14 Generac
®
Power Systems, Inc.
3.3
MANUAL TRANSFER AND
START-UP
To transfer electrical loads to the Standby (EMER-
GENCY) power source side and start the engine man-
ually, refer to the Owner’s Manual of the particular
transfer switch.
3.4
ENGINE GOVERNOR
ADJUSTMENTS
Engine speed governing is also controlled by the
engine control board. Connector J2 on the engine
control board interfaces with a governor driver mod-
ule and the Bosch throttle body. The engine governor
has been set by the factory during final testing of the
generator and, in most cases, should not be adjusted.
If, however, adjustments are necessary, or a new
engine control board is installed in the generator, the
following procedure should be followed (Figure 3.2):
1. Set all three potentiometers (pots) fully counter-
clockwise.
2. Under no load condition, increase the GAIN pot
as much as possible without causeing instability.
3. Apply 1/4, 1/2, 3/4 and full load to the unit.
Decrease the GAIN pot if there is instability at any
load point.
4. Under full load condition, increase the STABILI-
TY pot until the unit returns to 60 Hertz (or 50
Hertz in 50 Hertz applications).
5. Reduce load to 3/4, 1/2, 1/4 and no load.
Decrease the STABILITY pot if there is instability
at any load point.
6. Adjust differential pot to make the recovery to
load changes even faster and minimize load
change undershoot and overshoot. If it is set too
high it may introduce oscillations at some load. It
can be set to zero (full CCW) if a small amount
causes oscillations at some load.
Figure 3.2 — Engine Governor Adjustment
3.5
RETRANSFER AND SHUTDOWN
When utility power source voltage has been restored,
electrical loads may be transferred back to that
source and the generator can be shut down as follows:
• Verify that utility power supply voltage to the trans-
fer switch has been positively turned OFF, using
whatever means provided (such as utility main line
circuit breaker).
• Set the generator’s main circuit breaker to its OFF
or OPEN position.
• Let the generator engine run at no-load for a few
minutes, to stabilize internal unit temperatures.
• On the generator console, set the AUTO/OFF/
MANUAL switch to OFF. Wait for engine to come to
a complete stop.
• For transfer to utility position, refer to the Owner’s
Manual of the particular transfer switch.
• Turn on the utility power supply to the transfer
switch, using whatever means provided (such as a
utility main line circuit breaker). The utility power
source now powers the loads.
3.6
AUTOMATIC OPERATION
To set the system for fully automatic operation, pro-
ceed as follows:
• Check that load circuits are connected to the
utility power supply.
• Set the AUTO/OFF/MANUAL switch to its AUTO
position.
• Set the generator main circuit breaker to its ON or
CLOSED position.
3.7
WEEKLY EXERCISE CYCLE
The engine control board will start and run the gen-
erator once every seven days for approximately 12
minutes. If utility should fail during this exercise
period, the engine control board will transfer the load
to the generator output and continue to run until util-
ity returns.
On the day, and at the time of day chosen for the gen-
erator to exercise, set the weekly exercise cycle as fol-
lows:
1. Place the AUTO/OFF/MANUAL switch in the
AUTO position.
2. Press and hold the “Set Exercise” switch for three
seconds, then release.
At this time all five red LEDs will flash for approxi-
mately 10 seconds, then the engine will start and run
for it’s 12 minute exercise period, then shut down.
The generator will now start and run each week at the
same time.
If DC power to the control board is lost, the weekly
exercise setting will be lost. This is indicated by all five
red LEDs continually flashing. In this state the gener-
ator will still start and run in manual mode, or auto-
matically start and run if UTILITY is lost while in
AUTO mode, but it will not perform a weekly exercise
cycle.
PCB# 0E4906 REV.
R49
D17
J2
C2
C26
U7
C27
R44
Q2
D19
C30
RL1
2
L3
LED1
C4
R
25
C9
C21
D10
J1
R48
R1
U1
RL2
1
2
3
4
UNUSED
GTS/ATS
50/60 HZ
POSITION 1
50/60 HZ
ON = 50 HZ
OFF = 60 HZ
POSITION 2
GTS/ATS Select
ON = GTS
OFF = ATS (standard mode)
STABILITY
DIFFERENTIAL
DIP SWITCH
0 0
Section 3 — Operation
Generac Liquid-cooled Generators