piping through the wall into the sidewall vent base.
Use RTV silicone sealant to seal the air intake pipe. Mount and secure the sidewall vent base using stainless steel screws. Seal all gaps between the pipes and the sidewall.
Seal around the sidewall vent base to the wall ensuring no air gaps.
5. Assemble vent cap to vent base and securely attach using stainless steel screws.
Figure 15 - Sidewall Vent Cap
Vertical Direct Boiler Venting
For units with Lochinvar Crest boilers
(feature B4 = K, L, M, or N), the air intake and vent piping is installed to run vertically through the roof of the unit.
1. Remove shipping covers from openings in the roof.
34
Figure 14 - Sidewall Vent Base
Figure 16 - Roof Air Intake and Vent Piping
Shipping Covers
2. Attach air intake piping to the air inlet connector on the boiler and run vertically through the roof of the unit. The air intake pipes and fittings will either be all PVC or all stainless steel components.
WARNING
For units with PVC piping, use only primer and cement approved for use with PVC (ANSI/ASTM D2564).
WARNING
For units with stainless steel piping, all components must be installed in accordance with the manufacturer’s instructions to ensure all joints are secure and sealed correctly.
CAUTION
JOINT CONNECTIONS
The female end of each component incorporates a sealing gasket and a mechanical locking bond. Examine all components prior to installation.
Gaskets must be in proper position to prevent leakage.
Figure 17 - Typical Vertical Air Intake Piping
35
3. Insert the male end into the female section. Push the units together and turn them until half of the bead on the male end is covered by the flared edge of the female end. This creates the needed airtight seal for Category II, III, or IV appliances. Align the seams on the vent lengths and orient them upward on all horizontal applications.
4. Tighten the locking band with a nut driver until snug, plus a quarter turn. Before proceeding, recheck all joints end ensure that all male sections extend to the top of the flared female end and all clamps are tightened.
Figure 18 - Correct Joint Connection
5. Attach vent piping to the vent connector on the boiler and run vertically through the roof of the unit. All vent pipes and fittings will be stainless steel components.
WARNING
For units with stainless steel piping, all components must be installed in accordance with the manufacturer’s instructions to ensure all joints are secure and sealed correctly.
6. The air intake piping must terminate in a down turned 180
° return pipe no further than 2 feet horizontally from the center of the vent pipe. The placement avoids recirculation of flue products into the combustion air stream.
7. The vent piping must terminate in an up turned coupling with the top of the coupling or rain cap at least 36 inches above the air intake.
WARNING
For units with multiple boilers, terminate all vent pipes at the same height and all air intake pipes at the same height to avoid recirculation of flue products. Failure to do so may result in property damage, personal injury, or death.
Figure 19 - Incorrect Joint Connection
36
Figure 20 - Typical Vertical Vent Piping
Figure 21 - Vertical Termination of Air Intake and Vent Piping
37
Boiler Condensate Drain
Each boiler is provided with a neutralizer kit for neutralizing the condensate from the boiler. The condensate leaving the boiler is slightly acidic, typically with a pH of 3 to 5, and has the potential to harm the environment and the sewer system. The neutralizer kit raises the pH to a more neutral level before it is discharged to a common condensate drain line. The common condensate drain line has a threaded pipe connection where it passes through the sidewall of the unit. Connect the drain line to an appropriate waste line following applicable codes.
Split Unit Assembly
The larger LZ chillers may be shipped in two pieces which will need to be lifted into place separately then assembled into the completed unit. The following procedure should be used to complete the assembly.
1. The shipping covers over the open sections of the unit should be removed just before installation.
2. The larger section should be lifted first and set exactly in the desired location.
3. Once this section is in place, the provided neoprene gasket should be placed on the entire face of the open connection.
4. The smaller section should then be placed as close as possible to the first section.
5. After the crane rigging is removed, come-alongs should be attached to the nearest lifting lugs of both sections on each side base rail. The two sections should then be pulled together until the bases are flush. If necessary the internal braces at the connection location can be used to align the top of the two sections.
6. When the two sections are properly aligned, the provided splice parts should be installed. There is one internal splice on the base seam and external splices for the roof and both side panels. Before installing the side panel splices, polyurethane caulking should be applied to the top 6” of the panel joint starting at the bottom of the roof lip.
7. The water pipes should then be connected across the unit joint using the provided pipe sections and grooved couplings.
8. All electrical connections between the two sections are made using NEMA boxes inside the cabinet. These connections must be made per the unit wiring diagram and checked for ground faults before power is connected to the unit. Failure to do this could result live power being applied to loose wires.
Unit Mounting Isolation
For roof mounted applications or anytime vibration transmission is a factor, vibration isolators may be used.
Access Doors
Lockable access doors are provided to the compressor and control compartment. A separate access door is also provided to the evaporator and pumping package compartment.
A light switch is provided on the wall of the compressor and control compartment.
Low Ambient Operation
If the chiller is ordered with the low ambient head pressure control, the liquid system must use a glycol solution and the piping
38
must be insulated to be prepared for freezing conditions. Care must be taken in connecting electrical power to the heating tape and thermostat.
The AAON low ambient head pressure control is used to operate a refrigerant system down to 0°F outside air temperature.
As the ambient temperature drops, the condenser becomes more effective and decreases the head pressure. When the head pressure gets too low, there will be insufficient pressure to operate the expansion valve properly. During low ambient temperatures, it is difficult to start a system because the refrigerant will migrate to the cold part of the system (condenser) and make it difficult for refrigerant to flow.
The low ambient system maintains normal head pressure during periods of low ambient temperatures by controlling condenser air flow by modulating fan speed. By reducing condenser air flow, the condenser heat rejection capacity is reduced. This allows unit operation down to 0
°F.
During higher ambient temperatures, the entire condenser is required to condense refrigerant. During these higher ambient temperatures, full condenser air flow is required to maintain system capacity. The
VFD controlled condenser fan low ambient head pressure control will modulate the condenser air flow to maintain proper head pressure. Along with electronic expansion valves, VFD controlled condenser fans optimize system performance.
Electrical
The electrical power connections are made in the electrical control compartment.
The microprocessor control furnished with the unit is supplied with its own power supply factory wired to the main power of the outdoor mechanical room.
Verify the unit nameplate voltage agrees with the power supply. Connect power and control field wiring as shown on the unit specific wiring diagram provided with the unit.
Size supply conductors based on the unit
MCA rating. Supply conductors must be rated a minimum of 167°F (75°C).
Route power and control wiring, separately, through the utility entry. Do not run power and signal wires in the same conduit. Power and signal wires in the same conduit can cause electrical interference.
Protect the branch circuit in accordance with code requirements. The unit must be electrically grounded in accordance with local codes, or in the absence of local codes, the current National Electric Code,
ANSI/NFPA 70 or the current Canadian
Electrical Code CSA C22.1.
Power wiring is to the unit terminal block or main disconnect. All wiring beyond this point has been done by the manufacturer and cannot be modified without affecting the unit's agency/safety certification.
WARNING
Electric shock hazard. Before attempting to perform any installation, service, or maintenance, shut off all electrical power to the unit at the disconnect switches. Unit may have multiple power supplies. Failure to disconnect power could result in dangerous operation, serious injury, death or property damage.
39
WARNING
CONVENIENCE OUTLETS AND
SERVICE LIGHTS
Convenience outlet and service light circuits are wired to the incoming power side of the disconnect. These circuits will remain powered even when unit disconnect is off.
CAUTION
Installing Contractor is responsible for proper sealing of the electrical and gas entries into the unit. Failure to seal the entries may result in damage to the unit and property.
Startup technician must check for proper motor rotation for compressors, condenser fan motors, and pumps and check fan motor amperage listed on the motor nameplate is not exceeded. Motor overload protection may be a function of the variable frequency drive and must not be bypassed. Variable frequency drives are programmed to automatically rotate the fan in the correct rotation. Do not rely on fan with variable frequency drives for compressor rotation.
Note: All units are factory wired for
208/230V, 460V, or 575V. If unit is to be connected to a 208V supply, the transformer must be rewired to 208V service.
CAUTION
Scroll compressors are directional and will be damaged by operation in the wrong direction. High pressure switches on compressors have been disconnected after factory testing.
Rotation should be checked by a qualified service technician at startup using suction and discharge pressure gauges and any wiring alteration should only be made at the unit power connection.
Wire control signals to the unit’s low voltage terminal block located in the controls compartment.
If any factory installed wiring must be replaced, use a minimum 221°F (105°C) type AWM insulated conductors.
WARNING
BURNING FOAM INSULATION IS
TOXIC! Do not cut holes into any foam insulated panels with any flame producing cutter such as a plasma cutter or cutting torch.
40
CAUTION
Rotation must be checked on all
MOTORS AND COMPRESSORS of three phase units. Condenser fan motors should all be checked by a qualified service technician at startup and any wiring alteration should only be made at the unit power connection. Variable frequency drives are programmed to automatically rotate the fan in the correct rotation.
Do not rely on fans with variable frequency drives for compressor rotation.
Evaporative-Cooled Condenser Field Piping
Connections
There are at least two field water connections that must be made for the evaporative-cooled condenser. There is a
3/4” MPTF copper fitting city make up water connection and a 2” PVC socket drain
Figure 22. This drain should connect to a
sanitary sewer or other code permitted drain.
These connections can go through the base or the wall of the unit.
There is a cutout in the base with a cap that is 1” tall and the cap is sealed to the unit base to prevent any leaks in the unit from penetrating into the building. Any piping through the base should go through a field cutout in this cap. The pipes must be sealed to the cap once the piping is complete to prevent any leaks in the unit from penetrating into the building.
A field cutout must be made in the wall if the evaporative-cooled condenser piping is to go through the unit wall. This cutout must be sealed once the piping is installed to prevent water from leaking into the unit.
41
Figure 22 - Evaporative-Cooled Condenser Section Layout
Including Field Water Connections and Base Cutout
42
Startup
(See back of the manual for startup form)
WARNING
Electric shock hazard. Shut off all electrical power to the unit to avoid shock hazard or injury from rotating parts.
WARNING
Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury or loss of life. Startup and service must be performed by a
Factory Trained Service Technician.
Before starting the chiller for the first time, verify the following items have been checked:
1. Verify that electrical power is available and that the voltage is correct and the capacity is equal to or greater than the unit’s MOP listed on the nameplate. If the chiller has an evaporative cooled condenser, verify that the make-up water supply is available and properly connected.
2. Chillers selected to use standard water are provided with a connection for city make-up water, verify that this is available and properly connected.
Glycol chillers may be selected with an auto-glycol feeder. If present verify that this has been set up correctly and filled with the proper water-glycol mixture
(see Appendix XX). Open automatic air vents as shown in Appendix XX.
3. Before applying power, review the MCS
Controller manual provided with the chiller. Understand the operation of the controller display panel as well as the
MCS Connect PC program.
4. Verify that all crankcase heaters are operating correctly. The crankcase heaters must be energized for at least 24 hours before starting the compressors to clear any liquid refrigerant from the compressors.
5. Verify that the rotation of all pumps, motors, and compressors are correct.
The rotations have been checked at the factory, so if any motors that are not powered by a Variable Frequency Drive are operating backwards two phases should be switch at the unit power connection.
6. Verify that any remote stop/start device or BMS signal is connected to the chiller controller and requesting the chiller to start.
7. With the proper pumps running, verify that there is liquid flow through the chiller. This can be checked by monitoring the status of the chiller’s flow switch or verifying a pressure drop using the provided pressure gauges.
8. A building load of at least 25% of the chiller capacity should be present in order to properly check operation.
9. Complete the general check list at the top of the startup form to make a last check that the chiller is ready to operate.
Use the general check list at the top of the
LZ Series Startup Form to make a last check
that all the components are in place, water flow is present, and the power supply is energized.
