GAC ESD5500E Series User manual

1
Governors America Corp. © 2020 Copyright All Rights Reserved
ESD5500E Series Speed Control Unit 9-2020-F PIB1002
ESD5500E Series
Speed Control Unit
1
2
INTRODUCTION
SPECIFICATIONS
PERFORMANCE
Isochronous Operation ± 0.25 % or better
Speed Range / Governor 1 - 7.5 kHz Continuous
Speed Drift with Temperature ±1 % MAX
Idle Adjust Clockwise 60 % of Set Speed
Idle Adjust Counterclockwise Less than 1200 Hz
Droop Range 1 - 5 % regulation
Droop Adjust Maximum
(K-L jumpered)
400 Hz ±75 Hz per 1.0 A change
Droop Adjust Minimum
(K-L jumpered)
15 Hz ±75 Hz per 1.0 A change
Speed Trim Range ± 200 Hz
Remote Variable Speed
Range
500 - 7.5 kHz
Terminal Sensitivity
J
L
N
P
100 Hz ±15 Hz/Volt @ 5.0 kΩ Impedance
735 Hz ±60 Hz/Volt @ 65.0 kΩ Impedance
148 Hz ±10 Hz/Volt @ 1 MΩ Impedance
10 V DC Supply @ 20 mA MAX
INPUT / OUTPUT
DC Supply 12 V DC and 24 V DC Battery Systems
Transient and Reverse Voltage Protected*
Polarity Negative Ground (Case Isolated)
Power Consumption 50 mA continuous plus actuator current
Speed Signal Range
Speed Sensor Signal
1.0 - 50 V AC
1.0 - 120 V RMS
Actuator Current Range**
(77°F (25°C))
Minimum 1.0 A
Nominal 7.0 A
Peak 10.0 A
The ESD5500E Series Speed Control Unit is an all-electronic device designed to control
engine speed quickly and precisely in response to transient load changes.
The ESD5500E controls a wide variety of engines in isochronous or droop mode when
connected to a proportional electric actuator and magnetic speed sensor. The ruggedly
built ESD5500E series is designed to withstand the engine environment. Light-Force
variations are available.
MODEL DESCRIPTION
ESD5500E Multi-VDC / Standard Unit
ESD5520E Multi-VDC / Light-Force (Low-Current Optimized PID) / Enhanced Droop
ESD5522E Multi-VDC / Light-Force (Low-Current Optimized PID) / Enhanced Droop
for Cummins EFC Forward Acting (Normally Closed)
ESD5526E Multi-VDC / Light-Force (Low-Current Optimized PID) / Anti-Windup
Circuit (Gaseous) / Recommended for T1/T2 ATBs
ESD5528E Multi-VDC / Anti-Windup Circuit (Gaseous) / Recommended for T3/T4
ATBs
RELIABILITY
Vibration 1 g @ 20-100 Hz
Testing 100 % Functionally Tested
ENVIRONMENTAL
Ambient Temperature -40° to 85 °C (-40° to 180 °F)
Relative Humidity up to 95 %
All Surface Finishes Fungus Proof, Corrosion Resistant
COMPLIANCE / STANDARDS
Agency CE (EN55011, EN50081-2, EN50082-2),
RoHS, Lloyds Register,
DNV/GL, Bureau Veritas
PHYSICAL
Dimension See Wiring Diagram and Outline
Weight 1.20 lbf (0.54 kgf)
Mounting Any position, vertical preferred
* Protected against short circuit to actuator (shuts o󰀨 current to actuator), unit automatically turns on when short is removed.
** Protected against reverse voltage by a series diode. A 15 A fuse must be installed in the positive battery lead.

2
Governors America Corp. © 2020 Copyright All Rights Reserved
ESD5500E Series Speed Control Unit 9-2020-F PIB1002
Mount in a cabinet,
engine enclosure, or
sealed metal box.
Vertical orientation
allows uids to drain
in moist environ-
ments.
