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Cummins/Onan GFGA Generator Set

The Cummins/Onan GFGA is a 250 kW (562 kVA) Natural Gas, Propane (HD-5) standby generator set powered by a Cummins/Onan GTA28 engine. It is available at 120/208 V, 139/240 V, 220/380 V, 240/416 V, 254/440 V, 277/480 V and 347/600 V, single-phase, 60 Hz and rated 1734 A. It holds about 5.5 L (1.5 gal) of oil and 170 L (44.9 gal) of coolant, with a maximum ambient rating of 40 °C. Starting uses 1 group-8 battery rated 660 CCA at 24 V. The set measures 4267×2413×2489 mm (168.0×95.0×98.0 in), weighs about 6915 kg (15245 lb) and produces 79 dBA at 7 m. An integrated tank holds 659 L (174.1 gal), roughly 1.31 hours of runtime.

250 kW
Standby
28.0 L
Displacement
5.5 L
Oil capacity
2
Document types

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Specifications

FuelNatural Gas, Propane (HD-5)
Frequency60.0 Hz
Standby power250 kW
Standby kVA562
Prime power280 kW
EmissionsEPA SI NSPS Compliant Capable
ControllerDetector, PowerCommand 1.1, PowerCommand digital electronic
Oil capacity5.5 L
AlternatorADS308E (4-pole, Class Class H insulation)
Voltage options120/208 V, 127/220 V, 139/240 V, 220/380 V, 240/416 V, 254/440 V, 277/480 V, 347/600 V
PhaseThree Phase Reconnectable, Single Phase Non-Reconnectable, Three Phase Non-Reconnectable
Rated current[1734, 1640, 1503, 949, 867, 820, 752, 601] A
Power factor0.8
Circuit breaker80 A
Battery group8D
Battery cranking660 CCA
Battery voltage24 V
Battery quantity1
Coolant capacity170 L
Max ambient40 °C
Dimensions (L×W×H)4267×2413×2489 mm
Dry weight6915 kg
Sound level79.0 dBA @ 7 m
Fuel tank659.0 L
Tank runtime1.31 hr

Engine

Cummins/Onan GTA28
Oil capacity5.5 L
Coolant capacity45.0 L
Displacement28.0 L
AspirationTurbocharged & Aftercooled
Rated speed1500 rpm

Maintenance & consumables

for the Cummins/Onan GTA28
ItemSpecCapacityPart #Interval
Air filterIMPCO High Altitude, Low Pressure Gas System (Std)—
Fuel filter—
Oil filterFull Flow Filter Capacity – Replaceable Element Type - U.S. gal.—
Battery24 Volt, Cold Cranking Amperes – CCA 1800, Reserve Capacity - min. 640—
Belt—
Coolant170.0—
Coolant filter—
OilMulti-viscosity or straight weight single viscosity NATURAL GAS ENGINE OIL that meets Mil-2104A(CB), Mil-2104B (CC), Mil-2104C (CD/SC), CE and CF-4 specification. Ash Content between .15 and .85 of one percent.29.7 gal—
Spark plug—

Common questions

What size generator is the Cummins/Onan GFGA?

The Cummins/Onan GFGA is rated 250 kW standby (562.0 kVA).

Which engine powers the Cummins/Onan GFGA?

The Cummins/Onan GFGA is powered by the Cummins/Onan GTA28 engine.

What fuel type does the Cummins/Onan GFGA take?

The Cummins/Onan GFGA runs on Natural Gas, Propane (HD-5).

What's the oil capacity on a Cummins/Onan GFGA?

The Cummins/Onan GTA28 engine in the Cummins/Onan GFGA has an oil capacity of 5.5 liters.

Which alternator is fitted to the Cummins/Onan GFGA?

The Cummins/Onan GFGA uses a ADS308E alternator. It has 4 poles. Insulation class Class H.

Fuel consumption

RatingLoadL/hgal/h
Prime100%795.0210.0
Standby50%609.073.0
Standby75%810.0170.0
Standby100%163.043.0

Available documents

Spec sheet — Cummins-485-GFGA GTA28 (Cummins/Onan)Spec sheet — GTA28GGFGA (Cummins/Onan)Reference — GFGA (480-500) (Cummins/Onan)