43
Test the chiller operation by changing the
Run/Stop switch to “Run”, and enabling one system at a time. The compressors should not be placed in “Manual On” for any period longer that what is required to check for proper rotation. The Electronic Expansion
Valves will not function when the compressor is operated in this mode.
CAUTION
Rotation must be checked on all
MOTORS AND COMPRESSORS of three phase units. All motors, to include and not be limited to pump motors and condenser fan motors, should all be checked by a qualified service technician at startup and any wiring alteration should only be made at the unit power connection.
Using the circuit disable switches, cycle through all compressors to ensure they are operating within tolerance. While performing checks, use the startup form to record observations of compressor amps, refrigerant pressures and temperatures.
Pressure readings should be independently verified using a set of calibrated gauges. If necessary apply offsets to the unit controller’s readings through the MCS
Controls display or through the MCS
Connect PC program.
When all compressors have been observed to function correctly, enable all circuits and observe the chiller until it reaches a steady state of operation. If necessary, adjust leaving water setpoint to match desired target. For units with BMS communication, verify that the BMS system can access and modify all necessary points.
Chillers that are provided with single point piping connections for two evaporator
44 barrels are equipped with balancing valves on each heat exchanger. Flow should be balanced between the two evaporators by a hydronic systems balancing professional.
Note: For more information on programming the controller refer to the
MCS Controller manual provided with the chiller.
CAUTION
Before completing installation, a complete operating cycle should be observed to verify that all components are functioning properly.
Condenser Fan Pitch Adjustment
Units installed at elevations above 2,000 feet may require adjustment of the condenser fan pitch to achieve optimal performance. See
Table 4 or Table 5 for the correct pitch
values.
Table 4 - Air-Cooled Condenser Fan Pitch
Altitude Pitch
0-2,000’ (Factory Default) 35
°
2,000’-4,000’
37.5
°
Over 4,000’
40
°
Table 5 - Evaporative-Cooled Condenser
Fan Pitch
Altitude Pitch
0-6,000’ (Factory Default) 30
°
Over 6,000’
35
°
Multi-Wing Z Series Aluminum Fan Blade
Pitch Angle Setting Instructions
1. Maintain the balance of fan
Mark the hub castings across a joint, so the fan hub can be reassembled in the same orientation.
Mark the location of any balancing weight.
Balancing weight will be on the outer bolt circle, in the form of washers, and/or longer bolts, or an additional balancing nut.
Number the blades and blade sockets, so that they are replaced into their original position.
Bushing
Mount
Bushing Bushing
A
Bushing
Mount
B
Figure 24 - Bushing Mount Location
4. Determine the pin location groove
Disassemble fan on a flat surface and note in which groove the pin is located.
Figure 23 - Fan with the HUB on the top and
RET on the bottom.
2. Determine the direction of rotation
Right, R, is clockwise when facing the discharge side of the fan and Left, L, is counterclockwise when facing the discharge side of the fan.
3. Determine the bushing mount location
The bushing mount is the center section of the hub through which the fan is mounted to the shaft, and typically contains either setscrews or a center-tapered hole where the bushing inserts.
Location A is with the bushing mount on air inlet side of the fan.
Location B is with the bushing mount on air discharge side of the fan.
1 2 3 4
Figure 25 - RET with Pin in Groove 4
5. Determine whether the pin is in the HUB or RET
Figure 26 - Fan HUB and RET Castings
45
6. Determine the current blade pitch and the pin location for the new blades
Type
5Z
Bushing
Mount
A
B
Table 6 - Condenser Fan Pin Location (Bushing Mount)
Blade Pitch Angle
20°
- RET - RET RET RET HUB HUB HUB HUB
-
25°
HUB
28°
-
30°
HUB
33°
HUB
35°
HUB
38°
RET
40°
RET
45°
RET
50°
RET
Table 7 - Condenser Fan Pin Location (Rotation Direction)
Blade Pitch Angle
Type Rot.
5Z
R
L
20° 25° 28° 30° 33° 35° 38° 40° 45° 50°
- 4 - 3 2 1 4 3 2 1
- 1 - 2 3 4 1 2 3 4
7. Replace fan blades in the new pin location and reassemble the fan
Replace the blades with the pin in the 1, 2,
3, or 4 groove position of either the HUB or
RET. Assemble the fan making sure to place the blades in their previous blade sockets, to match up the previous orientation of HUB and RET and to replace any balancing weights in their previous locations. Tighten bolts in a cross pattern to 5-6 ft-lbs. of torque.
Multi-Wing W Series Black Glass
Reinforced Polypropylene Fan Blade Pitch
Angle Setting Instructions
Contact your local AAON representative to acquire the new pitch pins for the fan blades.
Note original position of retaining plates, center boss and all hardware including additional hardware used for balancing.
1. Remove all the bolts and nuts.
2. Determine blade rotation – on the concave side of the blade is a blade marking showing 6WR, 6WL, 7WL,
7WR, or 9WR. The “L” and “R” denote the rotation of the blade.
3. Replace the pitch insert in the blade root with an insert of the desired pitch.
Figure 27 - Pitch Insert
4. Replace blades to their original location.
5. Replace all nuts, bolts, and washers on the fan hub.
46
6. Replace retaining plates and center boss to original location.
7. Tighten nuts and bolts to 14 ft-lbs of torque.
Fan Assembly Bushings
The fan assembly bushings should be tightened to the specifications listed in the following table.
Table 8 - Fan Assembly Bushing Torque
Specifications
Bushing
H X 1.125"
H X 1.375"
SH X 1.125"
SH X 1.375"
Tightening Torque
(in-lbs.)
95
95
SD X 1.125"
SD X 1.375"
SD X 1.625"
SD X 1.875"
SK X 2.125"
108
108
108
108
108
108
180
Boiler System Startup
Before starting the boiler system for the first time, verify the following items have been checked:
1. Verify that electrical power is available and that the voltage is correct and the capacity is equal to or greater than the unit’s MOP listed on the nameplate.
Verify that the gas supply is connected, has been properly sized, and has been purged of air.
2. Immediately after turning on the gas supply, check piping for any leaks.
3. Verify that the city make-up water supply is available and properly connected.
Open automatic air vents as shown in
Appendix XX.
4. Before applying power, review the MCS
Controller manual provided with the chiller. Understand the operation of the controller display panel as well as the
MCS Connect PC program. Review manuals provided with each boiler for proper operation of boiler controls.
5. Verify that the rotation of all pumps is correct. The rotations have been checked at the factory, so if any motors that are not powered by a Variable
Frequency Drive are operating backwards two phases should be switch at the unit power connection.
6. Verify that any remote stop/start device or BMS signal is connected to the chiller controller and requesting the boiler system to start.
7. A building load of at least 25% of the boiler capacity should be present in order to properly check operation.
8. Complete the general check list at the top of the startup form to make a last check that the boiler system is ready to operate.
Test the boiler system operation by changing the Boiler Run/Stop switch to “Run”. The boiler building pump should then start and the boilers should stage on and modulate to maintain the leaving water target temperature. If not enough load is present to stage on each boiler, disable individual units through the boiler controls.
Use the startup form to record the full load boiler water in temperature and water out temperature as well as the amps for each individual boiler.
When all boilers have been observed to function correctly, enable all boilers through
47
boiler controls. Observe the system until it reaches a steady state of operation. If necessary adjust the boiler leaving water setpoint to match desired target. For units with BMS communication, verify that the
BMS system can access and modify all necessary points.
Each individual boiler is provided with flow balancing valves. Flow should be balanced between the two evaporators by a hydronic systems balancing professional.
Boiler Sequence of Operations
1. When both the boiler run/stop switch and the boiler BMS run/stop input (if
BMS communications are selected) are switched on, the unit controls will turn on the boiler building pump and enable the lead boiler.
2. If variable speed boiler building pump is selected, the controls will modulate the boiler to maintain the target difference between the pumps suction and discharge pressures. If the minimum
(default 5 psi) differential is not achieved within 60 seconds then the pump will be locked off and the next pump will start if available.
3. When the lead boiler is enabled it will modulate itself as well as stage and modulate any additional boilers to maintain the desired hot water temperature leaving the unit. This temperature is controlled through the chiller unit controller and can be reset through the BMS communications (if selected). If BMS communications are not selected, the target temperature can be reset based on the ambient air temperature. The default temperature target is 135° F with a minimum of 90°
F and a maximum of 180° F.
4. Each boiler will control its own individual pumps or valves as necessary as they are staged on and off.
Maintenance
General
Qualified technicians must perform routine service checks and maintenance. This includes reading and recording the condensing and suction pressures and checking for normal sub-cooling and superheat.
Air-cooled and evaporative-cooled condenser units require different maintenance schedules/procedures. Unit specific instructions for both types are included in this manual.
Refrigerant Filter Driers
Each refrigerant circuit contains a replaceable core filter drier. Replacement is recommended when there is excessive pressure drop across the assembly or moisture is indicated in a liquid line sight glass.
Figure 28 - Replaceable Core Filter Driers
48
Table 9 - Filter Drier Maximum Pressure
Drop
Circuit Loading Max. Pressure Drop
100%
50%
10 psig
5 psig
The filter driers are provided with pressure taps and shutoff valves for isolation when changing the core. For safety purposes a service manifold must be attached prior to filter maintenance.
WARNING
Service gauges MUST BE connected before operating the isolation valves for the liquid line filter drier.
WARNING
Prior to filter core service, a service manifold MUST BE attached to in and out pressure connections to assure no pressure exist during filter maintenance. Non-compliance could result in injury or violation of EPA regulations.
Evaporator/Heat Exchangers
Evaporators are direct expansion type with an electronic expansion valve to regulate refrigerant. Normally no maintenance or service work will be required.
Adjusting Refrigerant Charge
All AAON chillers are shipped with a full factory charge. Periodically adjusting the charge of a system may be required.
Adjusting the charge of a system in the field must be based on determination of liquid sub-cooling and evaporator superheat. On a system with an expansion valve liquid subcooling is more representative of the charge than evaporator superheat but both measurements must be taken.
CAUTION
Polyolester (POE) and Polyvinylether
(PVE) oils are two types of lubricants used in hydrofluorocarbon (HFC) refrigeration systems. Refer to the compressor label for the proper compressor lubricant type.
CAUTION
The Clean Air Act of 1990 bans the intentional venting of refrigerant
(CFC’s and HCFC’s) as of July 1,
1992. Approved methods of recovery, recycling or reclaiming must be followed. Fines and/or incarceration may be levied for non-compliance.
Before Charging
Refer to the unit nameplate as a reference when determining the proper refrigerant charge.
Unit being charged must be at or near full load conditions before adjusting the charge.
Units equipped with hot gas bypass must have the hot gas bypass valve closed to get the proper charge.
After adding or removing charge the system must be allowed to stabilize, typically 10-15 minutes, before making any other adjustments.
The type of unit and options determine the ranges for liquid sub-cooling and evaporator
superheat. Refer to Table 10 when
determining the proper sub-cooling.
49
Checking Liquid Sub-cooling
Measure the temperature of the liquid line as it leaves the condenser coil.
Read the gauge pressure at the liquid line close to the point where the temperature was taken. You must use liquid line pressure as it will vary from discharge pressure due to condenser coil pressure drop.
Convert the pressure obtained to a saturated temperature using the appropriate refrigerant temperature-pressure chart.
Subtract the measured liquid line temperature from the saturated temperature to determine the liquid sub-cooling.
Compare calculated sub-cooling to the table below for the appropriate unit type and options.
Verify the liquid pressure and temperature readouts before considering the sub-cooling reading valid.
Checking Evaporator Superheat
Measure the temperature of the suction line close to the compressor.
Read gauge pressure at the suction line close to the compressor.
Convert the pressure obtained to a saturated temperature using the appropriate refrigerant temperature-pressure chart.
Subtract the saturated temperature from the measured suction line temperature to determine the evaporator superheat.
