The Cummins/Onan QSX15-G8/G9 is an engine rated at 1500 rpm. It powers generator sets from Cummins/Onan, including the C400 D5e, C450 D5e, C450 D6e and C500 D5e. It holds 91 L (24.0 gal) of oil and 50.31 L (13.3 gal) of coolant.
Maintenance schedule
| Item | Spec | Capacity | Part # | Interval | |
|---|
| Air filter | | | — | 1250 hr | |
| Fuel filter | | | — | 1250 hr | |
| Oil filter | | | DS348-CPGK | 1250 hr | Amazon eBay |
| Battery | | | — | 1250 hr | |
| Belt | | | — | 1250 hr | |
| Coolant | | 50.31 Lt (US gal) | — | 1250 hr | |
| Oil | | 91.0 Lt (US gal) | — | 500 hr | |
| Spark plug | | | — | 1250 hr | |
Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.
Procedures
12AC Electrical Connections installation
⚠ Accidental starting of the generator set can cause severe personal injury or death. Prevent accidental starting by disconnecting the negative (–) cable from the battery terminal.
⚠ Improper wiring can cause a fire or electrical hazard.
⚠ Backfeed to utility system can cause electrocution or property damage. Do not connect to any building electrical system except through an approved device.
- Place the control panel run switch in the OFF position.
- Turn off or remove AC power from the battery charger.
- Remove the negative (–) battery cable from the set starting battery.
- Install the transfer switch, select generator output voltage, connect load cables and connect standard/optional AC equipment.
Battery Connections installation
⚠ Ignition of explosive battery gases can cause severe personal injury or death. Always connect negative (–) battery cable last to prevent arcing.
⚠ Ventilate battery area before working on or near battery.
- Make sure that the PCC is in the OFF mode before connecting the battery cables.
- Connect the positive battery cable before connecting the negative battery cable to prevent arcing.
- Service the batteries as necessary.
- If an automatic transfer switch is installed without a built-in charge circuit, connect a separate battery charger.
Coolant Heater Installation installation
⚠ The coolant heater must not be operated while the cooling system is empty or damage to the heater will occur.
- Connect the heater to a source of power that will be on during the time the engine is not running.
- Ensure the supply voltage and circuit current is correct for the heater element rating.
Current Transformer (CT) Installation installation
- Ensure the CT dot is facing toward the generator reconnection terminal block (conventional current flowing into the dot).
- Route the load lead (U, V or W) through the appropriate CT per the Reconnection Diagram.
- Connect CT secondary wire marked 1 to pin 1 of the CT.
- Connect CT secondary wire marked 2/3 to pin 3 for low voltage generator sets.
Current Transformer (CT) Installation Requirements installation
- The CT has a dot on one side; the dot must be facing toward the generator reconnection terminal block (conventional current flowing into the dot).
- A dot is also used to indicate pin 1 of the CT.
- Route the load lead (U, V or W) through the appropriate CT (refer to Reconnection Diagram).
- The CTs have dual secondaries (3 pins). CT secondary wire marked 1 is connected to pin 1; wire marked 2/3 is connected to pin 3 for low voltage generator sets.
DC Control Wiring Installation installation
⚠ Hazardous voltage! Ensure all power is off before performing control wire installation.
⚠ Always run control circuit wiring in separate metal conduit from AC power cables.
Tools: cable ties, flexible conduit
- Route the control wiring through the bottom of the control housing, keeping DC wiring away from high voltage AC wiring.
- Use cable ties to keep control wiring away from sharp edges and AC power cables within the control housing.
- Use 20 gauge stranded copper wire for digital connections less than 305 metres (1000 feet).
- Use 18 gauge stranded copper wire for digital connections 305 to 610 metres (1000 to 2000 feet).
- Determine the gauge of stranded copper wire for relay connections according to the devices attached.
Generator Heater Installation installation
⚠ Water or moisture inside a generator increases the possibility of flashing and electrical shock. Do not use a generator which is not dry inside and out.
- Connect the heater(s) terminals to a source of power that will be on during the time the engine is not running.
- Be sure the supply voltage and circuit amperage is correct for the heater element rating.
Grounding the Generator Set installation
⚠ Bonding and grounding must be done properly. All metallic parts that could become energized under abnormal conditions must be properly grounded.
- Make sure the generator set is grounded to earth in one location only.
- On generators without a circuit breaker, ground to the point indicated on the top of the generator.
- On generator sets with circuit breakers, use the ground lug provided in the circuit breaker box.
- For a 3-pole ATS, the generator neutral is connected to the ATS and is NOT bonded to ground at the generator.
- For a 4-pole ATS system, use a grounding electrode conductor and a bonding jumper to connect the generator neutral to ground.
Load Connections installation
- Bolt stranded load wires to the appropriate terminals on the generator reconnection terminal block or circuit breaker lugs.
- Connect terminals marked U, V, W and N to indicate line and neutral connections (U, V, W = L1, L2, L3; N = L0).
- Balance loads so that current flow from each line terminal (L1, L2 and L3) is about the same.
- Ensure each line current is within 10 percent of median value and no line current exceeds the nameplate rating.
