Woodward DSLC User manual

Installation and Operation Manual
DSLC™
Digital Synchronizer and Load Control
Manual 02007 (Revision D)

WARNING—DANGER OF DEATH OR PERSONAL INJURY
WARNING—FOLLOW INSTRUCTIONS
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. Failure to follow instructions can cause personal injury and/or
property damage.
WARNING—OUT-OF-DATE PUBLICATION
This publication may have been revised or updated since this copy was produced. To verify
that you have the latest revision, be sure to check the Woodward website:
www.woodward.com/pubs/current.pdf
The revision level is shown at the bottom of the front cover after the publication number. The
latest version of most publications is available at:
www.woodward.com/publications
If your publication is not there, please contact your customer service representative to get
the latest copy.
WARNING—OVERSPEED PROTECTION
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.
WARNING—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.
CAUTION—POSSIBLE DAMAGE TO EQUIPMENT OR PROPERTY
CAUTION—BATTERY CHARGING
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.
CAUTION—ELECTROSTATIC DISCHARGE
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.
IMPORTANT DEFINITIONS
•A WARNING indicates a potentially hazardous situation which, if not avoided, could result in
death or serious injury.
•A CAUTION indicates a potentially hazardous situation which, if not avoided, could result in
damage to equipment or property.
•A NOTE provides other helpful information that does not fall under the warning or caution
categories.
Revisions—Text changes are indicated by a black line alongside the text.
Woodward Governor Company reserves the right to update any portion of this publication at any time. Information
provided by Woodward Governor Company is believed to be correct and reliable. However, no responsibility is
assumed by Woodward Governor Company unless otherwise expressly undertaken.
© Woodward 1993
All Rights Reserved

Manual 02007 DSLC Digital Synchronizer and Load Control
Woodward i
Contents
ELECTROSTATIC DISCHARGE AWARENESS ................................................. IV
CHAPTER 1. GENERAL INFORMATION........................................................... 1
Introduction.............................................................................................................1
Application ..............................................................................................................1
Synchronizer...........................................................................................................1
Load Control ...........................................................................................................2
Process Control (full function models) ...................................................................3
VAR/PF Control (full function models)....................................................................3
Manual Organization ..............................................................................................4
CHAPTER 2. INSTALLATION........................................................................ 12
Introduction...........................................................................................................12
Unpacking.............................................................................................................12
Location ................................................................................................................12
Installation ............................................................................................................12
Electrical Connections..........................................................................................12
Shielded Wiring ....................................................................................................13
Power Supply .......................................................................................................13
Bus Potential Transformers..................................................................................14
Generator Potential Transformers........................................................................14
Generator Current Transformers..........................................................................14
Discrete Outputs...................................................................................................15
Discrete Inputs......................................................................................................16
LonWorks®Network .............................................................................................18
Speed Control Output...........................................................................................18
Analog Voltage Regulator Output.........................................................................18
Process Control Input...........................................................................................19
Remote Load Setting Input...................................................................................19
Installation Checkout Procedure ..........................................................................20
CHAPTER 3. CALIBRATION AND ADJUSTMENT ............................................ 21
Introduction...........................................................................................................21
Using the Hand Held Programmer .......................................................................21
Menu (Set Point) Descriptions..............................................................................27
Prestart Setup Procedure.....................................................................................40
DSLC Control Adjustments ..................................................................................41
Synchronizer Adjustment .....................................................................................43
Voltage Matching Adjustment...............................................................................47
Load Control Adjustment......................................................................................49
Process Control Adjustment.................................................................................55
VAR/PF Control Adjustments ...............................................................................57
Conclusion of Setup Procedures..........................................................................59
CHAPTER 4. SYNCHRONIZER DESCRIPTION ................................................ 60
Introduction...........................................................................................................60
Functional Description..........................................................................................60
CHAPTER 5. REAL POWER CONTROL DESCRIPTION ................................... 66
Introduction...........................................................................................................66
Power Sensor Theory of Operation......................................................................66
Load Sensor Hardware Description .....................................................................67
Power System Management Concepts................................................................67
Automatic Generator Loading Functions..............................................................71
Automatic Load Control Applications ...................................................................72
Reverse Power Relay Description .......................................................................75