The suction superheat should be 10-15°F with one compressor running. Inadequate suction superheat can allow liquid refrigerant to return to the compressors which will wash the oil out of the compressor. Lack of oil lubrication will
50 destroy a compressor. Liquid sub-cooling should be measured with both compressors in a refrigeration system running.
Compare calculated superheat to Table 10
for the appropriate unit type and options.
Table 10 - Acceptable Refrigeration Circuit
Values
Air-Cooled Condenser with Scroll
Compressors
Sub-Cooling
Superheat
7-12°F
10-15°F
Evaporative-Cooled Condenser with
Scroll Compressors
Sub-Cooling
Superheat
6-10°F
10-15°F
Adjusting Sub-cooling Temperatures
The system is overcharged if the sub-cooling temperature is too high and the evaporator is fully loaded (low loads on the evaporator result in increased sub-cooling) and the evaporator superheat is within the
temperature range as shown in Table 10
(high superheat results in increased subcooling)
Correct an overcharged system by reducing the amount of refrigerant in the system to lower the sub-cooling.
CAUTION
DO NOT OVERCHARGE!
Refrigerant overcharging leads to excess refrigerant in the condenser coils resulting in elevated compressor discharge pressure.
The system is undercharged if the superheat is too high and the sub-cooling is too low.
Correct an undercharged system by adding refrigerant to the system to reduce superheat and raise sub-cooling.
CAUTION
DO NOT OVERCHARGE!
Refrigerant overcharging leads to excess refrigerant in the condenser coils resulting in elevated compressor discharge pressure.
Table 11 - R-134a Refrigerant Temperature-Pressure Chart
25
27
28
30
32
34
36
°F
14
16
18
19
21
23
45
46
48
50
52
37
39
41
43
54
55
57
59
61
122
124
126
127
129
131
133
°F
111
113
115
117
118
120
135
136
138
140
142
144
145
147
149
151
153
154
156
158
73
75
77
79
81
82
84
°F
63
64
66
68
70
72
86
88
90
91
93
95
97
99
100
102
104
106
108
109
50
52
54
56
59
42
44
46
48
30
31
33
34
24
25
26
28
36
38
40
PSIG
15
16
17
18
19
21
22
114
118
121
125
129
133
137
141
145
79
82
85
88
91
94
97
100
104
107
111
PSIG
61
63
66
68
71
74
76
241
247
253
260
266
272
279
286
293
181
186
191
197
202
207
213
218
224
229
235
PSIG
149
154
158
163
167
172
177
51
F
48
49
44
45
46
47
40
41
42
43
36
37
38
39
32
33
34
35
28
29
30
31
24
25
26
27
20
21
22
23
PSIG
127.4
129.8
132.2
134.7
137.2
139.7
109.2
111.4
113.6
115.8
118.1
120.3
122.7
125.0
92.9
94.9
96.8
98.8
100.9
102.9
105.0
107.1
78.3
80.0
81.8
83.6
85.4
87.2
89.1
91.0
F
74
75
76
77
78
79
70
71
72
73
66
67
68
69
62
63
64
65
58
59
60
61
54
55
56
57
50
51
52
53
Table 12 - R-410A Refrigerant Temperature-Pressure Chart
PSIG
F
PSIG
F
PSIG
F
PSIG
142.2
144.8
147.4
150.1
152.8
155.5
158.2
161.0
80
81
82
83
84
85
86
87
234.9
110
364.1
140
540.1
238.6
111
369.1
141
547.0
242.3
112
374.2
142
553.9
246.0
113
379.4
143
560.9
249.8
114
384.6
144
567.9
253.7
115
389.9
145
575.1
257.5
116
395.2
146
582.3
261.4
117
400.5
147
589.6
163.8
166.7
169.6
172.5
175.4
178.4
181.5
88
89
90
91
92
93
94
265.4
118
405.9
148
596.9
269.4
119
411.4
149
604.4
273.5
120
416.9
150
611.9
277.6
121
422.5
281.7
122
428.2
285.9
123
433.9
290.1
124
439.6
294.4
125
445.4 184.5
95
187.6
190.7
96
97
298.7
126
451.3
303.0
127
457.3
193.9
197.1
98
99
307.5
128
463.2
311.9
129
469.3
200.4
100
316.4
130
475.4
203.6
101
321.0
131
481.6
207.0
102
325.6
132
487.8
210.3
103
330.2
133
494.1
213.7
104
334.9
134
500.5
217.1
105
339.6
135
506.9
220.6
106
344.4
136
513.4
224.1
107
349.3
137
520.0
227.7
108
354.2
138
526.6
231.3
109
359.1
139
533.3
52
Lubrication
All original motors and bearings are furnished with an original factory charge of lubrication. Certain applications require bearings be re-lubricated periodically. The schedule will vary depending on operating duty, temperature variations, or severe atmospheric conditions.
Bearings should be re-lubricated at normal operating temperatures, but not when running.
Rotate the fan shaft by hand and add only enough grease to purge the seals. DO NOT
OVERLUBRICATE.
Air-Cooled Condenser
The air-cooled condenser section rejects heat by passing outdoor air over the condenser coils for cooling of the hot refrigerant gas from the compressors. The heated air will discharge from the top of the section through the axial flow fans.
The condenser coils should be inspected yearly to ensure unrestricted airflow. If the installation has a large amount of airborne dust or other material, the condenser coils should be cleaned with a water spray in a direction opposite to airflow. Care must be taken to prevent damage to the coils.
E-Coated Coil Cleaning
Documented routine cleaning of e-coated coils is required to maintain coating warranty coverage.
WARNING
Electric shock hazard. Shut off all electrical power to the unit to avoid shock hazard or injury from rotating parts.
Surface loaded fibers or dirt should be removed prior to water rinse to prevent restriction of airflow. If unable to back wash the side of the coil opposite of the coils entering air side, then surface loaded fibers or dirt should be removed with a vacuum cleaner. If a vacuum cleaner is not available, a soft non-metallic bristle brush may be used. In either case, the tool should be applied in the direction of the fins. Coil surfaces can be easily damaged (fin edges bent over) if the tool is applied across the fins.
Use of a water stream, such as a garden hose, against a surface loaded coil will drive the fibers and dirt into the coil. This will make cleaning efforts more difficult. Surface loaded fibers must be completely removed prior to using low velocity clean water rinse.
A monthly clean water rinse is recommended for coils that are applied in coastal or industrial environments to help to remove chlorides, dirt, and debris. It is very important when rinsing, that water temperature is less than 130°F and pressure is than 900 psig to avoid damaging the fin edges. An elevated water temperature (not to exceed 130°F) will reduce surface tension, increasing the ability to remove chlorides and dirt.
CAUTION
High velocity water from a pressure washer or compressed air should only be used at a very low pressure to prevent fin and/or coil damages.
The force of the water or air jet may bend the fin edges and increase airside pressure drop. Reduced unit performance or nuisance unit shutdowns may occur.
53
Quarterly cleaning is essential to extend the life of an e-coated coil and is required
to maintain coating warranty coverage.
Coil cleaning shall be part of the unit’s regularly scheduled procedures. Failure to clean an maintenance e-coated coil will void the warranty and may result in reduced efficiency and durability.
CAUTION
Harsh chemicals, household bleach, or acid cleaners should not be used to clean outdoor or indoor e-coated coils. These cleaners can be very difficult to rinse out of the coil and can accelerate corrosion and attack the e-coating. If there is dirt below the surface of the coil, use the recommended coil cleaners.
For routine quarterly cleaning, first clean the coil with the below approved coil cleaner. After cleaning the coils with the approved cleaning agent, use the approved chloride remover to remove soluble salts and revitalize the unit.
Recommended Coil Cleaner
The following cleaning agent, assuming it is used in accordance with the manufacturer’s directions on the container for proper mixing and cleaning, has been approved for use on e-coated coils to remove mold, mildew, dust, soot, greasy residue, lint, and other particulate:
Enviro-Coil Concentrate, Part Number H-
EC01.
Recommended Chloride Remover
CHLOR*RID DTS™ should be used to remove soluble salts from the e-coated coil, but the directions must be followed closely.
This product is not intended for use as a
54 degreaser. Any grease or oil film should first be removed with the approved cleaning agent.
Remove Barrier - Soluble salts adhere themselves to the substrate. For the effective use of this product, the product must be able to come in contact with the salts. These salts may be beneath any soils, grease or dirt; therefore, these barriers must be removed prior to application of this product. As in all surface preparation, the best work yields the best results.
Apply CHLOR*RID DTS - Apply directly onto the substrate. Sufficient product must be applied uniformly across the substrate to thoroughly wet out surface, with no areas missed. This may be accomplished by use of a pump-up sprayer or conventional spray gun. The method does not matter, as long as the entire area to be cleaned is wetted. After the substrate has been thoroughly wetted, the salts will be soluble and is now only necessary to rinse them off.
Rinse - It is highly recommended that a hose be used, as a pressure washer will damage the fins. The water to be used for the rinse is recommended to be of potable quality, though a lesser quality of water may be used if a small amount of CHLOR*RID DTS is added. Check with CHLOR*RID
International, Inc. for recommendations on lesser quality rinse water.
Microchannel Coil Cleaning
Cleaning microchannel coils is necessary in all locations. In some locations it may be necessary to clean the coils more or less often than recommended. In general, a condenser coil should be cleaned at a minimum of once a year. In locations where there is commonly debris or a condition that causes dirt/grease build up it may be necessary to clean the coils more often.
Proper procedure should be followed at every cleaning interval. Using improper cleaning technique or incorrect chemicals will result in coil damage, system performance fall off, and potentially leaks requiring coil replacement.
Documented routine cleaning of microchannel coils with factory provided ecoating is required to maintain coating warranty coverage. Use the E-Coated Coil
Cleaning section for details on cleaning ecoated coils.
Field applied coil coatings are not recommended with microchannel coils.
Allowed Chemical Cleaners and
Procedures
AAON recommends certain chemicals that can be used to remove buildup of grime and debris on the surface of microchannel coils.
These chemicals have been tested for performance and safety and are the only chemicals that AAON will warrant as correct for cleaning microchannel coils.
There are three procedures that are outlined below that will clean the coils effectively without damage to the coils. Use of any other procedure or chemical may void the warranty to the unit where the coil is installed. With all procedures make sure
the unit is off before starting.
WARNING
electrical power to the unit to avoid shock hazard or injury from rotating parts.
The water pressure used to clean should not exceed 140 psi, from no closer than 3 inches from the coils, and with the water aimed perpendicular to the coils.
#1 Simple Green
Simple Green is available from AAON Parts and Supply (Part# T10701) and is biodegradable with a neutral 6.5 pH.
Recommendation is to use it at a 4 to 1 mix.
Use the following procedure.
1. Rinse the coil completely with water.
Use a hard spray but be careful not to bend or damage the fins. A spray that is too hard will bend the fins. Spray from the fan side of the coil.
2. With a pump sprayer filled with a mix of
4 parts water to one part Simple Green spray the air inlet face of the coil. Be sure to cover all areas of the face of the coil.
3. Allow the coil to soak for 10-15 minutes.
4. Rinse the coil with water as in step one.
5. Repeat as necessary.
#2 Vinegar
This is standard white vinegar available in gallons from most grocery stores. It has a pH of 2-3, so it is slightly acidic. Use the following procedure.
1. Rinse the coil completely with water.
Use a hard spray but be careful not to bend or damage the fins. A spray that is too hard will bend the fins. Spray from the fan side of the coil.
2. Use a pump sprayer filled with vinegar
(100%). Spray from the face of the coil in the same direction as the airflow. Be sure to cover all areas of the face of the coil.
3. Allow the coil to soak for 10-15 minutes.
4. Rinse the coil with water as in step one.
5. Repeat as necessary.
55
#3 Water Flush
This procedure can be used when the only material to cause the coil to need cleaning is debris from plant material that has impinged the coil face.
1. Rinse the coil completely with water.
Use a hard spray but be careful not to bend or damage the fins. A spray that is too hard will bend the fins. Spray from the fan side of the coil.
