VariStroke-II (VS-II) Electro-hydraulic Actuator

VariStroke-II (VS-II) Electro-hydraulic Actuator
Product Manual 26740
(Revision NEW, 1/2016)
Original Instructions
VariStroke-II (VS-II)
Electro-hydraulic Actuator
Optional Supplementary
Information
Installation and Operation Manual
Read this entire manual and all other publications pertaining to the work to be
performed before installing, operating, or servicing this equipment.
Practice all plant and safety instructions and precautions.
General
Precautions Failure to follow instructions can cause personal injury and/or property damage.
Revisions
This publication may have been revised or updated since this copy was produced.
To verify that you have the latest revision, check manual 26455, Customer
Publication Cross Reference and Revision Status & Distribution Restrictions, on
the publications page of the Woodward website:
www.woodward.com/publications
The latest version of most publications is available on the publications page. If
your publication is not there, please contact your customer service representative
to get the latest copy.
Proper Use
Any unauthorized modifications to or use of this equipment outside its specified
mechanical, electrical, or other operating limits may cause personal injury and/or
property damage, including damage to the equipment. Any such unauthorized
modifications: (i) constitute "misuse" and/or "negligence" within the meaning of
the product warranty thereby excluding warranty coverage for any resulting
damage, and (ii) invalidate product certifications or listings.
If the cover of this publication states "Translation of the Original Instructions"
please note:
The original source of this publication may have been updated since this
Translated translation was made. Be sure to check manual 26455, Customer Publication
Publications Cross Reference and Revision Status & Distribution Restrictions, to verify whether
this translation is up to date. Out-of-date translations are marked with . Always
compare with the original for technical specifications and for proper and safe
installation and operation procedures.
Revisions—Changes in this publication since the last revision are indicated by a black line
alongside the text.
Woodward reserves the right to update any portion of this publication at any time. Information provided by Woodward is
believed to be correct and reliable. However, no responsibility is assumed by Woodward unless otherwise expressly
undertaken.
Manual 26740
Copyright © Woodward 2016
All Rights Reserved
Manual 26740
VariStroke-II Electro-hydraulic Actuator
Contents
WARNINGS AND NOTICES ...........................................................................VII ELECTROSTATIC DISCHARGE AWARENESS ................................................ VIII REGULATORY COMPLIANCE ....................................................................... IX CHAPTER 1. GENERAL INFORMATION ........................................................... 1 Introduction .............................................................................................................1 VS-II Integrated, Remote Servo Valve Kit, and Remote Servo Valve
Construction ...........................................................................................................3 CHAPTER 2. SPECIFICATIONS .................................................................... 10 Physical and Performance Specifications ............................................................10 Environmental Specifications ...............................................................................11 Electrical Specifications ........................................................................................11 Cylinder Position Sensor (LVDT) Requirements (Remote Servo Only) ..............12 Hydraulic Specifications .......................................................................................13 Performance Index ...............................................................................................15 Diagrams ..............................................................................................................17 CHAPTER 3. INSTALLATION........................................................................ 33 Receiving Instructions ..........................................................................................33 Unpacking Instructions .........................................................................................33 Installation Instructions .........................................................................................34 CHAPTER 4. ELECTRICAL I/O..................................................................... 43 Electrical Connection Ports ..................................................................................43 Power Supply Inputs.............................................................................................43 Power Supply Requirement ..................................................................................43 CHAPTER 5. SERVICE TOOL INSTALLATION ................................................ 60 Setup ....................................................................................................................60 Installing the VariStroke-II Service Tool ...............................................................62 Getting Started with the VS-II Service Tool ..........................................................66 General Installation Check before Applying Power to the VS-II ...........................66 Connection Troubleshooting ................................................................................69 CHAPTER 6. CONFIGURATION, CALIBRATION, AND MONITORING ................. 71 Service Tool Sidebar ............................................................................................72 Identification Page ................................................................................................74 Status Overview Page ..........................................................................................75 Configuration and Calibration Page .....................................................................77 Actuator Calibration ..............................................................................................85 Manual Operation Page........................................................................................95 Input Configuration Page ......................................................................................96 Output Configuration Page .................................................................................102 Fault Status and Configuration Overview ...........................................................108 Fault Status and Configuration Overview Internals ............................................110 Position Controller Configuration Operation Page .............................................111 CHAPTER 7. DIAGNOSTICS ...................................................................... 123 Status Overview Page ........................................................................................123 Position Controller Page .....................................................................................126 Startup Checks Page..........................................................................................130 Driver Page .........................................................................................................133 Resolver and LVDT Diagnostics ........................................................................136 CHAPTER 8. ............................................................................................ 137 Woodward
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REPAIR AND TROUBLESHOOTING .............................................................137 General ...............................................................................................................137 Hardware Replacement ......................................................................................137 Troubleshooting ..................................................................................................138 General Faults ....................................................................................................139 I/O Diagnostics ...................................................................................................140 Demand Input Configuration...............................................................................141 Environmental Diagnostics .................................................................................143 Input Voltage Diagnostics ...................................................................................143 Valve Type Selection Diagnostics ......................................................................144 VariStroke-II (Feedback) Faults..........................................................................146 Servo Position Diagnostics .................................................................................147 Performance Faults ............................................................................................148 Internal Diagnostics ............................................................................................148 Maintenance .......................................................................................................150 CHAPTER 8. SERVICE OPTIONS ................................................................151 Product Service Options .....................................................................................151 Woodward Factory Servicing Options ................................................................152 Returning Equipment for Repair .........................................................................152 Replacement Parts .............................................................................................153 Engineering Services ..........................................................................................153 How to Contact Woodward .................................................................................154 Technical Assistance ..........................................................................................154 CHAPTER 9. ASSET MANAGEMENT AND REFURBISHMENT SCHEDULING
PERIOD ...................................................................................................155 CHAPTER 10. LONG-TERM STORAGE REQUIREMENTS ..............................155 REVISION HISTORY ..................................................................................156 DECLARATIONS .......................................................................................157 The following are trademarks of Woodward, Inc.:
ProTech
Woodward
The following are trademarks of their respective companies:
Modbus (Schneider Automation Inc.)
Pentium (Intel Corporation)
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Illustrations and Tables
Figure 1-1a. Integrated Actuator option VariStroke-II Key Features ......................3 Figure 1-1b. Remote Servo Kit option VariStroke-II Key Features ........................4 Figure 1-1c. Servo Valve option VariStroke-II Key Features .................................5 Figure 1-2. Hydraulic Power Cylinder Stroke Adjustment Options ........................6 Figure 1-3. Application Example ............................................................................8 Figure 1-4. Nomenclature and Ordering Number Encoder ....................................9 Figure 2-1 Maximum Transient Flow Rates .........................................................14 Figure 2-2 Maximum Steady State Flow Rate......................................................14 Figure 2-3 Performance Index Guide for V90 Actuators ......................................16 Figure 2-4 Performance Index Guide for V65 Actuators ......................................16 Figure 2-5a. VS-II Integrated Hydraulic Schematic ..............................................17 Figure 2-5b. VS-II Remote Servo Hydraulic Schematic .......................................17 Figure 2-1c. VS-II Servo Only Hydraulic Schematic ............................................18 Figure 2-2a. Typical VS-II Integrated with 10-inch (254 mm) Bore ......................19 Figure 2-2b. Typical VS-II Integrated with 10-inch (254 mm) Bore ......................20 Figure 2-3a. Typical VS-II Integrated with 12-inch (305 mm) Bore ......................21 Figure 2-3b. Typical VS-II Integrated with 12-inch (305 mm) Bore ......................22 Figure 2-4a. Typical VS-II Remote Kit with 10-inch (254 mm) Bore ....................23 Figure 2-4a. Typical VS-II Remote Kit with 10-inch (254 mm) Bore (Continued ..24 Figure 2-4b. Typical VS-II Hydraulic Cylinder for Remote Kit with 10-inch (254
mm) Bore .........................................................................................25 Figure 2-4b. Typical VS-II Hydraulic Cylinder for Remote Kit with 10-inch (254
mm) Bore (continued) ......................................................................26 Figure 2-5a. Typical VS-II Remote Kit with 12-inch (305 mm) Bore ....................27 Figure 2-5a. Typical VS-II Remote Kit with 12-inch (305 mm) Bore (continued) .28 Figure 2-5b. Typical VS-II Hydraulic Cylinder for Remote Kit with 12-inch (305
mm) Bore .........................................................................................29 Figure 2-5b. Typical VS-II Hydraulic Cylinder for Remote Kit with 12-inch (305
mm) Bore (continued) ......................................................................30 Figure 2-6a. Typical VS-II Servo Valve for Remote Mounting .............................31 Figure 2-6b. Typical VS-II Servo Valve for Remote Mounting .............................32 Figure 3-1a. VS-II Actuator Bottom Mount. Product Installation Interface—
Mounting Bolt Pattern ......................................................................35 Figure 3-1b. VS-II Actuator Top Mount. Product Installation Interface—Mounting
Bolt Pattern ......................................................................................35 Figure 3-1c. VS-II Remote Cylinder Bottom Mount. Product Installation
Interface—Mounting Bolt Pattern ....................................................36 Figure 3-1d. VS-II Remote Cylinder Top Mount. Product Installation Interface—
Mounting Bolt Pattern ......................................................................36 Figure 3-1e. VS-II Remote Servo Bottom Mount. Product Installation Interface—
Mounting Bolt Pattern ......................................................................37 Figure 3-2. Mounting Gap.....................................................................................38 Figure 3-3. Suggested Configuration ...................................................................41 Figure 3-4. Electrical Wiring Diagram...................................................................42 Figure 4-1. Power Wiring Recommendation ........................................................44 Figure 4-2. Input Power Interface Diagram ..........................................................45 Figure 4-3. Grounding terminal locations .............................................................47 Figure 4-4. LVDT 1 Interface Diagram .................................................................49 Figure 4-5. LVDT 2 Interface Diagram .................................................................49 Figure 4-6. RS-232 Interface Diagram .................................................................50 Figure 4-7. Analog Input Interface Diagram .........................................................51 Figure 4-8. Analog Output Interface Diagram ......................................................52 Figure 4-9. Discrete Input Interface Diagram .......................................................53 Figure 4-10. Discrete Output Interface Diagram ..................................................54 Figure 4-11. CAN Port 1 .......................................................................................56 Figure 4-12. CAN Port 2 .......................................................................................57 Woodward
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Figure 4-13. RS-485 Interface Diagram ...............................................................58 Figure 5-1. Service Port Connections...................................................................61 Figure 5-2. ToolKit License Agreement ................................................................62 Figure 5-3. VariStroke II Installation Wizard Welcome Screen ............................63 Figure 5-4. Installation End-User License Agreement..........................................63 Figure 5-5. Installation Install Page ......................................................................64 Figure 5-6. Service Tool Installation in Progress ..................................................64 Figure 5-7. Service Tool Installation Complete ....................................................65 Figure 5-7. Home Screen .....................................................................................67 Figure 5-8. Service Tool Connection Button ........................................................67 Figure 5-9. Service Tool Communications Port Selection ....................................68 Figure 5-10. Service Tool Main Screen ................................................................69 Figure 5-11. Service Tool Unable to Locate SID File ...........................................70 Figure 5-12. Service Tool Update Default Folder for SID Files ............................70 Figure 6-1. Service Tool Summary Faults and Control Buttons ...........................72 Figure 6-2. System Information Page ...................................................................74 Figure 6-3. Status Overview Page........................................................................75 Figure 6-4. Trending Properties Page ..................................................................76 Figure 6-5. Configuration and Calibration Page ...................................................77 Figure 6-6. Detailed Wizard Navigation Instructions ............................................78 Figure 6-7. VS-II Current Settings ........................................................................78 Figure 6-8. VS-II Configuration Editing Screen ....................................................79 Figure 6-9. VS-II Advanced Setup “Dynamics” ....................................................80 Figure 6-10. “Edit Config” for Dynamics settings:.................................................81 Figure 6-11. Position Redundancy Manager Page: .............................................82 Figure 6-12. Edit Config for Position Redundancy Manager ................................83 Figure 6-13. Startup Configuration Page ..............................................................84 Figure 6-14. Edit Config for Startup Configuration ...............................................84 6-15. VariStroke II Actuator Calibration Wizard....................................................85 Figure 6-16. VariStroke II Calibration Mode .........................................................86 Figure 6-17. Confirmation that VariStroke II has been locked in Calibration
Mode ................................................................................................86 Figure 6-18. Cylinder Position Sensor Final Selection .........................................87 Figure 6-19. Initializing Auto Zero Page ...............................................................87 Figure 6-20. Auto Zero Automatic Calibration Process Warning. ........................88 6-21. Successful Completion of Auto Zero Calibration.........................................89 Figure 6-22. Auto Max Calibration Page ..............................................................90 Figure 6-23. Auto Max Calibration in Progress Page ...........................................90 Figure 6-24. Auto Calibration Routine Complete Page ........................................91 Figure 6-25. VS-II Manual Calibration Page.........................................................91 Figure 6-26. Manual Stroke Page.........................................................................92 Figure 6-27. Manual Stroke Mode Complete Page ..............................................93 Figure 6-28. Save or Abort Configuration Changes Page ....................................94 Figure 6-29. Calibration Parameters Successfully Saved Page ..........................94 Figure 6-30. Manual Operation Page ...................................................................95 Figure 6-31. Input Configuration Page .................................................................96 Figure 6-32. Demand Input Source Dropdown Menu...........................................96 Figure 6-33. Manual Position Demand Input Source Page ..................................96 Figure 6-34. Analog Position Demand Input Mode Selection Page .....................97 Figure 6-35. Analog Demand Configuration Page ...............................................98 Figure 6-36. CANopen Position Demand Input Source Page ..............................99 Figure 6-37. CANopen Dual Demand Configuration Page ................................100 Figure 6-38. CANopen Communications Parameters Baud Rate Dropdown ....100 Figure 6-39 CANopen Configuration Global Settings Extended PDO
Dropdown.......................................................................................101 Figure 6-40. CANopen Single W/WO Analog Backup Configuration Page .......101 Figure 6-42. Output Configuration Page ............................................................102 Figure 6-43. Analog Output Mode Selection Dropdown Menu...........................102 Figure 6-44. Analog Output Mode Selection Actual Position .............................103 iv
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Figure 6-45. Actual Position ...............................................................................103 Figure 6-46. Analog Output Mode Selection Echo Setpoint...............................103 Figure 6-47. Echo Setpoint .................................................................................104 Figure 6-48. Analog Output Mode Selection Motor Current ...............................104 Figure 6-49. Motor Current .................................................................................104 Figure 6-50. Discrete Output Configuration........................................................105 Figure 6-51. Discrete Output 1 & 2 Configuration Dropdown Menus .................105 Figure 6-52. Discrete Output 1 Active Discrete 2 Speed Switch ........................106 Figure 6-53. Discrete Output 2 Flag Selection (1-4) ..........................................106 Figure 6-54. Discrete Output 1 Flag Selection (5-8) ..........................................107 Figure 6-55. Discrete Output 1 Active Flag Selection (5-8) Discrete Output 2
Active Flag Selection (1-4) ............................................................107 Figure 6-56. Fault Status and Configuration Overview Page .............................108 Figure 6-57. Process Fault and Status Flag Configuration Page .......................109 Figure 6-58. Fault Status and Configuration Overview Internals Page ..............110 Figure 6-59. Position Controller Configuration ...................................................111 Figure 6-60. Demand Input Filter Configuration .................................................112 Figure 6-61. Demand Filter Settings Mode Selection ........................................112 Figure 6-62. Bandwidth Filter Mode Settings .....................................................113 Figure 6-63. Demand Input Bandwidth Filter Display.........................................113 Figure 6-64. Demand Filter Settings Mode Noise Filter .....................................113 Figure 6-65. Demand Input Noise Filter .............................................................114 Figure 6-66. Demand Filter Settings Mode Bandwidth and Noise Filter ............114 Figure 6-67. Demand Input Bandwidth and Noise Filter ....................................114 Figure 6-68. Demand Filter Settings Mode Slew Rate Filter ..............................115 Figure 6-69. Demand Input Slew Rate Filter ......................................................115 Figure 6-70. Demand Filter Settings Mode Slew Rate and Bandwidth Filter .....115 Figure 6-71. Demand Input Slew Rate and Bandwidth Filter .............................116 Figure 6-72. Demand Filter Settings Mode Slew Rate and Noise Filter ............116 Figure 6-73. Demand Input Slew Rate and Noise Filter.....................................116 Figure 6-74. Demand Filter Settings Mode Slew Rate, Bandwidth and Noise
Filter ...............................................................................................117 Figure 6-75. Demand Input Slew Rate Bandwidth and Noise Filter ...................117 Figure 6-76. Zero Cut-off Configuration .............................................................118 Figure 6-77. Discrete Inputs Configuration.........................................................118 Figure 6-78. Silt Buster Configuration ................................................................120 Figure 6-79. Current Diagnostic Off ...................................................................120 Figure 6-80. Current Diagnostic Configuration – On ..........................................121 Figure 6-81. Position Error Configuration ...........................................................122 Figure 7-1. Status Overview Page .....................................................................123 Figure 7-2. Position Controller ............................................................................124 Figure 7-3 VariStroke II Input/Output State and Analog Values.........................124 Figure 7-4 Status Overview Trend Chart............................................................125 Figure 7-5. Trend Chart Trending Properties Page ............................................125 Figure 7-6. Position Controller Page ..................................................................126 Figure 7-7. Hydraulic Cylinder ............................................................................127 Figure 7-8. Servo Valve ......................................................................................129 Figure 7-9. Startup Checks.................................................................................130 Figure 7-10. Hydraulic Cylinder ..........................................................................131 Figure 7-11. Servo Valve ....................................................................................132 Figure 7-12 Driver Page .....................................................................................133 Figure 7-13. Driver Input/Output State ...............................................................133 Figure 7-14. Driver Input Data ............................................................................134 Figure 7-15. Driver Output Data .........................................................................134 Figure 7-16. Resolver and LVDT Position Sensors Diagnostics ........................136 Table 2-1. Physical and Performance Specifications ...........................................10 Table 2-1. Physical and Performance Specifications (Continued) .......................10 Table 2-2. Environmental Specifications ..............................................................11 Woodward
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Table 2-3. Electrical Specifications.......................................................................11 Table 2-4. Cylinder Position Sensor (LVDT) Requirements .................................12 (Remote Servo Only) ............................................................................................12 Table 2-5. Hydraulic Specifications ......................................................................13 Table 2-5. Hydraulic Specifications (Continued) ..................................................13 Table 2-2 Servo Valve Size and PI Constant .......................................................15 Table 3-1. VS-II Product Installation Interface......................................................34 Table 4-1. VS-II Power Requirements ..................................................................43 Table 4-2. Voltage Drop Using American Wire Gauge (AWG) ............................45 Table 4-3. Voltage Drop Using Wire Area (mm²) .................................................46 Table 4-3. LVDT Requirements ............................................................................48 Table 4-4. Recommended Maximum Cable Lengths per CiA DS-102 Standard .55 Table 4-5. CAN Port Pin Function ........................................................................57 Table 6-1. Discrete Input ....................................................................................119 Table 8-1. Service Spare Kit for On-Site Support ..............................................138 Table 7-1. VS-II Troubleshooting Guide .............................................................139 vi
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Warnings and Notices
Important Definitions





This is the safety alert symbol. It is used to alert you to potential
personal injury hazards. Obey all safety messages that follow this
symbol to avoid possible injury or death.
DANGER - Indicates a hazardous situation which, if not avoided, will result
in death or serious injury.
WARNING - Indicates a hazardous situation which, if not avoided, could
result in death or serious injury.
CAUTION - Indicates a hazardous situation which, if not avoided, could
result in minor or moderate injury.
NOTICE - Indicates a hazard that could result in property damage only
(including damage to the control).
IMPORTANT - Designates an operating tip or maintenance suggestion.
Overspeed /
Overtemperature /
Overpressure
Personal Protective
Equipment
The engine, turbine, or other type of prime mover should be
equipped with an overspeed shutdown device to protect
against runaway or damage to the prime mover with possible
personal injury, loss of life, or property damage.
The overspeed shutdown device must be totally independent
of the prime mover control system. An overtemperature or
overpressure shutdown device may also be needed for safety,
as appropriate.
The products described in this publication may present risks
that could lead to personal injury, loss of life, or property
damage. Always wear the appropriate personal protective
equipment (PPE) for the job at hand. Equipment that should
be considered includes but is not limited to:

Eye Protection

Hearing Protection

Hard Hat

Gloves

Safety Boots

Respirator
Always read the proper Material Safety Data Sheet (MSDS) for
any working fluid(s) and comply with recommended safety
equipment.
Start-up
Automotive
Applications
Woodward
Be prepared to make an emergency shutdown when starting
the engine, turbine, or other type of prime mover, to protect
against runaway or overspeed with possible personal injury,
loss of life, or property damage.
On- and off-highway Mobile Applications: Unless Woodward's
control functions as the supervisory control, customer
should install a system totally independent of the prime
mover control system that monitors for supervisory control
of engine (and takes appropriate action if supervisory control
is lost) to protect against loss of engine control with possible
personal injury, loss of life, or property damage.
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To prevent damage to a control system that uses an alternator or
battery-charging device, make sure the charging device is turned off
before disconnecting the battery from the system.
Battery Charging
Device
Electrostatic Discharge Awareness
Electrostatic
Precautions
Electronic controls contain static-sensitive parts. Observe the
following precautions to prevent damage to these parts:

Discharge body static before handling the control (with power to
the control turned off, contact a grounded surface and maintain
contact while handling the control).

Avoid all plastic, vinyl, and Styrofoam (except antistatic versions)
around printed circuit boards.

Do not touch the components or conductors on a printed circuit
board with your hands or with conductive devices.
To prevent damage to electronic components caused by improper
handling, read and observe the precautions in Woodward manual
82715, Guide for Handling and Protection of Electronic Controls,
Printed Circuit Boards, and Modules.
Follow these precautions when working with or near the control.
1. Avoid the build-up of static electricity on your body by not wearing clothing
made of synthetic materials. Wear cotton or cotton-blend materials as much
as possible because these do not store static electric charges as much as
synthetics.
2. Do not remove the printed circuit board (PCB) from the control cabinet
unless absolutely necessary. If you must remove the PCB from the control
cabinet, follow these precautions:

Do not touch any part of the PCB except the edges.

Do not touch the electrical conductors, the connectors, or the
components with conductive devices or with your hands.

