HomeCummins/OnanCummins/Onan 600 DFX-4XR

Cummins/Onan 600 DFX-4XR Generator Set

The Cummins/Onan 600 DFX-4XR is a 600 kW (750 kVA) Diesel (ASTM No. 2) standby generator set powered by a Cummins/Onan KT2300-G engine. It is available at 277/480 V, 3-phase and 60 Hz. It holds about 151.4 L (40.0 gal) of oil and 207.9 L (54.9 gal) of coolant. Starting uses 4 group-8 batteries rated 1620 CCA at 24 V.

600 kW
Standby
37.7 L
Displacement
151.4 L
Oil capacity
1
Document types

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

Typical fuel consumption for 600–605 kW Diesel generators →

Compare with other 600–605 kW Diesel generators →

Service parts for the 600 DFX-4XR

Grouped by system, with how many of each the parts manual calls for.

Air intake

1 required

Belts

1 required

Prices captured from merchant listings; some links are affiliate links. Confirm against your serial number before ordering.

Specifications

FuelDiesel (ASTM No. 2)
Frequency60.0 Hz
Standby power600 kW
Standby kVA750
Oil capacity151.4 L
AlternatorUV (4-pole)
Voltage options277/480 V
Phase3
Power factor0.8
Battery group8D
Battery cranking1620 CCA
Battery voltage24 V
Battery quantity4
Coolant capacity207.9 L

Engine

Cummins/Onan KT2300-G
Oil capacity151.4 L
Coolant capacity207.9 L
Displacement37.7 L
Rated speed1800 rpm

Maintenance & consumables

for the Cummins/Onan KT2300-G
ItemSpecCapacityPart #Interval
Air filterFilter, Air - Paper (Replacement)140-1371 Amazon eBay
Fuel filterspin-off, throw-away unit200 hr
Oil filterspin-off throw away elements; replace at every oil change
Batteryspecific gravity 1.280 at 80F
BeltBelt, Drive511-0059 Amazon eBay
Coolantcheck for rust or scale formation; flush if necessary207.9 litres
Coolant filterreplace periodically per General Maintenance section; compatible with plain water or ethylene glycol antifreeze; not compatible with stop-leak additives
OilAPI Class CC/CD, max sulphated ash 1.85%151.0 litres8 hr

Service intervals

17
ItemActionHoursMonthsNotes
Check Oil LevelCheck8 hrcheck approx. 15 min after shutdown; keep near FULL mark
Check Radiator CoolantCheck8 hr
Inspect SetInspect8 hr
Check Air CleanerCheck50 hr3 moclean if required; more often in dusty conditions
Check Cooling SystemCheck50 hr3 mocheck for rust or scale formation; flush if necessary
Clean and Inspect Crankcase BreatherClean50 hr
Inspect Fan BeltInspect50 hr3 moadjust to 1/2 inch depression between pulleys
Air Filter Cartridge - remove and shake out dirt, install new precleanerClean100 hrFRAM CA-250PL series
Change Crankcase OilChange100 hr3 mo
Clean and Inspect Battery Charging AlternatorInspect100 hr
Replace Oil Filter ElementReplace100 hr3 mo
Check all hardware, fittings, clamps, fasteners, exhaust system for securityCheck200 hr3 mowith set running, visually and audibly check exhaust system for leaks
Replace Fuel FilterReplace200 hr
Air Filter Cartridge - replace both precleaner and paper cartridgesReplace400 hrFRAM CA-250PL series
Generator Bearing InspectionInspect1000 hrinspect with unit running
Generator Bearing Replacement (prime power)Replace10000 hr24 mo
Generator Bearing Replacement (standby)Replace60 mo

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Service specifications

13
TypeItemValueUnitCondition
OtherAC frequency regulation0-3Hz Max.
PressureExternal prime pressure while cranking15psi (103 kPa)cranking for 15 seconds
PressureLow oil pressure shutdown14psi (96.53 kPa)
PressureMaximum permissible exhaust restriction (back pressure)3inches (76 mm) Hg
PressureMaximum return fuel line restriction4inches (100 mm) Hg
PressureNormal oil pressure50-70psi (345.0-483 kPa)immediately after start
PressureOil priming pressure30psi (207 kPa)priming procedure
SpeedOverspeed shutdown2100rpm
TemperatureCoolant operating temperature range165-195°F (73.9-90.6°C)
TemperatureHigh engine temperature shutdown205°F (96°C)
TorqueOil filter housing plug torque15 to 20lb-ft (20 to 27 N.m)
TorqueRotating rectifier diode torque30in. lb.or finger tight plus a quarter turn
VoltageAC voltage regulation±2%no load to full load, 0.8 PF