2. Spray and rinse the coil from the face.
CAUTION
Use pressurized clean water, with pressure not to exceed 140 psi.
Nozzle should be 6” and 80° to 90° from coil face. Failure to do so could result in coil damage.
Application Examples
The three procedures can be used to clean microchannel coils. They will fit with the application depending on the area. In some areas where the spring/summer has a large cottonwood bloom #3 might work fine if the unit is installed on an office building and no other environmental factors apply.
When a unit is installed where the sprinkler system has water being sprayed onto the condenser coil you might have better results using #2. Vinegar is slightly acidic and may help with the calcium build up from drying water. This also works well when grease is part of the inlet air to a condenser coil.
Generally the best and broadest based procedure is #1. The grease cutting effect of the Simple Green is good for restaurant applications.
56
Other Coil Cleaners
There are many cleaners on the market for condenser coils. Before using any cleaner that is not covered in this section you must get written approval from the AAON warranty and service department. Use of unapproved chemicals will void the warranty.
AAON testing has determined that unless a chemical has a neutral pH (6-8) it should not be used.
Beware of any product that claims to be a foaming cleaner. The foam that is generated is caused by a chemical reaction to the aluminum fin material on tube and fin coils and with the fin, tube, and coating material on microchannel coils.
Microchannel coils are robust in many ways, but like any component they must be treated correctly. This includes cleaning the coils correctly to give optimal performance over many years.
Evaporative-Cooled Condenser
Evaporative cooling equipment rejects heat by evaporating a portion of the recirculated water spray and discharging it from the unit with the hot, saturated air. As the spray water evaporates, it leaves behind the mineral content and impurities of the supply water. If these residuals are not purged from the water distribution system, they will become concentrated and lead to scaling, corrosion, sludge build-up and biological fouling.
A water treatment monitoring and control system has been furnished with this unit. Be sure to read the complete manual that has been furnished. All water treatment is a combination of bleed water and chemical treatment for proper control of the residuals and to prevent any biological contamination.
WARNING
Batch-loading chemicals into the unit is NOT PERMITTED. The control system must regulate the chemical feed.
Severe Operating Conditions Service
The following recommended maintenance procedures are basic requirements for normal operating environments. For severe operating conditions, the frequency of inspection and service should be increased.
Air containing industrial and chemical fumes, salt, dust, or other airborne contaminates and particulates will be absorbed by the recirculating water system and may form solutions and deposits harmful to the products and personnel.
Safety
The recirculating water system contains chemical additives for water quality control and biological contaminants removed from the air by the washing action of the water.
Personnel exposed to the saturated effluent, drift, or direct contact should use proper precaution. Proper location of the evaporative-cooled condenser requires good judgment to prevent the air discharge from entering fresh air intakes or to avoid allowing contaminated building exhaust from entering the condenser.
Follow local and national codes in locating the evaporative-cooled condenser but as minimum the evaporative-cooled condenser sump must be 15 feet from the nearest intake.
WARNING
The evaporative-cooled condenser must be thoroughly cleaned on a regular basis to minimize the growth of bacteria, including Legionella
Pneumophila, to avoid the risk of sickness or death. Service personnel must wear proper personal protective equipment. Do not attempt any service unless the fan motor is locked out.
Figure 29 - Proper Unit Location
Figure 30 - Improper Unit Locations
Performance
Improper location of the evaporative-cooled condenser may seriously degrade the capacity of the equipment. Make sure the equipment is located such that discharge air
57
from the condenser does not enter the condenser air inlet.
Warranties
Please refer to the limitation of warranties in effect at the time of purchase.
Condenser Tube Inspection
The coil is leak tested before shipment.
AAON will not be responsible for loss of refrigerant. It is the responsibility of the installer to verify that the system is sealed before charging with refrigerant. If the unit is operated during low ambient temperature conditions, freeze protection for the recirculating water system must be provided.
Freeze Protection
In order to prevent water temperatures from dropping below 50°F, this unit is equipped with a VFD on the fan motors when the refrigeration system is operating.
Recirculating Water System
Electric sump heaters are available to keep the sump water from freezing when the refrigeration system is not operating. An electric resistance heater is supplied in the vestibule when sump heaters are selected.
Note: The condenser should not be operated with the fan on and the pump cycled on and off to maintain head pressure control under any conditions. The unit is equipped with a water temperature controller which varies fan speed to maintain sump water temperature. This unit is not equipped with a compressor discharge pressure controller for fan speed modulation and therefore cannot be operated without water flow.
Startup
Do not start the evaporative-cooled condenser or compressors without installation of proper water treatment chemicals. Contact your local water
58 treatment expert for correct selection of water treatment chemical, adjustment of chemical feed and bleed rates.
Cleanliness
Dirt and debris may accumulate in the sump during shipping and storage. The sump should be cleaned prior to startup to prevent clogging the water distribution system. Any surfaces that show contamination should be cleaned ONLY with a commercial stainless steel cleaner to restore the initial appearance. The inlet screens should be inspected for foreign material.
Storage
Pumps removed from service and stored, must be properly prepared to prevent excessive rusting. Pump port protection plates must not be removed until the pump is ready to connect to the piping. Rotate the shaft periodically (At least monthly) to keep rotating element free and bearings fully functional.
For long term storage, the pump must be placed in a vertical position in a dry environment. Internal rusting can be prevented by removing the plugs at the top and bottom of the casing and drain or air blow out all water to prevent rust buildup or the possibility of freezing. Be sure to reinstall the plugs when the unit is made operational. Rust-proofing or packing the casing with moisture absorbing material and covering the flanges is acceptable. When returning to service be sure to remove the drying agent from the pump.
Pump Operation
Before initial start of the pump, check as follows:
1. Be sure that pump operates in the direction indicated by the arrow on the pump casing. Check rotation each time motor leads have been disconnected.
2. Check all connections of motor and starting device with wiring diagram.
Check voltage, phase and frequency of line circuit with motor name plate.
3. Check suction and discharge piping and pressure gauges for proper operation.
4. Turn rotating element by hand to assure that it rotates freely.
Running
Periodically inspect pump while running, but especially after initial start-up and after repairs.
1. Check pump and piping for leaks. Repair immediately.
2. Record pressure gauge readings for future reference.
3. Record voltage, amperage per phase, and kW.
Condenser Fan Motors
The direct drive condenser motors on
AAON evaporative-cooled condensers are
1200 rpm premium efficiency motors controlled by a VFD. These motors are totally enclosed air over motors with weep holes in the bottom end bell so that any condensation can drain out of the motor.
The motors have a small electric resistance heater installed inside the casing to keep the motors warm when they are deactivated.
The heaters are designed to keep the interior of the motor 10°F warmer than the surrounding ambient temperature. This prevents condensation from forming inside the motor.
Ensure that fan is tightly mounted to the motor shaft and the motor mounting bolts are aligned and secure.
Water Make Up Valve
The sump water level is controlled by a set of conductivity probes at different levels in the sump. This water level controller is located in the vestibule behind the condenser pump. There are four conductivity probes in this controller. There is a reference probe
(shown as “ref” on the wiring diagram). This probe is one of the two longest probes. The other long probe is the low water level probe
(shown as “lo” on the wiring diagram). The medium length probe is for the medium water level (shown as “med” on the wiring diagram). The short probe is for the high water level (shown as “hi” on the wiring diagram). There is a solenoid valve in the makeup water line that is activated by the water level controller. The water level controller determines the level of water in the sump based on conductivity between two probes. If the controller sees conductivity between two probes, it knows that water is at least at the level of that probe.
If the water in the sump is below the low probe, it will not allow the condenser pump or the sump heater to operate. It will activate the makeup water solenoid to try to fill the sump assuming water is flowing to the unit.
Once water is above the low probe, it will allow the condenser pump and sump heater
(if ordered and the ambient temperature is below 40°F) to operate. The makeup water solenoid will remain activated until water gets to the high water level. The makeup water solenoid will deactivate until water
59
gets to the medium water level. In normal operation, the water level should swing between the medium and high water levels.
The maximum high water level should be 1” below the overflow drain which occurs after the makeup water valve shuts off when the water level reaches the high level probe.
Figure 31 - Water Makeup Valve
Make up water supply pressure should be maintained between 15 and 60 psig for proper operation of the valve. The makeup water valve assembly should be inspected monthly and adjusted as required. Replace the valve seat if leakage occurs when the valve is in the closed position.
Water Treatment System
All AAON evaporative-cooled condensers come equipped with a water treatment system that should be maintained by a local water treatment professional trained in the water treatment of evaporative-cooled condensers. This system consists of a controller, three chemical pumps and storage tanks, a conductivity sensor, a motorized ball valve for water bleed and a water meter.
One chemical pump and tank is typically used for a de-scaling chemical to prevent scale from forming in the condenser. The
60 other two pumps and tanks are typically used for two different biocides (to kill any microorganisms that could grow in the condenser). Two biocides are used to prevent organisms from becoming resistant to one chemical.
The mineral content of the water must be controlled. All make up water has minerals in it. As water is evaporated from the condenser, these minerals remain. As the mineral content of the water increases, the conductivity of the water increases. The water treatment controller monitors this conductivity. As the water conductivity rises above set point, the controller will open a motorized ball valve on the discharge side of the condenser pump and dumps water into the condenser drain until conductivity is lowered. While the motorized ball valve is opened, the controller will not disperse chemicals.
The chemicals are dispersed by the water treatment controller based on the scheduled input by the water treatment professional.
The water meter measures the quantity of makeup water used by the condenser.
Any water treatment program must be compatible with stainless steel, copper, aluminum, ABS plastic and PVC. Batch feed processes should never be used as concentrated chemicals can cause corrosion.
Never use hydrochloric acid (muriatic acid) as it will corrode stainless steel.
Sequence of Operation for LZ Series units without Diagnostics
On a call for cooling, the condenser pump is activated. A pressure switch in the pump discharge is bypassed for six seconds by a time delay relay in order for the pump to establish recirculating water flow. If flow is not proven within the six seconds, the
pressure switch opens, breaking the safety circuit, thereby shutting down the entire system. This pressure switch is set to close at 3 psi and open at 1 psi.
A Johnson Controls S350C measures the water temperature in the pump discharge line. If the sump water temperature exceeds
105°F, the cooling system will be shut down thereby preventing damage to the evaporative-cooled condenser.
If a fault occurs in the evaporative-cooled condenser fan motor VFD, normally closed fault terminals on the VFD will interrupt the safety circuit, thereby shutting down the system.
If the VFD does fault and cannot be reset, there is a VFD bypass switch mounted near the VFD. This switch has four positions— line, off, drive, and test. The “line” position will bypass the VFD, sending power to the motor. In this position, the condenser fans will run at full speed. The “off” position will not allow power to pass through the switch.
This functions as a disconnect switch. The
“drive” position runs power through the
VFD. This is the normal operation for the switch. The “test” position routes power to the VFD but not to the motor. This is useful for running tests on the VFD without sending power to the motor.
A Johnson Controls A350P controls the
VFD speed. This device sends a 0-10 VDC signal to the VFD. This controller is set to maintain a sump temperature of 70°F. On a rise in sump temperature, the controller increases the voltage to the VFD, increasing the speed of the condenser fans. Conversely, on a drop in sump temperature, the controller will decrease the voltage to the
VFD, decreasing the speed of the condenser fans.
An outside air thermostat does not allow the condenser to operate when the ambient temperature is below 35°F.
Sequence of Operation for LZ Series units with Diagnostics
These units operate the same way as described in the previous section, except the unit controller operates the evaporativecooled condenser. These units can also operate down to 0°F when equipped with the low ambient head pressure control.
On units with diagnostics, each refrigerant system has suction and discharge pressure transducers and suction and discharge temperature sensors. Each compressor has a current transformer. The condenser pump is the first stage of condenser control and the condenser fans are the second stage of condenser control. The unit controller brings on the condenser stages based on the discharge pressures of each system. The system with the highest pressure will control the condenser staging.
