E
NGINE
G
OVERNING
ESD5550/5570 Series
S
YSTEM
Speed Control Unit
Installation
Adjustments
The speed control unit is rugged enough to be placed in a
control cabinet or engine mounted enclosure with other
dedicated control equipment. If water, mist, or condensation
may come in contact with the controller, it should be mount-ed
vertically. This will allow the fluid to drain away from the speed
control unit. Extreme heat should be avoided.
An overspeed shutdown device, independent of the gover-
nor system, should be provided to prevent loss of engine
control, which may cause personal injury or equipment dam-
age. Do not rely exclusively on the governor system electric
actuator to prevent overspeed. A secondary shutoff device,
such as a fuel solenoid, must be used.
Wiring
Basic electrical connections are illustrated in Diagram 2 (for
the ESD5550, ESD5555 and the ESD5570) and Diagram 3
(for the ESD5556 only). Actuator and battery connections to
Terminals A, B, E, and F should be #16 AWG (1.3 mm
2
) or
larger. Long cables require an increased wire size to mini-
mize voltage drops. The battery positive (+) input, Terminal
F, should be fused for 15 amps as illustrated.
Magnetic speed sensor wires connected to Terminals C and D
MUST BE TWISTED AND/OR SHIELDED for their entire
length. The speed sensor cable shield should ideally be con-
nected as shown in Diagram 2 or 3. The shield should be
insulated to insure no other part of the shield comes in con-tact
with engine ground, otherwise stray speed signals may be
introduced into the speed control unit. With the engine stopped,
adjust the gap between the magnetic speed sensor and the ring
gear teeth. The gap should not be any smaller than 0.020 in.
(0.45 mm). Usually, backing out the speed sensor 3/4 turn after
touching the ring gear teeth will achieve a satisfactory air gap.
The magnetic speed sensor voltage should be at least 1 VAC
RMS during cranking.
Before Starting Engine
Before starting the engine, check and/or adjust the POTs/
switches to the following settings. See Table 1 for the fac-
tory presets.
Start Engine
The speed control unit governed speed setting is factory set
at approximately engine idle speed. (1000 Hz., speed sen-
sor 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.
Adjusting Crank Termination (ESD5556 only)
To protect the engine from harm the CRANK TERMINATION
adjustment is factory set at full CCW [Lowest Setting]. To adjust
CRANK TERMINATION speed setting, rotate the CRANK
adjustment to full CW. Crank the engine and simul-taneously
turn the CRANK adjustment slowly CCW until the proper crank
termination speed is reached. In operation, when the cranking
termination set point is reached, the green CRANK LED will
illuminate. (Cranking has terminated).
The ESD5556 is set for manual reset. To reinstate engine
cranking, battery power must be removed and then reap-
plied which will recycle the control.
Adjusting Overspeed
When the engine is running at the desired speed, push and
hold the TEST button. Rotate the OVERSPEED adjustment
CCW until the red OVERSPEED LED lights and the relay
energizes. Current to the actuator will be removed and the
Table 1 factory presets
Adjustment / Switch
Potentiometer/Switch
Setting
Applicable Units
SPEED
25 turn
1470 Hz ± 50 Hz w/ min. trim
all
GAIN
270° turn
50%
all
STABILITY
270° turn
50%
all
DROOP
270° turn
0% (CCW)
all
IDLE
270° turn
1075± 75 Hz
all
STARTING FUEL RAMP
270° turn
100% (CW) Maximum Fuel
all
SPEED RAMP
270° turn
0% (CCW) Fastest
all
OVERSPEED
25° turn
100% (CW) Highest
all
CRANK TERMINATION
25° turn
0% (CCW) Lowest
ESD5556 only
SWI Lead Circuit
switch
ON
all
SW2 Soft Coupling
switch
OFF
all
