Specifications
| Fuel | Diesel |
|---|---|
| Frequency | 60.0 Hz |
| Standby power | 200 kW |
| Standby kVA | 250 |
| Oil capacity | 31.0 L |
| Alternator | 3 Phase 60 Hz YB |
| Phase | 3 |
| Power factor | 0.8 |
| Battery group | 8D |
| Battery voltage | 12 V |
| Battery quantity | 2 |
| Coolant capacity | 53 L |
| Dry weight | 2692 kg |
Engine
| Oil capacity | 39.7 L |
|---|---|
| Coolant capacity | 19.0 L |
| Aspiration | turbocharged |
| Rated speed | 1800 rpm |
Filters for the Cummins/Onan NT-855-G2
8Engine-mounted filters the filter manufacturers list for this engine family. These come from the engine, not from this generator set’s own parts list, so confirm against your serial number before ordering.
| System | Filter | Description | Cross-references | |
|---|---|---|---|---|
| Oil filter | P551670 | Lube Filter, Spin-On Full Flow | CUMMINS 298670, CUMMINS 299670, NAPA 1970, CARBOCOL 0026 | FridayParts $26.68 |
| Oil filter | P550777 | Lube Filter, Spin-On Bypass | CUMMINS 3021658, CUMMINS 33004232, NAPA 1749, BALDWIN B7577 | FridayParts $43.56 |
| Fuel filter | P550105 | Fuel Filter, Spin-On Primary | CUMMINS 154700, CUMMINS 154710, NAPA 3109, NAPA 3405 | buy |
| Fuel filter | P557440 | Fuel Filter, Spin-On Secondary | CUMMINS BM78672, BALDWIN BF970, LPM 00013505994, WALGAHN-MOTORENTECHN 00811464 | FridayParts $189.69 |
| Fuel / water separator | P550106 | Fuel Filter, Water Separator Spin-On | CUMMINS 154789, CUMMINS 156164, NAPA 3405, BALDWIN BF957-D | FridayParts $285.60 |
| Fuel / water separator | P558000 | Fuel Filter, Water Separator Spin-On Twist&Drain | CUMMINS 3308638, CUMMINS 3308683, NAPA 3405, NAPA 3693 | KuduParts $24.00 FridayParts $25.66 |
| Coolant filter | P554071 | Coolant Filter, Spin-On | CUMMINS 209604, CUMMINS 209606, NAPA 4071, WALGAHN-MOTORENTECHN 00811412 | FridayParts $397.60 |
| Coolant filter | P554073 | Coolant Filter, Spin-On | CUMMINS 209605, CUMMINS 209607, NAPA 4073, VERSATILE 00104040 | KuduParts $40.00 |
Maintenance & consumables
for the Cummins/Onan NT-855-G2| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | Check and replace if necessary at specified intervals | — | 250 hr | ||
| Fuel filter | Drain and change per maintenance schedule | — | 1000 hr | ||
| Oil filter | Per maintenance table at specified intervals | — | 250 hr | ||
| Battery | — | 1000 hr | |||
| Belt | Check tension and condition; replace if damaged | — | 50 hr | ||
| Coolant | Check level at shutdown intervals | 53.0 litres | — | 50 hr | |
| Coolant filter | Clean or replace as required. See Figure 7 for filter location and replacement procedure. | — | |||
| Oil | SAE 10W-30 (-13°C to 35°C), SAE 15W-40 (above -10°C), SAE 20W-40 (above 0°C) | 31.0 litres | — | 50 hr | |
| Spark plug | — |
Common questions
What size generator is the Cummins/Onan DFP 250?
The Cummins/Onan DFP 250 is rated 200 kW standby (250.0 kVA).
What engine does the Cummins/Onan DFP 250 use?
The Cummins/Onan DFP 250 is powered by the Cummins/Onan NT-855-G2 engine.
What kind of fuel does the Cummins/Onan DFP 250 run on?
The Cummins/Onan DFP 250 runs on Diesel.
What's the oil capacity on a Cummins/Onan DFP 250?
The Cummins/Onan NT-855-G2 engine in the Cummins/Onan DFP 250 has an oil capacity of 39.7 liters.
What is the cooling system capacity of the Cummins/Onan DFP 250?
The Cummins/Onan DFP 250 cooling system holds 53 liters (14.0 US gallons) for the radiator system including the engine, per the manufacturer specification sheet.
What is the dry weight of the Cummins/Onan DFP 250?
The Cummins/Onan DFP 250 has a dry weight of 2692 kg (5934 lb).
How many cold cranking amps does the Cummins/Onan DFP 250 require?
The Cummins/Onan DFP 250 uses 2 batteryies, 12 V each, group 8D, per the manufacturer specification sheet.
Which alternator is fitted to the Cummins/Onan DFP 250?
The Cummins/Onan DFP 250 uses a 3 Phase 60 Hz YB alternator.
Troubleshooting
6Symptoms & remedies
| Symptom | Cause | Remedy |
|---|---|---|
| Green RUN lamp lights following engine start-up | Indicates all engine systems are normal. No corrective action required. | |
| PRE HI ENGINE TEMP lamp lights. Engine continues to operate | 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, reduce load if possible by turning off non-critical loads; check air inlets and outlets and remove any obstructions to airflow; open doors or windows in generator area to increase ventilation; if engine can be stopped, follow procedure in step 3 |
| HI ENG TEMP lamp lights. Engine shuts down | 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: check coolant level and replenish if low; look for possible coolant leakage points and repair if necessary; check for obstructions to cooling airflow and correct as necessary; check for a slipping fan belt and tighten if loose; reset control and restart after locating and correcting problem; contact an Onan Dealer or Distributor if none of the above |
| PRE LO OIL PRES lamp lights. Engine continues to operate | 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 lamp lights. Engine shuts down | 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 lamp lights and engine stops cranking; or engine runs, shuts down, and LO OIL PRES lamp lights | Possible fuel system problem | Check for empty fuel tank, fuel leaks, or plugged fuel lines and correct as required; check for dirty fuel filter and replace if necessary (see MAINTENANCE section); check for dirty or plugged air filter and replace if necessary (see MAINTENANCE section); refer to Step 5; reset the control and restart after correcting the problem; contact an Onan Dealer or Distributor for service if none of the above |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing. Full Cummins/Onan DFP 250 troubleshooting guide (24 entries) →
Parts
5| Part # | Description | Qty | System | |
|---|---|---|---|---|
| 8342-1 | AIR FILTER | Air filter | Amazon eBay $24.77 FridayParts $44.80 | |
| 903-0124 | NA | NA | Service part / kit | Amazon eBay |
| 903-0204 | NA | NA | Service part / kit | Amazon eBay |
| 903-0500 | NA | NA | Service part / kit | Amazon eBay |
| 903-0604 | NA | NA | Service part / kit | Amazon eBay |
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
This page was generated from the 1 manufacturer document above by automated extraction; every figure shown is copied from one of them. How the data is compiled.