The unit controller will monitor the sump temperature and if it exceeds 105°F, it will reduce the number of compressors that are running. The unit controller monitors the condenser pump pressure switch. If this switch opens, it will not allow the compressors to operate. The unit controller also monitors the VFD fault status. If it receives a VFD fault, it will activate the alarm contacts on the unit controller. The
VFD will no longer run, but the compressors will run until the pressures or temperatures get too high. The controller will reduce the number of compressors to try to keep as much of the unit running as possible. The
VFD bypass switch can be set to “line” to operate the condenser fans at full speed.
Units with diagnostics can operate below
35°F down to 0°F. This is possible because of the finned de-superheat coil. When the
61
ambient temperature is below 32°F, the condenser pump will not operate. As the ambient temperature increases, the condenser pump will activate at 35°F. As the ambient temperature decreases, the condenser pump will deactivate at 32°F.
This dead band prevents the condenser pump from cycling too much. Below 32°F, the unit operates as an air-cooled condenser.
An optional sump heater operates when the ambient temperature is below 40°F to prevent the sump from freezing and offers freeze protection to 0°F.
Pump Maintenance
Cleaning - Remove oil, dust, water, and chemicals from exterior of motor and pump.
Keep motor air inlet and outlet open. Blow out interior of open motors with clean compressed air at low pressure.
Labeled Motors - It is imperative for repair of a motor with Underwriters’ Laboratories label that original clearances be held; that all plugs, screws, other hardware be fastened securely, and that parts replacements be exact duplicates or approved equals.
Violation of any of the above invalidates
Underwriters’ Label.
Fan Motor Maintenance
Same as pump maintenance.
Access Doors
If scale deposits or water is found around the access doors, adjust door for tightness.
Adjust as necessary until leaking stops when door is closed.
Bearings - Lubrication
Every 6 months or after a prolonged shut down. Use waterproof, lithium based grease.
Below 32°F - Esso Exxon or Beacon 325.
Above 32°F - Mobil Mobilox EP2, Shell
Alvania EP2, or Texaco RB2.
62
Recommended Monthly Inspection
1. Clean sump section interior. Dirt and other impurities which have accumulated in the sump should be removed from the sump area. Shut off makeup water ball valve and open the drain connection for flushing of the sump.
2. Clean dirt out of sump using a water hose (not a pressure washer).
3. Clean sump suction strainer.
4. Check water operating level. Adjust float as required.
5. Inspect fan motor(s) and water circulation pump(s) and lubricate per the lubrication nameplate or manufacture’s recommendations.
6. Inspect axial fans and eliminators removing any debris which may have accumulated during operation.
7. Inspect the water distribution system to insure that nozzles and spray orifices are functioning correctly. The inspection should be made with the circulation pump on and fans off.
Mist Eliminators
The mist eliminators must be correctly positioned when they are replaced during cleaning or service.
Air Inlet
Inspect the air inlet louvers and mist eliminators into the condenser section on a monthly basis to remove any paper, leaves or other debris that may block the airflow.
Stainless Steel Base Pan
The base pan under the tube bundles is stainless steel and may sometimes become tarnished due to contamination. These
surfaces should be inspected yearly to ensure they remain clean of any contamination that may result in damage.
Any surfaces that show contamination should be cleaned ONLY with a commercial stainless steel cleaner to restore the initial appearance.
Propeller Fans and Motors
The fans are directly mounted on the motor shafts and the assemblies require minimal maintenance except to assurance they are clear of dirt or debris that would impede the airflow.
Recommended Annual Inspection
In addition to the above maintenance activities, a general inspection of the unit surface should be completed at least once a year. Remove spray header and flush out.
Cleaning
Mechanical cleaning, including pressure washing, should never be performed as surfaces and seals could be damaged.
Chemical cleaning that is safe for stainless steel, copper, aluminum, ABS plastic and
PVC is the only acceptable means of cleaning the evaporative condenser. A proper water treatment program should reduce cleaning needs.
Water Quality
Table 13 - Recirculating Water Quality
Guidelines
PH 6.5 to 9.0
Hardness as CaCO
3
500 PPM Max
Alkalinity as CaCO
3
500 PPM Max
Total
Solids
Dissolved
2000 PPM Max
Chlorides as NaCl 1500 PPM Max
Sulfates 750 PPM Max
Cycles of concentration (the ratio of dissolved solids in recirculated water to dissolved solids in makeup water), should be determined and monitored frequently by a competent water treatment expert.
To limit cycles of concentration to maintain the above guideline, it is necessary to
“bleed” a certain portion of the recirculated water. This is achieved automatically with a solenoid valve actuated by a conductivity meter set at the desired conductivity corresponding to the desired cycles of concentration. It should be noted that these are guidelines and even though these individual values are met, under certain conditions the water quality can be aggressive. For example, water with very low alkalinity and levels of chlorides and sulfates approaching maximum recommended levels can be corrosive.
All AAON evaporative-cooled condensers are furnished with a bleed system fitting and valve to continuously remove a small portion of the recirculated water to keep the water quality within the above listed parameters. This device is located on the discharge side of the pump. It is important to note that since “bleed” rate is a function of evaporation rate (i.e., amount of heat rejected), if the bleed setting is manual based on design heat load, too much water will be removed when the heat load is less that design.
The AAON evaporative-cooled condenser is equipped with a de-superheater. The desuperheater coil is located above the mist eliminators. Approximately 22% of the total heat of rejection is accomplished with the de-superheater. Water usage of the AAON evaporative-cooled condenser is approximately 22% less than evaporativecooled condensers not equipped with a desuperheater.
63
One method of calculating evaporation and bleed in gallons per minute (gpm) is shown as follows:
Evaporation Rate
=
Total Heat of Rejection via Evaporation
= h fg
⁄ ×ρ lb gal ⁄
Total Heat of Rejection via Evaporation
525,000 (Btu hr ⁄ gpm)
Bleed Rate
Evaporation Rate
=
Cycles of Concentration − 1
Example:
A unit has 120 ton cooling capacity with a compressor EER = 15
Total Heat of Rejection
= Unit Capacity in Tons × 12000 ×
(1 +
3.413
EER
)
= 120 × 12000 ×
(1 +
3.413
15
)
= 1,767,648 Btu/hr
Total Full Load Heat of Rejection via
Evaporation
= Total Heat of Rejection ×
(1
– fraction of heat rejected by desuperheater)
= 1,767,648 Btu/hr × (1 – 0.22)
= 1,378,765 Btu/hr
Note that approximately 22% of the total heat of rejection is accomplished with the desuperheater at full load. So, the fraction of heat rejected by the desuperheater (in the equation above) is approximately 0.22 at full load and increases as the ambient dry bulb decreases.
Evaporation Rate
=
525,000 (Btu hr
⁄ gpm
)
= 2.63 gpm
64
Assuming 4 cycles of concentration:
Bleed Rate
=
2.63
4−1
= 0.87 gpm
Mechanical Cleaning
Do not attempt to mechanically clean the copper tubing in the evaporative-cooled condenser. Do not use wire brushes or any other mechanical device on the copper tubing. Severe damage may result. Contact your water treatment expert for recommendations on chemical cleaning procedures.
Service
If the unit will not operate correctly and a service company is required, only a company with service technicians qualified and experienced in both refrigerant chillers and air conditioning are permitted to service the systems to keep warranties in effect. If assistance is required, the service technician must contact AAON.
Replacement Parts
Parts for AAON equipment may be obtained from your local AAON representative.
When ordering parts reference the unit serial number and part number.
AAON Warranty, Service and Parts
Department
2424 S. Yukon Ave.
Tulsa, OK 74107
Ph: 918-583-2266
Fax: 918-382-6364 www.aaon.com
Note: Before calling, technician should have model and serial number of the unit available for the service department to help answer questions regarding the unit
Appendix - Water Piping Component Information
Water Pressure Reducing Valve
Water Pressure Reducing Valves are designed to reduce incoming water pressure to protect plumbing system components and reduce water consumption.
Overview
Standard construction includes Z3 sealed spring cage and corrosion resistant adjusting cage screws for outdoor/waterworks pit installations
Integral stainless steel strainer
Replaceable seat module
Bronze body construction
Serviceable in line
High temperature resistant reinforced diaphragm for hot water
Low pressure range 10 – 35psi (69 – 241 kPa)
Materials
Body: Bronze
Seat: Replaceable stainless steel
Integral Strainer: Stainless steel
Diaphragm: Reinforced EPDM
Valve Disc: EPDM
Standards
Meets requirements of ASSE Standard
1003; (ANSI A112.26.2); CSA Standard
B356; Southern Standard Plumbing Code and listed by IAPMO.
Teflon® is a registered trademark of E.I.
DuPont de Nemours & Company.
65
Capacity
Maintenance Instructions
To clean strainer remove the bottom plug and pull out strainer.
Adjustment
To adjust pressure setting, loosen the lock nut and turn the adjusting bolt clockwise to increase pressure, counter clockwise to decrease pressure.
Dimensions-Weights:
Note: Use a pressure gauge downstream to adjust and verify the pressure setting.
Troubleshooting
High System Pressure
If the downstream system pressure is higher than the set pressure under no flow conditions, the cause could be thermal expansion, pressure creep or dirt/debris on the seat. Thermal expansion occurs whenever water is heated in a closed system.
The system is closed when supply pressure exceeds 150 psi, or a check valve or backflow preventer is installed in the supply piping. To determine if this is the result of thermal expansion, try briefly opening the cold water tap. If the increased pressure is caused by thermal expansion, the pressure will immediately be relieved and the system will return to the set pressure.
66
Water Pressure Relief Valve
Overview
ASME Rated, Design Certified and Listed by C.S.A
.
Used for protection against excessive pressure on domestic storage tanks or tankless water heaters, the pressure relief valve has no temperature relieving element.
Standard setting, 125 psi Size 3⁄4" x 3⁄4"
(20mm x 20mm).
ASME construction and is tested, listed and certified by the National Board of Boiler and
Pressure Vessel Inspectors. seals and prevents any water from escaping from the system.
The float vent can also operate as an antivacuum device since it will permit air to enter the system when it must be drained. It can also be installed to permit the separation and dispersal of air while fluid is actually circulating in the system.
Overview
Body and cover are brass construction.
Air vent with silicone rubber seal.
Impurities do not usually affect function as maximum float line of water is always lower than the valve seal.
Float is high temperature resistant polyethylene.
Suitable for use with glycol systems.
Can be disassembled for inspection and cleaning.
ANSI Z21.22 “Relief Valves for Hot Water
Supply Systems.”
DESIGN CERTIFIED and listed by C.S.A.
Automatic Air Vent Valves
Automatic Air Vent Valves provide automatic air venting for hot or cold water distribution systems. These vents purge air that may be in the water system.
The vent valve utilizes a float to actuate the valve plug which is located at the top of the valve. Once the air is displaced and the system pressure is sustained, the valve plug
67
Operating Range:
Minimum working pressure: 1.45psi (10 kPa)
Maximum working pressure: 150psi (10 bars)
Temperature Range: 33°F – 240°F (5°C –
116°C)
Performance
The figure below shows the installation of the vent valve for the venting of air while the fluid is circulating in the system and the required increase in pipe size in order to obtain proper separation of air from water.
Performance curve details the quantity of air vented by the “Float Vent” according to the pressure in the system
.
Note: In order to get the best results in venting air from risers, use connecting pipes of at least 1⁄2" diameter between the “Float
Vent” valves and installation.
Installation
When the air vent valve is installed as shown, the air will not be vented while the fluid is circulating in the system, but it can vent when the system is shut off.
The valve should be mounted only in a vertical position as its operation is based on the vertical movement of the float.
While the air vent valve is in operation, back off the small vent cap two turns. This is the proper operating setting which will allow air to be vented from the system. It is advisable to leave the cap on to prevent impurities from entering the valve.