DSLC Digital Synchronizer and Load Control Manual 02007
ii Woodward
Contents
CHAPTER 6. VAR/POWER FACTOR CONTROL DESCRIPTION .......................76
Introduction...........................................................................................................76
VAR Control..........................................................................................................76
Power Factor Control............................................................................................76
Power Factor Sharing...........................................................................................77
CHAPTER 7. PROCESS CONTROL DESCRIPTION..........................................78
Introduction...........................................................................................................78
Description............................................................................................................78
CHAPTER 8. ECHELON LONWORKS®NETWORK..........................................80
Introduction...........................................................................................................80
Remote Metering ..................................................................................................81
Remote Control Inputs..........................................................................................84
Specifications .......................................................................................................84
CHAPTER 9. TROUBLESHOOTING................................................................85
Introduction...........................................................................................................85
Bench Tests..........................................................................................................85
LonWorks Network ...............................................................................................89
CHAPTER 10. SERVICE OPTIONS ................................................................94
Product Service Options.......................................................................................94
Woodward Factory Servicing Options ..................................................................95
Returning Equipment for Repair...........................................................................96
Replacement Parts ...............................................................................................96
Engineering Services............................................................................................97
How to Contact Woodward...................................................................................97
Technical Assistance............................................................................................98
APPENDIX A. DSLC CONTROL SETUP WORKSHEET ...................................99
Synchronizer Menu 1............................................................................................99
Load Control Menu 2 ............................................................................................99
Process Control Menu 3.................................................................................... 100
VAR/Power Factor Control Menu 4 ................................................................... 101
Configuration Menu 5 ........................................................................................ 102
APPENDIX B. DSLC CONTROL SPECIFICATIONS .......................................103
DSLC Control Part Numbers ............................................................................. 103
Electrical Specifications..................................................................................... 104
Environmental Specifications ............................................................................ 105
APPENDIX C. PART NUMBER CHANGES ....................................................106
DSLC™ CONTROL MENU SUMMARY........................................................107

Manual 02007 DSLC Digital Synchronizer and Load Control
Woodward iii
Illustrations and Tables
Figure 1-1a. DSLC Control (wye version shown)...................................................5
Figure 1-1b. DSLC Control Dimensions (wye version shown)...............................6
Figure 1-2. Hand Held Programmer.......................................................................7
Figure 1-3a. DSLC Plant Wiring Diagram ..............................................................8
Figure 1-3b. DSLC Plant Wiring Diagram ..............................................................9
Figure 1-3c. DSLC Plant Wiring Diagram ............................................................10
Figure 1-4. Control Options ..................................................................................11
Figure 2-1. Temporary Wiring for Transformer Phase Correction .......................15
Figure 2-2. DSLC Control in a Parallel Bus/Utility Parallel Application ................19
Figure 3-1. Hand Held Programmer Functions ....................................................22
Figure 4-1. Synchronizer Block Diagram .............................................................61
Figure 4-2. Synchronizer Wiring Diagrams (wye and open delta) .......................62
Figure 4-3. Synchronizer Block Schematic ..........................................................64
Figure 5-1. Droop Mode .......................................................................................68
Figure 5-2. Isochronous Mode .............................................................................69
Figure 5-3. Droop/Isochronous Load Sharing ......................................................70
Figure 5-4. Isochronous Load Sharing.................................................................71
Figure 5-5. Load Control Plant Wiring Diagrams (wye and open delta) ..............73
Figure 5-6. Reverse Power Trip ...........................................................................75
Figure 7-1. Process Control Block Diagram.........................................................79
Figure 8-1. Typical LON Setup.............................................................................80
Table 9-1. System Troubleshooting .....................................................................92