Dimensions
Avoid Extreme Heat
3INSTALLATION & OUTLINE DIAGRAM
in
[mm]
4WIRING

3
Governors America Corp. © 2020 Copyright All Rights Reserved
ESD5500E Series Speed Control Unit 9-2020-F PIB1002
TERMINAL DEFINITION NOTES
A & B Actuator (+/-) 16 AWG (1.3mm2) or larger wire
C & D Magnetic Speed Pickup
(D is ground)
• Wires must be twisted and/or shielded for their entire length
• Gap between speed sensor and gear teeth should not be smaller than 0.02 in. (.51mm)
• Speed sensor voltage needs to be at least 1 V RMS during crank
E & F Battery Power (-/+)
• 16 AWG (1.3mm2) or larger wire
• A 15 A fuse must be installed in the Positive battery lead to protect against reverse voltage
• Battery positive (+) input is Terminal F
G Ground Signal
H For 12 V systems with actuator currents above 5 A, may sometimes require a jumper between Terminals H and G
J Variable Speed 5 kΩ resistive nominal.
K & L Droop Select Active when closed
M Idle Select Close for Idle
N Accessory Input Load Sharing/Synchronizing, 0-10 V DC (5V Nominal, Reversed, 148 Hz/V). Shielded cabling recommended.
P Accessory Power Supply 10 V DC Output To Power GAC Load Sharing and Synchronizing Modules
When wiring ESD5500E Series controllers:
1. Use shielded cable for all external connections to the ESD controller.
2. One end of each shield, including the speed sensor shield, should be grounded to a single point on the ESD case.
3. Terminal A, B, E,and F should be 16 AWG or larger. Long cables require increased wire size to minimize voltage drops.
4. Battery positive (+) Terminal F should be fused for 15 A.
5. Magnetic speed sensors Terminals C and D must be twisted and or shielded for the entire length.
6. The gap between the speed sensor and the ring gear teeth should be smaller than 0.02 in [0.5 mm] usually backing out 3/4 turn after
touching ring gear teeth. Speed sensor voltage should be at lease 1 V AC RMS during cranking.
7. If auto synchronization is used alone, not with a load sharing module, use a 3 Ω resistor between Terminal N and P to match the voltage
between the speed control unit and the synchronizer.
8. When operating at the upper end of the control unit frequency range, add a jumper wire between Terminal G and J to increase the fre-
quency range of the control unit over 7000 Hz.
9. Terminal P is used to supply +10 V DC regulated supply to accessories. No more than 20 mA of current can be drawn from this supply.
Ground reference is Terminal G. A short circuit in this terminal can damage the speed control unit.
4WIRING (CONTINUED)
An overspeed shutdown device, independent of the governor system, must be provided to prevent loss of
engine control which may cause personal injury or equipment damage. Do not rely exclusively on the governor
system to prevent overspeed. A secondary shuto󰀨 device such as a fuel solenoid must be used.
ADDING A POTENTIOMETER
Use a single remote speed adjustment potentiometer to adjust engine
speed. Select the desired speed range and the corresponding potenti-
ometer value. If the exact range is not found select the next higher range
potentiometer. Connect the potentiometer as shown in the potentiometer
diagram.

4
Governors America Corp. © 2020 Copyright All Rights Reserved
ESD5500E Series Speed Control Unit 9-2020-F PIB1002
6START THE ENGINE
The speed control unit governed speed setting is factory set at approximately engine idle speed. (1000 Hz., speed sensor signal or 600 RPM)
If the engine does not start, adjustment of the speed potentiometer may be required.
Crank the engine with DC power applied to the governor system. The actuator will energize to the maximum fuel position until the engine
starts. The governor system should control the engine at a low idle speed. If the engine is unstable after starting, refer to Section 8 ADJUST-
ING FOR STABILITY.
7GOVERNOR SPEED SETTING
5ADJUSTMENTS BEFORE ENGINE STARTUP
Make sure the following adjustments are set before starting the engine.
GAIN Middle Position
STABILITY Middle Position
SPEED TRIM CONTROL Middle Position
STARTING FUEL Full CW (MAX fuel)
SPEED RAMPING Full CCW (fastest)
The governed speed set point is increased by clockwise rotation of the
SPEED adjustment control. Remote speed adjustment can be obtained
with an optional 5 kΩ Speed Trim Control potentiometer.