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Recommended fluids

FluidGradeStandardAmbientCapacityNotes
Coolantclean soft water with rust and scale inhibitor additive; ethylene glycol base antifreeze if freezing possible207.9 litres (55 gallons)do not use antifreeze with anti-leak/stop-leak additive if unit has coolant filter
Engine oil10Wbelow 23°C-10F (-23C) and below
Engine oilAPI Class CC/CD, max sulphated ash content 1.85%API151.0 litres (40 gallons)do not mix brands nor grades of oil
Engine oil307°C to 16°C20 to 60F (-7 to 16C)
Engine oil20-20W23°C to 1°C-10 to 30F (-23 to -1C)
FuelASTM No. 2 DieselASTM

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Procedures

5
Governor speed adjustment adjustment

⚠ Be prepared to assume manual control if adjustments are incorrect

Tools: screwdriver

  1. Remove four screws and cover from governor controller
  2. Disconnect wire from TB11-22 to disconnect starter solenoid
  3. Place Run-Stop-Remote switch to RUN; governor should stay at minimum fuel position
  4. Return switch to STOP and reconnect wire at TB11-22
  5. Position speed control rheostat to midrange (out 5 turns from low rpm)
  6. Adjust speed reference potentiometer counterclockwise four complete turns
  7. Start engine; adjust speed reference potentiometer clockwise/counterclockwise to reach correct rpm
  8. Adjust gain potentiometer clockwise then counterclockwise until stable and responsive
  9. Load and unload engine several times to confirm gain adjustment
  10. Shut down and restart engine to confirm no overspeed
  11. Replace governor control box cover
Generator support alignment to skid base installation

⚠ Generator support must be aligned to prevent premature bearing failure, vibration, drive disc failure

Tools: feeler gauge

  1. Set unit on mounting foundation with vibration isolators between skid base and foundation
  2. Secure skid base to isolators and isolators to foundation
  3. Remove two mounting bolts and use as jackscrews
  4. Raise generator and remove shims from between generator and support and skid base
  5. Adjust jackscrew tension and allow generator to hang free
  6. Measure clearance from skid base top to each generator support surface with feeler gauge
  7. Add 0.010 in (0.254mm) to each side to determine shim amount
  8. Turn jackscrews to allow clearance for placing shims
  9. Lower generator onto shims using jackscrews
  10. Recheck total clearance equals base-to-support clearance plus 0.010 in
  11. Remove jackscrews and reinstall as mounting bolts through support, shims, and skid base
  12. Secure and lock mounting bolts in place
Out-of-service protection (storage, up to six months) maintenance

⚠ For storage beyond six months refer to Cummins Service manual

Tools: tape

  1. Start and operate engine until thoroughly warm; disconnect fuel lines to filter and injector drain line
  2. Start engine on diesel fuel, then switch to preservative oil and run 5-10 minutes, stop engine and reconnect fuel lines
  3. Drain oil sump, fuel filters and fuel tank, reinstall drain plugs
  4. Disconnect electrical wiring, turn fuel pump shutoff valve fully counterclockwise, spray lubricating oil into intake manifold while cranking slowly
  5. Cover all openings with tape
  6. Drain coolant unless permanent antifreeze with rust inhibitor is used
  7. Store engine in dry, uniform temperature area
  8. Bar engine crankshaft two or three revolutions every three to four weeks
Preparing a stored engine for service maintenance

⚠ Do not smoke while servicing batteries - explosive gases emitted

  1. Clean accumulated dirt from exterior, remove covers, tape and wrappings
  2. Use suitable cleaner to remove rust preventive compound from unpainted surfaces
  3. Refill crankcase with clean lubricating oil; flush and fill cooling system
  4. Check coolant level, adjust or refill as necessary
  5. Connect batteries
  6. Verify no loads are connected to generator
  7. Perform prestart servicing and start engine
  8. Apply load to at least 50 percent of rated capacity
  9. Check all gauges read correctly
Priming the oil system maintenance

