The Wachendorf OPUS A3 is a generator-set controller. It is used on generator sets from Generac, including the MFH900.
| Symptom | Cause | Remedy |
|---|---|---|
| Blower fan not operating correctly | Remove ducting; check blower fan operation. | |
| Ducting too long for ambient conditions | Move unit closer to heat recipient if possible. | |
| Engine control system failure | Contact an IASD. | |
| Engine cranks but does not start | No fuel, Low oil level, Emergency shutdown switch is ON, Air in fuel system, Clogged fuel filter, Fuel is frozen, Injection pump failure, Electromagnetic type fuel pump failure | Verify there is no fuel leakage and replenish., Replenish oil to full., Turn emergency shutdown switch OFF., Purge air., Remove water and change element., Warm fuel pipes with hot water or wait until ambient temperature rises., Contact an IASD. |
| Engine failure | Contact an IASD. | |
| Engine has no power | Clogged air cleaner | Clean element. |
| Engine overheats | No coolant | Add coolant. |
| Engine rpm is set too high based on ambient temperature | Lower the engine rpm. | |
| Engine running is unstable | Fuel system failure, Water or air is in fuel system, Engine control system failure | Contact an IASD., Purge air or remove water., Contact an IASD. |
| Engine starts but stops shortly thereafter | Low idle, Clogged fuel filter, Clogged pre-fuel filter, Clogged air cleaner, Engine control system failure, Injection pump failure, Clogged strainer, Electromagnetic type fuel pump failure | Adjust by idling control equipment on the machine. If adjustment is not possible, contact ISUZU dealer., Remove water and change element., Clean or change element., Contact an IASD., Contact an IASD. |
| Exhaust smoke is black | Clogged air cleaner; Clean or change element. | |
| Exhaust smoke is white | Insufficient cooling | |
| Faulty temperature sensor | Check air outlet sensor operation. | |
| HTF pump drive sheared | Contact an IASD. | |
| HTF/hydraulic oil filters clogged | Check restriction gauges/replace HTF filters. | |
| Low HTF/hydraulic oil level | Check level on tank sight glass, adjust as needed; Inspect HTF hoses for leaks or loose fittings; Check fluid for foaming. | |
| Meter, lamp, or switch failure | Problem; Possible Cause; Solution | |
| No/low heat condition | Incorrect heater setting (target temperature too low) | Adjust heater output. |
| Oil pressure does not rise | Incorrect engine oil viscosity | Change with oil of correct viscosity. |
Fault codes and symptom→remedy steps extracted from this controller’s service/owner documentation; verify against the official manual before servicing. Aggregated from the service documentation of generator sets built on this controller.