Generac Power Systems MDG25IF4, Owner'S Manual

Page: 34 / 60

30 Owner’s Manual for Mobile Generator
Operation
Fine Voltage Adjustment
See Figure 3-6 . The potentiometer (A) allows manual
voltage adjustment of ±10%.
Figure 3-6. Potentiometer
Voltage Regulator
The analog voltage regulator controls the output of the
generator by regulating the current into the exciter field.
The voltage regulator is adjusted before shipment from
the factory. The regulator has four screwdriver adjustable
potentiometers that may be adjusted for under frequency
roll-off (U/F), U/F dip (DIP), stability (STAB), and voltage
(VOLT). Contact a GMASD for additional information
before attempting to adjust the voltage regulator.
NOTE: For units equipped with a Marathon D
automatic voltage regulator, see the Marathon operating
manual provided with the unit.
Customer Convenience
Receptacles
See
Figure 3-7
. The unit is equipped with five
receptacles. The 240/120V twist-lock receptacles are
rated at 50A each. The 120V GFCI receptacles are rated
at 20A each, with ground fault circuit interrupt (GFCI)
protection. The receptacles are not routed through the
main circuit breaker. Each receptacle has its own circuit
breaker, located directly above or next to the receptacle.
Each breaker is sized to the maximum rating of the
corresponding receptacle.
NOTE: Power to the receptacles is available any time
the generator is running, even if the main circuit breaker
is OFF (O). Verify equipment connected to the
receptacles is turned OFF before turning the breakers
ON (I).
NOTE: When the voltage selector switch is in position for
480/277V three-phase, voltage at the two GFCI
receptacles is 139 volts and the voltage at the three twist-
lock receptacles is 240/139 volts. Generac Mobile does
not recommend using the receptacles in the 480V
position. When the voltage selector switch is in position
for 208/120V three-phase, voltage at the two twist-lock
receptacles and the two GFCI receptacles is 208/120
volts.
Figure 3-7. Customer Convenience Receptacles
Main Circuit Breaker
The main circuit breaker is located on the main control
panel. See
Figure 3-8
. When the breaker is OFF (O),
power is interrupted to the connection lugs and optional
cam lock receptacles.
IMPORTANT NOTE: When the breaker is open, the
generator is powered.
The breaker may be switched ON (I) once the
connections have been made to the connection lugs or
the optional cam lock receptacles, and the unit has been
started and allowed to reach normal operating
temperature.
011196
A
CAUTION
(000303)
Equipment Damage. Verify voltage application
before making changes to factory settings. Incorrect
voltage applied to a load could result in equipment
damage.
A 50 A circuit breaker (3 locations)
B 20 A circuit breaker (2 locations
C 120 V GFCI receptacle (2 locations)
D 120/240 V twistlock receptacle (3 locations)
011197
A
B
C
D