DSLC Digital Synchronizer and Load Control Manual 02007
iv Woodward
Electrostatic Discharge Awareness
All electronic equipment is static-sensitive, some components more than others.
To protect these components from static damage, you must take special
precautions to minimize or eliminate electrostatic discharges.
Follow these precautions when working with or near the control.
1. Before doing maintenance on the electronic control, discharge the static
electricity on your body to ground by touching and holding a grounded metal
object (pipes, cabinets, equipment, etc.).
2. 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.
3. Keep plastic, vinyl, and Styrofoam materials (such as plastic or Styrofoam
cups, cup holders, cigarette packages, cellophane wrappers, vinyl books or
folders, plastic bottles, and plastic ash trays) away from the control, the
modules, and the work area as much as possible.
4. 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.
CAUTION—ELECTROSTATIC DISCHARGE
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.

Manual 02007 DSLC Digital Synchronizer and Load Control
Woodward 1
Chapter 1.
General Information
Introduction
This manual describes the Woodward DSLC™ Digital Synchronizer and Load
Control, both full and reduced function models (see Figure 1-1). The reduced
function models do not include the VAR/Power Factor Control or the Process
Control.
Application
The DSLC control is a microprocessor-based generator load control designed for
use with a Woodward speed control and an automatic voltage regulator to
provide synchronizing, paralleling, loading, and unloading of three-phase
generator sets. All transitions between DSLC functions are coordinated to
provide smooth operation.
DSLC functions include:
•Selectable for phase matching or slip frequency synchronizing with voltage
matching and automatic dead bus closure capability;
•Automatic generator loading and unloading for bumpless load transfer;
•Droop, base load, and isochronous load control capability;
•Process control for cogeneration, import/export, pressure control, or other
processes;
•Isochronous load sharing with other sets equipped with DSLC controls;
•VAR or power factor (PF) control (full function models only);
•Built in diagnostics;
•Multi-function adjustable high and low limit alarms and load switch with relay
driver outputs;
•Digital communications network to provide load sharing, VAR/PF sharing,
and other information exchange between controls;
•Full setup, metering, and diagnostic capability through a hand held
programmer terminal (Figure 1-2);
•Reverse power relay.
Synchronizer
The DSLC control uses digital signal processing techniques to derive both true
RMS voltages and relative phase of the fundamental frequencies of the bus and
generator voltage wave forms. Digital signal processing techniques offer
significantly improved measurement accuracy in the presence of wave form
distortions, particularly since the phase measurement does not depend on zero
crossings of the wave forms.
Either phase matching or slip frequency synchronizing may be selected. Phase
matching provides rapid synchronizing for critical standby power applications.
Slip frequency synchronizing guarantees that initial power flow is out of the
machine for larger generators. For both synchronizing methods, the DSLC
control uses actual slip frequency and breaker delay values to anticipate a
minimum phase difference between bus and generator at actual breaker closure.

DSLC Digital Synchronizer and Load Control Manual 02007
2 Woodward
The DSLC control provides a safe automatic dead-bus closure function. Dead-
bus closing permission is granted to only one DSLC control through locking
techniques done over the communications network. This assures that a race
condition will not cause two or more breakers to close simultaneously on the
dead bus.
Additional synchronizer features include voltage matching, time delayed
automatic multi-shot reclosing, auto-resynchronizing, and a synchronizer timeout
alarm. Each of these features may be enabled or disabled during setup.
Load Control
The load control uses digital signal processing techniques to provide significantly
improved accuracy and speed of response over conventional analog
measurement techniques. Accuracy is improved because the instantaneous
measurement of the voltage and current signal wave forms allows true RMS
measurement. Measuring true RMS power allows optimal load control in parallel
applications even in the presence of power line distortions. This method provides
faster response time because it eliminates the long integration times required
with analog circuits.
Load control begins at breaker closure when the load control function takes
control of the DSLC speed bias output directly from the synchronizer. The
matching of synchronizer slip frequency to initial load (unload trip level) can
result in a bumpless transfer to load control. On command, the adjustable ramp
allows smooth, time-controlled loading into base load, isochronous load sharing,
or process control. A ramp pause switch input allows holding of the load ramp for
warm-up or other purposes.
The base load control is selectable as either a proportional or integrating
controller. The proportional control provides smooth, stable control of load for
operation in parallel with frequency-stable systems. The integrating base load
control provides accurate load control when in parallel with a bus where
frequency may vary. The DSLC control provides switch inputs to allow raising or
lowering the internal digital base load reference. The control also provides a
4–20 mA (or 1–5 Vdc) analog input for remote load setting, if desired.
When unloading, an adjustable unload ramp provides time controlled unloading
to the unload trip level. When load reaches the unload trip level, the control
issues a breaker open command to separate the generator set from the system.
The ramp pause switch input is in effect while unloading to allow holding of the
unload ramp for cool-down or other purposes.
The load and unload ramps also provide smooth transition between base load,
isochronous load sharing, and process control any time the operating mode is
changed.
The DSLC control includes several additional load control features:
•Simple load droop operation provides safe operation in parallel bus
applications in the event of a circuit breaker aux contact failure;
•A frequency trimmer function provides accurate frequency control in
isochronous load sharing systems by compensating for small variations in
speed setting between units;
•Adjustable load switch output with independent pick-up and drop-out points
provides a signal when the specified load is exceeded. The load switch
output can be selected as a reverse power trip.