When replacing a PCB, keep the new PCB in the plastic antistatic
protective bag it comes in until you are ready to install it. Immediately
after removing the old PCB from the control cabinet, place it in the
antistatic protective bag.
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Regulatory Compliance
FINAL CERTIFICATIONS PENDING
European Compliance for CE Marking
EMC Directive:
Compliant with EMC Directive 2004/108/EC using
the following standards: EN 61000-6-2 (2005) Immunity for Industrial Environments and EN
61000-6-4 (2007) - Emissions for Industrial
Environments. Detailed test requirements per
section 2.4.5 of EMC.
ATEX – Potentially
Explosive
Atmospheres
Directive:
Compliant with ATEX Directive 94/9/EC using
harmonized standards IEC EN 60079-0:2006 and
either IEC EN 60079-1:2007 and/or IEC 6007915:2005. Zone 1, Category 2, Group IIG, Ex d IIB
T3, SIRA 14ATEX1028X. Zone 2, Category 3,
Group IIG, Ex nA IIC, T3, SIRA 14ATEX5029X.
Flame Path
Maximum Gap (mm)
Minimum Length (mm)
Housing to Spacer
0.20
42.14
Rotor to Spacer
0.15
26.57
Rotor to Bolt
0.114
31.15
Cover to Housing
0.114
29.29
Cover to Housing
0.114
14.58
Cover to Bolt
0.114
16.26
Other European and International Compliance:
Machinery Directive:
Compliant as partly completed machinery with
Directive 2006/42/EC of the European Parliament
and the Council of 17 May 2006 on machinery.
Pressure Equipment
Directive:
Compliant as “SEP” per Article 3.3 to Pressure
Equipment Directive 97/23/EC of 29 May 1997 on
the approximation of the laws of the Member
States concerning pressure equipment.
IECEx:
GOST R:
Woodward
IECEx CSA 13.0041X
RU C-US.MIII06.B.00071
TIIS:
TBD
KOSHA
TBD
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FINAL CERTIFICATIONS PENDING
North America Compliance:
Class I, Division 1, Groups C & D T3 and Class I,
Division 2, Groups A, B, C & D T3 for North
America (USA and Canada). Certificate Number
2669905.
Marine Compliance:
Product is designed to meet marine certification
requirements per Lloyds and ABS.
Ingress Protection
Rating:
Product meets the IEC EN 60529:1991 Ingress
Protection rating of IP66
Special Conditions for Safe Use:
Wiring must be in accordance with local jurisdictional authority.
Field wiring must be suitable for at least +85 °C and 10 °C above the
maximum fluid and ambient temperatures.
The maximum hydraulic oil temperature is 70 °C continuous.
The VS-II actuator must be used in ambient temperature range from –40 °C to
+85 °C.
Connect external safety ground terminal to earth ground.
EXPLOSION HAZARD—Do not connect or disconnect while
circuits are live unless area is known to be non-hazardous.
Substitution of components may impair suitability for Class I,
Division 1/2 or Zone 1/2 applications.
The external ground lugs shown on the installation drawing
must be properly connected to ensure equipotential bonding.
This will reduce the risk of electrostatic discharge in an
explosive atmosphere.
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Chapter 1.
General Information
Introduction
The VariStroke-II is a linear electro-hydraulic actuator that utilizes a doubleacting power cylinder with integrated electronic driver module, servo valve, and
redundant LVDT (Linear Variable Differential Transformer) position feedback
sensors to precisely control steam turbine valves. The actuator’s driver module
accepts one 4–20 mA position demand and compares it to the sensed actuator
shaft position to accurately control output shaft position.
The actuator’s output shaft position is controlled by a digital controller combined
with an integrated rotary servo valve that ports supply oil to and from its power
cylinder. The actuator digital controller architecture allows it to perform stable
position control during normal conditions, and also respond quickly to desired
valve step changes during system or plant transients. As a means of protecting
the turbine, an internal servovalve return spring forces the actuator to a failsafe
position upon any internal unit failure (electrical input power failure, position
sensor failure, processor failure, etc.).
The VariStroke-II actuator is part of a product family with many different models
available for purchase depending on the force, stroke, and redundancy needs.
This actuator is available with standard bore diameters and standard stroke
ranges. The VariStroke-II’s unique “variable stroke” capability also allows users
to customize/set the actuator’s exact stroke length in the field to meet their
requirement.
The VariStroke-II is factory and/or field configurable via a computer-based
service tool. The actuator’s PCI Service Tool uses a simple, user-friendly format
to allow users to easily configure, calibrate, and adjust all internal functions and
response settings. The VariStroke-II also includes a 4–20 mA output channel to
indicate output shaft position, and unit alarm and shutdown relay outputs for use
as unit health and status indications.
The total installed cost for the VariStroke-II is low because it is a fully integrated
actuator that has been completely assembled and tested at the factory. This
greatly reduces OEM and end-user fabrication time, testing time, and site
assembly time.
The VariStroke-II Actuator offers the following benefits to the user in comparison
to other electro-hydraulic actuators:
Dirt Tolerance—The VariStroke-II actuator is specifically designed for steam
turbine applications where turbine lube oil is also used to power the hydraulic
turbine control valve actuator(s). Steam turbine applications can be extremely
challenging for hydraulic control valve actuators as dirt, metal shavings, water,
and other contaminants (Babbitt, ammonia, etc.) are common in such oil
systems. Also due to the high temperatures at which steam turbines operate,
turbine oil breakdown is common, resulting in the creation of a sludge-type
substance and the varnishing of internal system components. However, the
VariStroke-II actuator is designed to operate reliably within such challenging
applications. Its corrosion-resistant materials, single moving rotary valve, 610 N
(137 lbf) of chip shear force, and self-cleaning port design allow it to operate in
such applications without experiencing undesirable sticking or dragging.
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Silt Buster—A patented self-cleaning feature that flushes silt and debris from the
servo valve. At the interval and amplitude selected by the user, this function
provides a very rapid motion of the servo valve spool, allowing any silt to be
flushed to the drain passage. This motion is followed immediately by a step of
equal amplitude in the opposite direction. The opposing symmetry of the impulse
results in no net change in fluid volume to the hydraulic power cylinder, and thus
does not interrupt the control of the turbine. This unique feature provides a high
degree of stability, reliability, and silt resistance.
Valve Rack Linearization (not currently available) — Because steam flow
through single and staged inlet steam valves tends to be non-linear throughout
their flow range, turbine controls must be de-tuned to compensate for instability
or sluggish control points throughout this range. As a way of allowing turbine
control optimization without detuning, the VariStroke-II includes an 11-point
linearization table to allow turbine OEMs or users to compensate for poor valve
linearization by digitally linearizing the control-to-valve flow relationship.
Side Load Capability—A common problem with turbine actuators is oil leaking
from their output shaft due to connection to valve rack linkages which have an
arc-type of motion. This motion results in side loading of the actuator shaft, and
after long periods may result in shaft-seal wear and resultant oil leakage.
Designed for a continuous side load of up to 10% of actuator output, the
VariStroke-II actuator incorporates a high-force precision bearing and triple-seal
technology on its output shaft to solve this typical application problem.
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VariStroke-II Electro-hydraulic Actuator
VS-II Integrated, Remote Servo Valve Kit, and
Remote Servo Valve Construction
The VariStroke-II Integrated actuator is made up of the following major
components (Figure 1-1a):
1. Hydraulic Power Cylinder
2. Rotary Servo Valve
3. Feedback Sensors: Redundant LVDTs (Linear Variable Differential
Transformer) – for hydraulic power cylinder position controlling
4. Integrated electronic driver module (PCB)
Figure 1-1a. Integrated Actuator option VariStroke-II Key Features
Woodward
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The VariStroke-II Remote Servo Valve Kit option (Figure 1-1b) contains the same
primary components as integrated version. This kit allows the Hydraulic Power
Cylinder to be mounted separately from the servo in applications where space is
constrained and user supplied hydraulic lines are used to connect the servo and
cylinder.
Figure 1-1b. Remote Servo Kit option VariStroke-II Key Features
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VariStroke-II Electro-hydraulic Actuator
The VariStroke-II Remote Servo Valve only (Figure 1-1c) contains just the Servo
Valve. The Remote Servo option allows the servo valve to be mounted in a
location away from the Hydraulic Power Cylinder in applications where space is
constrained. A customer supplied Hydraulic Power Cylinder, with Woodward
approved LVDT’s, can be used with this Servo Valve only option. Customer
supplied hydraulic lines are used to connect the servo and cylinder.
Figure 1-1c. Servo Valve option VariStroke-II Key Features
Hydraulic Power Cylinder
The simple and robust design of VS-II hydraulic cylinder is capable of consistent
performance for extended periods in challenging environments. The hydraulic
cylinder is designed to operate with a wide range of hydraulic pressures and with
high oil contamination. The actuation stroke range is electronically controlled and
can be adjusted precisely using PC service tool, allowing the actuator to be set
up to operate at user configured stroke lengths.
The hydraulic Power Cylinder is designed to be field replaceable (in turbine
shutdown condition).
The VariStroke-II Remote Servo Valve can be connected to any hydraulic
cylinder, however; proper operation requires that the VariStroke-II Stability
Equation be satisfied (see Chapter 2, Stability Specifications). In order to control
cylinder position, the Cylinder must be equipped with a Woodward LVDT position
feedback sensor(s). The position sensor(s) must meet the specifications listed in
Chapter 2.
Woodward
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Figure 1-2. Hydraulic Power Cylinder Stroke Adjustment Options
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VariStroke-II Electro-hydraulic Actuator
Rotary Servo Valve
The hydraulic valve has four ports: Supply, two Control Ports, and Drain/Tank.
With the hydraulic valve in its middle position, all ports are blocked. As the valve
rotates, the supply is connected to a control port while simultaneously connecting
the drain to the other control port. The combined action of the servo position
controller and cylinder position controller modulate the power cylinder position as
necessary to match the input demand.
A unique function included in in the control software, called “Silt Buster”, is a
periodic, symmetrically opposed impulse which flushes silt and debris from the
servo valve without causing undue wear. At the interval and amplitude selected
by the user, this function provides a very rapid motion of the servo valve spool
allowing any silt to be flushed to the drain passage. This motion is followed
immediately by a step of equal amplitude in the opposite direction. The opposing
symmetry of the impulse results in no net change in fluid volume to the hydraulic
power cylinder, and thus does not interrupt the control of the turbine. This unique
function provides a higher degree of stability, reliability, and silt resistance.
If the unit detects any diagnostic shutdown condition, or if the detected diagnostic
condition prevents reliable control, or if a loss of power occurs, the servo valve
return spring forces the servo valve to connect the appropriate control ports to
drain causing the power cylinder to move to the fail-safe position.
Servo Valve Actuator
The VS-II uses a rotary Limited Angle Torque (LAT) actuator. The permanent
magnet rotor is directly coupled to the servo valve. The position of the rotor is
measured by a resolver. The H-bridge drive is regulated by the microprocessor to
precisely control the servo valve position and maintain the cylinder position
demand.
Electronic Driver Module
The VS-II uses Woodward’s state-of-the-art VariStroke II as the driver for the
servo valve actuator control and for cylinder positon control. The VariStroke II is
packaged inside the servo valve enclosure. The VariStroke II accepts either an
analog (4-20 mA) or CAN position demand signal and uses +125 Vdc input
power supply. Redundant power supply terminals are included. The actuator
calibration and configuration can be performed using PC based service tool.
Cylinder Position Control
The cylinder position controller function of the VariStroke II adjusts the hydraulic
power cylinder position to match the feedback signal to the position demand
signal.
Both the servo valve position controller and cylinder position controller are
monitored by the VariStroke II to ensure accurate tracking.
The position controller regulates a Pulse Width Modulated (PWM) drive signal to
the servo valve actuator. The drive current to the actuator is regulated, transiently
allowing up to 40 Amps to be provided to move the actuator at its maximum
speed. A steady state current limit reduces the current to 20 amps after a few
seconds to protect the actuator and electronics.
Woodward
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Figure 1-3. Application Example
Ordering Information
The actuator must be sized to meet the application needs by matching an
appropriately sized servovalve to the hydraulic cylinder. It can be further
customized by choosing from the option table below (Figure 1-4).
Note: There are some limitations to combining certain servovalve-tohydraulic-cylinder sizes. Please consult Woodward for sizing
recommendation and availability.
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Figure 1-4. Nomenclature and Ordering Number Encoder
Woodward
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Chapter 2.
Specifications
Physical and Performance Specifications
Table 2-1. Physical and Performance Specifications
Bore Diameter (OD)
Rod Diameter (ID)
203.2 mm (8 inches)
88.9 mm (3.5 inches)
254.0 mm (10 inches)
114.3 mm (4.5 inches)
304.8 mm (12 inches)
114.3 mm (4.5 inches)
Stall Force (extending):
Extend Stall force can be obtained from following equation:
[in²  psi = lbf] or [mm²  MPa = N]
Stall Force (retracting):
Retract Stall force can be obtained from following equation:
Extending Slew Rate:
Retracting Slew Rate:
[in²  psi = lbf] or [mm²  MPa = N]
Configurable
Configurable
NOTE: Slew Rates for Remote Servo Applications may be 10–15% slower
due to pressure drop on servo to cylinder piping.
It is highly recommended that inlet supply pressure not decrease by
more than 10% of nominal value during slew/step.
Table 2-1. Physical and Performance Specifications (Continued)
Position Accuracy:
Position Repeatability:
LVDT Temperature Drift:
Failsafe Operation:
±1% of full stroke
±0.5% of full stroke
0.04% /°C
Internal return spring on servo valve
spool force the Hydraulic Power
Cylinder to extend or retract (part
number depended) in case of electrical
signal loss.
Make sure that the VS-II hydraulic connections are installed
correctly. Equipment damage is possible if the hydraulic connections
are attached incorrectly (backwards). Reversed hydraulic connects
will cause the actuator to operate backwards, making the fail-safe
position opposite of where the user expects it to be.
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VariStroke-II Electro-hydraulic Actuator
Environmental Specifications
Table 2-2. Environmental Specifications
Ambient Temperature:
Vibration Resistance:
Shock Resistance:
Corrosion resistance:
–40 to +85 °C / –40 to +185 °F
MIL-STD 810F, M514.5A, Cat. 4
(0.015 G²/Hz, 1.04 Grms)
US MIL-STD-810C method 516.2,
procedure 1
(10 G Peak, 11 ms duration, saw tooth)
Two part epoxy paint coating.
Designed for outdoor conditions
Electrical Specifications
Table 2-3. Electrical Specifications
Input Power Supply:
Current Consumption:
Demand Signal:
Analog Output Signal:
Discrete Output Signal:
Discrete Input Signal:
Cylinder Feedback Device:
Connections:
Electrical Conduit Ports:
Woodward
90 to 150 Vdc (125 Vdc Nominal)
2 A Continuous
10 A Transient (200 ms maximum)
4 to 20 mA into 400 k . >70 dB CMRR.
Common Mode Voltage Range ±100 V ,
Accuracy 0.1% of full scale @ 25 °C
4 to 20 mA. Maximum load: 500. Accuracy
0.5% of full scale @ 25 °C
Configurable NO or NC
0.5 A at 24 V (dc), max 32 V (dc)
0.5 A inductive at 28 (dc) 0.2 henry
Contact current 3.8 mA (typ.) @ input closed
Max input voltage 32 V (dc), High signal
threshold > 7 V; Low signal Threshold < 3 V
2x LVDT (Linear Variable Differential
Transformer)
Excitation: 3.0 VRMS at 5000 Hz
Power: Removable terminal block for 8 mm²
or 8 AWG
I/O: Removable terminal block for 0.5 to 1
mm² or 20 -16 AWG
Analog/Discrete I/O:4 x 0.750”-14 NPT
Power: 2x 0.750”-14 NPT
LVDT Conduit: 2x .500”-14 NPT
2 X Ground
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Cylinder Position Sensor (LVDT) Requirements
(Remote Servo Only)
Table 2-4. Cylinder Position Sensor (LVDT) Requirements
(Remote Servo Only)
Type:
Excitation:
Sum voltage:
Output Voltage Ratio:
Linearity:
Sensor Stroke Length (SSL):
Sensor Cable Length Limit:
12
Six wire, difference/sum, Woodward supplied
3.0 VRMS at 5000 Hz
Va + Vb = 1.2 VRMS
(Va-Vb)/(Va+Vb) = ±0.5 VRMS
±0.5% Full Stroke
1x Cylinder Mechanical Stroke Length ≤ SSL
≤ 1.5x Cylinder Mechanical Stroke Length.
Both LVDTs must be of equal length in
redundant applications
10 m (33 feet) maximum between sensor and
VariStroke-II. Shielded, <5nF lumped
capacitance
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Manual 26740
VariStroke-II Electro-hydraulic Actuator
Hydraulic Specifications
Table 2-5. Hydraulic Specifications
Fluid Type:
Fluid Pressure (p):
Petroleum-based or synthetic turbine and
hydraulic fluids; fire resistant turbine and
hydraulic fluids such as Fyrquel EHC
Part Number dependent. Maximum operating
pressure can be found on the product
nameplate. The minimum recommended
operating pressure of all VariStroke products
is 80 psi (5.51 bar)
It is recommended to set hydraulic system pressure
regulator to 110% or less of normal operating pressure to
prevent over-pressure.
Table 2-5. Hydraulic Specifications (Continued)
Proof Pressure:
Burst Pressure:
Fluid Temperature:
Fluid Cleanliness level:
Output Cylinder Action:
Hydraulic Connections:
Supply Fluid Flow:
Woodward
750 psig (51.71 bar)
1250 psig (86.16 bar)
15 to 70 °C / 59 to 158 °F continuous
ISO 4406 code 20/18/16 or cleaner
Double
Supply Port: 51mm (2”) ISO/DIS6162, DIN20066,
JIS8363 flange (SAE J518 Code 61 except for metric
bolt size)
Drain Port: 64mm (2.5”) ISO/DIS6162, DIN20066,
JIS8363 flange (SAE J518 Code 61 except for metric
bolt size)
Control ports C1 and C2: 51mm (2”) ISO/DIS6162,
DIN20066, JIS8363 flange (SAE J518 Code 61
except for metric bolt size)
Actuator and Servo OVBD: 32mm (1.25”)
ISO/DIS6162, DIN20066, JIS8363 flange (SAE J518
Code 61 except for metric bolt size) or -10 SAE J1926
Refer to the following figures for maximum transient
and steady state flow rate requirements.
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Figure 2-1 Maximum Transient Flow Rates
The figure above shows the estimated hydraulic flow
necessary to maintain optimum performance of the VS-II. If
the flow supplied to the actuator is lower than what is
specified, the actuator will continue to operate, but at reduced
performance.
Figure 2-2 Maximum Steady State Flow Rate
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VariStroke-II Electro-hydraulic Actuator
The figure above shows the estimated hydraulic flow
necessary during steady state operation for the V90 servo
valve. All other VS-II servo valve models will consume less
fluid during steady state operation.
Performance Index
Before purchasing or installing a VS-II actuator, the user should verify that
actuator configuration under consideration will have the desired performance at
nominal operating oil supply pressure. As shown in the relationship below, the
performance of the VS-II is dependent on servo valve size, oil supply pressure,
and the used cylinder volume. If the relationship below is satisfied, the actuator
will operate smoothly, with minimal limit cycle. If the relationship is not satisfied, a
Performance Index Warning light will be illuminated on the Basic Setup
Information screen in the Configuration & Calibration settings. The warning light
is also seen on the Calibration Manual Stroke screen.
If the relationship below is NOT satisfied, the actuator
performance will be less than optimal, resulting in possible
excessive limit cycle, accelerated wear, and/or unacceptable
step response overshoot. The actuator electronics will also
output an alarm to provide notification that a “not
recommended” configuration is being used, resulting in less
than optimal, and possibly unacceptable, performance.
PI
∗
P
π∗D
4
1
∗L
Where:
SupplyPressureinBAR
P
D
L
CylinderDiameterinCentimeters
StrokeLengthinCentimeters
Note: This is the used maximum stop position. It may or may not equal the
Cylinder Length.
PI
PerformanceIndex
(Listed in Table Below)
Table 2-2 Servo Valve Size and PI Constant
Servo Valve Size
V65*
1275**
V90
2460
* Servo valve size is currently unavailable and is scheduled for future release.
** Value for PIConstant is estimated.
Woodward
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Figure 2-3 Performance Index Guide for V90 Actuators
Figure 2-4 Performance Index Guide for V65 Actuators
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Manual 26740
VariStroke-II Electro-hydraulic Actuator
Diagrams
VS-II Integrated Hydraulic Schematic
Figure 2-5a. VS-II Integrated Hydraulic Schematic
VS-II Remote Servo Hydraulic Schematic
Figure 2-5b. VS-II Remote Servo Hydraulic Schematic
Woodward
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Manual 26740
VS-II Servo Only Hydraulic Schematic
Figure 2-1c. VS-II Servo Only Hydraulic Schematic
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Manual 26740
VariStroke-II Electro-hydraulic Actuator
Outline Dimensions and Installation Features for Integrated
Servo-Cylinder
Figure 2-2a. Typical VS-II Integrated with 10-inch (254 mm) Bore
Woodward
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Figure 2-2b. Typical VS-II Integrated with 10-inch (254 mm) Bore
20
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Manual 26740
VariStroke-II Electro-hydraulic Actuator
Figure 2-3a. Typical VS-II Integrated with 12-inch (305 mm) Bore
Woodward
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Manual 26740
Figure 2-3b. Typical VS-II Integrated with 12-inch (305 mm) Bore
22
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Manual 26740
VariStroke-II Electro-hydraulic Actuator
Outline Dimensions and Installation Features for Remote
Servo Kit
Figure 2-4a. Typical VS-II Remote Kit with 10-inch (254 mm) Bore
Woodward
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Manual 26740
(12.00)
(11.14)
(11.70)
(9.63)
(8.57)
(6.00)
(.05)
(2.68)
267-075
9999-3198
8/2015
(5.00)
(7.75)
Figure 2-4a. Typical VS-II Remote Kit with 10-inch (254 mm) Bore (Continued
24
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Manual 26740
VariStroke-II Electro-hydraulic Actuator
Figure 2-4b. Typical VS-II Hydraulic Cylinder for Remote Kit with 10-inch
(254 mm) Bore
Woodward
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Manual 26740
Figure 2-4b. Typical VS-II Hydraulic Cylinder for Remote Kit with 10-inch
(254 mm) Bore (continued)
26
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Manual 26740
VariStroke-II Electro-hydraulic Actuator
Figure 2-5a. Typical VS-II Remote Kit with 12-inch (305 mm) Bore
Woodward
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Manual 26740
Figure 2-5a. Typical VS-II Remote Kit with 12-inch (305 mm) Bore (continued)
28
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Manual 26740
VariStroke-II Electro-hydraulic Actuator
Figure 2-5b. Typical VS-II Hydraulic Cylinder for Remote Kit
with 12-inch (305 mm) Bore
Woodward
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Manual 26740
Figure 2-5b. Typical VS-II Hydraulic Cylinder for Remote Kit
with 12-inch (305 mm) Bore (continued)
30
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Manual 26740
VariStroke-II Electro-hydraulic Actuator
Outline Dimensions and Installation Features for Remote
Servo Only Version
Figure 2-6a. Typical VS-II Servo Valve for Remote Mounting
Woodward
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Figure 2-6b. Typical VS-II Servo Valve for Remote Mounting
NOTES
1.
These general reference outline drawings apply to Woodward VS-II only.
Consult Woodward for the most current outline drawing.
2.
Installation Orientation. Orientation vertical approximately as shown See
elsewhere in this manual for other installation recommendations.
3.
Service Manual Replacement Parts