8ADJUSTING FOR STABILITY
Once the engine is running at operating speed and at no load, the
following governor performance adjustments can be made to increase
engine stability.
5.000 (127)
Ø0.266
(6,6)
CW
*SEE SPECIFIC ACTUATOR PUBLICATION FOR PROPER
WIRING OF ACTUATOR BASED ON BATTERY VOLTAGE
1.031
(26)
*
OPTIONAL ACTUATOR
CABLE SHIELDING TO
MEET CE DIRECTIVE
5.750(146)
5.000
(127)
5.500
(140)
ABCDEFGH JLMN P
ACTUATOR
PICK-UP
BATTERY AUX 10V
OUTPUT
C1 OFF
ON
LEAD CIRCUIT
OFF
ON C2
SOFT COUPLING
BATTERY
_+S1
FUSE
15A MAX
GROUND REFERENCE
ADD JUMPER FOR 12V
BATTERY OR ACTUATOR
CURRENTS ABOVE 5A
SPEED TRIM
CONTROL - 5K
K
CLOSE FOR DROOP
CLOSE FOR IDLE
ACTUATOR
MAGNETIC
PICK-UP
DROOP IDLE
- +
CAUTION
ENGINE SPEED CONTROL
COMPONENT. WHEN INSTALLING
OR SERVICING REFER TO
PRODUCT PUBLICATION.
SPEED CONTROL UNIT
ACCESSORY POWER
SUPPLY
ACCESSORY INPUT
DROOP
IDLE
SPEED
E3
GAIN
STABILITY
SWITCH
PROFILE
SPEED
RAMPING
STARTING
FUEL
E2
E1
DEAD TIME
COMPENSATION
JUMPER
S/N :
MODEL:
GAC
OVERNORS
MERICA
ORP.
MADE IN AGAWAM, MA U.S.A.
ESD5500E
WD554
5.000 (127)
Ø0.266
(6,6)
CW
*SEE SPECIFIC ACTUATOR PUBLICATION FOR PROPER
WIRING OF ACTUATOR BASED ON BATTERY VOLTAGE
1.031
(26)
*
OPTIONAL ACTUATOR
CABLE SHIELDING TO
MEET CE DIRECTIVE
5.750(146)
5.000
(127)
5.500
(140)
ABCDEFGH JLMN P
ACTUATOR
PICK-UP
BATTERY AUX 10V
OUTPUT
C1 OFF
ON
LEAD CIRCUIT
OFF
ON C2
SOFT COUPLING
BATTERY
_+S1
FUSE
15A MAX
GROUND REFERENCE
ADD JUMPER FOR 12V
BATTERY OR ACTUATOR
CURRENTS ABOVE 5A
SPEED TRIM
CONTROL - 5K
K
CLOSE FOR DROOP
CLOSE FOR IDLE
ACTUATOR
MAGNETIC
PICK-UP
DROOP IDLE
- +
CAUTION
ENGINE SPEED CONTROL
COMPONENT. WHEN INSTALLING
OR SERVICING REFER TO
PRODUCT PUBLICATION.
SPEED CONTROL UNIT
ACCESSORY POWER
SUPPLY
ACCESSORY INPUT
DROOP
IDLE
SPEED
E3
GAIN
STABILITY
SWITCH
PROFILE
SPEED
RAMPING
STARTING
FUEL
E2
E1
DEAD TIME
COMPENSATION
JUMPER
S/N :
MODEL:
GAC
OVERNORS
MERICA
ORP.
MADE IN AGAWAM, MA U.S.A.
ESD5500E
WD554
PARAMETER PROCEDURE
GAIN 1. Rotate the GAIN adjustment clockwise until instability develops.
2. Gradually move the adjustment counterclockwise (CCW) until stability returns.
3. Move the adjustment one division further counterclockwise to ensure stable performance (270° potentiometer).
4. If instability persists, adjust the next parameter.
STABILITY Follow the same adjustment procedure, steps 1 - 3, as the GAIN parameter.