Mounting the Generator Set installation
⚠ The use of unapproved isolators may result in harmful resonances and may void the generator set warranty.
Tools: anchored mounting bolts, flat washer, hexagonal nut, 38mm x 152mm pipe
- Mount the generator set on a substantial and level base such as a concrete pad; the pad must be non-combustible material.
- Use 16mm (5/8 inch) anchored mounting bolts to secure the generator bedframe to the base.
- Secure the generator bedframe to the skid using flat washer and hexagonal nut for each bolt.
- Insert the 38mm x 152mm (1-1/2 x 6 inch) pipe over the mounting bolts to allow minor adjustment for alignment.
Moving the Generator Set installation
⚠ Do not lift the generator set by attaching to the engine or alternator lifting points.
⚠ Before lifting/transportation of the generator set ensure the fuel tank is empty.
⚠ Never stand underneath a lifted generator set.
Tools: shackles, chains, spreader bars, crane/hoist, ropes
- Attach the lifting device to the lifting points only, using suitable shackles, chains and spreader bars.
- Slowly tighten the slings and inspect the lifting attachments before commencing a full lift.
- Hoist the generator set slowly using the indicated lifting points only.
- Guide the generator set with ropes at a safe distance to prevent uncontrolled rotation.
- Move the generator set to the desired location and place in position, bringing the set down slowly.
- Loosen the slings, unhook and remove the shackles.
Positioning a Generator Set Using a Forklift Truck installation
⚠ Do not attempt to lift a generator set with an undersized forklift truck.
⚠ Transportation and handling by forklift trucks must only be undertaken by suitably trained and experienced personnel.
Tools: forklift truck
- Position the arms of the forklift under the frame or pallet, making sure the mainframe is resting on the arms.
- Lift and handle the equipment slowly.
- Set down the generator set in its final position slowly.
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Parts cataloged across the Cummins/Onan QSX15 family
39| Part # | Description | Category |
|---|
| AF25544 | Recommended air cleaner element - (heavy duty) primary element | air_filter |
| AF25545 | Recommended air cleaner element - (heavy duty) secondary element | air_filter |
| 0908-0101 | Lead Acid Battery | battery |
| 3375044 | Torque Wrench | belt |
| 19802521 | ECM Dataplate | ecm |
| 3331096 | Cummins, Part No. 3331096 | fuel_filter |
| 3376807 | Engine coolant and fuel filter wrench | fuel_filter |
| FS1007 | Fleetguard® Nelson®, Part No. FS1007 | fuel_filter |
| M-4376220 | Juego Junta Superior N. ° de Pieza | gasket |
| M-4376221 | Juego Junta Inferior N. ° de Pieza | gasket |
| 3375049 | Oil Filter Wrench | oil_filter |
| 3406810 | Combination Full-Flow/Bypass Lubricating Oil Filter Cummins Part No. 3406810 | oil_filter |
| 0908-0203 | | operator_manual |
| 0908-0204 | | operator_manual |
| 0908-0230 | Generator Set Operator Manual | operator_manual |
| 0908-0107 | Radiator Information | other_service |
| 0908-0110 | Health and Safety (Diesel Generator Sets) | other_service |
| 0908-0219 | Alarm Module (option) | other_service |
| 17200015 | Engine Shutdown | other_service |
| 17690172 | Engine Braking System | other_service |
| 17800006 | Engine Model | other_service |
| 3163156 | Service cable for InPower™ | other_service |
| 3666423 | | other_service |
| 3822735 | Plastic bead blasting media | other_service |
| 3886301 | InPower™ electronic service tool | other_service |
| 960-0174B | | other_service |
| A035H139 | Switch, Pushbutton | other_service |
| A040U808 | Harness, Control − Door (Includes Items 30 & 31) | other_service |
| A046Y204 | Shield, Wiring | other_service |
| M-3685996 | Intake Valve | other_service |
| M-5473065 | 150mm Kit de Motor M-5473066 | other_service |
| M-5473069 | 152mm Kit de Motor M-5473070 | other_service |
| M-5473074 | Kit de Motor M-5473075 | other_service |
| TB3-5 | Generator Set Control Panel Terminal Block | other_service |
| TB3-6 | Generator Set Control Panel Terminal Block | other_service |
| ol204vt | Torque Peak | other_service |
| M-5473087 | Piston Kit | piston_kit |
| M-5484414 | Piston Pin | piston_pin |
| M-3686661 | Valvula de escape - M-3686661 | valve |
Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.
Common questions
What is the oil capacity of the Cummins/Onan QSX15-G8/G9?
The Cummins/Onan QSX15-G8/G9 engine has an oil capacity of 91.0 liters.
Which generators use the Cummins/Onan QSX15-G8/G9 engine?
The Cummins/Onan QSX15-G8/G9 powers 6 generator set(s), including Cummins/Onan C400 D5e, Cummins/Onan C450 D5e, Cummins/Onan C450 D6e, Cummins/Onan C500 D5e, Cummins/Onan C500 D6e.
How often should you change the oil in the Cummins/Onan QSX15-G8/G9?
The Cummins/Onan QSX15-G8/G9 oil change interval is every 500 hours.