Servo Valve – Consult Woodward for part number

Hydraulic Power Cylinder – Consult Woodward for part number

Manual – Consult Woodward for part number

LVDT – Consult Woodward for part number

Seals Kit(s) – Consult Woodward for part number

Electronics module– Consult Woodward for part number
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Chapter 3.
Installation
Receiving Instructions
The VS-II is carefully packed at the factory to protect it from damage during
shipping; however, careless handling during shipment can result in damage. If
any damage to the VS-II is discovered, immediately notify both the shipping
agent and Woodward.
Unpacking Instructions
Carefully unpack the VS-II and remove it from the shipping container. Do not
remove the hydraulic, electric blanking covers and hydraulic power cylinder’s
output threaded shaft mesh until you are ready to mount the unit.
External fire protection is not provided in the scope of this product. It
is the responsibility of the user to satisfy any applicable
requirements for their system.
Take care not to damage the electronics cover’s seal, the cover
surface, the threads, or the VS-II housing mating surface while
removing or replacing the cover.
For Division 1/Zone 1 products: Proper torque on all joints is very
important to ensure that the unit is sealed properly.
Due to typical noise levels in engine and turbine environments,
hearing protection should be worn when working on or around the
VS-II.
The surface of this product can become hot enough or cold enough
to be a hazard. Use protective gear for product handling in these
circumstances. Temperature ratings are included in the specification
section of this manual.
For lifting and transportation use lifting straps fitted through both
lifting lugs provided with the product. Support vertical position of the
VS-II during transportation.
Woodward
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Installation Instructions
General
See the outline drawings (Figures 2-2, 2-3, 2-4, 2-5, and 2-6) and Specifications
for:

Outline dimensions

Hydraulic connections and fitting sizes

Electrical connections

Weight of the VS-II
A vertical actuator position is generally preferred to conserve floor space as well
as ease of making electrical and hydraulic connections, however; the VS-II can
be mounted in any attitude.
Allow space for removal of the front cover for access to the terminal blocks and
to see the status LEDs on the printed circuit board.
If the VS-II actuator is to be installed in close proximity to uninsulated/unshielded
steam valves or piping, radiation heat shields should be installed between the
actuator and these hot surfaces.
Do not mount the Integrated VariStroke-II actuator or the Remote
servovalve directly to any surface with a temperature greater than
85° C. Doing so may cause the electronic control to overheat and
shut down.
The hydraulic power cylinder, when using a remote servovalve, may be mounted
in areas with ambient temperatures up to 120 ° C.
The VS-II Integrated Actuator is designed to be fully supported by the Hydraulic
Power Cylinder Mating Surface. For the Remote Servo Kit and Servo only
configurations, the Hydraulic Power Cylinder and the Servo are each mounted
separately as defined below. The individual VS-II actuator and Servovalve bolt
patterns, bolts, and bolting torque recommendations are in presented in Table 31 and Figures 3-1a through 3-1e.
Table 3-1. VS-II Product Installation Interface
VariStroke-II
Cylinder Bore
Size [mm] (in)
(Fig. 3-1a,b,c,d)
[254]
(10)
[305]
(12)
VariStroke
-II Remote
Servovalve
(Fig. 3-1e)
V65
Dim. “A”
[mm](in)
Dim. “B”
[mm](in)
[228.6]
(9)
[266.7]
(10.5)
[228.6]
(9)
[266.7]
(10.5)
34
Min Thread
Depth [mm]
(in)
M30x3.5
M30x3.5
Dim. ‘A’
[mm](in)
Dim. ‘B’
[mm](in)
Dim. ‘C’
[mm](in)
[127](5)
[197]
(7.75)
[197]
(7.75)
[127](5)
[127](5)
V90
Thread
“C”
[127](5)
[44]
(1.75)
[44]
(1.75)
Min.
Bolt
Grade
8.8
8.8
Bolting
Torque
[Nm]
(lbf-ft)
[490–600]
(360-440)
[490–600]
(360-440)
Thread
“D”
Min Thread
Depth [mm]
(in)
Min.
Bolt
Grade
M12x1.75
[23] (.90)
8.8
M12x1.75
[23] (.90)
8.8
Bolt
Tolerance
Class
6g
6g
Bolting
Torque
[Nm]
(lbf-ft)
[54–68]
(40-50)
[54–68]
(40-50)
Bolt
Tolerance
Class
6g
6g
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Manual 26740
VariStroke-II Electro-hydraulic Actuator
Figure 3-1a. VS-II Actuator Bottom Mount. Product
Installation Interface—Mounting Bolt Pattern
Figure 3-1b. VS-II Actuator Top Mount. Product
Installation Interface—Mounting Bolt Pattern
Woodward
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Figure 3-1c. VS-II Remote Cylinder Bottom Mount. Product Installation
Interface—Mounting Bolt Pattern
Figure 3-1d. VS-II Remote Cylinder Top Mount. Product
Installation Interface—Mounting Bolt Pattern
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Figure 3-1e. VS-II Remote Servo Bottom Mount. Product Installation Interface—
Mounting Bolt Pattern
Minimum Bolt Grade, Bolting Torque and Thread Engagement
Recommendation is valid for low carbon steel mounting surface to
which product is bolted. For different configuration please consult
Woodward for torque and bolts grade recommendations.
Woodward
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Figure 3-2. Mounting Gap
The VS-II Actuator is designed for support by the Hydraulic Power
Cylinder Mating Surfaces, either top or bottom mount. Additional
supports are neither needed nor recommended.
The servovalve part of the Integrated Actuator is not designed to
support any load from the actuator (cylinder). The installation must
maintain the minimum required gap between servovalve and the
actuator mounting surface to prevent any loads being transmitted to
the servovalve. For reference see outline drawings (Figures 2-2 and
2-3).
Mounting deviations from that recommended by Woodward might
cause assembly damage, improper performance or operator injury
risk.
Improper mounting may be considered as a violation of warranty
conditions.
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To prevent damage to the actuator from excessive side loading, the
maximum allowable linkage misalignment from the actuator output
shaft (rod) is 5°.
Make sure that the linkages and couplings connecting the VS-II
output shaft to the turbine are appropriately sized and are able to
withstand the stall force and dynamic loads.
VS-II actuator lifting is allowed ONLY by using two provided lifting
eyes on the hydraulic power cylinder. The VS-II Servovalve lifting is
allowed ONLY by using two provided lifting eyes on the servovalve.
Support the VS-II in the vertical position during transportation.
Make sure that the crane, cables, straps, and all other lifting
equipment used for VS-II lifting are able to support the VS-II weight.
See outline drawings for VS-II weights.
Hydraulic Connections
For the VS-II Integrated Actuator or Servovalve there are two hydraulic
connections that must be made to each actuator: supply and drain. For Remote
Servovalve installations, additional hydraulic connections must be made between
the servovalve and the hydraulic power cylinder.
Hydraulic Connections:
 Supply Port: 51mm (2”) ISO/DIS6162, DIN20066, JIS8363 flange (SAE J518
Code 61 except for metric bolt size)
 Drain Port: 64mm (2.5”) ISO/DIS6162, DIN20066, JIS8363 flange (SAE J518
Code 61 except for metric bolt size)
 Control ports C1 and C2: 51mm (2”) ISO/DIS6162, DIN20066, JIS8363
flange (SAE J518 Code 61 except for metric bolt size)
 Actuator and Servo Overboard Drain (OVBD): 32mm (1.25”) ISO/DIS6162,
DIN20066, JIS8363 flange (SAE J518 Code 61 except for metric bolt size) or
-10 SAE J1926
Note: SAE J518, JIS B 8363, ISO/DIS 6162 AND DIN 20066 are
interchangeable, except for bolt sizes. VS-II uses metric bolt sizes.
Hydraulic connection tightening torques:

Hydraulic Supply & Drain:
4x M12x1.75 Screws Torque to (72 – 88) Nm, (53 - 65 lbf-ft)

Hydraulic Control Ports:
4x M12x1.75 Screws Torque to (72 – 88) Nm, (53 - 65 lbf-ft)

Overboard Drain Ports:
4x M10x1.5 Screws Torque to (45 - 55) Nm, (27 - 40 lbf-ft)
Before installing the VS-II, all hydraulic lines must be thoroughly
flushed to remove all contamination.
Make provisions for proper filtration of the hydraulic fluid that will supply the
actuator. The system filtration should be designed to assure a supply of hydraulic
oil with a target cleanliness level of ISO 4406 code 20/18/16 or cleaner.
Woodward
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The tubing connected to the actuator must be constructed to eliminate any
transfer of vibration or other forces to the actuator.
The hydraulic supply to the actuator is to be 51 mm (2 inch) tubing, or larger,
capable of supplying 681 L/min (180 US gal/min) at 34.47 bar / 500 psig.
The hydraulic drain should be 63.5 mm (2.5 inch) tubing, or larger, and must not
restrict the flow of fluid from the actuator. The drain pressure must not exceed 10%
of supply pressure or 3.5 bar (50 psig), whichever is less, under any condition.
Pipe diameters to both the Supply and Drain connections should be maximized,
within reason, to ensure that flow losses and restrictions are minimized. For the
same reason, pipe lengths should be kept to a minimum.
It is highly recommended that inlet supply pressure at the actuator
inlet not be allowed to decrease by more than 10% of nominal value
during slew/step.
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The hydraulic supply capacity should be large enough to supply the required
slew rate of the attached servo system (See Hydraulic Supply Specifications).
Significant reductions in dynamic performance, slew speed, and load capacity
will be caused when the VS-II does not receive the required flow and pressure.
Note: It is strongly recommended that a high volume hydraulic accumulator
be positioned on the supply line as close to the VariStroke-II actuator as
possible in order to maintain supply pressure and flow.
The supply pressure at the actuator inlet should remain within 10% of the set
operating pressure during a full slew. See Figure 3-3 below.
Suggested Configuration
Load
Hydraulic Accumulator
Maximize Accumulator
Capacity
Rotary Actuator
Hydraulic Supply
100 – 500 psi
Hydraulic Cylinder
Servovalve
Drain
Minimize Pipe Lengths /
Maximize Pipe Diameter
Figure 3-3. Suggested Configuration
Do not remove any test port connection plugs when hydraulic supply
pressure is applied. All required hydraulic connections must be
made before hydraulic pressure is applied. Hydraulic test ports
provided for use by authorized service personnel only.
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Electrical Connections
An overall electrical wiring diagram is shown in Figure 3-4. Detailed wiring
requirements for these connections will follow in the remainder of the Electrical
Connections section. The RS-232 connection is covered in Chapter 5 (Installing
and Running the PC Service Tool).
Figure 3-4. Electrical Wiring Diagram
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Chapter 4.
Electrical I/O
Electrical Connection Ports
A total of six 0.750-14 NPT electrical connection ports are provided for Electrical
I/O conduits or cable glands. See Outline drawings 2-2 through 2-6 for locations.
The Power Supply port should be used only for power supply cables. Low level
signal cables must be separated from the power cables. Wiring must be per
applicable Regulatory Compliance requirements.
Power Supply Inputs
The VS-II is designed with redundant power supply inputs through internal diode
isolation power capability. The redundant power supply input option is ideal for
users to use two separate power supplies at the same time. If one of the inputs is
lost, drops low, or experiences temporary power loss, the other power input will
take over without being affected by the first input. The user is provided with four
terminals (each terminal is sized for 8 AWG wire), two pairs each of positive and
negative, in order to allow the redundant power supply connections.
Power Supply Requirement
The VS-II requires dc input voltage within the range of 90 to 150VDC and wiring
sized appropriately to provide the nominal voltage at the VS-II input terminals
(during transients) to operate within specification. We recommend that the user
provide appropriate power and fusing as shown in Table 4-1 in order to safely
operate the VS-II.
An AC input power converter is available for conversion of 110/220VAC distribution
systems to dc input power for the VS-II. Each converter is an AC–to-DC power
supply capable of supplying power to the VS-II for all operating conditions. Since
the VS-II accepts redundant power inputs, the user can optionally use two of the
converters for redundancy.
The orderable part number is 1784-3171. Refer to the associated manual for
installation guidelines and restrictions.
Overcurrent protection devices recommended in this manual are
intended to provide protection against faults which result in
increased current flow, and therefore, increased heating and the
probability of the start and spread of fire.
Table 4-1. VS-II Power Requirements
Nominal
Voltage
125 Vdc
Description
Values
Input Voltage Range
Steady State Current
90 Vdc to 150 Vdc
2 A continuous
10 A transient for 200 ms depending on
the stroke of the output shaft
15 A, 250 V Slow Blow (time delay—
minimum I²t rating of 1200 A²s)
20 A, 250 V minimum
Transient Current
Fuse
Circuit Breaker
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Power Wiring
The VS-II is not equipped with an input power switch. Proper input power wiring
to the VS-II is crucial to its operation; therefore, we recommend that a safety
input power switch be provided for installation and servicing. Do not use a fuse
as a switch. A circuit breaker meeting the power supply requirement may be
used for this purpose. It is important that proper wiring be applied during system
installation to avoid an unwanted power trip or ground loop. Figure 4-1 illustrates
the right and wrong ways to wire the power cable to the VS-II.
The VS-II is provided with power terminals that are suitable for the selected
supplied line voltage application. Positive and negative pins are designated for
each input power entry that are sized for 8 AWG wire. This allows for redundancy
in the power supply input. If one of the inputs is lost, or drops low, then the other
input will take over the operation without being affected by the first input or dealing
with any temporary loss of operation. The two inputs of the connector are
independent from each other through internal diode isolation. Ideally these
redundant inputs would be used with two separate power supplies, but can be tied
together for operation with a single supply and redundant wiring (Figure 4-2). For
increased reliability, Woodward recommends that you always takes advantage of
the dual 8 AWG wiring configuration for your power supply requirements.
Figure 4-1. Power Wiring Recommendation
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Figure 4-2. Input Power Interface Diagram
Power Input Cable Requirements
Cable selection and sizing are very important to avoid power loss during driver operation.
The power supply input at the VS-II driver’s input terminals must always provide
the required nominal voltage for the driver, especially under transient conditions.
The input power wire must comply with local code requirements and be of sufficient
size such that the power supply voltage minus the voltage loss in the two lead wires
to the VS-II driver does not drop below the driver input minimum voltage requirement.
American Wire Gauge Voltage Drop
A standard wire gauge voltage drop at maximum ambient temperature is
provided in Table 4-2 to assist the cable selection.
Table 4-2. Voltage Drop Using American Wire Gauge (AWG)
Wire Gauge (AWG)
8
10
12
Voltage Drop per
Meter @ 10 A RoundTrip (V)
0.05
0.083
0.131
Voltage Drop Per Foot
@ 10 A Round-Trip (V)
0.016
0.025
0.040
A guideline for allowable voltage drop is to size wire for <5% of the nominal
voltage under maximum transient conditions. Maximum transient current can be
found in Table 4-1.
Voltage Drop Calculation Using American Wire Gauge
Example: A 10 AWG wires will drop 0.025 V/ft at 10 A at maximum ambient
temperature. Using 100 feet between the VS-II driver and the power supply
would provide a voltage drop of 100 x 0.025 = 2.5 V. It is very important to
ensure the voltage at the driver’s input terminal is within the product power input
specification in order to achieve the maximum performance.
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Wire Area Voltage Drop
A standard wire area voltage drop at maximum ambient temperature is provided
in Table 4-3 to assist the cable selection.
Table 4-3. Voltage Drop Using Wire Area (mm²)
Wire Gauge (mm²)
10
6
4
Voltage Drop Per
Meter @ 10 A RoundTrip (V)
0.043
0.072
0.108
Voltage Drop Per Foot
@ 10 A Round-Trip (V)
0.013
0.022
0.033
Example: 6 mm² wires will drop 0.072 V/m at 10 A. Using 50 meters between the
VariStroke II driver and the power supply would provide a voltage drop of 50 x 0.072
= 3.6 V.
The voltage at the VS-II input power terminal block must always stay
within the input voltage specification in order for the VS-II to operate
correctly. There is no cable length limitation to the input power of the
VS-II as long as the voltage at the VS-II power input terminal is within
the VS-II voltage range specification.
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Unit Grounding
The unit housing must be grounded using the designated EMC ground
connection point and PE ground connection points circled in Figure 4-3, top and
bottom, respectively.
Figure 4-3. Grounding terminal locations
For the PE connection, use required type (typically green/yellow, 2.5 mm² /
12 AWG) as necessary to meet the installation safety ground requirements. For
the EMC ground connection, use a short, low-impedance strap or cable (typically
> 3 mm² / 12 AWG and < 46 cm / 18 inches in length). Torque the ground lugs to
5.1 N·m (3.8 lb-in).
In cases where the EMC ground configuration also meets installation
safety ground requirements, no additional PE ground is required.
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LVDT Feedback
There is a 5 kHz excitation signal that is sent out to the LVDT’s primary coil from
the driver, and secondary coil voltages (VA & VB) are sent back. These signals
are then translated through a resolver to digital (RDC) algorithm, and from the
output of that block the processor calculates the hydraulic power cylinder
position. This information is then fed into the control model at the appropriate
intervals. VS-II features redundant LVDTs that are used to monitor the hydraulic
power cylinder’s linear position.
The LVDT’s are pre-wired in the Integrated VS-II actuators and no LVDT wiring
by the installer is required.
For Remote Servo kits and Servo Only installations: The LVDT feedback
should be appropriately wired and shielded according to instructions in this
manual and the length of the wires should be limited to 10 m and the lumped
capacitance should be limited to 5 nF (Figures 4-4 & 4-5).
LVDT Requirements:
Table 4-3. LVDT Requirements
Type:
Excitation:
Sum Voltage:
Output Voltage Ratio:
Linearity:
Sensor Stroke Length (SSL):
Sensor Cable Length Limit:
Six wire, difference/sum, Woodward supplied
3.0 VRMS at 5000 Hz
Va + Vb = 1.2 VRMS
(Va - Vb)/(Va + Vb) = ±0.5 VRMS
±0.5% Full Stroke
1x Cylinder Mechanical Stroke Length ≤ SSL
≤ 1.5x Cylinder Mechanical Stroke Length.
Both LVDTs must be of equal length in
redundant applications
10 m (33 feet) maximum between sensor and
VariStroke-II. Shielded, <5nF lumped
capacitance
LVDT Signal Requirement:
Primary (Generated from VS-II)
Frequency: 5 kHz
Voltage: Controlled by VS-II
VA and VB (Signal returned from the position sensor).
Max Voltage: ±1.5 V.
LVDT Wiring Requirements:





48
Shielding: Per drawing below
The maximum capacitance of the shielded twisted pair resolver cables
should be less than a total of 5 nF (not including internal capacitance) in
order to meet positioning accuracy and performance specifications
Maximum Run Length: 10 m
Wire Gauge Range: 16–20 AWG
Keep this and all other low level signal cables separated from motor cables
and input power cables to avoid unnecessary coupling (noise) between
them.
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Figure 4-4. LVDT 1 Interface Diagram
Figure 4-5. LVDT 2 Interface Diagram
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RS-232 Service Port
The RS-232 port (Figure 4-6) should only be used during the VS-II Configuration
with the Service Tool. See Chapter 5 for the detailed description of the
configuration for this positioner. All normal operation command and monitoring
should be done through the Ethernet, CAN, or other command and feedback
type depending on the positioner configuration. It is recommended that an RS232 isolator be applied when using the serial port in order to avoid any possible
communication issues. The reason for this is that the port is not isolated, and we
would like to avoid any potential ground loops or unnecessary EMI noise
coupling related to PC connections and typical industrial environments. The
RS-232 port requires a straight-through cable.
Figure 4-6. RS-232 Interface Diagram
RS-232 Communication Specification:

Data Rate: fixed baud rate at 38.4 kbps

Isolation: 1500 Vac from input power
Wiring Requirements:

External RS-232 Isolator is Recommended (Phoenix Contact
PSM-ME-RS-232/RS-232-P, Woodward P/N 1784-635)

Straight-through cable type

Keep this and all other low level signal cables separated from motor cables
and input power cables to avoid unnecessary coupling (noise) between
them.
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Analog Input
The analog input for the VS-II is a 4–20 mA configuration used as the position
command (demand) input.
Figure 4-7. Analog Input Interface Diagram
Analog Input Specification:

Analog 4–20 mA: Range is 2 to 22 mA

Max. temperature Drift: 200 ppm/°C

Calibrated Accuracy: 0.1% of FS

Common Mode Voltage: 100 V

Common Mode Rejection Ratio: –70 dB @ 500 Hz

Isolation: 400 k from each terminal to Digital Common
1500 Vac from Input Power
Wiring Requirements:

Individually shielded twisted pair cable

Keep this and all other low level signal cables separated from motor cables
and input power cables to avoid unnecessary coupling (noise) between
them.

Maximum Run Length: 100 m

Wire Gauge Range: 16–20 AWG (0.5 to 1.3 mm³)
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Analog Output
The analog output of the VS-II is in the form of a 4–20 mA output and can drive
load resistances up to 500. This output is configured to report actual hydraulic
power cylinder position. This output is designed for monitoring and diagnostic
purposes only, and is not meant for any type of closed loop feedback.
Figure 4-8. Analog Output Interface Diagram
Analog Output Specification:

Calibrated Accuracy: 0.5% of full range

Output Range: 4 to 20 mA

Load Range: 0  up to 500 

Maximum Temperature Drift: 300 ppm/°C

Isolation: 500 Vac from Digital Common, 1500 Vac from Input Power
Wiring Requirements:

Individually shielded twisted pair cable

Keep this and all other low level signal cables separated from motor cables
and input power cables to avoid unnecessary coupling (noise) between
them.