Normally, adjustments made at no load achieve satisfac-
tory performance. If further performance improvements
are required, refer to Section 12 TROUBLESHOOTING.
NOTE
5.000 (127)
Ø0.266
(6,6)
CW
*SEE SPECIFIC ACTUATOR PUBLICATION FOR PROPER
WIRING OF ACTUATOR BASED ON BATTERY VOLTAGE
1.031
(26)
*
OPTIONAL ACTUATOR
CABLE SHIELDING TO
MEET CE DIRECTIVE
5.750(146)
5.000
(127)
5.500
(140)
ABCDEFGH JLMN P
ACTUATOR
PICK-UP
BATTERY AUX 10V
OUTPUT
C1 OFF
ON
LEAD CIRCUIT
OFF
ON C2
SOFT COUPLING
BATTERY
_+S1
FUSE
15A MAX
GROUND REFERENCE
ADD JUMPER FOR 12V
BATTERY OR ACTUATOR
CURRENTS ABOVE 5A
SPEED TRIM
CONTROL - 5K
K
CLOSE FOR DROOP
CLOSE FOR IDLE
ACTUATOR
MAGNETIC
PICK-UP
DROOP IDLE
- +
CAUTION
ENGINE SPEED CONTROL
COMPONENT. WHEN INSTALLING
OR SERVICING REFER TO
PRODUCT PUBLICATION.
SPEED CONTROL UNIT
ACCESSORY POWER
SUPPLY
ACCESSORY INPUT
DROOP
IDLE
SPEED
E3
GAIN
STABILITY
SWITCH
PROFILE
SPEED
RAMPING
STARTING
FUEL
E2
E1
DEAD TIME
COMPENSATION
JUMPER
S/N :
MODEL:
GAC
OVERNORS
MERICA
ORP.
MADE IN AGAWAM, MA U.S.A.
ESD5500E
WD554
IMPORTANT:
Speed Adjustment Is a 25
Turn Potentiometer

5
Governors America Corp. © 2020 Copyright All Rights Reserved
ESD5500E Series Speed Control Unit 9-2020-F PIB1002
PROCEDURE
Start the engine and maintain at an idle speed for a period of time
prior to accelerating to the operating speed. This method separates
the starting process so that each may be optimized for the lowest
smoke emissions.
1. Replace the connection between Terminals M & G with a tog-
gle switch or a normally open water jacket temperature switch.
Other optical switch combinations can be used.
2. Start the engine.
3. If the starting smoke is excessive, the STARTING FUEL may
need to be adjusted slightly CCW.
4. If the starting time is too long, the STARTING FUEL may need
to be adjusted slightly CW.
5. When the switch opens, adjust the SPEED RAMPING for the
least amount of smoke when accelerating from idle speed to
rated speed.
One of two methods of operation for the ESD5500E may be selected: Operating Speed or Idle.
METHOD 1 - OPERATING SPEED
PROCEDURE
Start the engine and accelerate directly to the operating speed (Gen-
erator Sets, etc.).
5.000 (127)
Ø0.266
(6,6)
CW
*SEE SPECIFIC ACTUATOR PUBLICATION FOR PROPER
WIRING OF ACTUATOR BASED ON BATTERY VOLTAGE
1.031
(26)
*
OPTIONAL ACTUATOR
CABLE SHIELDING TO
MEET CE DIRECTIVE
5.750(146)
5.000
(127)
5.500
(140)
ABCDEFGH JLMN P
ACTUATOR
PICK-UP
BATTERY AUX 10V
OUTPUT
C1 OFF
ON
LEAD CIRCUIT
OFF
ON C2
SOFT COUPLING
BATTERY
_+S1
FUSE
15A MAX
GROUND REFERENCE
ADD JUMPER FOR 12V
BATTERY OR ACTUATOR
CURRENTS ABOVE 5A
SPEED TRIM
CONTROL - 5K
K
CLOSE FOR DROOP
CLOSE FOR IDLE
ACTUATOR
MAGNETIC
PICK-UP
DROOP IDLE
- +
CAUTION
ENGINE SPEED CONTROL
COMPONENT. WHEN INSTALLING
OR SERVICING REFER TO
PRODUCT PUBLICATION.
