Cummins/Onan GN550-DG-A3 Engine Engine
The Cummins/Onan GN550-DG-A3 is a 0.06 L naturally_aspirated engine rated at 3000 rpm. It powers generator sets from Cummins/Onan, including the K400 and K450.
Also known as: Onan GN550-DG-A3
Engine specifications
| Displacement | 0.055 L |
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| Aspiration | naturally_aspirated |
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| Rated speed | 3000 rpm |
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Generator sets powered by this engine
2Common problems
7- Only slight output voltage is delivered (3 ~ 6V)
Cause: Worn brush or faulty contact surface of slip ring
Fix: Clean brush contact and slip ring, or replace brush - Rated output voltage is not available
Cause: Abnormal load circuit, blown circuit breaker (S.T.D., voltage 10%)
Fix: Remove abnormality in load circuit and replace fuse - Pilot lamp does not light and output voltage is OV
Cause: Faulty contact of receptacles or disconnected wiring inside of control box
Fix: Repair or replace - Output voltage is not delivered
Cause: Disconnected wiring
Fix: Repair or replace stator coil, demagnetization of permanent magnet, clean brush contact and slip ring, repair or replace brush, or repair or replace sub coil - Output voltage is more than S.T.D. voltage by 30%
Cause: Defective AVR
Fix: Replace - Output voltage OV
Fix: Set the switch to the desired AC or DC position - Fluctuation of engine revolution is abnormal
Cause: Disconnected or punctured AVR capacitor, faulty brush contact, excessive initial current, low engine output, faulty engine governor
Fix: Replace capacitor, check for wear, wear amount, and contamination of contacting surface of brush and clean if necessary, repair or replace
Compiled from service & troubleshooting documentation across every generator set that uses the Cummins/Onan GN550-DG-A3.
Maintenance schedule
| Item | Spec | Capacity | Part # | Interval | |
|---|
| Air filter | Foam wrapper + cartridge element; clean/re-oil foam each service, replace cartridge every 6 cleanings or yearly. | | — | 25 hr | find |
| Fuel filter | Fuel filter/cock cleaning per periodic maintenance chart; no cartridge part number given. | | — | | find |
| Oil | API SE/SF class engine oil; 10W-30 below -10C, SAE#20 below 15C, SAE#30 above 15C. First change at 10 hrs, then every 50 hrs. | | — | 50 hr | |
Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.
Common questions
What is the displacement of the Cummins/Onan GN550-DG-A3?
The Cummins/Onan GN550-DG-A3 has a displacement of 0.055 liters.
Which generators use the Cummins/Onan GN550-DG-A3 engine?
The Cummins/Onan GN550-DG-A3 powers 2 generator set(s), including Cummins/Onan K400, Cummins/Onan K450.
How often should you change the oil in the Cummins/Onan GN550-DG-A3?
The Cummins/Onan GN550-DG-A3 oil change interval is every 50 hours.
What is a common problem with the Cummins/Onan GN550-DG-A3 engine?
A commonly reported issue on generators using the Cummins/Onan GN550-DG-A3 is: Only slight output voltage is delivered (3 ~ 6V). Cause: Worn brush or faulty contact surface of slip ring. Fix: Clean brush contact and slip ring, or replace brush.