HomeCummins/OnanCummins/Onan QSX15

Cummins/Onan QSX15 Generator Set

The Cummins/Onan QSX15 is a 500 kW (550 kVA) standby generator set powered by a Cummins/Onan QSX15 engine. It is available at 50 V and 60 V. It holds about 91 L (24.0 gal) of oil and 42 L (11.1 gal) of coolant, with a maximum ambient rating of 55 °C. The set measures 2269×1332×1669 mm (89.3×52.4×65.7 in) and weighs about 1658 kg (3655 lb).

500 kW
Standby
15.0 L
Displacement
91.0 L
Oil capacity
3
Document types

Specifications

Standby power500 kW
Prime power444 kW
Oil capacity91.0 L
Voltage options50 V, 60 V
Coolant capacity42.0 L
Max ambient55 °C
Dimensions (L×W×H)2269×1332×1669 mm
Dry weight1658 kg

Engine

Cummins/Onan QSX15
Displacement15.0 L
Aspirationturbocharged
Rated speed1800 rpm

Maintenance & consumables

for the Cummins/Onan QSX15
ItemSpecCapacityPart #Interval
Air filterCheck1500 hr find
BeltCheck250 hr find
Coolant filterReplace1500 hr find
Fuel filterReplace6000 hr find
OilSevere Duty, Normal Duty, Light Duty24000 hr
Oil filterSevere Duty, Normal Duty, Light Duty24000 hr find

Troubleshooting

17
SymptomCauseRemedy
The yellow lamp is illuminated.The engine is in need of repair at the first available opportunity.
The warning light flashes for 30 seconds at key-on.Maintenance required (if maintenance monitor is enabled) or Water-in-fuel is detected.Replace the secondary fuel filter if water is drained from the primary water-separating fuel filter.
Engine overspeed during cranking.Do not depress the accelerator pedal or move the accelerator lever from the idle position while cranking the engine.
Starting motor damage.Do not engage the starting motor for more than 30 seconds and wait 2 minutes between each attempt to start (electrical starting motors only).
Engine does not start after three attempts.Check the fuel supply system. Absence of blue or white exhaust smoke during cranking indicates no fuel is being delivered.
Low oil pressure within 15 seconds after starting.Shut off the engine immediately to reduce the possibility of engine damage. The low oil pressure troubleshooting procedure is located in Troubleshooting Symptoms (Section TS).
Engine overheating.Reduce the power output of the engine by releasing the accelerator pedal or shifting the transmission to a lower gear, or both, until the temperature returns to the normal operating range. If the engine temperature does not return to normal, shut off the engine and refer to Troubleshooting Symptoms (Section TS) or contact a Cummins Authorized Repair Location.
Engine misfires, vibration, unusual noises, sudden changes in operating temperatures or pressures, excessive smoke, loss of power, increased oil consumption, increased fuel consumption, or leaks.Look and listen for these changes as they can indicate service or engine repair is needed.
The Shutdown (Alarm) indications can only be acknowledged when the engine is stopped and the Run/Stop switch is in the ‘Stop’ state.
When a shutdown alarm condition is recognized by the ECM, the user must acknowledge this alarm before the engine can be re-started.
The Fault Acknowledge feature can also be activated electronically using inPower™. This is accomplished by setting the Fault Acknowledge Command parameter to ‘Acknowledge’.
Snapshot data allows the relationship between the fault condition and the state of the ECM inputs and outputs, at the time the condition occurred, to be captured and viewed to assist in troubleshooting.
The Stationary or Cranking Tests can be aborted at any moment when commanded to do so using the Cummins InPower™ electronic service tool. This is accomplished by setting the Built in Test Command toggle parameter to ‘Test-Abort’.
During the Outputs test all meter drivers, lamp/relay drivers and diagnostic LEDs will be exercised.
The Lamp/Relay Driver supply voltage at connector 03 is normally on when the ECM is powered. During engine start-up the ECM will turn this supply voltage off for a 1.5 second interval as a means of testing the lamps/relays driven by the supply.
Immediately following the Output Tests, the Fuel Shut-Off Test will be initiated.
The Starter Test will be performed immediately following the Fuel Shut-Off Test, only when the Cranking Test is being performed.

Symptom → cause → remedy extracted from this model’s service/owner documentation; verify against the official manual before servicing.

Parts

7
Part #DescriptionQtySystem
M-4376220Upper Gasket SetGasket buy
M-4376221Lower Gasket SetGasket buy
M-5473087Piston KitPiston kit buy
M-5484414Piston PinPiston pin buy
3163156Service cable for InPower™Service part / kit buy
3822735Plastic bead mediaService part / kit buy
3886301InPower™ electronic service toolService part / kit buy

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
Prime
Prime100%107.028.4
Standby
Standby100%123.032.4

Available documents

Engine specSpec sheetService manual