68
Dimensions – Weights:
Maintenance
No maintenance is normally necessary.
However, if the FV-4M1 is disassembled for inspection or cleaning it is important that when re-assembling to ensure that the spring loaded lever properly engages under the float collar
Pumps - Installation and Operating
Instructions
Introduction
This document contains specific information regarding the safe installation, operating and maintenance of Vertical In-Line pumps and should be read and understood by installing, operating and maintenance personnel. The equipment supplied has been designed and constructed to be safe and without risk to health and safety when properly installed, operated and maintained. The instructions following must be strictly adhered to. If clarification is needed on any point please contact Armstrong quoting the equipment serial number.
CAUTION
No Installation of this equipment should take place unless this document has been read and understood.
Where under normal operating conditions the limit of 68°C/155°F (Restricted Zone)
69
for normal touch, or 80°C/176°F
(Unrestricted Zone) for unintentional touch, may be experienced, steps should be taken to minimize contact or warn operators/users that normal operating conditions will be exceeded. In certain cases where the temperature of the pumped liquid exceeds the above stated temperature levels, pump casing temperatures may exceed
100°C/212°F and not withstanding pump insulation techniques appropriate measures must be taken to minimize risk for operating personnel.
Storage
Pumps removed from service and stored, must be properly prepared to prevent excessive rusting. Pump port protection plates must not be removed until the pump is ready to connect to the piping. Rotate the shaft periodically (At least monthly) to keep rotating element free and bearings fully functional.
For long term storage, the pump must be placed in a vertical position in a dry environment. Internal rusting can be prevented by removing the plugs at the top and bottom of the casing and drain or air blow out all water to prevent rust buildup or the possibility of freezing. Be sure to reinstall the plugs when the unit is made operational. Rust-proofing or packing the casing with moisture absorbing material and covering the flanges is acceptable. When returning to service be sure to remove the drying agent from the pump.
Handling Large VIL Units
One effective way of lifting a large pumping unit is to place lifting hooks through the motor lifting rings or straps around the upper part of the motor. The pump and motor unit will free-stand on the casing ribs.
Remove the coupling guard and place (2) lifting straps through the pump/motor
70 pedestal, one on each side of the motor shaft and secure to the lifting device.
With the straps in place, using a spacer bar if necessary to protect the motor fan cover, the whole assembly can now be lifted securely.
Note: Handling, transportation and installation of this equipment should only be undertaken by trained personnel with proper use of lifting equipment.
Remove coupling guard and place lifting straps on each side of coupling, use spacer bar if necessary to protect motor fan cover.
Vertical Inline Pump Lifting Strap
Positioning:
Note: All split-coupled pumps contain a tapped hole in the motor bracket above the discharge flange for draining the well. Pipe this drain hole to a floor drain to avoid overflow of the cavity caused by collecting chilled water condensate or from seal failure.
Pump Piping - General
CAUTION
Use Caution. Piping may carry high temperature fluid.
CAUTION
Discharge valve only is to be used to throttle pump flow.
The discharge valve only is to be used to throttle pump flow, not the suction valve.
Care must be taken in the suction line layout and installation, as it is usually the major source of concern in centrifugal pump applications
Alignment
Alignment is unnecessary on close-coupled pumps as there is no shaft coupling.
Split-coupled units are accurately aligned at the factory prior to being shipped and do not need re-aligning when installed.
Pump Operation
CAUTION
Do not run pumps with discharge valve closed or under very low flow conditions.
Starting Pump
Ensure that the pump turns freely by hand, or with some mechanical help such as a strap and lever on larger pumps. Ensure that all protective guarding is securely fixed in position.
The pump must be fully primed on start up.
Fill the pump casing with liquid and rotate the shaft by hand to remove any air trapped in the impeller. On split coupled units, any air trapped in the casing as the system is filled must be removed by the manual air vent in the seal flush line. Close-coupled units are fitted with seal flush/vent lines piped to the pump suction area. When these units operate residual air is drawn out of the pump towards the suction piping.
“Bump” or energize the motor momentarily and check that the rotation corresponds with the directional arrow on the pump casing. To reverse rotation of a three phase motor, interchange any two power leads.
Start the pump with the discharge valve closed and the suction valve open, and then gradually open the discharge valve when the motor is at operating speed. The discharge valve may be cracked” or open slightly at start up to help eliminate trapped air.
When stopping the pump: Close the discharge valve and de-energize the motor.
DO NOT run the pump against a closed discharge valve for an extended period of time. (A few minutes maximum)
Star-Delta motor starters should be fitted with electronic/mechanical interlocks that have a timed period of no more than 40 milliseconds before switching from star
(Starting) to delta (Run) connection yet allow the motor to reach full star (Starting) speed before switching to delta (Run).
Should the pump be noisy or vibrate on start-up a common reason is overstated system head. Check this by calculating the pump operating head by deducting the suction pressure gauge value from the discharge gauge reading. Convert the result into the units of the pump head as stated on the pump nameplate and compare the values. Should the actual pump operating
71
head be significantly less than the nameplate head value it is typically permissible to throttle the discharge isolation valve until the actual operating head is equal to the nameplate value.
Any noise or vibration usually disappears.
The system designer or operator should be made aware of this soon as some adjustment may be required to the pump impeller diameter or drive settings, if applicable, to make the pump suitable for the system as installed.
CAUTION
Check rotation arrow prior to operating the unit.
Check rotation arrow prior to operating the unit. The rotation of all Vertical In-Line units is “clockwise” when viewed from the drive end. (Looking from on top of / behind the motor)
General Care
Vertical In-Line pumps are built to operate without periodic maintenance, other than motor lubrication on larger units. A systematic inspection made at regular intervals, will ensure years of trouble-free operation, giving special attention to the following:
Keep unit clean
Keep moisture, refuse, dust or other loose particles away from the pump and ventilating openings of the motor.
Avoid operating the unit in overheated surroundings (Above 100ºF/40ºC).
WARNING
Electric shock hazard. Before attempting to perform any service or maintenance on pumping unit, disconnect power source to the driver, LOCK IT OFF and tag with the reason.
Any possibility of the unit starting while being serviced must be eliminated.
If mechanical seal environmental accessories are installed, ensure water is flowing through the sight flow indicator and that filter cartridges are replaced as recommended.
Lubrication
Pump
Lubrication is not required. There are no bearings in the pump that need external lubrication service.
Large Series split-coupled units are installed with a shaft bushing located beneath the impeller that is lubricated from the pump discharge. This bearing is field removable for service on the 20x20x19 size without disturbing the motor or other major pump components.
Motor
Follow the lubrication procedures recommended by the motor manufacturer.
Many small and medium sized motors are permanently lubricated and need no added lubrication. Generally if there are grease fittings evident the motor needs periodic lubrication, and if there are no grease fittings evident, no periodic lubrication is required.
72
Check the lubrication instructions supplied with the motor for the particular frame size indicated on the motor nameplate.
Mechanical Seal
Mechanical seals require no special attention. The mechanical seal is fitted with a flush line. The seal is flushed from discharge of the pump casing on splitcoupled pumps and is flushed/vented to the suction on close coupled pumps.
The split-coupled pump is flushed from the pump discharge because the mechanical seal chamber is isolated from the liquid in the pump by a throttle bushing. Because the seal chamber is isolated, seal environmental controls such as filters and separators, when installed in the split-coupled flush line are very effective, as only the seal chamber needs cleansing, and will prolong seal life in
HVAC systems.
Do not run the pump unless properly filled with water as the mechanical seals need a film of liquid between the faces for proper operation.
Mechanical seals may ‘weep’ slightly at start-up. Allow the pump to continue operating for several hours and the mechanical seal to ‘seat’ properly prior to calling for service personnel.
System Cleanliness
Before starting the pump the system must be thoroughly cleaned, flushed and drained and replenished with clean liquid.
Welding slag and other foreign materials,
“Stop Leak” and cleaning compounds and improper or excessive water treatment are all detrimental to the pump internals and sealing arrangement.
Proper operation cannot be guaranteed if the above conditions are not adhered to.
CAUTION
Double Check Prior to Startup
Note
Particular care must be taken to check the following before the pump is put into operation:
1. Pump primed?
2. Rotation OK?
3. Lubrication OK?
4. Pipe work properly supported?
5. Voltage supply OK?
6. Overload protection OK?
7. Is the system clean?
8. Is the area around the pump clean?
Warranty
Does not cover any damages to the equipment resulting from failure to observe the above precautions.
73
Noise Levels
Estimated Pumping Unit Sound Power Level, Decibels, A-Weighted, at 1 m (3 ft.) from unit.
Vibration Levels
Vertical In-Line pumps are designed to meet vibration levels set by Hydraulic Institute Standard
HI Pump Vibration 9.6.4. Standard levels are as detailed below:
Dual Pump Specific Information
Dual Pump Flapper Valve Operating
Instructions
This unit is fitted with internal valves to allow isolation of one pump for service and to automatically prevent recirculation of the flow when only one pump is running.
Procedure for Parallel or Stand-By
Pumping
Discharge and suction valve stems should be locked in the center position. This is indicated by both locking handles in the vertical position and the center pin of the locking arms (4) locked by the handles. This procedure allows the discharge flapper valves to pivot freely and locks the suction valve firmly in the center position.
74
Procedure for Isolation of One Side
1. Stop the pump to be serviced.
2. Close and lock the suction and discharge valves: as per instructions below.
3. Ensure seal flush line interconnection valve is closed and drain the isolated casing.
4. Service isolated pump as required.
Procedure for Starting the Pump after
Servicing
1. Ensure serviced pump is fully reassembled including all seal flush lines and drain plugs.
2. Fill the dry casing with system fluid by opening the seal flush line interconnecting valve and the air vent fitting.
3. Allow the pressure to equalize in the two casings, if necessary, by opening seal flush line interconnected valve.
4. Unlock the discharge valve as per instructions below.
5. Unlock the suction valve as per instructions below.
NOTE: Keep hands and tools away from locked suction valve arm, as the differential pressure may cause the arm to rotate quickly with force when unlocked.
6. Close the seal flush line interconnect valve and restart pump.
Valve Operation - Refer to following 3”, 4”
& 6” valve illustration and the 8” valve illustration.
Discharge Valve
This valve performs the dual function of automatically sealing the discharge of the inactive pump when one pump is running and can manually be closed and locked to isolate one pump for service.
Automatic Flapper Operation
In the flapper mode the two halves of the discharge valve are free to pivot independently under normal operating conditions. The locking handle (3) should be secured with the set screw (11) in the vertical position with the center pin of the locking arm (4) trapped by the locking handle (3).
Manual Valve Locking
The locking feature of this valve is to ensure a positive seal (leak proof) of the discharge port on the pump to be serviced.
Note: Ensure the pump to be isolated is not operating before attempting to release the locking mechanism. Failure to do so may result in injury to the operator and/or damage to the pump.
Locking
1. Loosen discharge side set screw (11) to release the locking handle (3).
2. Rotate the discharge side locking handle
(3) so that the handle points toward the pump to be serviced and secure in the horizontal position, using set screw (11).
This releases the discharge locking arm
(4).
3. Rotate discharge valve shaft (16) towards the pump to be isolated. The orientation of the shaft is indicated by the center pin on the locking arm (4).
4. Raise the locking handle (3) so that the cam on the base of the handle forces the pin of the locking arm (4) towards the pump to be isolated. The locking handle
(3) should be raised to between 45 degrees and the vertical position.
5. Tighten set screw (11) to lock the locking handle (3) in position.
This handle should not be rotated past the vertical position.
Note: Ensure the isolated pump is not operating before attempting to release the locking mechanism. Failure to do so may result in injury to the operator and/or damage the pump.