SPEED CONTROL UNIT
ACCESSORY POWER
SUPPLY
ACCESSORY INPUT
DROOP
IDLE
SPEED
E3
GAIN
STABILITY
SWITCH
PROFILE
SPEED
RAMPING
STARTING
FUEL
E2
E1
DEAD TIME
COMPENSATION
JUMPER
S/N :
MODEL:
GAC
OVERNORS
MERICA
ORP.
MADE IN AGAWAM, MA U.S.A.
ESD5500E
WD554
METHOD 2 - IDLE SPEED
10 METHODS OF OPERATION
1. Remove the connection between Terminals M and G.
2. Start the engine and adjust the SPEED RAMPING for the least
smoke on acceleration from idle to rated speed.
3. If the starting time is too long, the STARTING FUEL may need to
be adjusted slightly clockwise (CW).
Full CCW = Fastest
Full CW = MAX Fuel
5.000 (127)
Ø0.266
(6,6)
CW
*SEE SPECIFIC ACTUATOR PUBLICATION FOR PROPER
WIRING OF ACTUATOR BASED ON BATTERY VOLTAGE
1.031
(26)
*
OPTIONAL ACTUATOR
CABLE SHIELDING TO
MEET CE DIRECTIVE
5.750(146)
5.000
(127)
5.500
(140)
ABCDEFGH JLMN P
ACTUATOR
PICK-UP
BATTERY AUX 10V
OUTPUT
C1 OFF
ON
LEAD CIRCUIT
OFF
ON C2
SOFT COUPLING
BATTERY
_+S1
FUSE
15A MAX
GROUND REFERENCE
ADD JUMPER FOR 12V
BATTERY OR ACTUATOR
CURRENTS ABOVE 5A
SPEED TRIM
CONTROL - 5K
K
CLOSE FOR DROOP
CLOSE FOR IDLE
ACTUATOR
MAGNETIC
PICK-UP
DROOP IDLE
- +
CAUTION
ENGINE SPEED CONTROL
COMPONENT. WHEN INSTALLING
OR SERVICING REFER TO
PRODUCT PUBLICATION.
SPEED CONTROL UNIT
ACCESSORY POWER
SUPPLY
ACCESSORY INPUT
DROOP
IDLE
SPEED
E3
GAIN
STABILITY
SWITCH
PROFILE
SPEED
RAMPING
STARTING
FUEL
E2
E1
DEAD TIME
COMPENSATION
JUMPER
S/N :
MODEL:
GAC
OVERNORS
MERICA
ORP.
MADE IN AGAWAM, MA U.S.A.
ESD5500E
WD554
5.000 (127)
Ø0.266
(6,6)
CW
*SEE SPECIFIC ACTUATOR PUBLICATION FOR PROPER
WIRING OF ACTUATOR BASED ON BATTERY VOLTAGE
1.031
(26)
*
OPTIONAL ACTUATOR
CABLE SHIELDING TO
MEET CE DIRECTIVE
5.750(146)
5.000
(127)
5.500
(140)
ABCDEFGH JLMN P
ACTUATOR
PICK-UP
BATTERY AUX 10V
OUTPUT
C1 OFF
ON
LEAD CIRCUIT
OFF
ON C2
SOFT COUPLING
BATTERY
_+S1
FUSE
15A MAX
GROUND REFERENCE
ADD JUMPER FOR 12V
BATTERY OR ACTUATOR
CURRENTS ABOVE 5A
SPEED TRIM
CONTROL - 5K
K
CLOSE FOR DROOP
CLOSE FOR IDLE
ACTUATOR
MAGNETIC
PICK-UP
DROOP IDLE
- +
CAUTION
ENGINE SPEED CONTROL
COMPONENT. WHEN INSTALLING
OR SERVICING REFER TO
PRODUCT PUBLICATION.
SPEED CONTROL UNIT
ACCESSORY POWER
SUPPLY
ACCESSORY INPUT
DROOP
IDLE
SPEED
E3
GAIN
STABILITY
SWITCH
PROFILE
SPEED
RAMPING
STARTING
FUEL
E2
E1
DEAD TIME
COMPENSATION
JUMPER
S/N :
MODEL:
GAC
OVERNORS
MERICA
ORP.
