HomeCummins/OnanCummins/Onan K3500

Cummins/Onan K3500 Generator Set

The Cummins/Onan K3500 is a 3 kW (3 kVA) regular-grade gasoline standby generator set powered by a Cummins/Onan GS280-DG-A3 engine. It is available at 420 V and 240 V, 3-phase, 60 Hz and rated 25 A. It holds about 0.9 L (0.2 gal) of oil. An integrated tank holds 8.5 L (2.2 gal).

3 kW
Standby
0.276 L
Displacement
0.9 L
Oil capacity
0
Document types

How to read your Cummins/Onan serial & model number →

Typical fuel consumption for 0–5 kW Gasoline generators →

Compare with other 0–5 kW Gasoline generators →

Specifications

Fuelregular-grade gasoline
Frequency60.0 Hz
Standby power3 kW
Standby kVA3
Oil capacity0.9 L
Voltage options420 V, 240 V
Phasethree-phase
Rated current25 A
Power factor100
Battery voltage12 V
Battery quantity1
Fuel tank8.5 L

Engine

Cummins/Onan GS280-DG-A3
Oil capacity0.92 L
Displacement0.276 L
Aspirationnaturally_aspirated
Rated speed3600 rpm

Maintenance & consumables

for the Cummins/Onan GS280-DG-A3
ItemSpecCapacityPart #Interval
Air filterFoam wrapper + cartridge element; clean/re-oil foam each service, replace cartridge every 6 cleanings or yearly.25 hr
Fuel filterFuel filter/cock cleaning per periodic maintenance chart; no cartridge part number given.
Oil filter
Battery
Belt
Coolant
OilAPI SE/SF class engine oil; 10W-30 below -10C, SAE#20 below 15C, SAE#30 above 15C. First change at 10 hrs, then every 50 hrs.50 hr
Spark plugGap 0.6-0.7mm (GS130/GS280 engines), 0.7mm (K1400/K3000), 1.0mm (K2100/GN1850), 0.7mm (K1800), varies by model.50 hr

Common questions

How many kW is the Cummins/Onan K3500?

The Cummins/Onan K3500 is rated 3 kW standby (3.0 kVA).

What engine is in the Cummins/Onan K3500?

The Cummins/Onan K3500 is powered by the Cummins/Onan GS280-DG-A3 engine.

What fuel type does the Cummins/Onan K3500 take?

The Cummins/Onan K3500 runs on regular-grade gasoline.

How much oil does the Cummins/Onan K3500 take?

The Cummins/Onan GS280-DG-A3 engine in the Cummins/Onan K3500 has an oil capacity of 0.92 liters.

Troubleshooting

6

Symptoms & remedies

SymptomCauseRemedy
Crankcase pressure might blow out hot oil and cause serious burns.Do not attempt to check oil while the generator set is running. Add oil until it reaches the top of the oil port.
Fuel level indicator looks damaged or loose.Install a new indicator before starting generator set.
Generator set operates on a slight grade, and the fuel tank is completely filled.Do not fill completely if the generator set will operate on a slight grade.
Faulty electrical equipment connected to the generator presents an electrical shock hazard.Check all electrical equipment for frayed cords or breaks in the insulation before using. Properly applied and maintained ground fault circuit interrupters can afford additional protection against the hazard of electrical shock.
Pilot lamp does not light and output voltage is OVFaulty contact of receptacles or disconnected wiring inside of control boxRepair or replace
Output voltage is not deliveredDisconnected wiringRepair or replace stator coil, demagnetization of permanent magnet, clean brush contact and slip ring, repair or replace brush, or repair or replace sub coil

Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing. Full Cummins/Onan K3500 troubleshooting guide (12 entries) →

Parts

4
Part #DescriptionQtySystem
981-0123Recoil Starter Control Panel1Recoil starter Amazon eBay
M-1534Air Cleaner1Air cleaner Amazon eBay
K2100STARTINGService part / kit Amazon eBay FridayParts $44.52
K3500STARTINGService part / kit Amazon eBay FridayParts $13.88

Service, wear & replacement parts referenced for this model and its engine — confirm the exact part for your serial number. See the full parts catalog to search and cross-reference.

Available documents