Maximum Run Length: 100 m

Wire Gauge Range: 16–20 AWG (0.5 to 1.3 mm³)

Shielding: per drawing above
Discrete Inputs
The VS-II has five discrete inputs. Terminals 63, 64, and 65 are configured for
Run Enable, Reset, and Auxiliary Trip at the factory, while terminals 66 and 67
are not used as a default as shown in Figure 4-9. See Chapters 5 and 6 to learn
more about configuration of the input and how to make changes if necessary.
The two states that the inputs expect are tied to the isolated ground terminals 68,
69, and 70 provided or to the +18 V isolated input to the control. There are five
inputs and only three ground terminals provided, so it may be necessary to use
one ground for multiple inputs. This is understood and allowable. Through the
software, the user can configure these inputs as active high (open) or active low
(ground) depending on the wiring preference. We recommend that the discrete
inputs be configured as active low in order to protect against broken wires. A
broken wire will look like an open input, which will be the inactive state. This is
especially important in the case of a shutdown input. External power is not
necessary for these inputs as the isolation is provided internally.
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Figure 4-9. Discrete Input Interface Diagram
Discrete Input Specification

Trip Points:
o If the input voltage is less than 3 V the input is guaranteed to detect a
low state (input voltage<3 V = LO).
o If the input voltage is greater than 7 V the input is guaranteed to detect
a high state (input voltage >7 V = HI).
o The open state will look like a high state to the controller, and,
therefore the two states of the input are open or tied to ground.
o The hysteresis between the low trip point and the high trip point will be
greater than 1 V.

Contact Types; The inputs will accept either:
o A dry contact from each terminal to ground or
o An open drain/collector switch to ground

Isolation: 500 Vac from Digital Common, 1500 Vac from Input Power
Wiring Requirements:

Keep this and all other low level signal cables separated from motor cables
and input power cables to avoid unnecessary coupling (noise) between
them.

Maximum Run Length: 100 m

Wire Gauge Range: 16–20 AWG
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Discrete Outputs
There are two Discrete Outputs on the VS-II. Either output can be configured to
react to any or all the Alarms/Shutdowns in the positioner. The outputs can also
be configured as active on or active off. See Chapters 5 and 6 to learn more
about configuration of the input and how to make changes if necessary. The
outputs can be used as high side or low side drivers depending on user
preference. We recommend, however, that the output be used as a high side
driver as shown in the diagram below. This configuration will make some
common wiring faults to ground more detectable.
Figure 4-10. Discrete Output Interface Diagram
Discrete Output Specification:

External Power Supply Voltage Range: 18–32 V

Maximum Load Current: 500 mA

Protection:
o The outputs are short circuit protected
o The outputs are recoverable after short circuit is removed

Response Time: Less than 2 ms

On-state Saturation Voltage: less than 1 V @ 500 mA

Off-state Leakage Current: less than 10 µA @ 32 V

Hardware Configuration Options: The outputs can be configured as highside or low-side drivers, but we recommend that they be used as high side
drivers if possible.

Isolation: 500 Vac from Digital Common, 1500 Vac from Input Power
Wiring Requirements:

Individually shielded twisted pair cable

Keep this and all other low level signal cables separated from motor cables
and input power cables to avoid unnecessary coupling (noise) between them.

Maximum Run Length: 100 m

Wire Gauge Range: 16-20 AWG (0.5 to 1.3 mm³)

Shielding: per drawing above
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CAN Communication Ports 1 and 2
The VS-II device may be controlled via CAN communication. There are two possible
modes: CANopen single with or without analog backup, CANopen dual, and
CANopen Virtual.
1. The CANopen single with or without backup: This mode uses CAN port 1 for
communication. Optionally it is possible to configure (by CAN communication) the
analog input as a backup signal. By default, the analog input is a backup signal. (See
analog input section for how to interface and setup an analog input.)
2. CANopen Dual: This mode uses CAN port 1 and CAN port 2. If the two ports are
working correctly, information received from CAN port 1 is used. If communication by
CAN port 1 is not possible any more (detected by communication time out), CAN port
2 is used for communication.
3. CANopen Virtual: This mode is used when two VS-II units are linked together. This
mode is currently not supported by the software/firmware in VS-II
The CAN communication baud rate can be selected using the Service Tool. The
possible options are:

125 kbps

250 kbps

500 kbps
Per CiA DS-102 Standard, the following are the recommended maximum cable
lengths. Differences in the baud rate and the cable length affect the number of
units that can be put onto a network.
Table 4-4. Recommended Maximum Cable Lengths per CiA DS-102 Standard
Baud Rate
500 Kbps
250 Kbps
125 Kbps
Cable Length
100 m
250 m
500 m
Number of VS-II on link
15
7
3
The use of controlled impedance (120 ohm) cable is recommended
for proper CANbus operation. See ISO 11898 series standards for
further information.
For communication wiring, use wires with a temperature rating of at
least 5 °C above surrounding ambient. All other functions use wires
with a temperature rating of at least 10 °C above surrounding
ambient.
Discharge to chassis prior to connecting or disconnecting CAN
connector.
If CAN port 1 is used, see Figure 4-11 of the CAN port interface. See the Analog
Input section above for the analog interface diagram.
Pins 45 and 46 are the termination jumper. Connecting these two pins with a
short wire on the connector will enable an internal 120  resistor between CAN
high and CAN low wire. This may help with the termination.
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If internal termination is used, disconnecting the terminal block will
result in communication disruption of all CAN devices on the
network, not just the VS-II. If this is not desired, do not use the
internal termination—use external termination.
Figure 4-11. CAN Port 1
Pins 47 and 48 are the CAN High and CAN low wires typically found on a CAN
system.
Pins 49 and 50 are two additional CAN high and CAN low pins. These can be
used to daisy chain the CANbus to the next device, without the need for a
junction box.
If the daisy chain is used, disconnecting the connector will
disconnect the complete CANbus. Other devices communicating on
the CANbus will not be able to communicate any more. If this is not
desired, do not daisy chain the VS-II.
Pin 51 is the CAN ground. The VS-II side of the CAN link is galvanically isolated
from the VS-II, ground, and system common. Therefore, there is a need to
connect the isolated ground to the ground of the user control.
Pin 52 is the ground of the VS-II. This pin is also used to terminate the wiring shield.
Discharge to chassis prior to connecting or disconnecting CAN
connector.
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Figure 4-12. CAN Port 2
If you are using dual can communication mode, there are two identical communication
ports. Port 1 and port 2 are wired identically. For description, see port 1.
Table 4-5. CAN Port Pin Function
Pin Number
45
46
47
48
49
50
51
52
72
73
74
75
76
77
78
79
Function
CAN 1 Termination jumper
CAN 1 Termination jumper
CAN 1 High in
CAN 1 Low in
CAN 1 High out
CAN 1 Low out
CAN 1 ISO GND
CAN 1 Shield
CAN 2 Termination jumper
CAN 2 Termination jumper
CAN 2 High in
CAN 2 Low in
CAN 2 High out
CAN 2 Low out
CAN 2 ISO GND
CAN 2 Shield
See Chapter 6 for more information on CANopen communications.
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RS-485 Communication Port
The VS-II provides an isolated RS-485 communication port (Figure 4-13). This
port can be used for a long-distance connection to the control system to utilize
the Service Tool.
Figure 4-13. RS-485 Interface Diagram
RS-485 Port Specification (Service Port)

Baud Rate: Fixed at 38.4 kbps

Isolation: 500 Vac from Digital Common, 1500 Vac from input power
Wiring Requirements:

Individually shielded twisted pair cable

Keep this and all other low level signal cables separated from motor cables
and input power cables to avoid unnecessary coupling (noise) between
them.

Maximum Run Length: 100 m

Wire Gauge Range: 16–20 AWG

Shielding: per drawing above
General Wiring Information
The VS-II has 6x 0.750-14 NPT wiring entries. It is important to use different
wiring entries for low-signal cables and input power cables to avoid unnecessary
coupling (noise) between them. It is recommended to use either the entry at the
bottom or lower left (when facing the servo valve front access cover) for input
power cables.
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When wiring using cable and cable glands, the gland fitting (not included with
VS-II actuator) must meet the same hazardous locations criteria as the VS-II.
Follow all manufacturer installation recommendations and special conditions for
safe use that are supplied with the cable gland. The cable insulation must have a
temperature rating of at least 85 °C and 10 °C above the maximum ambient and
fluid temperature.
Use of appropriately certified cable glands or sealing device is
required for all entries to the flameproof enclosure to maintain the
method of protection.
Strip the cable insulation (not the wire insulation) to expose 12 cm of the
conductors. Strip the wire insulation 5 mm from each conductor. Mark wires
according to their designation and install connectors, if required.
Remove the front access cover. Pass the wires through the cable gland (not
provided) or conduit fitting and attach to the printed circuit board terminal blocks
in accordance with their wiring diagram. Snap the terminal blocks into the header
terminal blocks on the PCB. Tighten the terminal block flange screws to 0.5 Nm
(4.4 lb-in).
Install the PE ground and EMC ground straps to the lugs provided. Tighten to
5.1 Nm (45 lb-in).
For Class I, Division 1 products: Conduit seals must be installed
within 46 cm (18 inches) of the conduit entry when the VS-II is used
in Class I, Division 1 hazardous locations.
Tighten the cable gland fitting per manufacturer’s instructions or pour the conduit
seal to provide strain relief for the cable and to seal the interface between the
wiring cable and the VS-II.
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Chapter 5.
Service Tool Installation
The VS-II includes a software-based Programming and Configuration tool (PCT)
that can be loaded onto a computer and used to:

Change maximum stop position and cylinder size settings.

Calibrate the final cylinder.