Manual 02007 DSLC Digital Synchronizer and Load Control
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•Load raise and lower inputs can be used to adjust speed before
synchronizing.
•Voltage raise and lower inputs can be used to adjust voltage before
synchronizing.
Process Control (full function models)
A cascade PID process controller is provided for cogeneration, import/export
control, pond level maintenance, pressure maintenance, or other application. An
adjustable bandwidth signal input filter, flexible PID controller adjustments, an
adjustable deadband, and control selectable for direct or indirect action, allow the
process control to be used in a wide variety of applications.
A 4–20 mA (or 1–5 Vdc) process transmitter provides the process signal to the
DSLC control. The control includes an internal digital process reference which
may be controlled by raise and lower switch contact inputs or by an external
4–20 mA (or 1–5 Vdc) remote process reference. The output of the process
control provides the cascade load reference to the base load control.
Adjustable ramps allow smooth entry to or exit from the process control mode.
When the process control mode is selected, an adjustable ramp moves the load
reference in a direction to reduce the process control error. When the error is
minimized, or the reference first reaches either the specified high or low load
pick-up limits, the process controller is activated. When a limit is reached, the
control will hold the load reference at that limit until process control is obtained.
When unloading from the process control, an adjustable unload ramp provides
time controlled unloading to the unload trip level. When load reaches the unload
trip level, the DSLC control automatically issues a breaker open command to
remove the generator set from the system. The ramp pause switch input allows
holding of the unload ramp for cool-down or other purposes.
Additional functions include selectable and adjustable process high and low limit
switches and alarm activation.
VAR/PF Control (full function models)
The VAR/PF functions control the reactive power component of the generator in
parallel systems. In an infinite bus system, the controller compares either the
kVAR load or power factor (selectable) on the generator with an adjustable
internal reference and makes corrections to the voltage regulator until the
desired kVAR load or power factor is obtained. For higher performance, an
analog output can be directly connected to compatible voltage regulators with
analog voltage setting input. The control has raise and lower voltage discrete
inputs for manual voltage adjustment. The control also has raise and lower
contact outputs to activate a voltage regulator MOP when an analog input is not
provided on the AVR.
The DSLC control provides power factor sharing between units for isolated bus
or isochronous parallel systems. The control computes an average power factor
for the system and uses it as the reference input to the power factor controller.
The control includes an adjustable voltage reference and voltage trim function in
the sharing function to maintain system voltage at the desired level.