Unlocking
1. Open the interconnecting valve on the seal flush line to pressurize the serviced pump and vent air through bleeder valve on series 4302
2. Close these valves once the pressure is equalized and air removed.
3. Loosen set screw (11) and lower locking handle (3) to the horizontal position, secure with set screw (11).
4. Rotate valve to center position so that the center pin of the locking arm (4)
75
locates in the recess on the locking handle (3).
5. Loosen set screw (11) and raise locking arm (3) to the vertical position, locking the center pin in the locking arm recess, secure with set screw (11).
Suction Valve
Manual Operation
The suction side valve is designed for use as a manually operated isolation valve. This valve is not designed to automatically pivot as the discharge flappers do.
WARNING
Care should be taken when performing procedures 3 and 4. Read instructions carefully.
Locking
1. Loosen suction side set screw (11) to release the locking handle (3).
2. Rotate the suction side locking handle
(3) so that the handle points towards the pump to be serviced and secure in the horizontal position, using set screw (11).
This releases the suction locking arm
(4).
Note: The locking handle (3) should only be rotated towards the pump stopped for service. The suction valve is designed to prevent the locking handle (1) from rotating towards the running pump, as the suction of the running pump could cause the valve to slam shut with sufficient force to injure the operator and/or cause damage to the pump.
Do not attempt to circumvent this safety feature.
3. Rotate the suction valve towards the pump to be isolated. The orientation of the shaft is indicated by the center pin on the locking arm (4).
76
4. Loosen set screw (11) and raise the locking handle (3) so that the cam on the base on the handle forces the pin of the locking arm (4) towards the pump to be isolated. The locking handle (3) should be raised to between 45 degrees and the vertical position.
This handle should not be rotated past the vertical position.
5. Tighten set screw (11) to secure the locking handle (3) in position.
WARNING
Care should be taken when performing procedures 3 and 4. Read instructions carefully.
Unlocking
1. Open the interconnecting valve on the seal flush line to pressurize the serviced pump and vent air through bleeder valve on series 4302. Close these valves once the pressure is equalized and air removed.
2. Loosen set screw (11) and lower locking handle (3) to the horizontal position, secure with set screw (11).
NOTE: Keep hands and tools away from suction valve locking arm when freed by locking handle as differential pressure may cause arm to rotate quickly with force when unlocked.
3. Rotate valve to center position so that the center pin of the locking arm (4) is located in the recess on the locking handle (3).
4. Loosen set screw (11) and raise locking arm (3) to the vertical position, locking the center pin in the locking arm recess, secure with set screw.
77
78
Horizontal and Vertical Expansion Tanks
ASME PRE-PRESSURIZED
DIAPHRAGM EXPANSION TANKS
FOR HEATING & COOLING SYSTEMS
Vessel Description
Tanks are ASME constructed and precharged. They are designed to absorb the expansion forces and control the pressure in heating/cooling systems.
The system’s expanded water is contained behind a heavy-duty diaphragm fully compatible with water/glycol mixtures preventing tank corrosion and water logging problems.
The factory set pre-charge for these tanks is
12 psig (83 kPa).
Materials
Shell – Carbon Steel
Diaphragm – Heavy Duty Butyl
Operating Conditions
Maximum Working Temperature - 240°F
(115°C)
Maximum Working Pressure – 125 psi (862 kPa)
Maintenance Steps & Procedure
Visually inspect tank for damage, which may occur during transit.
Factory pre-charge pressure may not be correct for the installation. Tank MUST be pre-charged to system design fill pressure
BEFORE placing into operation. Remove pipe plug covering the valve enclosure.
Check and adjust the charge pressure by adding or releasing air for each application.
Note: If the system has been filled, the tank must be isolated from the system and the tank emptied before charging. This ensures all fluid has exited the diaphragm area and proper charging will occur.
If the pre-charge adjustment is necessary, oil and water free compressed air or nitrogen gas may be used. Check the pre-charge using an accurate pressure gauge at the charging valve and adjust as required. Check air valve for leakage. If evident, replace the
Schrader-type tire valve core.
Do not depend on the valve cap to seal the leak.
After making sure air charge is correct, replace pipe plug over the charging valve for protection.
Set tank in place and pipe system connection to system. Be sure to include isolation valve(s) and drain.
Purge air from system BEFORE placing tank into operation. All models have system water contained behind diaphragm.
When filling the system with water, open valves to tank to ensure that any residual air in the tank is displaced by water.
It is recommended that the pre-charge be checked annually to ensure proper system protection and long life for the vessel.
79
Installation
The Suction Guides may be installed in any arrangement feasible the arrangement of the pump flange bolt-holes.
Suction Guides
Introduction
Suction Guides are designed for bolting directly onto the suction flange of horizontal or vertical shaft centrifugal pumps.
Operating Limits
The suction guide is designed to be a four-
function fitting. Each Suction Guide is a 90º elbow, a Pipe Strainer and a Flow Stabilizer.
It may also be used as a Reducing Elbow, should the suction piping be larger than the pump inlet
.
Inspection
Suction Guides are thoroughly tested and inspected before shipment to assure they meet with your order requirements. All units must be carefully examined upon arrival for possible damage during transit. Any evidence of mishandling should be reported immediately to the carrier and noted on the freight bill.
Operation
No special attention need be paid to the
Suction Guide at start-up. The fitting is stationary and will strain the pumped fluid and stabilize the flow into the pump automatically.
80
Temporary strainer must be removed
following system clean up.
After all debris has been removed from the system, or a maximum of 24 running hours, stop the pump and close the pump isolation valves. Drain the Suction Guide by removing the drain plug or opening the blowdown valve, if installed
Remove the Suction Guide cover and remove the strainer assembly from the valve body.
A temporary fine-mesh start-up strainer is tack-welded to the permanent stainless steel strainer. This temporary strainer should now be removed from the permanent strainer.
The fine-mesh strainer is designed to remove small particulate from new piping systems and could easily clog with debris if left in place. This will be detrimental to the operation of the pump.
Inspect the cover O-ring and replace if necessary.
Replace the permanent strainer into the fitting body, once the temporary strainer is removed.
Replace the cover into the body. Ensuring that the strainer is properly seated, tighten the cover bolts diagonally, evenly and firmly.
Glycol Auto Fill Unit
The glycol auto fill unit (GLA) is designed to maintain the HVAC system pressure by adding the appropriate mix of glycol and water to the system. During the normal operation of the HVAC system, fluid is lost causing a drop in the system pressure.
Standard Unit
When the system pressure drops below the set point on the pressure switch, the GLA pump is started adding fluid from the GLA tank into the HVAC system. When the system pressure returns to normal operating conditions, the pump stops. As the tank empties, a level switch is actuated preventing the pump from running dry.
Ultra Unit
When the system pressure drops below the set point on the pressure switch, the GLA pump is started adding fluid from the GLA tank into the HVAC system. When the system pressure returns to normal operating conditions, the pump stops. As the tank empties, a level switch is actuated lighting the low level pilot light. If the system is not filled, a second level switch stops the pump(s) preventing the pump(s) from running dry. Should the system be overfilled, a high level alarm is actuated by level switch. Dry contacts can be provided for remote indication of the above conditions.
A manual “push to mix” switch is provided for agitation of the contents of the GLA unit.
The switch starts the pump and opens the return line solenoid valve circulating the fluid.
Duplex units are equipped with a manual alternator to equalize wear on the pumps.
Essential Safety Requirements
Glycol is toxic and the glycol supplier’s safety instructions must be adhered to. In critical areas a retaining wall should be used to contain any spillage or leakage.
Overflows should be arranged not to contaminate drainage systems.
It is recommended that initial commissioning be carried out with water.
81
The flow rates from the unit are designed for makeup rates. It is therefore suggested that the system is back-filled with due precautions taken to avoid contamination.
Glycol is sometimes subject to bacterial attack and can become slimy as a result.
AAON recommend the addition of a suitable biocide. The dosage should be calculated on the amount of water glycol mixture added and not the total tank contents. If bacterial attack occurs on untreated mixtures the unit should be drained, flushed and refilled with fresh mixture and dosed with biocide.
Check that the supply voltage and overload protection is correct.
Guards and covers must not be removed during operation.
The pipework from the system to the expansion vessels should not be insulated.
For systems operating above 200°F (93°C), an anti-gravity loop with a minimum height of 6 feet, (or an intermediate vessel) should be installed to provide thermal protection to the expansion tanks.
The ball float valve is fitted with a lowpressure seat; a high-pressure seat is attached to the float valve and should be fitted if required.
Pressure Switch Adjustment
Low system pressure – PS1
High system pressure – PS2
Duty pump control switch – PS3
Standby pump control switch (where fitted)
– PS4
For each switch, set the delivery to the required pressure. Then very slowly turn the adjusting screw on the switch until the contacts change.
The high system pressure switch should first be set higher than the required pressure by turning the screw clockwise and the setting then made by turning the screw counterclockwise until the switch contacts changeover.
The other switches should first be set lower than the required pressure by turning the screw counter-clockwise and the setting then made by turning the screw clockwise until the switch contacts changeover.
A pipe plug is provided on the outlet to allow connection of a test pump to simulate differing system pressures to check switch settings.
The Ultra versions of the GLA have the capability of controlling duty and standby pumps from a single pressure switch.
GLA Ultra Settings
The extra functionality of Ultra units is integral. The only selectable option is
Manual or Automatic reset of alarm conditions. DIP switch 1, on the display board should be set to OFF for auto reset
(Factory setting), and ON for manual reset.
On alarm conditions, the MUTE switch will mute the buzzer. In manual reset mode this
MUTE switch will reset the alarms after the fault condition has been cleared. Other switches change the mode of the printed circuit board for use with other products. For
GLA application, all switches except 1 and 7 must be set to OFF.
Priming the makeup pumps:
1. Close suction isolating valve.
2. Fill the glycol-mixing tank.
3. Remove the upper vent plug from the makeup pump.
4. Open suction isolation valve until water flows out of this tapping.
5. Close valve and replace plug.
82
6. Repeat for standby pump (where fitted).
7. Close the system-isolating valve.
8. Open suction isolating valve.
9. Switch on unit, initially both pumps will run. As the pressure reaches the pump control switch threshold, the pumps will switch off.
10. Check all piping for leaks following shipping.
11. Crack open system valve. The pressure will fall and the pump will start and maintain pressure.
Powered agitation (Ultra model only):
A solenoid valve is fitted to provide powered agitation of the mixture.
Automatically this valve is periodically opened and the duty pump starts creating circulation through the pump and mixing tank. Automatic mixing is inhibited when there is a system demand for makeup.
A switch is provided for manual agitation when adding glycol to the mixing tank.
Topping up with glycol:
The mixing tank is calibrated in liters and
US gallons. The normal top up level is 53
US gallons (200 liters).
1. Calculate the amount of water needed and add or drain to the correct level.
2. Add the required amount of glycol.
3. Operate the manual-agitating switch.
4. Check the mixture percentage.
The unit is now ready for service.
Flo-Trex Combination Valve
Introduction
The Flo-Trex combination valves are designed for installation on the discharge side of centrifugal pumps, and incorporate three functions in one valve:
1. Drip-tight shut-off valve
2. Spring closure design, Non-slam check valve
3. Flow throttling valve
Armgrip Flange Adapter Installation
1. Position the two halves of the Armgrip flange adapter on the valve body ensuring that the lugs on each half of the flange adapters are located between the anti-rotation lugs on the valve body (as shown).
Insert two bolts of specified size (Table A1) to secure the halves of the flange adapter to the valve body (as shown).
Table A1. Armgrip Flange Adapter Details
125 psi/150 psi 250 psi/300 psi
Valve Size Ductile Iron Bolt Ductile Iron Bolt
2-1/2
3
4
5
No. Size No. Size
4 5/8 8 3/4
4
8
5/8
5/8
8
8
3/4
3/4
6
8
10
12
8
8
8
12
12
3/4
3/4
3/4
7/8
7/8
8
12
12
16
3/4
3/4
7/8
1
16 1-1/8
83
The gasket cavity should face out to the adjoining flange.