Tools: hand or motor-driven priming pump

  1. Remove oil inlet line from turbo-charger housing, fill bearing housing with clean oil, replace line, repeat for second turbo
  2. Fill crankcase to L (low) mark on dipstick
  3. Remove plug from head of oil filter housing and connect priming pump from clean lubricating oil source
  4. Prime until 30 psi (207 kPa) pressure is obtained
  5. Disconnect wire from fuel solenoid valve, close throttle, crank engine maintaining 15 psi (103 kPa) external prime for 15 seconds
  6. Remove external priming equipment, replace plug in filter housing, torque 15-20 lb-ft (20-27 N.m)
  7. Reconnect wire to fuel shut-off valve
  8. Complete oil fill to H (high) mark on dipstick

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Common questions

What size generator is the Cummins/Onan 600 DFX-4XR?

The Cummins/Onan 600 DFX-4XR is rated 600 kW standby (750.0 kVA).

Which engine powers the Cummins/Onan 600 DFX-4XR?

The Cummins/Onan 600 DFX-4XR is powered by the Cummins/Onan KT2300-G engine.

What kind of fuel does the Cummins/Onan 600 DFX-4XR run on?

The Cummins/Onan 600 DFX-4XR runs on Diesel (ASTM No. 2).

What's the oil capacity on a Cummins/Onan 600 DFX-4XR?

The Cummins/Onan KT2300-G engine in the Cummins/Onan 600 DFX-4XR has an oil capacity of 151.4 liters.

What alternator does the Cummins/Onan 600 DFX-4XR use?

The Cummins/Onan 600 DFX-4XR uses a UV alternator. It has 4 poles.

What air filter fits the Cummins/Onan 600 DFX-4XR?

The Cummins/Onan 600 DFX-4XR uses air filter part number 140-1371.

Troubleshooting

6

Symptoms & remedies

SymptomRemedy
Fault lamp lights and engine stops cranking after approximately 75-seconds.See engine service manual for troubleshooting fuel system. After correcting fault, reset engine monitor relay by placing Run-Stop/Reset-Remote switch to Stop/Reset position, depressing Reset button, then to the required running position.
Engine runs, shuts down, cranks for 75-seconds, cranking cycle stops, light ON.Check fuel supply.
"Low oil pressure shutdown."Check— a. Oil level. Replenish if necessary. b. Sensor. Faulty sensor will shut down engine. c. Refer to engine service manual for troubleshooting guide for oil system.
"High engine temperature shutdown."Check— a. Coolant level. Replenish is necessary. b. City water cooled sets. Check water flow, valves, etc. c. Check sensor; check thermostat.
DizzinessGet out into fresh air immediately.
Weakness and SleepinessGet out into fresh air immediately.

Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing. Full Cummins/Onan 600 DFX-4XR troubleshooting guide (8 entries) →

Parts

16
Part #DescriptionQtySystem
130-1032Tube, Coolant - Right Side1Hose Amazon eBay
130-1033Tube, Coolant - Left Side1Hose Amazon eBay
130-1043Tube, Coolant - Lower1Hose Amazon eBay
140-1370Air Cleaner (Includes Replacement Filter)2Air filter Amazon eBay
140-1371Filter, Air - Paper (Replacement)2Air filter Amazon eBay
191-0688Alternator - Includes Regulator (Motorola #70D44039B04)1Alternator Amazon eBay
193-0108Sender, Oil Pressure Gauge1Sensor Amazon eBay $119.99
193-0109Sender, Temperature - Engine Coolant1Sensor Amazon eBay
309-0178'Switch, Thermostatic - Hi Engine Coolant Temperature1Sensor Amazon eBay $350.00
309-0179'Switch, Thermostatic - Hi Engine Coolant Temperature1Sensor Amazon eBay
309-0269Switch, Low Engine Temperature (S4)1Sensor Amazon eBay
309-0272Regulator, Voltage - 24 VDC (Used on 35 A MP Alternator)1Alternator Amazon eBay
511-0059Belt, Drive1Belt Amazon eBay
100-1383Replacement Engine (Cummins Model KT2300G)1Service part / kit Amazon eBay
130-1044Radiator, Engine Coolant1Service part / kit Amazon eBay
309-01691 Begin Spec G 25 261Service 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.

Fuel consumption

RatingLoadL/hgal/h
Standby100%48.446.0

Available documents

Operator's manual — 960-0317 Onan DFX Operator's and Parts Manual (5-1976) (Cummins/Onan)