MADE IN AGAWAM, MA U.S.A.
ESD5500E
WD554
9STARTING FUEL ADJUSTMENT
The engine’s exhaust smoke at start-up can be minimized by complet-
ing the following adjustments:
1. Place the engine in idle by connecting Terminals M and G.
2. Adjust the IDLE speed for as low a speed setting as the appli-
cation allows. Idle speed must be set for proper start fuel and
speed ramping function, even if the idle feature is not used.
3. Adjust the STARTING FUEL CCW until the engine speed begins
to fall. Increase the STARTING FUEL slightly so that the idle
speed is returned to the desired level.
4. Stop the engine.

6
Governors America Corp. © 2020 Copyright All Rights Reserved
ESD5500E Series Speed Control Unit 9-2020-F PIB1002
11 ADDITIONAL FEATURES AND OPTIONAL WIRING
IDLE SPEED SETTING
If the IDLE speed setting was not adjusted as detailed in Section 9 Starting
Fuel Adjustment, then place the optional external selector switch in the IDLE
position.
The idle speed set point is increased by the clockwise rotation of the IDLE
adjustment control. When the engine is at idle speed, the speed control unit
applies droop to the governor system to ensure stable operation.
If not using the idle method, you can lower idle to the bare minimum (even if it’s
not being used) for smoke reduction.
5.000 (127)
Ø0.266
(6,6)
CW
*
SEE SPECIFIC ACTUATOR PUBLICATION FOR PROPER
WIRING OF ACTUATOR BASED ON BATTERY VOLTAGE
1.031
(26)
*
OPTIONAL ACTUATOR
CABLE SHIELDING TO
MEET CE DIRECTIVE
5.750(146)
5.000
(127)
5.500
(140)
ABCDEFGH JLMN P
ACTUATOR
PICK-UP
BATTERY AUX 10V
OUTPUT
C1 OFF
ON
LEAD CIRCUIT
OFF
ON C2
SOFT COUPLING
BATTERY
_+S1
FUSE
15A MAX
GROUND REFERENCE
ADD JUMPER FOR 12V
BATTERY OR ACTUATOR
CURRENTS ABOVE 5A
SPEED TRIM
CONTROL - 5K
K
CLOSE FOR DROOP
CLOSE FOR IDLE
ACTUATOR
MAGNETIC
PICK-UP
DROOP IDLE
- +
CAUTION
ENGINE SPEED CONTROL
COMPONENT. WHEN INSTALLING
OR SERVICING REFER TO
PRODUCT PUBLICATION.
SPEED CONTROL UNIT
ACCESSORY POWER
SUPPLY
ACCESSORY INPUT
DROOP
IDLE
SPEED
E3
GAIN
STABILITY
SWITCH
PROFILE
SPEED
RAMPING
STARTING
FUEL
E2
E1
DEAD TIME
COMPENSATION
JUMPER
S/N :
MODEL:
GAC
OVERNORS
MERICA
ORP.
MADE IN AGAWAM, MA U.S.A.
ESD5500E
WD554
LEAD CIRCUIT & SOFT COUPLING
Switch 1(C1) controls the Lead Circuit. The normal position is ON.
Move the switch to the OFF position if there is fast instability in the
system.
Switch 2(C2) controls a circuit designed to eliminate fast erratic gover-
nor behavior, caused by very soft or worn couplings in the drive train
between the engine and generator.
The normal position is OFF. Use the ON position if you experience
fast erratic engine behavior between the engine and generator due to
a soft coupling.
C1 OFF
ON
LEAD CIRCUIT
OFF
ON C2
SOFT COUPLING
DROOP
IDLE
SPEED
C1 OFF
ON
LEAD CIRCUIT
OFF
ON C2
SOFT COUPLING
DROOP
IDLE
SPEED
ACCESSORY INPUT
The Auxiliary Terminal N accepts input signals from load sharing units,
auto synchronizers, and other governor system accessories, GAC ac-
cessories are directly connected to this terminal.
