Voltage Regulation; Derating For Altitude; Wet Stacking - Generac Power Systems Magnum MTT25 Operating Manual

1. Once the engine is up to temperature and running
smoothly, switch the main circuit breaker (A) to the
ON (I) position.
2. Switch the lights and receptacle panel main circuit
breaker to the ON (I) position.
3. With the main circuit breaker on, switch each
individual circuit breaker for the lights (B) to the ON
(I) position, one at a time.
4. The ballast indicator lights (C) will come on and
continue to get brighter as the lights warm up, and
then remain on. This confirms that power is coming
from the ballasts to the lights.
5. If an indicator light does not come on, the ballast may
need to be serviced. If the indicator light comes on
and stays lit, but the related light is not illuminated,
check the bulb or the mast wiring. Refer to
6. The lights require a warm up period of 5-15 minutes before they reach full output. If the lights are shut down,
they require a cool down period of approximately 10 minutes before they can be switched on again.
7. The light tower uses four 1000W bulbs. When checking or replacing the bulbs, wipe them with a clean cloth to
avoid leaving any grease, oil residue or fingerprints on the glass. Any residue can create a hot spot on the bulb,
causing premature bulb failure.
Bulbs become extremely hot when in use. Allow bulb fixture to cool 10-15 minutes before

VOLTAGE REGULATION

The electronic voltage regulator controls the output of the generator by regulating the current into the exciter field.
The regulator has three screwdriver adjustable potentiometers that may be adjusted for voltage, stability and voltage
roll-off (U/F). The voltage regulator on your unit is adjusted before shipment from the factory. Contact Magnum Power
Products LLC for additional information before attempting to adjust the voltage regulator.

DERATING FOR ALTITUDE

All units are subject to derating for altitude and temperature; this will reduce the available power for operating tools
and accessories connected to the receptacles. Typical reductions in performance are 2-4% for every 1000 ft (305
m) of elevation and 1% per 10ºF (5.6ºC) increase in ambient air temperature over 72ºF (22ºC).

WET STACKING

The unit is powered by a diesel engine. Diesel engines are susceptible to wet stacking if lightly loaded. Wet stacking
occurs when an engine is run at less than 30% of its full load capacity, causing unburned fuel to accumulate in the
exhaust system. Wet stacking can be detected by continuous black exhaust when the unit is under a constant load.
It can also cause fouling of injectors and buildup on engine valves. Diesel engines operate properly when applied
loads are between 30% and 100% capacity. Appropriate generator sizing is determined by the anticipated load. If
the unit is in a wet stack condition, load the unit heavily for five hours or until the exhaust is clear.
30
"Troubleshooting the Lights" on page 45.
CAUTION
handling or lowering the mast.
A B C
MAN AUT
kW
0
Ready
PF 0.00
RPM 0
0
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