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Governors America Corp. © 2021 Copyright All Rights Reserved
ESD5550-5570 Series Speed Control Unit
1-2021-E1
PIB1003
acceSSorY InPUT
Auxiliary Terminal N accepts input signals from load sharing units, auto synchronizers, and other governor system accessories.
GAC accessories are directly connected to this terminal. Terminal N connections must be shielded.
If the auto synchronizer is used alone, not in conjunction with a load sharing module, a 3 Ω resister should be connected between
Terminals N and P. This is required to match the voltage levels between the speed control unit and the synchronizer.
noTe
Terminal P su10 volt regulated supply to provide power to GAC governor system accessories. up to 20 mA of current can be drawn
from this supply. Ground reference is Terminal G.
A short circuit on Terminal P can damage the speed control unit.
acceSSorY SUPPLY
aDDInG a PoTenTIomeTer
use a single remote speed adjustment potentiometer to
adjust engine speed. Select the desired speed range and the
corresponding potentiometer value.
If the exact range is not found select the next higher range
potentiometer. Connect the potentiometer as shown in the
WIRING diagram.
SPeeD ranGe
PoTenTIomeTer
900 Hz
1K
2,400 Hz
5K
3,000 Hz
10K
3,500 Hz
25K
3,700 Hz
50K
4
WIRINg (CONTINUED)
5
ADJUSTMENTS
Before starting the engine, check and/or adjust the potentiometer and following settings as desired.
Before STarTInG THe enGIne
The speed control unit governed speed setting is factory set at approximately engine idle speed 1000 Hz., speed sensor signal).
Crank the engine with DC power applied to the governor system. The governor system should control the engine at a low idle speed. If the
engine is unstable after starting, turn the GAIN and STABILITy adjustments CCW until the engine is stable.
STarTInG THe enGIne
aDJUSTmenT / SWITcH
PoTenTIomeTer / SWITcH
facTorY SeTTInG
noTeS
SPEED
25 turn
1470 Hz ± 50 Hz w/ min. trim
GAIN
270° turn
50%
Middle position
STABILITy
270° turn
50%
Middle position
DROOP
270° turn
0% (CCW)
IDLE
270° turn
1075± 75 Hz
STARTING FuEL RAMP
270° turn
100% (CW) Maximum Fuel
SPEED RAMP
270° turn
0% (CCW) Fastest
OVERSPEED
25 turn
100% (CW) Highest
SW1 Lead Circuit
switch
ON
SW2 Soft Coupling
switch
OFF