Terminal N is sensitive (145 Hz/V). Accessory connections
must be shielded.
When an accessory is connected to Terminal N, the speed will de-
crease and the speed adjustment must be reset.
If the auto synchronizer is used alone, not in conjunction with a load shar-
ing module, a 3 Ω resistor 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
ACCESSORY SUPPLY
The +10 volt regulated supply, Terminal P, can be utilized 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.
2750 Hz x 60 seconds = 1500 RPM
110 Teeth
A short circuit on this terminal can damage the speed control unit.
Do not connect Terminals N and P directly to each other.

7
Governors America Corp. © 2020 Copyright All Rights Reserved
ESD5500E Series Speed Control Unit 9-2020-F PIB1002
The ESD5500 series of controllers have the ability to expand the speed range by placing a jumper wire across terminals
G and J. The standard range is 7400 Hz however this is based on the operating speed and the number of ywheel teeth
(see formula). If your application is above this frequency, or near it – place the jumper and test again. This is an important step if your engine
is not able to reach rated speed but the actuator is not saturated.
NOTE
SPEED DROOP OPERATION
Droop is typically used for the paralleling of engine driven generators. When in droop operation, the engine speed will decrease as engine load
increases. The percentage of droop is based on the actuator current change from no engine load to full load.
Place the optional external selector switch in the DROOP position. DROOP is increased by clockwise rotation of the DROOP adjustment
control.
After the droop level has been adjusted, the rated engine speed setting may need to be reset. Check the engines speed and adjust that speed
setting accordingly.
Though a wide range of droop is available with the internal control, droop level requirements of 10% are unusual. If droop
levels experienced are higher or lower than those required, contact GAC for assistance.
NOTE
A single remote speed adjustment potentiometer can be used to adjust the engine speed continuously over a specic speed range.
Select the desired speed range and corresponding potentiometer value (See Variable Speed Table). If the exact range cannot be found, select
the next higher range potentiometer.
To maintain engine stability at the minimum speed setting, a small amount of droop can be added using the DROOP adjustment. At the max-
imum speed setting the governor performance will be near isochronous, regardless of the droop adjustment setting.
An additional xed resistor may be placed across the potentiometer to obtain the exact desired range. Connect the speed
range potentiometer as shown to the right using Terminals G and J. Contact GAC for assistance if you experience di󰀩culty
obtaining the desired variable speed governing performance.
REMOTE VARIABLE SPEED OPERATION
NOTE
VARIABLE SPEED TABLE
SPEED FREQUENCY RANGE POTENTIOMETER VALUE
900 Hz 1 kΩ
2400 Hz 5 kΩ
3000 Hz 10 kΩ
3500 Hz 25 kΩ
3700 Hz 50 kΩ
Conversion Formulas
HertzMAG PICKUP = (RPM x #Teeth)
60 RPM = (HertzMAG PICKUP x 60)
#Teeth
11 ADDITIONAL FEATURES & OPTIONAL WIRING (CONTINUED)

8
Governors America Corp. © 2020 Copyright All Rights Reserved
ESD5500E Series Speed Control Unit 9-2020-F PIB1002
STEP WIRES CHECK PROBABLE CAUSE
1 F(+) & E(-)
Battery Supply
Voltage
(12 or 24 V DC)
1. DC battery power not connected. Check for blown fuse.
2. Low battery voltage
3. Wiring error
2 C(+) & D(-) 1.0 V AC RMS min. while
cranking
1. Gap between speed sensor and gear teeth too great. Check Gap.
2. Improper or defective wiring to the speed sensor. Resistance between D and C should be 160 to
1200 Ω. See your specic mag pickup data for resistance.