DSLC Digital Synchronizer and Load Control Manual 02007
4 Woodward
The DSLC control has a selectable voltage range alarm which is activated if the
analog output to the voltage regulator reaches high or low saturation. The DSLC
control also has selectable and adjustable high and low voltage limit switches
and alarm outputs.
Manual Organization
See page iv for important electrostatic discharge awareness information. The
DSLC control is an electronic device containing sensitive components. While the
control is designed for safe handling in the industrial environment, certain
precautions must be observed during handling and shipping.
Chapter 2 covers DSLC control installation and wiring, including each major
group of connections, along with any special instructions.
Chapter 3 covers DSLC control configuration, setup, and adjustment. The
chapter explains the purpose of each set point and recommended initial value.
Chapters 4 through 7 explain the major functions of automatic synchronizing,
load control, process control, and kVAR and power factor control.
Chapter 8 describes the Echelon Local Operating Network (LON) used by the
DSLC control to communicate between units.
Chapter 9 provides a troubleshooting guide. Due to extensive built-in diagnostics,
DSLC control installation may be tested and verified quickly.
Chapter 10 describes how to return a control to Woodward in the event of
damage or failure of an internal component.
At the end of the manual is a setup work sheet that provides a guide to setup and
a place to record setup values for future reference.

Manual 02007 DSLC Digital Synchronizer and Load Control
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Figure 1-1a. DSLC Control (wye version shown)

DSLC Digital Synchronizer and Load Control Manual 02007
6 Woodward
Figure 1-1b. DSLC Control Dimensions (wye version shown)

Manual 02007 DSLC Digital Synchronizer and Load Control
Woodward 7
Figure 1-2. Hand Held Programmer

DSLC Digital Synchronizer and Load Control Manual 02007
8 Woodward
Figure 1-3a. DSLC Plant Wiring Diagram
(for 120/240 V wye switch gear configurations)

Manual 02007 DSLC Digital Synchronizer and Load Control
Woodward 9
Figure 1-3b. DSLC Plant Wiring Diagram
(for 120 V open delta switch gear configurations)

DSLC Digital Synchronizer and Load Control Manual 02007
10 Woodward
Figure 1-3c. DSLC Plant Wiring Diagram
(for 240 V open delta switch gear configurations)

Manual 02007 DSLC Digital Synchronizer and Load Control
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Figure 1-4. Control Options

DSLC Digital Synchronizer and Load Control Manual 02007
12 Woodward
Chapter 2.
Installation
Introduction
This chapter provides the general information for site selection, installation, and
wiring of the DSLC™ control.
Unpacking
Before unpacking the control, refer to the inside front cover of this manual for
WARNINGS and CAUTIONS. Be careful when unpacking the control. Check for
signs of damage such as bent or dented panels, scratches, loose or broken
parts. If any damage is found, immediately notify the shipper.
Location
When selecting a location for mounting the DSLC control, consider the following:
•Protect the unit from direct exposure to water or to a condensation-prone
environment.
•The continuous operating range of the DSLC control is –40 to +70 °C (–40
to +158 °F).
•Provide adequate ventilation for cooling. Shield the unit from radiant heat
sources.
•Do not install near high-voltage, high-current devices.
•Allow adequate space in front of the unit for servicing.
•Do not install where objects can be dropped on the terminals.
•Ground the chassis for proper safety and shielding.
•The control must NOT be mounted on the engine.
Installation
Select a mounting location for the DSLC control (see considerations above).
Locate and drill six (6) holes for mounting hardware (not furnished; see Figure
1-1 for locations). Tap the holes for machine screws or bolts. Install the unit and
secure with the mounting hardware.
Electrical Connections
This section covers typical wiring connections, as shown in Figure 1-3. For other
applications, contact Woodward for assistance.
Connect the terminals as shown in Figure 1-3. When making the connections,
observe the following:
•Make all connections using insulated terminals. Use 0.5 mm² (20 AWG) or
larger stranded wire.
•Make sure that all wires shown as shielded on the wiring diagram are
stranded, twisted-pair, shielded wire.
•Do not place shielded wires in the same cable conduits with high-voltage or
high-current carrying cables.

