Generator is Overheating

GENERATOR BUILDS VOLTAGE FROM STARTUP, THEN GOES TO LOW (RESIDUAL) VOLTAGE

CAUSE	CHECK AND REMEDY
Regulator protective circuit operating	Check indicators on regulator. Correct problems and adjust regulator as is required. Refer
	to regulator manual.

CAUSE

Generator is overloaded Clogged ventilating screens High room temperature or altitude Insufficient circulation of cooling air

Unbalanced load

CHECK AND REMEDY

Reduce load. Check with ammeter and compare with nameplate rating.

Clean air passages.

Improve ventilation or reduce load.

Generator location and enclosure design must provide adequate airflow and minimize recirculation of hot air.

The load on each leg should be as evenly balanced as possible and should not exceed rated current on any one leg.

GENERATOR PRODUCES MECHANICAL NOISE

CAUSE	CHECK AND REMEDY
Defective bearing	Replace bearing.
Loose or misaligned coupling	Tighten, realign, or replace coupling.
Belt slap or loose guards	Check belt tensioning. Check belt guard fasteners.

EQUIPMENT RUNS NORMALLY ON UTILITY POWER, BUT WILL NOT RUN ON GENERATOR

CAUSE	CHECK AND REMEDY
Distorted voltage waveform	Analyze load. Excessive SCR (thyristor) loading will cause distortion. Some equipment
	may be sensitive to distorted waveforms. Refer to Marathon Electric.
Improper generator voltage or	Check nameplates of devices comprising the load. Compare required voltage and
frequency	frequency with that of the generator. Adjust driver speed and/or generator voltage as
	necessary to match generator output to load requirements.

CAUTION: Compare required voltage, frequency, and kVA with generator nameplate to ensure adequate generator capacity. If in doubt, consult Marathon Electric for information regarding generator capacity.