3. Defective speed sensor
3 P(+) & G(-) 10 V DC, Internal Supply
1. Short on Terminal P
2. Defective speed control unit
4F(+) & A(-) 1.0 - 2.0 V DC while
cranking
1. SPEED potentiometer set too low
2. Short/open in actuator wiring
3. Defective speed control
4. Defective actuator, see your actuator manual for troubleshooting
SYSTEM INOPERATIVE
12 TROUBLESHOOTING
If the engine governing system does not function, the fault may be determined by performing the voltage tests described in Steps 1 through
4. Positive (+) and negative (-) refer to meter polarity. Should normal values be indicated during troubleshooting steps, and then the fault may
be with the actuator or the wiring to the actuator. Tests are performed with battery power on and the engine o󰀨, except where noted. See your
actuator publication for actuator testing procedures.
INSUFFICIENT MAGNETIC SPEED SIGNAL
A strong magnetic speed sensor signal eliminates the possibility of missed or extra pulses. The speed control unit will govern well with 1.0 V RMS
speed sensor signal. A speed sensor signal of 3 V AC or greater at governed speed is recommended. Measurement of the signal is made at
Terminals C and D.
The amplitude of the speed sensor signal can be raised by reducing the gap between the speed sensor tip and the engine ring gear. The gap
should not be any smaller than 0.02 in [0.5 mm]. When the engine is stopped, back the speed sensor out by 3/4 turn after touching the ring gear
tooth to achieve a satisfactory air gap.
INSTABILITY
INSTABILITY CHECK PROBABLE CAUSE
Fast Periodic
The engine seems to jitter
with a 3 Hz or faster irregu-
larity of speed.
1. Make sure switch C1 is set to OFF.
2. Readjust the GAIN and STABILITY for optimum control.
3. Remove the E1 to E2 jumper. Readjust GAIN and Stability afterward.
4. Turn o󰀨 other electrical equipment that may be causing interference.
Slow Periodic An irregularity of speed
below 3 Hz.
1. Readjust the GAIN and STABILITY
2. Adjust the DEAD TIME COMPENSATION by adding a capacitor from posts E2 to E3 (negative on
E2). Start with 10 mF and increase until instability is eliminated.
Check fuel system linkage during engine operation for:
• binding
• high friction
• poor linkage
Non-Periodic Erratic Engine Behavior
Increasing the GAIN should reduce the instability but not totally correct it.
If this is the case, there is most likely a problem with the engine itself. Check for:
• engine mis-rings
• erratic fuel system
• load changes on the generator set voltage regulator
If throttle is slightly erratic, but performance is fast, move switch C1 to the OFF position.

9
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ESD5500E Series Speed Control Unit 9-2020-F PIB1002
UNSATISFACTORY PERFORMANCE
SYMPTOM CHECK PROBABLE CAUSE
Engine
Overspeed
1. Do Not Crank. Apply DC
power to the governor
system.
1. After the actuator goes to full fuel, disconnect the speed sensor at Terminal C and D. If the actuator
is still at full fuel-speed then the speed control unit is defective.
2. If the actuator is at minimum fuel position and there exists an erroneous position signal, then check
speed sensor cable.
2.
Manually hold the engine
at the desired running
speed. Measure the DC
voltage between Termi-
nals A(-) & F(+) on the
speed control unit.
If the voltage reading is 1.0 to 1.5 V DC:
• SPEED adjustment is set above desired speed
• Defective speed control unit
If voltage reading is above 1.5 V DC then check for:
• actuator binding
• linkage binding
If the voltage reading is below 0.8 V DC:
• Defective speed control unit
Actuator does not
energize fully
1. Measure the voltage at
the battery while cranking.
If the voltage is less than:
• 7V for a 12V system, or
• 14V for a 24V system, Then: Check or replace battery.
2.
Momentarily connect
Terminals A and F. The
actuator should move to
the full fuel position.
1. Actuator or battery wiring in error
2. Actuator or linkage binding
3. Defective actuator
3.
Measure frequency of
magnetic speed pickup
(or calculate).
If above 7000 Hz then add jumper to Terminal G and J.
Engine remains
below desired
governed speed
1.
Measure the actuator
output, Terminals A &
B, while running under
governor control.
1. If voltage measurement is within 2 V DC of the battery supply voltage level, then fuel control is
restricted from reaching full fuel position, possibly due to mechanical governor, carburetor spring, or
linkage interference.
2. SPEED parameter set too low
12 TROUBLESHOOTING (CONTINUED)