HomeCummins/OnanCummins/Onan DFM 275

Cummins/Onan DFM 275 Generator Set

The Cummins/Onan DFM 275 is a 250 kW (312 kVA) Diesel standby generator set powered by a Cummins/Onan NTA 855 G1 engine. It is available at , 3-phase and 60 Hz. It holds about 31 L (8.2 gal) of oil and 72 L (19.0 gal) of coolant. Starting uses 2 group-8 batteries at 12 V. The set weighs about 2937 kg (6475 lb).

250 kW
Standby
31.0 L
Oil capacity
0
Document types

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Specifications

FuelDiesel
Frequency60.0 Hz
Standby power250 kW
Standby kVA312
Oil capacity31.0 L
Alternator3 Phase 60 Hz YB
Phase3
Power factor0.8
Battery group8D
Battery voltage12 V
Battery quantity2
Coolant capacity72 L
Dry weight2937 kg

Engine

Cummins/Onan NTA 855 G1
Oil capacity31.0 L
Coolant capacity72.0 L
Rated speed1800 rpm

Common questions

What size generator is the Cummins/Onan DFM 275?

The Cummins/Onan DFM 275 is rated 250 kW standby (312.0 kVA).

What engine does the Cummins/Onan DFM 275 use?

The Cummins/Onan DFM 275 is powered by the Cummins/Onan NTA 855 G1 engine.

Is the Cummins/Onan DFM 275 diesel or gas?

The Cummins/Onan DFM 275 runs on Diesel.

What is the oil capacity of the Cummins/Onan DFM 275?

The Cummins/Onan NTA 855 G1 engine in the Cummins/Onan DFM 275 has an oil capacity of 31.0 liters.

What alternator does the Cummins/Onan DFM 275 use?

The Cummins/Onan DFM 275 uses a 3 Phase 60 Hz YB alternator.

Troubleshooting

6

Fault codes

CodeMeaningRemedy
PRE HI ENGINE TEMP*2. PRE HI ENGINE TEMP lamp lights. Engine continues to operate.2. Indicates engine has begun to overheat and engine temperature has risen to approximately 205°F (97°C). If generator is powering non-critical and critical loads and cannot be shutdown, use the following: a. Reduce load if possible by turning off non-critical loads. b. Check air inlets and outlets and remove any obstructions to airflow. c. Open doors or windows in generator area to increase ventilation. If engine can be stopped, follow procedure in step 3.
HI ENG TEMP*3. HI ENG TEMP lamp lights. Engine shuts down.3. Indicates engine has overheated (engine temperature has risen above 215°F/102°C) or coolant level is low (sets with coolant level sensor). Allow engine to cool down completely before proceeding with the following checks: a. Check coolant level and replenish if low. Look for possible coolant leakage points and repair if necessary. b. Check for obstructions to cooling airflow and correct as necessary. c. Check for a slipping fan belt and tighten if loose. d. Reset control and restart after locating and correcting problem. Contact an Onan Dealer or Distributor if none of the above.
PRE LO OIL PRES*4. PRE LO OIL PRES lamp lights. Engine continues to operate.4. Indicates engine oil pressure has dropped to 20 psi (138 kPa). If generator is powering critical loads and cannot be shut down, wait until next shutdown period and then follow step 5 procedure. If engine can be stopped, follow procedures in step 5.
LO OIL PRES*5. LO OIL PRES lamp lights. Engine shuts down NOTE: See also step 6.5. Indicates engine oil pressure has dropped to 14 psi (97 kPa). Check oil level, lines and filters. If oil system is okay but oil level is low, replenish. Reset control and restart. Contact an Onan Dealer or Distributor if oil pressure is not in the range of 50 to 70 psi (345 to 483 kPa).
OVERCRANK*6. OVERCRANK lamp lights and engine stops cranking.

Symptoms & remedies

SymptomRemedy
*1. Green RUN lamp lights following engine start-up.1. Indicates all engine systems are normal. No corrective action required.

Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing. Full Cummins/Onan DFM 275 troubleshooting guide (24 entries) →

Available documents