Configure the inputs and outputs

View diagnostic flags
An unsafe condition could occur with improper use of these software
tools. Only trained personnel should have access to these tools.
Setup
The PC Service Tool or Programming and Configuration Tool is a software
application which runs on Windows-based PC or laptop. It requires a physical
RS-232 connection between the computer and the VS-II. The physical
connection can be made by connecting to the VS-II at the Service Port (RS-232).
The electronics enclosure cover must be removed to access this port on the
electronic control board. Remove the twenty (20) M12 screws that are around
the perimeter of the cover and carefully remove the cover. Take care to not lose
the O-ring seal or damage the mating surfaces of the cover and the servovalve
body.
Note: When replacing the electronics enclosure cover, ensure that the Oring seal is completely seated in the O-ring groove and that the mating
surfaces are clean, install the cover and M12 screws, and torque the M12
screws to 68-81 Nm (50–60 ft-lbf).
Use a straight-through serial cable (not null modem). For newer PCs or laptops
with USB ports, a USB-to-serial converter is required. An approved converter can
be obtained from Woodward P/N 8928-1151.
Woodward offers a serial cable as a kit that can be ordered. The part number for
this kit is 8928-7323, which contains a 10-foot long (3 m) DB9-F to DB9-M
straight-through cable.
Note: this cable has two nuts on the screws on the female end that need to
be removed prior installing this end.
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Figure 5-1. Service Port Connections
Do not to damage the O-ring cover seal, the cover surface, or the VS-II
servovalve surface while removing or replacing the cover. Damage to
sealing surfaces may result in moisture ingress, fire, or explosion.
Clean the surface with rubbing alcohol if necessary. Inspect the cover
joint surfaces to ensure that they are not damaged or contaminated.
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Installing the VariStroke-II Service Tool
Use the following installation procedure to install the VariStroke-II Service Tool
(Programming and Configuration Tool).
Locate/obtain VS-II Service Tool Installation CD provided with each VS-II.
(Alternatively, the VS-II Service Tool Installation file can be downloaded from
Woodward’s website [www.woodward.com/software]). Search for VariStroke II.
To run the installation program follow the installation instructions (shown below).
1.
Double click on the install file 9927-2325_xxx.exe. (Note: xxx is a
placeholder for the revision of the install package i.e. 9927-2325_NEW.exe.
or 9927-2325_A.exe are examples of Rev NEW and Rev A versions.). If the
following screen appears, this means there is a new version of ToolKit which
needs to be installed on the PC.
Figure 5-2. ToolKit License Agreement
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2.
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The Tool launches and the Welcome screen is displayed. Click on “Next”.
Figure 5-3. VariStroke II Installation Wizard Welcome Screen
3.
The EULA screen appears. Accept the terms of the License Agreement by
checking the checkbox, then click “Next” to continue.
Figure 5-4. Installation End-User License Agreement
4. The Install page appears. “Create shortcut for this program on the desktop” is
set as the default. Uncheck this box if you do not want a Service Tool icon on
your desktop. Click on “Install”.
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Figure 5-5. Installation Install Page
5.
The Installation of the Service tool will proceed.
Figure 5-6. Service Tool Installation in Progress
6.
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When the installation is finished, the Installation Complete screen will
appear. The “Launch when setup exits” box in the lower left is unchecked by
default. You do not want to launch the Service tool until the VS-II has been
connected to the computer through a serial cable. At launch the Service tool
detects which COM port is connected to the VS-II.
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If you launch the service tool application before you connect the
serial cable between the computer and the VS-II the service tool will
not detect the new serial connection. To detect the connection you
will have to exit and re-launch the service tool.
7.
When you click on “Finish” you will exit the installation wizard.
Figure 5-7. Service Tool Installation Complete
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Getting Started with the VS-II Service Tool
The VS-II Service Tool communicates with the VS-II via RS-232 connection. The
PC (personal computer), running the VS-II Service Tool is connected to the VS-II
using a 9-pin straight-through serial cable. Connect the serial cable to the
RS-232 Service Port on the back side of the VS-II and an unused RS-232 serial
port (COM port) on the PC side.
Refer to the appropriate VS-II Outline drawing for the exact location of the VS-II
Service port (marked RS232 SERVICE PORT). Also, refer to the section RS-232
Service Port section in Chapter 2 for the technical specifications of the RS-232
Service Port.
The serial cable used to connect the VS-II to the PC running the VS-II
Service Tool has to be set up as straight-through configuration. Do
NOT use a serial cable with Null-Modem configuration to connect the
VS-II to the PC!
General Installation Check before Applying Power to the VS-II
1.
2.
3.
Verify the power source is set to within the input operating voltage range.
Always make sure that the power at the driver is within the input power
range to ensure the operation of the VS-II.
Verify all VS-II cable connections are properly installed, including EMC
ground and PE ground, and I/O cable shield grounding termination. See
Chapter 4.
In the case of using Analog input as demand source, verify that the input
command is between 4 to 20 mA.
Check all wiring from point to point, all connections, and
terminations to ensure having proper installation before applying
power to the VS-II.
Verify that hydraulic supply pressure is not present at the VS-II
before applying power to the VS-II or unexpected motion of the
output shaft may occur.
Failure to follow general installation check prior to applying the
power to the driver could damage the turbine due to overspeed
conditions if the actuator shuts down in the wrong direction.
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Connecting and Disconnecting the VS-II Service Tool
1. After the VS-II and the PC have been connected via the serial cable and
power is applied to the VS-II, the VS-II Service Tool can be started from
the Windows Start menu or a shortcut on the Desktop (if applicable). The
service tool will launch and the next screen you will see will be the Home
Screen of the VS-II service Tool.
Figure 5-7. Home Screen
2. Connection to the VS-II is made by clicking the connect button on the
tool bar.
Figure 5-8. Service Tool Connection Button
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You will then see the following screen in Figure 5-9.
Figure 5-9. Service Tool Communications Port Selection
Select the network connection that the serial cable is connected to. Select your
available network and then set “Baud Rate” to “AutoDetection”. Press the
“Connect” button. The Service Tool will connect to the VS-II within a few
seconds. When it does, the “Connect” button in the ribbon will be grayed-out and
the “Disconnect” button will be activated. The Service tool is now connected and
communicating with the VS-II and you can calibrate, configure and control the
VS-II through the service tool.
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Figure 5-10. Service Tool Main Screen
If the Service Tool does not establish a successful connection to the VS-II after
approximately 30 seconds, or the VS-II Service Tool annunciates that it cannot
find the correct SID file, refer to the next section “Connection Troubleshooting”
for further information.
When you want to end your session and disconnect the Service Tool from the
VS-II press the “Disconnect” button. The Service tool will cease communication
with the VS-II, the “Disconnect” button will be grayed-out and the “Connect”
button will be activated. The service tool is now ready to communicate with the
VS-II the next time you press the “Connect” button.
Connection Troubleshooting
Service Tool Does Not Connect to VS-II
If the communication has not been established after approximately 30 seconds,
disconnect the Service Tool from the VS-II by either selecting the disconnect
button or using ‘Device’ and ‘Disconnect’ from the main tool bar.
Check the serial connection between the VS-II and the PC and make sure the
straight-through serial cable is connected correctly on the PC and VS-II side.
Verify that the serial cable is securely connected to the selected communication
port on the VS-II and the PC. Also check that the power supply is connected and
turned on.
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Service Tool Cannot Find the Correct SID File
The communication between the VS-II Service Tool and the VS-II is based on the
Service Interface Definition (SID) file that defines the communication variable mapping.
If the SID file is missing, communication between the VS-II Service Tool and the VS-II
is not possible. The SID file is included in the Service Tool software installation
package and is installed to directory chosen during the Service Tool install.
A dialog box similar to the following appears upon trying to connect if the Service
Tool cannot find the correct SID file to communicate with the VS-II.
Figure 5-11. Service Tool Unable to Locate SID File
If this occurs, select the browse button and choose the ‘C:\Program
Files\Woodward\Toolkit Definitions’ folder (default setting) or any custom folder
for SID files selected during the installation process of the Service Tool.
To change the settings for default folders for SID files, select ‘Options’ from the
‘Tools’ menu on the main tool bar.
Figure 5-12. Service Tool Update Default Folder for SID Files
Highlight the SID files option and the select ‘Modify’. Using the browser, choose
the folder where the SID file is located. When finished select ‘OK’.
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Chapter 6.
Configuration, Calibration, and
Monitoring
The VS-II Service Tool is organized in to a series of pages that allow the VS-II to
be set up for proper operation. The following section will outline the various
pages and their functions.
The engine, turbine, or other type of prime mover should be
equipped with an overspeed shutdown system to protect against
runaway or damage to the prime mover with possible personal injury,
loss of life, or property damage.
The overspeed shutdown system must be totally independent of the
prime mover control system. An overtemperature or overpressure
shutdown system may also be needed for safety, as appropriate.
An unsafe condition could occur with improper use of these software
tools. Only trained personnel should have access to these tools.
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Service Tool Sidebar
The sidebar shown below is present on every Service Tool page. Included in this
sidebar are operational status indicators and information, as well as “Shortcuts”
for changing Demand Input Source or navigating to commonly accessed Service
Tool pages.
Figure 6-1. Service Tool Summary Faults and Control Buttons
Alarm LED:
When this LED indicator is illuminated yellow, the unit has detected an operating
condition, which is outside of recommended operating parameters, but the VS-II
is still operating. The cause of alarm conditions should be determined and
corrected to prevent damage to the turbine, VS-II, or other auxiliary equipment.
Refer to Chapter 7 for a list of Alarm conditions.
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Shutdown LED:
When this LED indicator is illuminated red, a shutdown condition has been
invoked. This state may have occurred because the analog inputs are not in the
4–20 mA range, or the Run Enable discrete input is selected and not on, or the
Shutdown button has been pressed. After checking that the analog demands and
the Run Enable are OK, refer to Chapter 7 for a list of Shutdown conditions if the
problem persists.
Demand Input Source:
This shows the currently selected actuator position demand source. Possible
options are: Analog Input, CAN OPEN digital input, and Manual Position.
Change Source:
This button pops up a screen that allows the Demand Input source to be
selected. Possible options are: Analog Input, CAN OPEN digital input, and
Manual Position. Analog Input and CAN OPEN digital input are for demand
signals from an external control and Manual Position is used for manual
positioning from within the Service Tool.
Shutdown button:
This button can be used to invoke a shutdown condition and move the actuator to
the minimum position.
The SHUTDOWN button will move the VS-II to 0% position. This will
potentially shut down the Prime Mover (Turbine)!
Reset Control
This button will reset the control from a shutdown condition, provided the cause
of the shutdown has been cleared. Identified causes of shutdown conditions can
be found on the Fault Status/Configuration page. All diagnostic flags will be
cleared if the diagnostic condition is no longer present.
The Reset button will reset the VS-II if diagnostic condition(s) are no
longer present. The valve/actuator system will become active! Ensure
system is tagged out or ready to operate before issuing the Reset
command. Stay clear of any moving parts WHEN resetting the control.
Reset Stored Errors
Operational errors are stored in non-volatile memory until cleared by pressing
this button. This button will reset the stored faults, on screens that indicate stored
faults, if the diagnostic condition(s) are cleared. Only pressing the Reset Stored
Errors button resets the stored flag, a power cycle will not clear these flags.
Stored faults will not affect the operation of the VS-II.
Navigation Buttons
Pressing these buttons will navigate you to the most commonly used pages of
the VS-II Service Tool. Pages can also be accessed by using the dropdown
menu at the top of the Toolkit Window.
Diagnostics Buttons
Pressing these buttons will navigate you to the pages with operational values that
could be useful for diagnostics and troubleshooting.
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Identification Page
This page will display system information about the VS-II Actuator/servo that is
currently connected to the PC Service Tool.
Figure 6-2. System Information Page
Controller Identification
(Driver P/N, S/N, Revision): These fields display the Electronic Driver Part
Number (B_P/N), Serial Number (B_S/N), and Revision Number. This
information is entered automatically by the VS-II software.
Valve Identification (Actuator P/N, Revision, S/N): These fields display the
Actuator Assembly Part Number (P/N), Revision Number, and Serial Number
(S/N). This information is entered automatically by the VS-II software.
PC Service & Diagnostic Tool Version: This field displays the Version of
Firmware installed. This information is entered automatically by the VS-II
software.
Firmware Version: This field displays the firmware part number and version of
the software programmed into the VS-II driver. This information is entered
automatically by the VS-II software.
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Status Overview Page
This page monitors the VS-II core operational values.
Figure 6-3. Status Overview Page
Position readings:
Position demand is the position command in % of full (100%) calibrated stroke.
Actual position is the actuator hydraulic cylinder position in % of full (100%)
calibrated stroke. It is the average of the two cylinder position sensor readings.
Actual positions sensor 1 and 2 are the hydraulic cylinder position readings in
% of full (100%) calibrated stroke from each of the two LVDT position sensors.
Motor Control Parameters:
Actual current is the instantaneous current going to the Servovalve control
motor.
Actual current (filtered) is the average current going to the Servovalve control
motor. The instantaneous current is constantly changing and the average gives
a better assessment of control current.
Discrete Input and Discrete Output Status: The status of the discrete inputs
and outputs is shown in Figure 6-3 and will annunciate when active. The discrete
input and output behavior is user configurable on the Input and Output
configuration pages.
Analog Values:
Demanded Current is the current on the analog terminals
Input Voltage 1 is the voltage at the supply terminals 1.
Input Voltage 2 is the voltage at the supply terminals 2.
Internal Bus Voltage is the voltage on the VS-II internal power Bus.
Input Current is the current into the VS-II.
Power Board Temperature is the temperature measured on the power board of
the VS-II.
Control Board Temperature is the temperature measured on the control board
of the VS-II.
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Trending Plot/ Graph:
This graph will display the current demanded position, the actual measured
feedback position of the final cylinder, and the servovalve motor current with
respect to time. The “Start” button in the upper left hand corner of the graph
starts the trending process. Pressing the Stop button freezes the currently
displayed values. Pressing the Start button again erases the last traces and
restarts the trending process.
Pressing the Properties button opens the Trending Properties window. From this
window trend screen properties such as time span and sample rate can be
changed.
The Export feature will export data collected during the trending process for
further analysis in a spreadsheet.
Figure 6-4. Trending Properties Page
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Configuration and Calibration Page
The Configuration and Calibration page can be used to set the VS-II operating
pressure and cylinder diameter to the desired value and to start the calibration
process. The “wizards” will guide you through the actuator configuration and
calibration. The “wizards” will remember where you are in the process and will
return you to where you left off if you navigate to a different page to view or set
something else.
To prevent personal injury or death and damage to equipment, the
controlled prime mover must not be allowed to run or operate during
any of the following procedures. The main steam valve or main fuel
control must be turned off to prevent operation of the controlled
system.
To enable the Configuration and Calibration functions of the VS-II
must be shutdown by any of the following methods. Press the
Shutdown button when in any of the three demand input source
selections, or when in analog or CAN demand input source, set the
RUN ENABLE line low, and/or put your analog input demand(s)
below 2 mA (suggest 0 mA).
Figure 6-5. Configuration and Calibration Page
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Actuator Configuration
Press the Configure button to begin the actuator configuration wizard. The following
screen will appear, which gives detailed instructions for navigation using the wizard.
Figure 6-6. Detailed Wizard Navigation Instructions
To begin the actuator configuration, press “Next” and the following screen will appear:
Figure 6-7. VS-II Current Settings
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This page displays the operational settings stored in the VS-II. If the Supply
pressure or the Final Cylinder (hydraulic power cylinder) diameter is incorrect, or
the status is “USER CONFIGURATION NOT DONE”, press the Edit Config
button in the upper right corner of the screen to edit them. The VS-II will not
respond to position demand input until this setup is completed and confirmed by
setting the status to “USER CONFIGURATION DONE”.
If the Performance Index Warning is on, the hydraulic pressure may be too high
for optimum performance with this cylinder diameter. See the “Performance
Index” section in Chapter 2 for more detailed information.
When the “Edit Config” button is pushed, the following screen will appear:
Figure 6-8. VS-II Configuration Editing Screen
The valid range of supply pressures is between 3.5 and 34.4 bar. After setting
the correct supply pressure and cylinder diameter, make sure that “Confirm
Basic Setup” is set to “USER CONFIGURATION DONE” to confirm setup.
The VS-II will not respond to position demand input until this setup is confirmed.
Click “OK” when done and the wizard will save the values and return to the
previous page. “Apply” will also save the values, but you must press the “Cancel”
button to return to the previous page (the newly saved values will not be
canceled.) The “Cancel” button will only cancel unsaved values and return you
to the previous page.
Failure to input the correct Supply Pressure can result in unstable
actuator performance. Ensure that this setting is correct and that the
system pressure regulators and accumulators do not allow more
than a ±10% variation in Supply Pressure.
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Stability: Certain combinations of Supply Pressure and Cylinder
Volume can cause the actuator to operate at reduced performance.
See the “Performance Index” section in Chapter 2 for more detailed
information.
Press “Home” to return to the Home Page and start Calibration.
The “Advanced” button is used to access the more advanced Configuration Options.
These are pre-configured from the factory and normally do not need to be changed.
The Advanced Setup includes the following:
 Control Bandwidth
 Slew Rate limit
 Slow Zone
 Position Sensor Redundancy
 Servo Valve Startup Spring Check
 Final Cylinder LVDT Position Sensor Startup Check
When the “Advanced” button is pushed, the following screen will appear:
Figure 6-9. VS-II Advanced Setup “Dynamics”
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Press the “Edit Config” button in the upper right corner of the screen to edit any of the
values shown on this screen or press “Next” to go to the next page to edit settings not
shown on this screen. Continue to press “Next” until the settings you want to access are
shown, then press “Edit Config”
Figure 6-10. “Edit Config” for Dynamics settings:
Control Bandwidth:
Bandwidth affects how fast the actuator will respond to a position demand
change. The higher this setting is set, the quicker the actuator will respond.
However, it will be more sensitive to electrical noise on the signal. Valid settings
are between 0.5 and 10 Hz. The default setting is 5 Hz and this is recommended
for most applications. Consider utilizing analog output to monitor actuator
position if service tool usage is not an option to verify the bandwidth setting is
correct. If too high it could cause limit cycle which would lead to premature
product wear, or if too low, reduced performance or outer loop instability.
Slew Rate Setting:
This setting allows a maximum limit to be set on the actuator rate of travel in % of
full travel/second. Valid values are between 1 and 1000 %/second. The higher
values, such as 1000 %/second, do not necessarily mean the actuator will move
at that rate, but would be the maximum rate allowed by the control if supply
pressure was high enough/load low enough to achieve this rate. The rate limit
should be set to a lower value if a high rate is undesirable for the operation of the
turbine.
Slow Zone Setting:
This can be thought of as Soft Seating, similar to a hydraulic cushion except that
it is electronically controlled by the VS-II control and servovalve. This function
can be used to limit the steam valve seating velocity in order to lengthen the life
of the valve.
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The Slow Zone feature will not function in some shutdown
conditions. Loss of cylinder position feedback, loss of electrical
power, or an internal electronics fault will result in loss of the Soft
Seating functionality.
Slow Zone “Edge” adjustment sets the position at which the actuator slew rate
limit will switch from the Operation Slew Rate Limit to the Slow Zone Rate.
Slow Zone “Rate” is the slew rate, in %/second, of the actuator in the Slow Zone.
This adjustment sets the slew rate limit of the actuator when the position is below
the Slow Zone Edge value. Note: This only limits rate of travel in the direction
toward 0%. Valid values are 0 to 50% for the Edge, and 1 to 51%/second for
Rate.
Incorrect Slew Rate Limits and Soft Seating adjustments can result in
high seating velocities that may damage equipment.
Configuration of the Slow Zone settings and Slew Rate Limits can
result in excessively slow closing speeds.
The engine, turbine, or other type of prime mover should be equipped
with an overspeed shutdown device to protect against runaway or
damage to the prime mover with possible personal injury, loss of life,
or property damage.
Figure 6-11. Position Redundancy Manager Page:
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Figure 6-12. Edit Config for Position Redundancy Manager
Dual Position Sensor Signal Selection:
Since the redundant LVDT sensor outputs will be slightly different due to sensor
calibration variation, how the LVDT sensor outputs are used by the control needs
to be defined. “Use Maximum’ uses the LVDT signal that is highest, “Use
Minimum” uses the LVDT signal that is lowest, and “Use Average” uses the
average of both LVDT signals. In addition to defining which sensor(s) is used
during normal operation, “Selection” will affect which direction a momentary
“bump” in actuator position will be if there is a failure of one or the other sensor.
For example, if set to “Use Minimum” and the sensor reading minimum fails, the
control will switch to the sensor reading maximum, which will in turn affect a
momentary “bump” of the actuator position toward minimum.
Position Sensor (LVDT) Difference Settings:
“Alarm difference” is the threshold level that a cylinder position sensor error
alarm will be annunciated. “Shutdown difference” is the threshold level at which
a shutdown will be initiated.
Linearization Table Page:
Note: The Linearization Table is not implemented for VariStroke II
Service Tool 9927-2325.
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Figure 6-13. Startup Configuration Page
Figure 6-14. Edit Config for Startup Configuration
Servo Valve Startup Check: Spring Check:
Upon startup and reset commands, the VS-II performs a brief test to ensure that the
servo valve return spring is functioning properly. This is performed before moving the
actuator away from the fail-safe position and will not move the actuator. It is
recommended that this check be “Enabled”.
Final Cylinder LVDT Position Sensor Startup Check:
This test is performed anytime the control is initializing the servovalve control for
operation and checks both LVDT position sensors for proper function. It is recommended
that this check be “Enabled”.
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Actuator Calibration
The VariStroke-II Actuator has an electronically variable stroke length to match
the stroke of the valve it is attached to, adjustable anywhere between 50 and
100% of the mechanical stroke of the hydraulic power cylinder. To calibrate the
actuator to the valve stroke, the first step of the Calibration is to verify that the
correct LVDT sensitivity is entered. After that, there is an Auto Zero function,
where the control strokes the actuator to find the “zero” position of the valve
stroke. Next, the maximum valve position is found, which can be done either
automatically or manually. Finally, the VS-II can be manually stroked to verify
the stroke settings.
Press the “Calibrate” button to begin the actuator calibration wizard. The
following screen will appear, which gives detailed instructions for navigation
using the wizard. The VS-II must be in shutdown mode to use the calibration
wizard.
6-15. VariStroke II Actuator Calibration Wizard
Press “Next” to enter the Calibration Mode.
Note: the VariStroke II must be Shutdown to enter Calibration Mode. To
do this, press the ‘Shutdown” button when in any of the three selectable
demand input source selections, or when in analog or CAN demand input
source, set the RUN ENABLE line low, and/or put the analog input
demand(s) below 2 mA (suggest 0 mA).
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Figure 6-16. VariStroke II Calibration Mode
Press “Next”:
Figure 6-17. Confirmation that VariStroke II has been locked in Calibration Mode
Press “Next” to set up the LVDT’s:
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Figure 6-18. Cylinder Position Sensor Final Selection
On this page, nothing needs to be done if a complete Woodward integrated or
remote VS-II was purchased. If a non-Woodward power cylinder is used, or if an
LVDT is replaced, enter the LVDT Sensitivity values here.
If only one LVDT is used, or if one is damaged, the sensor that is to be used by
the VS-II control can also be selected on this page.
Press “Next” to begin Calibration of the actuator and the following screen
appears:
Figure 6-19. Initializing Auto Zero Page
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Potential damage to linkage and/or attachments can occur if the
linkage and/or attachments are not designed to withstand the full stall
force of the actuator at the supplied operating pressure. It is the
installer’s responsibility to verify the structural capabilities of the
linkage and/or attachments. IF the linkage and/or attachments CANNOT
WITHSTAND THE FULL STALL FORCE of the actuator DO NOT USE
“Auto Zero” or “AutoMaxCal” with the linkage connected to the
actuator. Instead, “Auto Zero” and “ManualCal” must be used with the
linkage disconnected to set the desired stroke length and offsets.
Turning on the hydraulic supply can cause the actuator to move.
Ensure all personnel are clear of moving components before turning on
the hydraulics and/or initiating the calibration sequence.
Before beginning calibration the VS-II must have power and hydraulic pressure supplied
to the unit.
If the Calibration Complete Shutdown indicator on the screen is red, press the “Reset
Control” button before pressing “Next”.
Auto Zero
Press “Next” to start the Auto Zero process. Pressing this button will open the VS-II
servo valve, causing the actuator to move toward the minimum/fail-safe position. Once a
physical stop is contacted, the VS-II will capture this as the mechanical minimum
position.
The actuator may move rapidly toward the minimum position,
depending on initial position and hydraulic supply pressure.
Figure 6-20. Auto Zero Automatic Calibration Process Warning.
When Auto Zero is complete, the following screen will appear:
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6-21. Successful Completion of Auto Zero Calibration
Press “Next” to access the Max Calibration selection screen. On this screen
there will be a choice of either ManualCal or AutoMaxCal. AutoMaxCal will
move the actuator from 0% until it either reaches (stalls out against) the
maximum end of the valve/linkage travel or the end of the mechanical stroke of
the VS-II actuator.
AutoMaxCal
Potential damage to linkage and/or attachments can occur if
the linkage and/or attachments are not designed to withstand
the full stall force of the actuator at the supplied operating
pressure. It is the installer’s responsibility to verify the
structural capabilities of the linkage and/or attachments. IF
the linkage and/or attachments CANNOT WITHSTAND THE
FULL STALL FORCE of the actuator DO NOT USE “Auto Zero”
or “AutoMaxCal” with the linkage connected to the actuator.
Instead, “Auto Zero” and “ManualCal” must be used with the
linkage disconnected to set the desired stroke length and
offsets.
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Figure 6-22. Auto Max Calibration Page
Press “AutoMaxCal” to start the automatic process that automatically finds the
maximum mechanical stroke limit or press “ManualCal” to manually set the
maximum stroke limit (see Manual Calibration section below).
After pressing “AutoMaxCal”, the VS-II servo valve will slightly open to slowly
move the actuator toward the maximum position. Once a physical stop is
contacted, the VS-II will capture this as the mechanical maximum position. The
actuator will then slowly return to the minimum positon.
Figure 6-23. Auto Max Calibration in Progress Page
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Followed by the Auto Calibration Routine Complete page.
Figure 6-24. Auto Calibration Routine Complete Page
Press “Next” to go to the next screen, Manual Calibration, which is the same
screen that would have been reached by pressing “ManualCal” earlier in this
section.
Manual Calibration
Manual Calibration can be used to set both the minimum (0 %) and maximum (100%)
final cylinder positions or to modify the positions from the automatic calibration positions.
Figure 6-25. VS-II Manual Calibration Page
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0% actuator position (corresponding to 0% position demand) can be offset from
the mechanical end of travel stop found by the “Auto Zero” function. For
example, if the linkage was adjusted such that the final cylinder was offset 3mm
above its minimum travel position when the steam valve was in the closed
position (before the Auto Zero function was run), then inputting -3mm (or any
value less than “0”) into the Final Cylinder 0% Position box will cause the VS-II to
apply closing force to the valve/linkage when 0% position (4 mA) is demanded.
This feature can be used to assure that the steam valve continues to fully close if
there is a thermal expansion dimensional change or steam valve wear.
If the AutoMaxCal was not used, then the Maximum Position must be
specified now. This position is specified in millimeters and is the maximum
allowed travel distance from the mechanical travel minimum position found
during the Auto Zero function, not the 0% position if you are using a 0% position
offset.
Manual Stroke (calibration mode)
It is recommended that the VS-II actuator be manually stroked from minimum to
maximum position to verify correct operation and that the steam valve fully opens
and closes with current settings. Additionally, for installations where the linkage
was disconnected for calibration because it could not withstand the full stall force
of the actuator, it is extremely important to verify that the actuator travel matches
the steam valve so that the linkage is not damaged when it is reconnected.
The Manual Stroke mode will cause the actuator to move. Ensure all
personnel are clear of moving components before entering manual
stroke mode.
Press “Next”, then “Manual Stroke” to advance to the Manual stroke page.
Figure 6-26. Manual Stroke Page
The manual stoke page contains a trending chart, Final Cylinder Position (mm)
bar meter, Calibration Point setting, Manual Position demand input, and Slew
Rate input.
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Actuator movement can be monitored and viewed using this trend chart. To do
so, press “Start” at the top left corner of the trend chart. The properties of the
chart can be changed using properties button. The data can be exported using
the Export button. Real time actuator position is also seen in the bar meter on
the right side of the screen.
Improper linkage adjustment or calibration could result in the steam
valve not fully closing at the 0% position. Use the manual stroking
function to verify that the VS-II can fully close the steam control
valve. Visually verify that the actuator travel direction matches the
demand signal and that the opening and closing directions are
correct.
The Calibration of the actuator can be changed by inputting new values into the
0% and 100% calibration boxes. This will overwrite the values from the Auto Cal
and Manual Cal process. The settings can be verified or tested by inputting the
values directly into the Manual Position demand box and hitting Enter.
Alternatively, the up and down arrows can be used to change the demanded
position, in 1% or 10% of the displayed value steps. The rate at which the
actuator slews can be set by inputting the desired rate into the Slew Rate box.
Note: This only affects the slew rate for Manual Operation.
For normal operation, the slew rate limit that is used was set during the
configuration process done earlier.
Cylinder Position Sensors, Final Cylinder Position, User Stroke, and
Performance Warning are informational only and cannot be adjusted.
If the Performance Index Warning light is illuminated it means that the
Configuration (Servovalve size, operating pressure, cylinder displacement) may
not provide optimal performance. Overshoot and limit cycle may be
unacceptable. See the Performance Index section in Chapter 2 for more
information.
When complete, press “Done”
Figure 6-27. Manual Stroke Mode Complete Page
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Press “Next” to continue, or “Abort” to exit without saving.
Figure 6-28. Save or Abort Configuration Changes Page
If satisfied with the Calibration settings displayed, press “Save”, or “Abort” to exit
without saving.
Figure 6-29. Calibration Parameters Successfully Saved Page
Press “Done” to return to the home page. A “Calibration Complete Shutdown” is
issued upon completion of Calibration. This flag can be viewed on the “Fault
Status/Configuration” page. This will need to be cleared before the VS-II can
begin normal operation by pressing “Reset Control”.
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Manual Operation Page
This page is different than the Manual Operation page that is within the
Configuration Calibration Wizard. No changes can be done to the configuration
from this page, unlike within the wizard.
To prevent personal injury or death and damage to equipment, the
controlled steam turbine must not be allowed to run or operate
during any of the following procedures. The main steam valve must
be turned off to prevent operation of the controlled system.
Once the Manual Operation button is pressed, the following screen will be
displayed below the trend chart. Actuator movement can be monitored and
viewed using this trend chart. To do so, press “Start” at the top left corner of the
trend chart. To change the cylinder position, change the Position Request value
(see below). Demand Input Source must be set to “Manual Position” and the
control must be in operational mode, not shutdown, for manual operation to work.
Press “Change Source” to select Manual Position, and press Reset Control to
exit Shutdown mode.
Figure 6-30. Manual Operation Page
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Input Configuration Page
The Input Configuration page provides the user with the ability to change the
input source and to modify or edit the configuration of the selected source. These
will be explained in detail in the following sections.
Figure 6-31. Input Configuration Page
Demand Input Selection Demand Input Source
This is accessed by clicking the Change Source button on the upper Right corner
of the Input Configuration page. The dropdown menu offers three options for
selecting source Manual Position, Analog Input, and CAN Open Digital Input.
Figure 6-32. Demand Input Source Dropdown Menu
Manual Position Demand
This results from selecting the Manual Position Demand option from the Demand
Input Source dropdown menu.
Figure 6-33. Manual Position Demand Input Source Page
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Position Readings of Position Demand and Actual Position are displayed in
percentages and the blue Manual Operation button when selected navigates you
back to the Manual Operation Page.
Do not use this unless prime mover is locked off!
Analog Position Demand Configuration
This results from selecting the Analog Input option from the Demand Input
Source dropdown menu. These indicators show the analog input mode and the
actual set position in percent of position (%) resulting from the currently active
analog input configuration.
Figure 6-34. Analog Position Demand Input Mode Selection Page
Additionally, the Analog Position Demand section of the image above includes
High and Low Input warnings with the indication of function shutdown as
operational (green) or inoperable (red).
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Analog Demand Configuration
This results from selecting the “Edit Config” button (located in the right-middle of
the Analog Position Demand Input Source page). This page provides access to
the Mode Selection dropdown menu and the ability to adjust the 4-20 mA Input
Scaling and 4-20 mA Diagnostic Ranges settings.
Figure 6-35. Analog Demand Configuration Page
Default values are displayed after the Edit Config button is selected. Mode
selection is made through the dropdown menu and the other valve configurations
are made by toggling the up/down arrow buttons or by writing the desired values
in the windows.
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CANopen Position Demand Input Source Page
This page is opened after selecting Can Open Digital Input from the source
dropdown menu. These indicators indicate the CANopen Mode (Single
CANopen with or without Analog Backup, Dual CANopen or CANopen
Virtual), the active port, and Set Position value shown in percent position
(%). There are also colored indicators showing status and error messages
as applicable.
Figure 6-36. CANopen Position Demand Input Source Page
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CANopen Dual Demand Configuration Page
CANopen Dual is when both CAN communication ports are to be used
simultaneously for redundancy. The Global Settings configuration is
explained in the section below. The CANopen Redundancy Manager
Configuration while in CANopen Dual mode allows the user to identify which
Node ID are applicable for Port 1 and Port 2.
Figure 6-37. CANopen Dual Demand Configuration Page
CANopen Communications Parameters Baud Rate Dropdown
Menu
This menu enables the user to select between 125K, 250K, and 500K Baud rate
to match the desired equipment settings.
Figure 6-38. CANopen Communications Parameters Baud Rate Dropdown
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CANopen Configuration Global Settings Extended PDO
Dropdown Menu
This dropdown allows the user to select to enable or disable the Extended PDO.
The enabling of extended PDOs means that the user will have access to all of
the available PDOs (1 through 8, inclusive). If disabled, then only PDOs 1
through 4, inclusive, are accessible. You also have the ability to adjust the
Timeout value either by typing in a specific value or by clicking the up/down
arrows which will increase/decrease the timeout interval.
Figure 6-39 CANopen Configuration Global Settings Extended PDO Dropdown
CANopen Single With/Without Analog Backup Configuration
Page
Selecting this option from the communications settings adds Analog input options
to the digital communications parameters. You have the option to turn off the
analog input settings, use the 4-20 milliamp not latched, or 4-20 milliamp Not
Latched configuration. For additional information, refer to the Analog Input
Settings section above.
Figure 6-40. CANopen Single W/WO Analog Backup Configuration Page
CANopen Virtual Configuration Page
Note: The CANopen Virtual option is not currently supported by VS-II
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Output Configuration Page
The scaling, and diagnostic settings for the analog output are displayed on the
Analog Output Configuration page. This has been combined with the Discrete
Output Configuration on the same page.
Figure 6-42. Output Configuration Page
Analog Output Mode Selection Dropdown Menu
The VariStroke II control variable represented by the analog output signal is
configurable from the Mode Selection pull-down list.
The following options can be selected:

Turned Off

Actual Position

Echo Setpoint

Motor Current (quadrature current)

Servo Position
Figure 6-43. Analog Output Mode Selection Dropdown Menu
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Analog Output Mode Selection Actual Position
By adjusting the output scaling values, the selected VariStroke II control variable
can be can be adjusted to match those observed at the transmitting device.
Figure 6-44. Analog Output Mode Selection Actual Position
Actual Position
This page displays the position scaling selections made on the configuration
page with real-time incrementing Demand Current value in milliamps and the
Actual Position in incrementing percentages.
Figure 6-45. Actual Position
Analog Output Mode Selection Echo Setpoint
The ability to adjust the Output Position Scaling values is identical to the Actual
Position configuration.
Figure 6-46. Analog Output Mode Selection Echo Setpoint
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Echo Setpoint
This display page contains the Output Position Scaling values set on the
Configuration page with the Demanded Current fixed at the Echo Setpoint and
the real-time incrementing Actual Position values displayed by percentage.
Figure 6-47. Echo Setpoint
Analog Output Mode Selection Motor Current
The Motor Current Configuration page allows the user to adjust the Output Motor
Current Scaling values.
Figure 6-48. Analog Output Mode Selection Motor Current
Motor Current
This page displays the output motor current scaling values set on the previous
page and the real-time incrementing Demanded Current in milliamps and the
Actual Current in Amps.
Figure 6-49. Motor Current
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Discrete Output Configuration
The Discrete Output Configuration page contains displays and edit configuration
options for Discrete Output 1 and Discrete Output 2. The main configuration of
the discrete outputs is performed on this page. Each of the discrete outputs is
configured in the same manner. Each of the two discrete outputs can be
configured to activate (or de-activate) upon detection of any of fault conditions
monitored by the VariStroke II.
The image below is how the display looks when both outputs are turned off. The
indicators on the first row display blue when the output is enabled or turned on
and display gray when the output is turned off. To configure Output 1 or Output 2
click the appropriate red “Edit Config” button.
Figure 6-50. Discrete Output Configuration
Discrete Output 1 & 2 Configuration Dropdown Menus
The drop down menus are identical for both the Discrete Output 1 and Discrete
Output 2 configuration and offer Turned Off, Speed Switch, Active When
Diagnostic is Detected, and In-Active when Diagnostic is Detected as userselected options. Select the behavior of the discrete output from the dropdown
menu.
Figure 6-51. Discrete Output 1 & 2 Configuration Dropdown Menus
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Discrete Output 1 Active Discrete 2 Speed Switch
Each discrete output may be configured independently of the other. If you select
a combined flag, (indicated by column beneath the Edit Config button) typically
there is no need to select any individual flags (displayed in figures 6-52 through
6-54 below). In the example in figure 6-52 Output 1 is active mode with a
combined flag of Shutdown Internal selected and no individual flags selected.
Output 2 mode is set to Speed Switch.
Figure 6-52. Discrete Output 1 Active Discrete 2 Speed Switch
Discrete Output 2 Flag Selection (1-4)
If you do not select a combined flag, using the next button brings you to the page
to configure flags 1-4 which are to be used for this output. Select one box from
the list below each flag and you will see the selected flags with a check in the box
to the left of the individual flag.
Figure 6-53. Discrete Output 2 Flag Selection (1-4)
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Discrete Output 1 Flag Selection (5-8)
The same situation is displayed below showing the options available for flags 58. Remember Discrete Output 1 and Discrete Output 2 have identical selections.
Figure 6-54. Discrete Output 1 Flag Selection (5-8)
Discrete Output 1 Active Flag Selection (5-8) and Discrete
Output 2 Active Flag Selection (1-4)
Figure 6-55 shows the results of the previous selections of combined and
individual selections. Both Outputs are on and error flags 1-4 (Output 2) and flags
5-8 (Output 2) show the error codes for each error flag selected.
Figure 6-55. Discrete Output 1 Active Flag Selection (5-8)
Discrete Output 2 Active Flag Selection (1-4)
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Fault Status and Configuration Overview
Some of the VariStroke II’s process fault and status flags are user-configurable.
The configuration of these process fault and status flags is done on the Process
Fault and Status Flag Configuration page.
Clicking the Internal VariStroke II Fault Status button redirects the service tool
Fault Status and Configuration Overview page to the Fault Status and
Configuration Overview Internals page.
Figure 6-56. Fault Status and Configuration Overview Page
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Process Fault and Status Flag Configuration Page
Clicking the “Edit Config” button on the lower/right corner of the page opens the
Process Fault and Status Flag Configuration page. All of the Diagnostics shown
on this screen are user-configurable, i.e. they can all be either enabled or
disabled (using the left button) or configured as Alarm (AL in yellow) or Shutdown
(SD in red) (using the right button).
Figure 6-57. Process Fault and Status Flag Configuration Page
Alarm: Enunciated, but no effect on control behavior.
Shutdown: Enunciated with shutdown of the device.
Off: The condition will not show up in an overall Alarm or Shutdown status, but
the individual indicator will still show the actual status.
Modification of these settings could affect operation and plant
diagnostics annunciation! An appropriate review of the settings is
recommended PRIOR to making these modifications!
Disabling diagnostic flags or changing their function from Shutdown
to Alarm could result in a dangerous condition! An appropriate
review of the settings is recommended PRIOR to making these
modifications!
In the case of the analog input, EGD or PWM input diagnostics, if
either one of these inputs is not used, the associated diagnostics are
automatically disabled. It is not necessary to disable these
diagnostics explicitly.
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In some cases, if the VariStroke II is operated continuously under
conditions where one or more of these diagnostic conditions are
detected, some performance degradation or reduction in component
life may occur. It is the responsibility of the user to configure these
settings to ensure safe operation.
Each process fault or status flag can be configured as either an alarm or
shutdown, and can be configured as either active, or disabled. In the
presence of detected condition, a diagnostic configured as a shutdown will
result with the VariStroke II overriding the setpoint and directing the actuator
to the failsafe position (in most cases 0%). If a diagnostic is configured as
an alarm, the detected condition will be annunciated on the service tool, and
a discrete output if selected, but the VariStroke II will continue to control. A
disabled diagnostic, will be annunciated, and will not generate a shutdown
condition.
Fault Status and Configuration Overview Internals
This page is display only and no configuration actions may be taken by the
operator. Select the blue “Return To Fault Status” button to the Fault Status and
Configuration Overview page.
Figure 6-58. Fault Status and Configuration Overview Internals Page
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Position Controller Configuration Operation Page
The Position Controller Configuration menu indicates the general overview of the
actuator operation. The individual configuration edit options will be described in
separate sections below.
Figure 6-59. Position Controller Configuration
Note: Proceed with caution. Editing the configuration with the VariStroke II
in the wrong state of operations may result in errors or damage.
Before modifying any settings of the VariStroke II, make sure the
device is shut down. Modifying settings with the unit in operation
may result in unexpected behavior!
The SHUTDOWN button will move the valve to 0% position. This will
potentially shut down the Prime Mover!
The setpoint filter is implemented in series with the control model.
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Demand Input Filter Configuration
This group contains the settings for the setpoint filter. If the input filter is
turned off the setpoint signal is not filtered. The bandwidth filter acts to limit
the system response to the specified settings (required by some
applications). The noise suppression filter attenuates the amplitude of low
amplitude, high frequency noise signals (due to speed pickup anomalies, or
transducer noise). The input filter is used to shape the frequency response
characteristics of the valve/actuator system for bandwidth, noise and slew
rate limiting to certain applications.
Mode Selections:
 Input Filter Off
 Bandwidth Filter
 Noise Filter
 BW and Noise Filter
 Slew Rate Filter
 Slew Rate and BW Filter
 Slew Rate and Noise Filter
 Slew Rate, BW, and Noise Filter
Figure 6-60. Demand Input Filter Configuration
Figure 6-61. Demand Filter Settings Mode Selection
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Bandwidth Filter Mode Settings
The active bandwidth frequency and damping factor is displayed when the
bandwidth filter is selected. The Bandwidth (Corner Frequency) in Hertz and the
Damping Factor may be set by overwriting the values or clicking on the up/down
arrows.
Figure 6-62. Bandwidth Filter Mode Settings
Demand Input Bandwidth Filter Display
After the Demand Filter Settings are selected in Bandwidth Mode, this display is
what you may expect to see on the Demand Input Filter Configuration page.
Figure 6-63. Demand Input Bandwidth Filter Display
Noise Filter Mode Settings
When you select the Noise Filter Mode, you may configure the Noise
Suppression Threshold and the Noise Suppression Gain (Below Threshold).
Figure 6-64. Demand Filter Settings Mode Noise Filter
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Demand Input Noise Filter Display
The active noise filter setting field is displayed when noise filter is selected.
Figure 6-65. Demand Input Noise Filter
Demand Filter Settings Mode Bandwidth and Noise Filter
This page allows the filter to be set for a bandwidth and noise combination
function. You may configure the same settings for Bandwidth and Noise
filters.
Figure 6-66. Demand Filter Settings Mode Bandwidth and Noise Filter
Demand Input Bandwidth and Noise Filter
This is the resulting display after configuring the Bandwidth and Noise Filter.
Figure 6-67. Demand Input Bandwidth and Noise Filter
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Demand Filter Settings Mode Slew Rate Filter
The filter is displayed in percentage per second and limits the maximum rate of
change determined by the user adjusting the filter.
Figure 6-68. Demand Filter Settings Mode Slew Rate Filter
Demand Input Slew Rate Filter
This is the resulting display after configuring the Slew Rate Filter.
Figure 6-69. Demand Input Slew Rate Filter
Demand Filter Settings Mode Slew Rate and Bandwidth Filter
This page allows the filter to be set for slew rate and bandwidth combination
function.
Figure 6-70. Demand Filter Settings Mode Slew Rate and Bandwidth Filter
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Demand Input Slew Rate and Bandwidth Filter
This is the resulting display after configuring the Slew Rate and Bandwidth Filter.
Figure 6-71. Demand Input Slew Rate and Bandwidth Filter
Demand Filter Settings Mode Slew Rate and Noise Filter
This page allows the filter to be set for slew rate and noise combination function.
Figure 6-72. Demand Filter Settings Mode Slew Rate and Noise Filter
Demand Input Slew Rate and Noise Filter
This is the resulting display after configuring the Slew Rate and Noise Filter.
Figure 6-73. Demand Input Slew Rate and Noise Filter
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Demand Filter Settings Mode Slew Rate, Bandwidth and Noise
Filter
This page allows the filter to be set for slew rate, bandwidth and noise
combination function.
Figure 6-74. Demand Filter Settings Mode Slew Rate, Bandwidth and Noise Filter
Demand Input Slew Rate Bandwidth and Noise Filter
This is the resulting display after configuring the Slew Rate, Bandwidth, and
Noise Filter.
Figure 6-75. Demand Input Slew Rate Bandwidth and Noise Filter
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Zero Cut-off Configuration
Currently, this feature is not used in VariStroke II. This is not active and can be
disregarded.
Figure 6-76. Zero Cut-off Configuration
Discrete Inputs Configuration
This tool provides you the ability to select or deselect any combination of five
discrete inputs (DI1, DI2, DI3, DI4, and/or DI 5). Each of these options are
available with each selection on the dropdown menu except for Turned Off. The
remaining options are Shutdown Reset/Reset, AUX3, AUX3 SD+Reset, and
Shutdown Reset/Reset Fast. These selections are automated or “Plug and Play”
and are described below in detail.
Note: Several special modes can override the availability of these inputs.
Specifically, CAN HW ID mode or any valve types using a motor brake can
capture one or more of Discrete Inputs.
Figure 6-77. Discrete Inputs Configuration
Discrete Inputs Action
The behavior of the discrete input can be selected from the drop-down list on this
screen.

Turned Off

Shutdown Reset / Reset

AUX3

AUX3 SD+Reset
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If the Shutdown Reset / Reset mode is selected, the discrete inputs behave as
follows:
Table 6-1. Discrete Input
Discrete Input #
1
2
3
4
5
Behavior
Shutdown / Reset
Reset
N/A
N/A
N/A
If Discrete Input 1 is triggered while the VariStroke II is running, a shutdown
command will be issued and the VariStroke II will be shut down. If the Discrete
Input 1 is triggered while the VariStroke II is shut down, a reset command will be
issued and it will be reset to start up and resume its normal operation.
If Discrete Input 2 is triggered while the VariStroke II is running, a reset command
will be issued, which does not have any effect on the operation of the VariStroke
II. However, if the VariStroke II is shut down the issued reset command will start
up the VariStroke II and it will reset the alarm.
Discrete Inputs 3-5 are not used. They have been implemented for future use.
The default behavior of these discrete inputs is that their state is true or positive
when the discrete input is active or the input contact is closed. De-selecting the
input box will reverse this default behavior. This behavior can be modified
individually for each discrete input.
Modification of these settings could affect operation of the
VariStroke II! An appropriate review of the settings is
recommended PRIOR to making these modifications!
Modification of these settings could affect operation and plant
diagnostics annunciation! An appropriate review of the settings is
recommended PRIOR to making these modifications!
Each discrete output can be triggered by any of the process fault and status flags
detected within the VariStroke II. To select which diagnostics will trigger the
discrete output, select the check box to the left of the desired diagnostic. If more
than one diagnostic is selected the discrete output will be triggered if any single
condition is detected. This behavior acts as an OR condition.
Shutdown Reset/Reset
An automated response to a signal originating from an outside source that has a
1 second filter. This response will shut down the actuator and reset any error
flags that may have been displaying an error.
AUX3
A channel that receives an external input related to an external safety measure
being initiated.
AUX3 SD+Reset
A channel that receives an external input related to an external safety measure
being initiated which is combined with a shutdown message and a reset
message being communicated.
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Silt Buster Configuration
This configuration is dependent upon the valve or actuator that is being read by
the VariStroke II and the settings are not configurable by the user. This page is a
display only and displays servo valve activity which are perturbations (small
vibrations) that are introduced into the valve to prevent silt build up. Mode
Selection is factory set to Active. The Period is the delay between perturbations
and is specified in units of days. Amplitude is displayed in percentages of zero to
100%. Impulse half duration is displayed in milliseconds.
Figure 6-78. Silt Buster Configuration
Current Diagnostic Configuration – Off
With the current diagnostic drop down selected in the “OFF’ position, there are
no additional options available.
Figure 6-79. Current Diagnostic Off
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Current Diagnostic Configuration – On
With the current diagnostic dropdown selected in the ‘ON’ position, the only
configuration option is either on or off. Each of the settings available in Current
Diagnostic Limit Set 1, 2, and 3 are user configurable.
Figure 6-80. Current Diagnostic Configuration – On
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Position Error Configuration
This display only functionality has two displays, Hydraulic Cylinder Position Error
and Servo Position Error.
Figure 6-81. Position Error Configuration
Hydraulic Cylinder Error consists of the following:
 Alarm Limit displayed in percent position
 Alarm Delay Time displayed in seconds
 Shutdown Limit displayed in percent position
 Shutdown Delay Time displayed in seconds
Servo Position Error consists of the following:
 Alarm Limit displayed in percent position
 Alarm Delay Time displayed in seconds
 Shutdown Limit displayed in percent position
 Shutdown Delay Time displayed in seconds
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Chapter 7.
Diagnostics
This chapter includes the pages that are useful for diagnostics. It includes Status
Overview, Position Controller, Startup Checks, and Driver pages.
Status Overview Page
The Status Overview page contains the Position Controller (readout only), the
VariStroke II Input/Output State (readout only), Analog Values, and the Trend
Chart (user configurable). Each of these will be described in detail in the sections
below.
Figure 7-1. Status Overview Page
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Position Controller
The Position Controller contains Position Reading and Motor Control Parameter
readouts which show the user information necessary to observe the real-time
performance of the actuator being controlled by the VariStroke II.
Figure 7-2. Position Controller
VariStroke II Input/Output State and Analog Values
Figure 7-3 VariStroke II Input/Output State and Analog Values
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Status Overview Trend Chart
Figure 7-4 Status Overview Trend Chart
Trend Chart Trending Properties Configuration Page
Figure 7-5. Trend Chart Trending Properties Page
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Position Controller Page
This page is display only and no configuration actions may be taken by the
operator.
Figure 7-6. Position Controller Page
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Hydraulic Cylinder
Hydraulic Cylinder Contains Position Readings, Hydraulic Cylinder LVDT 1
Feedback, Hydraulic Cylinder LVDT 2 Feedback, Hydraulic Cylinder Feedback 1
& 2 Difference, and Hydraulic Cylinder State.
Figure 7-7. Hydraulic Cylinder
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Position Readings





Position Demand is displayed in a value of percentage
Actual Position is a real-time display in a value of percentage
Cylinder Position Alarm error flag
Cylinder Position Shutdown error flag
LVDT Position Sensor 1&2 error flag
Hydraulic Cylinder LVDT 1 Feedback




Actual Position Sensor 1 is a real-time display in a value of percentage.
LVDT Position Sensor 1 A error flag
LVDT Position Sensor 1 B error flag
LVDT Position Sensor 1 Excitation error flag
Hydraulic Cylinder LVDT 2 Feedback




Actual Position Sensor 2 is a real-time display in a value of percentage.
LVDT Position Sensor 2 A error flag
LVDT Position Sensor 2 B error flag
LVDT Position Sensor 2 Excitation error flag
Hydraulic Cylinder Feedback 1 & 2 Difference



Difference between LVDT Position Sensor 1&2 is a real-time display in a
value of percent position.
LVDT Position Sensor Difference Alarm error flag
LVDT Position Sensor Difference Shutdown error flag
Hydraulic Cylinder State
The current state of the hydraulic cylinder control algorithm is displayed in the
State window.
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Servo Valve
This is not user configurable display of the Servo Position, Servo Spring Check,
Servo Current Uses, and Servo State.
Figure 7-8. Servo Valve
Servo Position




Servo Position Demand
Actual Position - real-time display in a value of percentage
Position Error Shaft Alarm error flag
Position Error Shaft Shutdown error flag
Servo Spring Check




Woodward
Spring Check Measure Time to Close – value displayed in milliseconds
Spring Check Position at Time Out – value displayed in percentage
Spring Check Current High error flag
Spring Check Error flag
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Manual 26740
Servo Current Uses



Actual Current - real-time display in a value of amps
Actual Current (Filtered) - real-time display in a value of amps
Actual Current Limit - real-time display in a value of amps
Servo State
The current state of the Servo control algorithm is displayed in the State window.
Startup Checks Page
This page is display only and no configuration actions may be taken by the
operator. The available fields may change depending on what is applicable for
the connected actuator.
Figure 7-9. Startup Checks
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Hydraulic Cylinder
This field is display only and not user configurable. It contains Startup Limit LVDT
1 and LVDT 2 plus a readout if the startup check is enabled or disabled.
Figure 7-10. Hydraulic Cylinder
Startup Limit LVDT 1




Sensor 1 Maximum
Actual Average Startup Position
Sensor 1 Minimum
Startup LVDT Position Sensor 1 error flag
Startup Limit LVDT 2




Sensor 2 Maximum
Actual Average Startup Position
Sensor 2 Minimum
Startup LVDT Position Sensor 2 error flag
Startup Check Enable/Disable
The status of the startup check is displayed in the Startup Check window.
Woodward
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VariStroke-II Electro-hydraulic Actuator
Manual 26740
Servo Valve
This field is display only and not user configurable. It contains Startup Check
Servo and Shaft 1 Range Limits.
Figure 7-11. Servo Valve
Startup Check Servo




Startup Position Upper Limit
Actual Average Startup Position
Startup Position Lower Limit
Startup Close Valve Shaft 1 error flag
Shaft 1 Range Limits




132
Upper Range Limit
Actual Position
Lower Range Limit
Valve Shaft 1 Range Limit error flag
Woodward
Manual 26740
VariStroke-II Electro-hydraulic Actuator
Driver Page
This page is display only and no configuration actions may be taken by the
operator. The available fields may change depending on what is applicable for
the connected actuator.
Figure 7-12 Driver Page
Driver Input/Output State
This section displays which discrete inputs and output are active (blue) or
inactive (gray)
Figure 7-13. Driver Input/Output State
Woodward
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Manual 26740
Driver Input Data
This section displays the Input Power Information to include Input Voltages 1 and
2, Internal Bus Voltage, and Input Current (Amps)
Figure 7-14. Driver Input Data
Driver Output Data
This portion of the Driver page displays VariStroke II Driver Output Information,
Analog Output information, and VariStroke II Temperatures information and are
described in detail in the sections below the image.
Figure 7-15. Driver Output Data
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Driver Output Information