Manual 02007 DSLC Digital Synchronizer and Load Control
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•Connect the cable shields to chassis ground. Shields are grounded at the
control end only for inputs and at the speed control and voltage regulator
end for outputs.
•Make sure that cable shields are carried through all intermediate terminal
blocks from signal source to signal termination.
•Do not subject any wiring to temperatures above 100 °C (212 °F).
•Avoid kinks or sharp bends in the wiring. Make sure that all connections are
tight.
For additional wiring information, see Woodward manual 25070, Electronic
Control Installation Guide.
Install and wire the other units and actuators in your system using instructions in
applicable manuals.
Shielded Wiring
All shielded cable must be twisted conductor pairs. Do not attempt to tin the braided
shield. All signal lines should be shielded to prevent picking up stray signals from
adjacent equipment. Wire exposed beyond the shield should be as short as
possible, not exceeding 50 mm (2 inches). The other end of the shields must be left
open and insulated from any other conductor. See Woodward application note
50532, Interference Control in Electronic Governing Systems, for more information.
Where shielded cable is required, cut the cable to the desired length and prepare
the cable as instructed below.
1. Strip outer insulation from both ends, exposing the braided or spiral
wrapped shield. Do not cut the shield.
2. Using a sharp, pointed tool, carefully spread the strands of the shield.
3. Pull inner conductor(s) out of the shield. If the shield is the braided type,
twist it to prevent fraying.
4. Remove 6 mm (1/4 inch) of insulation from the inner conductors.
5. Connect wiring and shield as shown in plant wiring diagram.
Installations with severe electromagnetic interference (EMI) may require
additional shielding precautions, such as wire run in conduit or double shielding.
Contact Woodward for more information.
Power Supply
The DSLC control requires a nominal voltage source of 18 to 40 Vdc, 18 W.
Power to the control should be maintained whenever the generator set is
available for service.
CAUTION—APPLY POWER
Power must be applied to the DSLC control at least 15 seconds prior to
expected use. The control must have time to do its power up diagnostics
and establish its location in the local area network to become operational.
Failure of the diagnostics will disable control function and de-energize
(activate) the alarm relay.

DSLC Digital Synchronizer and Load Control Manual 02007
14 Woodward
Power supply output must be of a low impedance type for proper operation of the
control. DO NOT power a control from a high voltage source containing dropping
resistors and zener diodes. If batteries are used for operating power, an
alternator or other battery charging device is necessary to maintain a stable
supply voltage.
Run power supply leads directly from the power source to the control, connecting
the negative (neutral) lead to terminal 1, and the positive lead (line) to terminal 2.
DO NOT POWER OTHER DEVICES WITH LEADS COMMON TO THE
CONTROL. Avoid long wire lengths.
CAUTION—DO NOT APPLY POWER
Do NOT apply power to the control at this time. Applying power may damage
the DSLC control.
NOTES
The DSLC control receives its current and voltage input signals from
standard metering current transformers (CTs) and potential transformers
(PTs). The selection of these PTs and CTs will have an effect on
synchronizer voltage and phase matching and load sensing accuracy.
Identical potential transformers should be used for the generator and bus
voltages. CTs should provide 5 amperes RMS at full load for best
performance of the system.
The following sections describe the potential connections for the
synchronizer and power sensor functions. Various DSLC controls have been
designed to accommodate PTs wired in 120 Vac wye, 240 Vac wye, 120 Vac
open delta, and 240 Vac open delta. Contact your local authorized distributor
or Woodward for the latest DSLC control part numbers (Appendix B shows
part numbers as of publication date of this manual).
Bus Potential Transformers
The synchronizer potential input on the DSLC control is connected to the
secondary of 120 or 240 Vac potential transformers. The bus phase A must
correspond to phase A of the generator as wired to the load sensor. See Figure
1-3 for bus potential transformer wiring. Bus phase rotation must correspond to
the generator rotation for proper synchronizer operation.
Generator Potential Transformers
The generator potential inputs on the DSLC control are connected to the
secondary of 120 or 240 Vac potential transformers. Generator phase rotation
must correspond to the bus rotation for proper synchronizer operation. See
Figure 1-3 for generator potential transformer wiring.
Generator Current Transformers
The generator current inputs on the DSLC control are connected to the output of
current transformers, which in turn is placed around one conductor of one phase
of the generator circuit being monitored.