2. Lubricate the inner and outer diameter of the gasket with the lubricant provided or a similar non-petroleum based water soluble grease.
3. Press the gasket firmly into the flange cavity ensuring that the sealing lip is pointed outward. When in place, the gasket should not extend beyond the end of the pipe (as shown).
4. Position the adjoining flange or the pipe to the Armgrip flange adapter and install the remaining bolts. The two locking bolts should be tightened first in order to position the flange correctly.
Note: Care should be taken to ensure that the gasket is not pinched or bent between flanges.
5. Tighten remaining nuts evenly by following bolting instructions, so that the flange faces remain parallel (as shown in the figure labeled Recommended Bolt
Tightening Procedure). Flange bolts should be tightened to 70 ft-lbs torque minimum to assure firm metal to metal contact. When raised face flanges are sued, there will be a gap between the faces of the outer diameter.
6. Flange gaskets are not interchangeable with other mechanical pipe couplings or flange gaskets.
Recommended Bolt Tightening Procedure
Field Conversion (Straight to Angle
Pattern Valve:
1. Open valve at least one complete turn.
2. Remove the body bolts from valve body using Allen Key
3. Rotate one half of the valve body 180° making sure the lower valve seat and O ring stay in position. Inspect the O ring for any cuts or nicks and replace if necessary.
4. Replace body bolts and torque evenly to
70 ft-lbs.
Flow Measurement with the valve in the
Wide Open position
Where approximate indication of flow is acceptable the Flo-Trex valve can be used.
Step 1. Measure and record the differential pressure across the valve.
CAUTION
Safety glasses should be worn.
Probes should not be left inserted into fittings for long periods of time as leakage may result.
84
Step 2. With valve in fully open position, locate the differential pressure on the
Performance curve, and for the given valve size in use, read the corresponding flow rate.
Flow Measurement with the valve in the throttled position
Step 1. The valve stem with its grooved rings and positioning sleeve is the flow indicator scale for the throttled position of the valve.
The quarter turn graduations on the sleeve, with the scribed line on the stem provide an approximate flow measurement.
Note: The valve is shipped in closed position. The indicator on the plastic sleeve is aligned with the vertical scribed line on the stem.
Step 2. Record the size of the valve and stem position using the flow indicator scale.
Calculate the percentage of valve opening based on the number of rings at the fully open position.
Valve Size 2-1/2 3 4 5 6 8 10 12
Number of
Rings
(valve fully open)
5 5 6 9 10 12 18 28
Step 3. Measure and record the differential pressure across the valve in the throttled position.
Step 4. Locate percentage of valve opening on the flow characteristic curve. For the given valve, record the percentage of maximum flow rate.
Step 5. Locate the differential pressure determined for the valve in the throttled position on the Flo-Trex Performance
Curve. Determine the flow rate for the given valve size at this differential pressure.
Step 6. Calculate the flow rate of the valve in the throttled position by multiplying the flow rate (Step 5) by the percentage of maximum flow rate (Step 4).
Example:
Valve size: 4 in.
Differential pressure is 5.4 ft
Number of open rings is 3.
From the table, the number of rings for the 4 in valve fully open is 6.
Divide open rings by total, 3/6 = 50% throttled.
From the Flo-Trex performance curve, a 4 in. valve with 5.4 ft of pressure drop represents a flow of 400 USgpm
From the flow characteristic curve, a 4 inch valve at 50% open represents 34% of maximum flow.
The approximate flow of a 4 inch valve with a 5.4 ft pressure drop when 50% throttled is:
(400 x 34)
100
=136 USgpm
(25.2
x 34)
100
=8.57 L/s
85
Note: To prevent premature valve failure
it is not recommended that the valve operate in the throttled position with more than 25 ft pressure differential.
Instead the pump impeller should be trimmed or valves located elsewhere in the system to partially throttle the flow.
Operation
To assure tight shut-off, the valve must be closed using a wrench with 25 to 30 ft-lbs of torque.
To assure trouble free check valve operation and shut-off operation, the valve should be periodically opened and closed to keep valve seat and valve disc guide stem free of buildup of system contaminants.
Repacking of Flo-Trex valve under full system pressure
If it is necessary, the stem O ring can be changed under full system pressure.
CAUTION
Safety glasses should be worn.
Step 1. Record the valve setting.
Step 2.
Turn the valve stem counterclockwise until the valve is fully open and will not turn any further. Torque to a maximum of 45 ft-lbs. This will ensure good metal to metal contact and minimal leakage.
Step 3. The valve bonnet may now be removed. There may be a slight leakage, as the metal to metal backseating does not provide a drip-tight seal.
Step 4. Clean exposed portion of valve stem being careful not to leave scratches.
Step 5. Remove and replace the O ring gasket.
Step 6. Install the valve bonnet.
Step 7. Tightening the valve bonnet is necessary to stop any leaks.
Step 8. Open valve to balance set point as recorded in Step 1.
Note: On valve sizes of 2-1/2 inch and 3 inch, the full open position is 5 turns, though the valve will open to 5-1/2 turns which is just back of seating of valve.
Seat Replacement
Step 1. Drain the system and remove valve from piping.
Step 2. Remove the body bolts from the body using an Allen Key.
Step 3. Remove seat and O Ring. O rings are not used on valves of 8 inches or larger.
Step 4. Inspect and clean O ring cavity and install new O ring and seat. Valve disc stem should be inspected and replaced if worn.
Valve stem O ring should be replaced at this time as discussed under Repacking of Flo-
Trex section.
86
Pressure-Temperature Limits
Flo-Trex Cross Section
87
LZ Series Startup Form
Job Name:_______________________________________________ Date:______________
Address:______________________________________________________________________
______________________________________________________________________________
Model Number:_________________________________________________________________
Serial Number:_____________________________________________ Tag:_______________
Startup Contractor:______________________________________________________________
Address:______________________________________________________________________
_______________________________________________________
Pre Startup Checklist
Installing contractor should verify the following items.
Phone:______________
1. Is there any visible shipping damage?
2. Is the unit level?
3. Are the unit clearances adequate for service and operation?
4. Do all access doors open freely and are the handles operational?
5. Have all shipping braces been removed?
Yes No
Yes No
Yes No
Yes No
Yes No
6. Have all electrical connections been tested for tightness?
7. Does the electrical service correspond to the unit nameplate?
8. On 208/230V units, has transformer tap been checked?
Yes No
Yes No
Yes No
9. Has overcurrent protection been installed to match the unit nameplate requirement?
10. Have all set screws on the fans been tightened?
11. Do all fans rotate freely?
Yes No
Yes No
Yes No
12. Does the field water piping to the unit appear to be correct per design parameters?
Ambient Temperature
Ambient Dry Bulb Temperature ________°F
Yes No
Ambient Wet Bulb Temperature ________°F
88
Water/Glycol System
1. Has the entire system been flushed and pressure checked?
2. Have isolation valves to the chiller been installed?
3. Have isolation valves to the boiler been installed?
4. Has the entire system been filled with fluid?
5. Has air been bled from the heat exchangers and piping?
Yes No
Yes No
Yes No
Yes No
Yes No
6. Is there a minimum load of 50% of the design load?
7. Has the water piping been insulated?
Yes No
Yes No
8. Is the glycol the proper type and concentration (N/A if water)? Yes No
9. What is the freeze point of the glycol (N/A if water)? ______________________________
Chiller Configuration
Air-Cooled Condenser Evaporative-Cooled Condenser
Low Ambient Control
No Water Leaks
Chilled Water In Temperature ________°F
Boiler Configuration
No Water Leaks Boiler Water Flow ________ gpm
Boiler Building Water Flow ________ gpm Boiler Safety Check
Condenser Safety Check
Water Flow ________ gpm
Chilled Water Out Temperature ________°F
89
Compressors/DX Cooling
Check Rotation
Number Model # L1 L2 L3
5
6
7
8
9
10
11
1
2
3
4
12
Refrigeration System 1 - Cooling Mode
Pressure
Saturated
Temperature
Discharge
Suction
Liquid
Refrigeration System 2 - Cooling Mode
Discharge
Pressure
Saturated
Temperature
Suction
Liquid
Refrigeration System 3 - Cooling Mode
Pressure
Saturated
Temperature
Discharge
Suction
Liquid
Line
Temperature
Line
Temperature
Line
Temperature
Head
Pressure
PSIG
Sub-cooling
N/A
N/A
Sub-cooling
N/A
N/A
Sub-cooling
N/A
N/A
Suction
Pressure
PSIG
Superheat
N/A
N/A
Superheat
N/A
N/A
Superheat
N/A
N/A
Crankcase
Heater
Amps
90
Refrigeration System 4 - Cooling Mode
Pressure
Saturated
Temperature
Discharge
Suction
Liquid
Refrigeration System 5 - Cooling Mode
Pressure
Saturated
Temperature
Discharge
Suction
Liquid
Line
Temperature
Line
Temperature
Refrigeration System 6 - Cooling Mode
Saturated
Pressure
Temperature
Discharge
Suction
Liquid
Line
Temperature
Refrigeration System 7 - Cooling Mode
Pressure
Saturated
Temperature
Discharge
Suction
Liquid
Line
Temperature
Refrigeration System 8 - Cooling Mode
Saturated
Pressure
Temperature
Discharge
Suction
Liquid
Line
Temperature
Sub-cooling
N/A
N/A
Sub-cooling
N/A
N/A
Sub-cooling
N/A
N/A
Sub-cooling
N/A
N/A
Sub-cooling
N/A
N/A
Superheat
N/A
N/A
Superheat
N/A
N/A
Superheat
N/A
N/A
Superheat
N/A
N/A
Superheat
N/A
N/A
91
9
10
11
12
5
6
7
8
Condenser Fans
Alignment
Number hp
1
2
3
4
17
18
19
20
21
22
13
14
15
16
23
24
Condenser Pumps
Check Rotation
Number
1
2 hp
92
L1
L1
Check Rotation
L2
Nameplate Amps________
L3
L2 L3
Pumping Package
Chiller Pump #1
Chiller Pump #2
Chiller Pump #3
Chiller Pump #4 hp
Chiller Building Pump #1
Chiller Building Pump #2
Boiler Building Pump #1
Boiler Building Pump #2
Boilers
Boiler Water In Temperature ________°F
Boiler
1
Amps
3
5
7
L1 L2 L3 Flow (gpm)
Boiler Water Out Temperature ________°F
Boiler
2
Amps
4
6
8
93
Maintenance Log
This log must be kept with the unit. It is the responsibility of the owner and/or maintenance/service contractor to document any service, repair or adjustments. AAON Service and Warranty Departments are available to advise and provide phone help for proper operation and replacement parts. The responsibility for proper start-up, maintenance and servicing of the equipment falls to the owner and qualified licensed technician.
Entry Date Action Taken Name/Tel.
94
Literature Change History
July 2015
Initial version.
95
AAON
2425 South Yukon Ave.
Tulsa, OK 74107-2728
Phone: 918-583-2266
Fax: 918-583-6094 www.aaon.com
LZ Series
Installation, Operation, &
Maintenance
V45100 · Rev. A · 150715
It is the intent of AAON to provide accurate and current product information. However, in the interest of product improvement, AAON reserves the right to change pricing, specifications, and/or design of its product without notice, obligation, or liability.
AAON
®
Copyright © AAON, all rights reserved throughout the world.
and AAONAIRE
®
are registered trademarks of AAON, Inc., Tulsa, OK.
advertisement
Key Features
- Staged or variable-speed R-410A scroll compressors
- High efficiency air-cooled microchannel condenser coils
- Factory engineered primary or primary/secondary pumping packages
- Factory installed three chemical water treatment
- Factory installed compression tank
- Brazed plate or shell and tube evaporators
- Factory installed option boxes for field installed accessories
- Phase and brownout protection
- Single point non-fused disconnect power switch