Actual Current: Displayed in positive or negative value of Amplitude, this
represents the instantaneous servo motor current.
Actual Current (Filtered): Displayed in positive or negative value of
Amplitude, this represents, the servo motor current, but with a filter to smooth
out the reading. The filtered current reading is intended to be more of a time
average of the servo current.
Current Phase A: Displayed in positive or negative value of Amplitude, this
represents the current measured in one of the two sensors in the driver
output. It is equal in amplitude (within sensor tolerance) but opposite polarity
of the Current Phase B reading.
Current Phase B: Displayed in positive or negative value of Amplitude, this
represents the current measured in one of the two sensors in the driver
output. It is equal in amplitude (within sensor tolerance) but opposite polarity
of the Current Phase A reading.
PWM Phase A: Displayed in positive or negative value of Amplitude, this
represents the duty cycle setting of the output section and is related to the
Actual Current value. It can be used as troubleshooting information if the
servo motor is operating correctly.
Analog Output
Demanded Current which is displayed in milliamps and represents the output
value selected in the Analog Output Configuration.
Control Board Temperatures
Control Board Temperature which is displayed in degrees Celsius, enables the
user to monitor the temperature of the VariStroke II control board and be aware
of an over temperature situation or nominal operating temperature. Power Board
Temperature is also displayed in degrees Celsius and provides real-time
monitoring of the power board temperature.
Woodward
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VariStroke-II Electro-hydraulic Actuator
Manual 26740
Resolver and LVDT Diagnostics
The Resolver and LVDT Diagnostics page is a display only page which has
Resolver and LVDT Position Sensors Diagnostics including Resolver, LVDT
Position Sensor 1, and LVDT Position Sensor 2. Each of these functions will be
described in detail below.
Figure 7-16. Resolver and LVDT Position Sensors Diagnostics
Resolver
This portion of the page displays Position in a value of percentage of Electrical
Revolutions, Amplitude in percentage of maximum Analog Digital Converter, and
Gain in percentage of maximum output.
LVDT Position Sensor 1
This portion of the page displays Position in a value of percentage of Electrical
Revolutions, Amplitude in percentage of maximum Analog Digital Converter, and
Gain in percentage of maximum output.
LVDT Position Sensor 2
This portion of the page displays Position in a value of percentage of Electrical
Revolutions, Amplitude in percentage of maximum Analog Digital Converter, and
Gain in percentage of maximum output.
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Chapter 8.
Repair and Troubleshooting
To prevent possible serious personal injury, or damage to
equipment, be sure all electric power, hydraulic pressure, and rod
end force have been removed from the actuator before beginning any
maintenance or repairs.
Due to typical noise levels in turbine environments, hearing
protection should be worn when working on or around the VS-II
actuator.
General
The VariStroke-II is warranted to be free from defects in materials and
workmanship, when installed and used in the manner for which it was intended,
for a period of 36 months from the date of shipment from Woodward.
It is recommended that all repairs and servicing of the VariStroke-II be performed
by Woodward or its authorized service facilities.
Use of a cable gland or stopping plug that does not meet the hazardous area
certification requirements or thread form or thread size will invalidate the
suitability for hazardous locations.
Never remove or alter the nameplate as it bears important information which may
be necessary to service or repair the unit.
Hardware Replacement
Woodward recommends the following service spares to be on-site for support
services necessary between major overhauls of the actuator. If it is determined
that any hardware needs replacement, contact Woodward for instruction
manuals, videos and assistance at www.woodward.com. For a complete
inspection, overhaul and certification of the unit at the recommended service
interval identified by Woodward, please refer to Chapter 8 on service options
available for your needs.
The following is a list of service spare kits for on-site support to order when you
first install your new unit:
Woodward
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VariStroke-II Electro-hydraulic Actuator
Manual 26740
Table 8-1. Service Spare Kit for On-Site Support
Woodward Item Number
9907-1287
9907-1288
8923-2020
8923-2021
8923-2022
1680-1104-10
1680-1104-15
1680-1104-20
1680-1104-25
1680-1104-30
1680-1104-35
1680-1104-40
1680-1104-45
8923-2023
8923-2024
Description
V90v-E Hydraulic Servo, Fail Extend
V90V-E Hydraulic Servo, Fail Retract
Manifold Seal Replacement Kit
Cylinder Seal Replacement Kit, 10 Inch DIA
Cylinder Seal Replacement Kit, 12 Inch DIA
LVDT, 4 Inch Stroke
LVDT, 6 Inch Stroke
LVDT, 8 Inch Stroke
LVDT, 10 Inch Stroke
LVDT, 12 Inch Stroke
LVDT, 14 Inch Stroke
LVDT, 16 Inch Stroke
LVDT, 18 Inch Stroke
LVDT Connector Replacement Kit
DVP Replacement Kit.
Troubleshooting
General
The following troubleshooting guide will help you isolate trouble with the servo
valve, hydraulic power cylinder, control circuit board, wiring, and system
problems. Troubleshooting beyond this level is recommended ONLY when
complete facility control testing is available.
Troubleshooting Procedure
This table is a general guide for isolating system problems. In general, most
problems are a result of incorrect wiring or installation practices. Make sure that
the system wiring, input/output connections, controls and contacts are correct
and in good working order. Complete the checks in order. Each check assumes
that the preceding checks have been completed and any problems have been
corrected.
The table has been ordered in the sequence of appearance of the diagnostic in
the VariStroke-II service tool.
Be prepared to make an emergency shutdown of the turbine, or other
type of prime mover, to protect against runaway or overspeed with
possible personal injury, loss of life, or property damage.
EXPLOSION HAZARD—Do not remove covers or connect/disconnect
electrical connectors unless power has been switched off or the area
is known to be non-hazardous.
ELECTRICAL SHOCK HAZARD—Follow all local plant and safety
instructions/precautions before proceeding with Troubleshooting the
VS-II Control.
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The external ground lugs shown on the installation drawing must be
properly connected to ensure equipotential bonding. This will reduce
the risk of electrostatic discharge in an explosive atmosphere.
Table 7-1. VS-II Troubleshooting Guide
General Faults
Problem
Cause
It is normal for this to occur when a
shutdown position has been
commanded from an external
source. I.E. Service Tool, Digital
Communication or Discrete Input.
This is also normal when the Analog
Demand signal has been turned off
or set out of range.
Shutdown
Detection:
Shutdown command sent by
Service Tool, Analog Demand out
of range, digital communication
protocols (CAN open),
Run Enable, or diagnostic.
Unexpected command from digital
communication.
Discrete input (run enable) wiring
problem.
Run Enable configuration problem.
Critical Alarm / Diagnostic triggered
a shutdown
Erratic control
Woodward
Take away shutdown command and
reset VS-II for normal operation.
Ensure the VS-II has a valid demand
signal (4-20 mA).
Take away shutdown command and
reset VS-II for normal operation.
Fix wiring problem.
Ensure the Used / Not Used settings
inside the VS-II match the
Active/Inactive settings of the
controller. Settings can be modified
using the Service Tool.
If the Run Enable is not used, disable
this function using the Service Tool.
Using the Service Tool, view the
Alarms / Shutdowns page to
determine the fault. Use the
remainder of this chapter to
determine the cause and solution to
the fault.
Position Sensor Loop Power Output
Overloaded (Remote Servo Only)
Ensure position sensor wiring and
power supply are connected
correctly. See Chapter 3: Cylinder
Position Feedback Analog Inputs
Diagnostic triggered an Alarm and/or
Shutdown
Using the Service Tool, view the
Alarms / Shutdowns page to
determine the fault. Use the
remainder of this chapter to
determine the cause and solution to
the fault.
Faulty demand signal/electrical
noise on demand signal
Check demand signal connections
and wiring for proper shielding. Use
cables/conduits that are separated
from power wiring
Alarm
Detection:
Alarm or Shutdown has been
detected.
Remedy
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VariStroke-II Electro-hydraulic Actuator
Slow Slew Rates
Loss or reduction in hydraulic supply
pressure
Manual 26740
Ensure that hydraulic pressure at the
servovalve does not drop more than
10% during a full slew. Consider
adding a high volume hydraulic
accumulator to the supply line
adjacent to the VariStroke. See
Chapter 2 : Hydraulic Specifications
I/O Diagnostics
Problem / Alarm
Power-up Reset
Detection:
CPU reset by a power up event.
Watchdog Reset
Detection:
CPU reset without a power up
event.
Ext. Shutdown Position
Detection:
Command sent by Digital
communication protocols like:
EGD, CANopen.
External Shutdown
Detection:
Command sent by Service Tool or
digital communication protocols
like: EGD, CANopen or discrete
inputs.
Auxiliary 3 SD Position
Cause
It is normal for the Power Up Reset
diagnostic to occur upon power up
of the VS-II (or after momentary
power interruption).
If this occurs while the VS-II is
powered, and the diagnostic is
triggered during a fast position
transient, most likely the power
infrastructure is not delivering the
power needed.
It is normal for this to occur after the
software is updated.
A software lockup occurred.
It is normal for this to occur when a
shutdown position has been
commanded from an external
source, i.e. Service Tool, or Digital
Communication.
Unexpected command from digital
communication.
Remedy
Issue a reset to the VS-II.
During transient:
Check power supply, terminal voltage
at the VS-II during a 0-100% position
transient, check wire gauge and
length, fuses or other resistive
components in the power supply
system.
Issue a reset to the VariStroke-II.
If the cause is not a software update:
Contact Woodward Technical
Support.
Take away command and reset
VariStroke-II for normal operation.
Take away command and reset
VariStroke-II for normal operation.
It is normal for this to occur when a
shutdown position has been
commanded from an external
source, i.e. Service Tool, Digital
Communication or Discrete Input.
Unexpected command from digital
communication.
Take away command and reset
VariStroke-II for normal operation.
Discrete input wiring problem.
Fix wiring problem.
Discrete input configuration problem.
Ensure the Active/Inactive settings
inside the VariStroke-II match the
Active/Inactive settings of the
controller. Settings can be modified
using the Service Tool.
Auxiliary 3 Shutdown Position circuit
is open.
Auxiliary 3 configured incorrectly
Take away command and reset
VariStroke-II for normal operation.
If the Discrete Input is not used,
disable this function using the Service
Tool.
Ensure the Aux 3 Active/Inactive
settings inside the VS-II match the
Active/Inactive settings of the
controller. Settings can be modified
using the Service Tool in Position
Controller Config/ Discrete inputs
Config section
If the Aux 3 is not used, disable this
function using the Service Tool by
checking Active (open contact=no
shutdown)
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VariStroke-II Electro-hydraulic Actuator
Demand Input Configuration
Problem
Analog Input High
Detection:
The analog demand input is above
the diagnostic threshold. This is a
user configurable parameter.
Typically 22 mA.
Analog Input Low
Detection:
The analog input is below the
diagnostic threshold. This is a user
configurable parameter. Typically 2
mA.
Cause
Short in wiring to external voltage.
Control system 4 to 20 mA output
has failed high.
Incorrect user configurable
parameter in the electronics module
for the max input diagnostic.
VS-II internal electronics failure.
Wiring is disconnected or loose.
Short in wiring to external voltage.
Control system 4 to 20 mA output
has failed high.
Incorrect user configurable
parameter in the electronics module
for the max input diagnostic.
VS-II internal electronics failure.
The CANopen ID’s in the control
system and in the DVP are not the
same.
The CANopen baud rate in the
control system and the DVP are not
the same.
Digital Com 1 Error
Detection:
When you have selected the
CANopen communication as the
input, and the fast messages (fast
data and synch) from the control
system to port 1 are received slower
than the timeout parameter setup in
the CANopen configuration this flag
will be set.
Time out time is set too fast for the
rate group you are running in the
control system.
CANopen termination resistors
incorrect or not installed.
CANopen wiring issue, lost
connectors or defective wires.
CANopen wire type incorrect (too
high capacitive values)
CANopen wire(s) are too long,
and/or stub are too long.
Digital Com 2 Error
Detection:
When you have selected the
CANopen communication as you
input, and the fast messages (fast
data and synch) from the control
system to port 2 are received slower
Woodward
The CANopen ID’s in the control
system and in the DVP are not the
same.
The CANopen baud rate in the
control system and the DVP are not
the same.
Remedy
Check wiring for shorts to positive
voltages.
Check the current to the analog
input to the VS-II. Fix control
system.
Verify the 4–20 mA Diagnostic
Range: High Limit Value using the
VS-II Service Tool.
Contact Woodward Technical
Support for further assistance.
Check terminals and connections.
Check wiring for shorts to positive
voltages or ground
Check the current to the analog
input to the VS-II. Fix control
system.
Verify the 4–20 mA Diagnostic
Range: High Limit Value using the
VS-II Service Tool.
Contact Woodward Technical
Support for further assistance.
Change the DVP or Control system
Node ID’s and make them the
same. Make sure every DVP on the
network has a unique Node ID.
Change the DVP or control system
baud rate so they are the same. All
nodes on a network need to have
the same baud rate.
Confirm that the timeout value is
longer than the rate group settings.
For example: values used are 10
msec rate group, timeout value
40msec Check if this timeout is
acceptable from a prime mover
operation and safety.
Install or correct the termination
resistors, see CANopen installation
part of the manual.
Measure and/or inspect the cable
and cable connections and
repair/replace defective cables and
cable connections
Select approved CANopen cables.
See installation instruction section
of the manual.
Place components closer, or reduce
the baud rate. See installation
section of the manual. Check that
you do not overload the CANopen
network if you reduce the baud rate.
See CANopen timing section of the
manual.
Change the DVP or Control system
Node ID’s and make them the
same. Make sure every DVP on the
network has a unique Node ID.
Change the DVP or control system
baud rate so they are the same. All
nodes on a network need to have
the same baud rate.
141
VariStroke-II Electro-hydraulic Actuator
than the timeout parameter setup in
the CANopen configuration this flag
will be set.
Time out time is set too fast for the
rate group you are running in the
control system.
CANopen termination resistors
incorrect or not installed.
CANopen wiring issue, lost
connectors or defective wires.
CANopen wire type incorrect (too
high capacitive values)
CANopen wire(s) are too long,
and/or stub are too long.
Digital Com 1 & 2 And/Or Analog
Backup Error
Detection:
This flag will be set when all
communication is lost
Com 1 and Com 2 in dual CANopen
mode
-orCom 1 and Analog backup in single
CANopen with backup.
Digital Com Analog Tracking
Alarm
Detection:
When the difference between the
demanded position on the CANopen
port 1 and the analog backup is
larger than the difference value
parameter for longer than the time
value parameter, this flag will be
set.
In Dual CANopen mode the
difference between port1 and port 2
demanded position is calculated.
Digital Com Analog Tracking
Shutdown
Detection:
When the difference between the
demanded position on the CANopen
port 1 and the analog backup is
larger than the difference value
parameter for longer than the time
value parameter this flag will be set.
142
When this flag is set, you also will
have the Digital Com 1 and 2 flag
set (if dual CANopen is selected) or
the Digital com 1 and Analog high or
analog low flag set ( if single
CANopen with backup)
Manual 26740
Confirm that the timeout value is
longer than the rate group settings.
For example: values used are 10
msec rate group, timeout value
40msec Check if this timeout is
acceptable from a prime mover
operation and safety.
Install or correct the termination
resistors, see CANopen installation
part of the manual.
Measure and/or inspect the cable
and cable connections and
repair/replace defective cables and
cable connections
Select approved CANopen cables.
See installation instruction section
of the manual.
Place components closer, or reduce
the baud rate. See installation
section of the manual. Check that
you do not overload the CANopen
network if you reduce the baud rate.
See CANopen timing section of the
manual.
Follow the Cause’s and Remedy’s
for these flags. These are explained
in detail in this table.
The analog system has an error that
has not resulted in a high or low
error flag being set.
Correct the analog system.
The Control system does not keep
the two redundant signals the same.
(The values are scaled different or
from a different source in the
program, or the timing is incorrect.)
If the analog backup is used, the
analog system accuracy is outside
the alarm value set.
Debug and correct control system.
Too long of a delay between analog
and CANopen when values are set
the same.
The analog system has an error that
has not resulted in a high or low
error flag being set.
The Control system does not keep
the two redundant signals the same.
(The values are scaled different or
from a different source in you
program, or the timing is in correct.)
If the analog backup is used, the
analog system accuracy is outside
the alarm value set.
Make alarm value bigger if
acceptable for this application or
make analog system accuracy
better.
Determine the delay and if
acceptable for the application,
correct the difference time delay
time in the DVP.
Correct the analog system.
Debug and correct control system.
Make alarm value bigger if
acceptable for this application or
make analog system accuracy
better.
Woodward
Manual 26740
In Dual CANopen mode we will
calculate the difference between
port1 and port 2 demanded position.
VariStroke-II Electro-hydraulic Actuator
Too long a delay between analog
and CANopen when values are set
the same.
Too long a delay between analog
and CANopen when values are set
the same.
Environmental Diagnostics
Problem
Electronics Temp. High
Detection:
The Control Board temperature sensor
indicates a temperature above 140° C.
Electronics Temp. Low
Detection:
The Control Board temperature sensor
indicates a temperature below –45° C.
Driver Temp. High
Detection:
The heat sink temperature is above
115 Degrees C
Cause
The ambient temperature of the
driver is higher than allowed by
specification.
The Temperature sensor is
defective.
The ambient temperature of the
driver is lower than allowed by
specification.
The Temperature sensor is
defective.
The ambient temperature of the
driver is above specification.
The Temperature sensor is
defective.
Remedy
Reduce ambient temperature to
within specification limits.
The ambient temperature of the
driver is far above specification.
Reduce ambient temperature to
within specification limits.
Check if there are other heat
sources on the mounting surface
heating up the ambient
temperature around the VariStrokeII.
Check if the driver is using more
current than normal to position the
valve.
Increase ambient temperature to
within specification limits.
Driver Temp. High Limit
Detection:
The heat sink temperature is above
130 Degrees C.
Driver Temp. Low Limit
Detection:
The heat sink temperature is below –
45° C.
Driver Temp. Sensor Failed
The ambient temperature of the
driver is far above specification.
The ambient temperature of the
driver is below specification.
The temperature sensor has
failed.
Contact Woodward Technical
Support for further assistance.
Increase ambient temperature to
within specification limits.
Contact Woodward Technical
Support for further assistance.
Reduce ambient temperature to
within specification limits.
Contact Woodward Technical
Support for further assistance.
Contact Woodward Technical
Support for further assistance.
Detection:
The temperature sensor is at min or
max.
Input Voltage Diagnostics
Problem
Input Voltage 1 or 2 High
Detection:
The measured voltage at Input 1 or 2
is higher than the specification limit:
150 VDC
Input Voltage 1 or 2 Low
Detection:
The measured input voltage on input
number 1 is lower than the
specification limit: 90 VDC
Woodward
Cause
Power supply and/or setting
incorrect for application.
Excessive charging voltage and/or
battery failure.
Power supply has problem
regulating the voltage at the input
terminals during high current
transients.
Power is not connected to this
input. (Dual inputs are provided
for redundancy)
The power supply is not capable
of delivering the transient current.
The Power supply wiring is
incorrectly sized for the required
transient current.
Remedy
Check input voltage and correct
voltage to within specification
limits.
Determine if the power supply is of
the correct type to be used with the
VariStroke-II. See power supply
section in this manual.
If redundancy is not required,
jumper power to both inputs.
Determine if the power supply is
capable of delivering the transient
current. See power supply section
in this manual.
Determine if the wiring is according
to the manual.
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VariStroke-II Electro-hydraulic Actuator
Excessive resistance in the wiring
due to fuses, connectors, etc. that
limits the max transient current to
the driver.
Manual 26740
Determine if there is excessive
resistance in the power supply
wiring and correct.
Contact Woodward Technical
support for appropriate procedure
to evaluate the power
infrastructure.
Valve Type Selection Diagnostics
Problem
Cause
Remedy
Failure to read the ID module on the
valve/actuator system.
See associated diagnostics on the
Actuator Type Selection Screen in
the Service Tool.
If “ID Module Not Detected” is
annunciated, check wiring to the ID
module.
See Fault Status/Configuration
Overview Internals Screen in the
VariStroke-II Service Tool.
If “Invalid Parameter(s)” is
annunciated, the calibration records
are corrupt in the ID module.
Contact Woodward Technical
Support for a copy of the correct
parameter file. Servovalve Serial
Number will need to be provided.
See Fault Status/Configuration
Overview Internals screen in the
VariStroke-II Service Tool. If
“EEPROM Read/Write Failed” or
“Invalid Parameter(s)” is
annunciated Contact Woodward
Technical Support
Auto Detect Error
Detection:
This diagnostic is only enabled
when the VariStroke-II has been
configured for auto detection. (See
Auto detection Section)
This diagnostic is set when:
The VariStroke-II fails to
communicate with the ID module
due to write or read problems or the
calibration records in the ID module
are corrupted (CRC16 failure)
ID module calibration record
corrupted.
VariStroke-II non-volatile memory
error.
The VariStroke-II fails to write the
calibration records into the nonvolatile memory.
User has connected a different
valve to the VariStroke-II.
Type / Serial Number Error
Detection:
If during power up the VariStroke-II
detects a valve/actuator system with
a different serial number or valve
type this diagnostic will be
annunciated.
ID Module Not Detected
Detection:
144
User has loaded a parameter set to
the VariStroke-II that does not
match this valve/actuator system
serial number.
ID module factory calibration
incorrect for this valve type / serial
number.
Failure to read the ID module on the
valve/actuator system.
A reset will force the VariStroke-II
to retry auto detection of the
connected valve.
See the Actuator Type Selection
Screen in the Service Tool.
Verify the “Type” and “Serial
Number” match the valve/actuator
system connected to the VariStrokeII.
Use the auto detection function or
down load the actuator specific
calibration file into the VariStroke-II
for the correct serial number.
Operation of the VariStroke-II
with incorrect parameter files can
cause personal injury and/or
property damage.
Contact Woodward Technical
Support for further assistance.
See associated diagnostics on the
Actuator Type Selection Screen in
the Service Tool.
Woodward
Manual 26740
VariStroke-II Electro-hydraulic Actuator
During power up, the control model
the ID Module cannot be read.
ID module calibration record
corrupted.
The valve does not have an ID
module.
If “ID Module Not Detected” is
annunciated, check wiring to the ID
module.
See Process Fault & Status
Overview Internals Screen in the
VariStroke-II Service Tool.
If “Invalid Parameter(s)” is
annunciated the calibration records
are corrupt in the ID module.
Contact Woodward Technical
Support for a copy of the correct
parameter file. Valve Serial Number
will need to be provided.
Contact Woodward Technical
Support for a copy of the correct
parameter file. Valve Serial Number
will need to be provided.
The correct parameter file must
be uploaded into the VariStrokeII. Any reset command via the
VariStroke-II Service Tool or any
other applicable method (e.g.
Discrete Input) will force the
driver to use the internally stored
parameters. This will allow the
VariStroke-II to function without
an ID module.
Incorrect Power Board
Detection:
During power up the VariStroke-II
checks the ID module to determine
the power board needed for the
valve/actuator system. If the power
board ID required and the power
board detected do not match, this
diagnostic will be annunciated.
ID Module Version Not Supported
Valve/actuator system does not
match the VariStroke-II power
board.
VariStroke-II software does not
support ID module version.
Update Software. Contact
Woodward Technical Support for
upgrade to the latest revision of the
VariStroke-II software.
VariStroke-II software does not
support this actuator type.
Update software. Contact
Woodward Technical Support for
upgrade to the latest revision of the
VariStroke-II software.
Detection:
This diagnostic is annunciated if the
actuator type reported by the
valve/actuator system in the ID
module is not supported by the
VariStroke-II software.
Type Not Supported
Detection:
This diagnostic is annunciated if the
actuator type reported by the
Woodward
It is the user’s responsibility to
make sure the correct parameters
are stored in the VariStroke-II!
Operation of the VariStroke-II
with incorrect parameter files can
cause personal injury and/or
property damage.
Contact Woodward Technical
Support to determine the correct
VariStroke-II and valve/actuator
system for your application.
145
VariStroke-II Electro-hydraulic Actuator
valve/actuator system in the ID
module is not supported by the
VariStroke-II software.
Control Model Not Running
This flag is not an actual error, it
indicates that the control model has
not been started yet.
Manual 26740
Wait until the control model is
started and this flag will turn off
automatically.
Check other flag(s) to determine
why the control model has not
started
VariStroke-II (Feedback) Faults
Problem
LVDT Position Sensor 1 or 2 ,
(coil)A or B Error
Cause
Feedback sensor wiring fault or
failed sensor coil.
Detection:
Coil voltage outside of 0.3 to 0.9
VRMS
Start-up LVDT Position 1 Error
Detection:
During manufacturing at the factory,
the LVDT is mechanically adjusted
for a nominal min stop value of 25.0.
During power up and initialization
the VariStroke-II verifies that the
actuator is located at the min stop.
This diagnostic occurs if LVDT
Position Sensor 1 is not within
range given by the Sensor 1
Minimum and Sensor 1 Maximum
values.
Start-up LVDT Position 2 Error
Detection:
During manufacturing at the factory,
the LVDT is mechanically adjusted
for a nominal min stop value of 25.0.
During power up and initialization
the VariStroke-II verifies that the
actuator is located at the min stop.
This diagnostic occurs if LVDT
Position Sensor 2 is not within
range given by the Sensor 2
Minimum and Sensor 2 Maximum
values.
Calibration values specific to the
valve/actuator serial number are
incorrect as stored in the
VariStroke-II.
The Valve is not closed during the
start-up check.
The wiring to the LVDT is not
connected.
Remedy
Check all connections between the
LVDT and the Electronic Control;
check for any impediment to motion.
Check coil resistance
If problem persists, service will be
required.
Use the auto detection function (for
valves equipped with the ID module)
or down load the calibration file
(based on serial number and
calibration date) for the VariStrokeII.
Review the results shown on the
Startup Checks Screen.
If this occurs intermittently, it may
be necessary to check for high
operating friction in the steam valve,
linkage, or actuator. Contact
Woodward for further assistance.
Check the LVDT wiring.
The LVDT setting has moved
Contact Woodward Technical
Support for further assistance.
Calibration values specific to the
valve/actuator serial number are
incorrect as stored in the
VariStroke-II.
Use the auto detection function (for
valves equipped with the ID module)
or down load the calibration file
(based on serial number and
calibration date) for the VariStrokeII.
Review the results shown on the
Startup Checks Screen.
If this occurs intermittently, it may
be necessary to check for high
operating friction in the steam valve,
linkage, or actuator. Contact
Woodward for further assistance.
Check the LVDT wiring.
The Valve is not closed during the
start-up check.
The wiring to the LVDT is not
connected.
The LVDT setting has moved
Contact Woodward Technical
Support for further assistance.
Oil contamination levels above
specification limits causing
servovalve sticking.
Ensure oil supply meets specified
cleanliness requirements. Replace /
filter oil and flush the valve with
clean oil. If problem persists, service
may be required. Contact
Woodward Technical Support for
further assistance.
Spring Check Current High
Detection:
During the startup spring test the
VariStroke-II will check that the
current to be below a given
threshold at a set position where the
startup check is started. This is to
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Manual 26740
VariStroke-II Electro-hydraulic Actuator
make sure that there is no fluid flow
through the servo valve that will
change the time it takes to close the
servo by spring. If the current is not
below the threshold this flag will be
set.
Spring Check Failed
Detection:
During startup check the VariStrokeII controller will open the servo valve
(without moving the final cylinder)
and then turn off the driver power to
the servo. The return spring will
close the valve. The time until the
valve reaches zero % position is
measured. If this time is longer than
the set time parameter, this flag will
be set and assume the return spring
was not capable of closing the
servo.
LVDT Position Sensor Difference
Alarm
Detection:
The difference between the
feedback signals of LVDT Position
Sensor 1 and LVDT Position Sensor
2 is greater than the set alarm limit
value.
LVDT Position Sensor Difference
Shutdown
Detection:
The difference between the
feedback signals of LVDT Position
Sensor 1 and LVDT Position Sensor
2 is greater than the set alarm limit
value.
Calibration Complete Shutdown
There is fluid flow through the servo
valve
Turn off hydraulic supply and restart
VariStroke-II.
Broken return spring
Service is required. Contact
Woodward Technical Support for
further assistance.
Ensure oil supply meets specified
cleanliness requirements. Replace /
filter oil and flush the valve with
clean oil. If problem persists, service
may be required. Contact
Woodward Technical Support for
further assistance.
Servo valve seizure
Alarm Limits too set too tight
LVDT not calibrated correctly
Alarm Limits too set too tight
LVDT not calibrated correctly
It is normal for this to occur at the
completion of calibration
Set alarm range wider. Go to
Configure and Calibration,
Advanced.
Sensors need calibration. Contact
Woodward Technical Support for
further assistance.
Set alarm range wider. Go to
Configure and Calibration,
Advanced.
Sensors need calibration. Contact
Woodward Technical Support for
further assistance.
Verify that there is a valid demand
signal and reset control
Servo Position Diagnostics
Problem
Position Error Shaft Alarm
Detection:
The Servo Valve is unable to
maintain position within the
tracking error fault limits. This will
trigger an Alarm
Cause
Oil contamination levels above
specification limits causing
servovalve sticking
Remedy
Ensure oil supply meets specified
cleanliness requirements. Replace /
filter oil and flush the valve with clean
oil. If problem persists, service may
be required.
Excessive Valve Wear
Service is required.
VS-II electronics failure.
Contact Woodward Technical
Support for assistance.
Position Error Shaft Shutdown
Detection:
The Servo Valve is unable to
position within the tracking error
fault limits. This will trigger a
Shutdown
Cylinder Position Alarm
Detection:
The Power Cylinder is unable to
position within the tracking error
Woodward
Sticking/seized Steam Valve and/or
linkage friction excessive or binding
Excessive thermal growth in linkage
preventing cylinder from reaching
end positions.
Clean steam valve. Clean, lube,
align linkage to reduce
friction/binding.
Lower the ambient temperature of the
VariStroke-II and/or linkage or
recalibrate when hot. If this is not
147
VariStroke-II Electro-hydraulic Actuator
fault limits. This will trigger an
Alarm
Cylinder Position Shutdown
Detection:
The Power Cylinder is unable to
position within the tracking error
fault limits. This will trigger a
Shutdown
Contamination in the valve/actuator
system.
Low oil supply pressure supplied to
the VariStroke-II
Excessive Valve/Actuator Wear
Faulty / erratic LVDT position sensor
feedback
Manual 26740
possible, consider disabling this
diagnostic.
Ensure oil supply meets cleanliness
requirements. Replace / filter oil and
flush the valve with clean oil. If
problem persists, service may be
required.
Identify cause of low oil pressure and
correct. Ensure that the force
required to move the valve and
linkage does not exceed 2/3 the stall
force of the VariStroke-II at the
operating hydraulic pressure.
Service is required.
Check all connections to the final
cylinder; check for any impediment to
motion.
If problem persists, service will be
required.
Performance Faults
Problem
Performance Index Warning
Detection:
The settings for Supply Pressure,
Cylinder Diameter, Final Cylinder 0%
Position, and Final Cylinder 100%
Position do not meet the Performance
Index criteria.
Cause
Remedy
Incorrect configuration and
calibration settings.
The VS-II servo valve is too large
for the set cylinder volume.
See Chapter 2: Stability
Specifications for the details of this
alarm.
Internal Diagnostics
Problem
Cause
Remedy
An internal error has occurred in
the driver.
Service required.
Detection:
Internal +24 V is outside acceptable
range of 22.1 V to 30.7 V.
1.8 V Failed
Internal electronics failure.
Contact Woodward Technical
Support for further assistance.
Detection:
Internal 1.8 V is outside acceptable
range of 1.818 V to 2.142 V.
+12 V Failed
Internal electronics failure.
Contact Woodward Technical
Support for further assistance.
Detection:
Internal +12 V is outside acceptable
range of 10.6 V to 15.8 V.
–12 V Failed
Internal electronics failure.
Contact Woodward Technical
Support for further assistance.
Detection:
Internal –12 V is outside acceptable
range of –13.7 V to –8.6 V.
5 V Failed
Internal electronics failure.
Contact Woodward Technical
Support for further assistance.
24 V Failed
Detection:
Internal 5 V is outside acceptable
range of 4.86 V and 6.14 V.
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5 V Reference Failed
Internal electronics failure.
Contact Woodward Technical
Support for further assistance.
Detection:
Internal 5 V reference is outside
acceptable range.
5 V RDC Ref. Failed
Internal electronics failure.
Contact Woodward Technical
Support for further assistance.
Detection:
Internal 5 V RDC reference is outside
acceptable range.
ADC Failed
Internal electronics failure.
Contact Woodward Technical
Support for further assistance.
Detection:
Internal ADC in processor core has
stopped running.
RDC DSP Failed
Internal electronics failure.
Contact Woodward Technical
Support for further assistance.
Detection:
DSP that runs the Resolver-to-digital
converter has stopped running.
ADC SPI Failed
Internal electronics failure.
Contact Woodward Technical
Support for further assistance.
An internal error has occurred in
the driver.
Internal problem with the
electronics
Service required.
Internal problem with the
electronics
Contact Woodward Technical
Support for further assistance.
A short exists between phases of
the motor or wiring.
Check for phase to phase shorts in
the wiring. Check for phase to
phase short in the motor.
Check for phase to ground shorts
in the wiring. Check for phase to
ground (earth ground, motor
housing) short in the motor.
Check for phase to power supply
positive short in wiring.
Detection:
External ADC in processor core has
stopped running.
Electronics Fault
Int. Bus Voltage High
Detection:
The internal bus voltage sensor is at
max.
Int. Bus Voltage Low
Contact Woodward Technical
Support for further assistance.
Detection:
If the internal bus voltage Sensor is at
min
Driver Current Fault
Detection:
The Driver fault is detected by
monitoring the currents in the driver
output stages.
Current Phase A High
Detection:
The phase A current sensor is at max
output.
Current Phase A Low
Detection:
The phase A current sensor is at min
output.
Current Phase B High
Detection:
The phase B current sensor is at max
output.
Woodward
A short exists between a phase
and the ground (wiring or motor)
A short exists between phase and
power supply positive (Wiring
problem)
Internal electronics problem. (This
is unlikely, the Driver Current
Fault is designed to protect the
driver from damage)
Internal electronics failure.
Contact Woodward Technical
Support for further assistance.
Contact Woodward Technical
Support for further assistance.
Internal electronics failure.
Contact Woodward Technical
Support for further assistance.
Internal electronics failure.
Contact Woodward Technical
Support for further assistance.
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VariStroke-II Electro-hydraulic Actuator
Current Phase B Low
Detection:
The phase B current sensor is at min
output.
Input Current High
Detection:
The Input current sensor is at max
output.
Input Current Low
Detection:
The Input current sensor is at min
output.
No Power Board Found
Detection:
During power up the control board will
read the power board. This diagnostic
will be set if no Power Board is found.
Power Board Calib. Error
Detection:
During power up the calibration record
in the control is set to “No Power
Board” this diagnostic will be set.
Power Board ID Error
Detection:
During power up, the Power board ID
and the stored ID in the calibration
record do not match.
EEPROM Read Failed
Detection:
After multiple retries and data
comparison the software is not able to
read from the non-volatile memory.
EEPROM Write Failed
Detection:
After multiple retries and data
comparison the software is not able to
write to the non-volatile memory.
Invalid Parameters(s)
Detection:
CRC16 check failures on both
parameter sections.
Invalid Parameter Version
Manual 26740
Internal electronics failure.
Contact Woodward Technical
Support for further assistance.
The Current sense circuit has
failed.
Contact Woodward Technical
Support for further assistance.
The Current sense circuit has
failed.
Contact Woodward Technical
Support for further assistance.
VariStroke-II internal electronics
failure or there is no power board
connected.
Contact Woodward Technical
Support for further assistance.
The control board has not been
calibrated during electrical
production.
Contact Woodward Technical
Support for further assistance.
The Power board has been
changed to a different type after
calibration.
Contact Woodward Technical
Support for further assistance.
Internal electronics failure.
Contact Woodward Technical
Support for further assistance.
Internal electronics failure.
Contact Woodward Technical
Support for further assistance.
If a new embedded program has
been loaded the parameters have
not been updated.
Refer to the embedded software
update procedure to update the
parameters. Cycle power to restart
the VariStroke-II.
Contact Woodward Technical
Support for further assistance.
Contact Woodward Technical
Support for further assistance.
Internal electronics failure.
Internal electronics failure.
Detection:
Version information not correct in the
non-volatile memory.
Maintenance
To maximize the life of the VS-II, please refer to the maintenance
recommendation in Chapter 9: Asset Management and Refurbishment
Scheduling Period
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Chapter 8.
Service Options
Product Service Options
If you are experiencing problems with the installation, or unsatisfactory
performance of a Woodward product, the following options are available:

Consult the troubleshooting guide in the manual.

Contact the manufacturer or packager of your system.

Contact the Woodward Full Service Distributor serving your area.

Contact Woodward technical assistance (see “How to Contact Woodward”
later in this chapter) and discuss your problem. In many cases, your
problem can be resolved over the phone. If not, you can select which course
of action to pursue based on the available services listed in this chapter.
OEM and Packager Support: Many Woodward controls and control devices are
installed into the equipment system and programmed by an Original Equipment
Manufacturer (OEM) or Equipment Packager at their factory. In some cases, the
programming is password-protected by the OEM or packager, and they are the best
source for product service and support. Warranty service for Woodward products
shipped with an equipment system should also be handled through the OEM or
Packager. Please review your equipment system documentation for details.
Woodward Business Partner Support: Woodward works with and supports a
global network of independent business partners whose mission is to serve the
users of Woodward controls, as described here:

A Full Service Distributor has the primary responsibility for sales, service,
system integration solutions, technical desk support, and aftermarket
marketing of standard Woodward products within a specific geographic area
and market segment.

An Authorized Independent Service Facility (AISF) provides authorized
service that includes repairs, repair parts, and warranty service on Woodward's
behalf. Service (not new unit sales) is an AISF's primary mission.

A Recognized Engine Retrofitter (RER) is an independent company that
does retrofits and upgrades on reciprocating gas engines and dual-fuel
conversions, and can provide the full line of Woodward systems and
components for the retrofits and overhauls, emission compliance upgrades,
long term service contracts, emergency repairs, etc.

A Recognized Turbine Retrofitter (RTR) is an independent company that
does both steam and gas turbine control retrofits and upgrades globally, and
can provide the full line of Woodward systems and components for the
retrofits and overhauls, long term service contracts, emergency repairs, etc.
You can locate your nearest Woodward distributor, AISF, RER, or RTR on our
website at:
www.woodward.com/directory
Woodward
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Manual 26740
Woodward Factory Servicing Options
The following factory options for servicing Woodward products are available
through your local Full-Service Distributor or the OEM or Packager of the
equipment system, based on the standard Woodward Product and Service
Warranty (5-01-1205) that is in effect at the time the product is originally shipped
from Woodward or a service is performed:

Replacement/Exchange (24-hour service)

Flat Rate Repair

Flat Rate Remanufacture
Replacement/Exchange: Replacement/Exchange is a premium program
designed for the user who is in need of immediate service. It allows you to
request and receive a like-new replacement unit in minimum time (usually within
24 hours of the request), providing a suitable unit is available at the time of the
request, thereby minimizing costly downtime. This is a flat-rate program and
includes the full standard Woodward product warranty (Woodward Product and
Service Warranty 5-01-1205).
This option allows you to call your Full-Service Distributor in the event of an
unexpected outage, or in advance of a scheduled outage, to request a
replacement control unit. If the unit is available at the time of the call, it can
usually be shipped out within 24 hours. You replace your field control unit with
the like-new replacement and return the field unit to the Full-Service Distributor.
Charges for the Replacement/Exchange service are based on a flat rate plus
shipping expenses. You are invoiced the flat rate replacement/exchange charge
plus a core charge at the time the replacement unit is shipped. If the core (field
unit) is returned within 60 days, a credit for the core charge will be issued.
Flat Rate Repair: Flat Rate Repair is available for the majority of standard
products in the field. This program offers you repair service for your products with
the advantage of knowing in advance what the cost will be. All repair work carries
the standard Woodward service warranty (Woodward Product and Service
Warranty 5-01-1205) on replaced parts and labor.
Flat Rate Remanufacture: Flat Rate Remanufacture is very similar to the Flat
Rate Repair option with the exception that the unit will be returned to you in “likenew” condition and carry with it the full standard Woodward product warranty
(Woodward Product and Service Warranty 5-01-1205). This option is applicable
to mechanical products only.
Returning Equipment for Repair
If a control (or any part of an electronic control) is to be returned for repair,
please contact your Full-Service Distributor in advance to obtain Return
Authorization and shipping instructions.
Return for Repair Instruction
Should the VS-II need to be returned for repair, attach a tag on the unit and
include the following information on the tag:

Return authorization number

Customer's name and address

The name and location where the equipment is installed

Complete Woodward part number and serial number

Description of the problem

Instructions as to what type of repair is to be done
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Protective Packing
The following procedures are used for protective packaging of the VS-II, if
returning for repair:
1. Install shipping plates or plugs in all hydraulic connection ports or seal with
tape.
2. Wrap the VS-II with packaging materials that will not damage the surface of
the unit.
3. Place in a double-walled packing box.
4. Secure the unit inside of the box by removing all of its degrees of the
freedom using straps and belts, do not damage the unit.
5. Place at least 10 cm of tightly packed, industry-approved, shock-absorbing
material around the unit.
6. Secure the box with strong metal straps around the outside of the box to
increase the strength of the box.
Replacement Parts
When ordering replacement parts for controls, include the following information:

The part number(s) (XXXX-XXXX) that is on the enclosure nameplate;

The unit serial number, which is also on the nameplate.
Engineering Services
Woodward offers various Engineering Services for our products. For these services,
you can contact us by telephone, by email, or through the Woodward website.

Technical Support

Product Training

Field Service
Technical Support is available from your equipment system supplier, your local FullService Distributor, or from many of Woodward’s worldwide locations, depending
upon the product and application. This service can assist you with technical
questions or problem solving during the normal business hours of the Woodward
location you contact. Emergency assistance is also available during non-business
hours by phoning Woodward and stating the urgency of your problem.
Product Training is available as standard classes at many of our worldwide
locations. We also offer customized classes, which can be tailored to your needs
and can be held at one of our locations or at your site. This training, conducted
by experienced personnel, will assure that you will be able to maintain system
reliability and availability.
Field Service engineering on-site support is available, depending on the product
and location, from many of our worldwide locations or from one of our FullService Distributors. The field engineers are experienced both on Woodward
products as well as on much of the non-Woodward equipment with which our
products interface.
For information on these services, please contact us via telephone, email us, or
use our website: www.woodward.com.
Woodward
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Manual 26740
How to Contact Woodward
For assistance, call one of the following Woodward facilities to obtain the address
and phone number of the facility nearest your location where you will be able to
get information and service.
Electrical Power Systems
Engine Systems
Turbine Systems
Facility ---------------- Phone Number
Brazil -------------- +55 (19) 3708 4800
China ----------- +86 (512) 6762 6727
Germany --------- +49 (0) 21 52 14 51
India --------------- +91 (124) 4399500
Japan -------------- +81 (43) 213-2191
Korea -------------- +82 (51) 636-7080
Poland -------------- +48 12 295 13 00
United States ---- +1 (970) 482-5811
Facility ---------------- Phone Number
Brazil -------------- +55 (19) 3708 4800
China ----------- +86 (512) 6762 6727
Germany ------- +49 (711) 78954-510
India --------------- +91 (124) 4399500
Japan -------------- +81 (43) 213-2191
Korea -------------- +82 (51) 636-7080
The Netherlands - +31 (23) 5661111
United States ---- +1 (970) 482-5811
Facility ---------------- Phone Number
Brazil -------------- +55 (19) 3708 4800
China ----------- +86 (512) 6762 6727
India --------------- +91 (124) 4399500
Japan -------------- +81 (43) 213-2191
Korea -------------- +82 (51) 636-7080
The Netherlands - +31 (23) 5661111
Poland -------------- +48 12 295 13 00
United States ---- +1 (970) 482-5811
You can also locate your nearest Woodward distributor or service facility on our
website at:
www.woodward.com/directory
Technical Assistance
If you need to telephone for technical assistance, you will need to provide the following information.
Please write it down here before phoning:
Your Name
Site Location
Phone Number
Fax Number
Engine/Turbine Model Number
Manufacturer
Number of Cylinders (if applicable)
Type of Fuel (gas, gaseous, steam,
t )
Rating
Application
Control/Governor #1
Woodward Part Number & Rev. Letter
Control Description or Governor Type
Serial Number
Control/Governor #2
Woodward Part Number & Rev. Letter
Control Description or Governor Type
Serial Number
Control/Governor #3
Woodward Part Number & Rev. Letter
Control Description or Governor Type
Serial Number
If you have an electronic or programmable control, please have the adjustment setting positions or
the menu settings written down and with you at the time of the call.
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Chapter 9.
Asset Management and Refurbishment
Scheduling Period
This product is designed for continuous operation in a typical industrial
environment and includes no components that require periodic service. However,
to take advantage of related product software and hardware improvements, we
recommend that your product be sent back to Woodward or to a Woodward
authorized service facility after every five to ten years of continuous service for
inspection and component upgrades. Please refer to the above service programs
when returning products.
Chapter 10.
Long-Term Storage Requirements
Units that will not be put into service within twelve months should be packaged
for long-term storage as described in Woodward manual 25075, Commercial
Preservation Packaging for Storage of Mechanical-Hydraulic Controls.
Woodward
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Revision History
Initial Release—

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Declarations
Woodward
157
VariStroke-II Electro-hydraulic Actuator
158
Manual 26740
Woodward
We appreciate your comments about the content of our publications.
Send comments to: [email protected]
Please reference publication
26740.
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PO Box 1519, Fort Collins CO 80522-1519, USA
1000 East Drake Road, Fort Collins CO 80525, USA
Phone +1 (970) 482-5811
Email and Website—www.woodward.com
Woodward has company-owned plants, subsidiaries, and branches, as well as authorized distributors and
other authorized service and sales facilities throughout the world.
Complete address / phone / fax / email information for all locations is available on our website.
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