02/25/21
Message Overview:
Message Description:
APU Generator (APUG) has failed.
Possible Causes:
- APU Generator (AGEN) (G3)
- Auxiliary Generator Control Unit (AGCU) (PCB9)
- Auxiliary Generator Power-Module (AGPM) (PCB10)
- Auxiliary Power Center (Aux DCPC)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin:
- AW300-24-0038 - Nuisance "ELECTRICAL FAULT" CAS Message Upon Engine or APU Shut Down.
- AW300-24-0115 - Introduction of Improved Generator P/N A3579-102
- AW300-24-0132 - Power Module (PMOD) P/N R3608-011 - Generator Failures at High Engine Speed
- AW300-24-0137 - Y06 Electrical System Upgrade
- AW300-24-0162 - Service Bulletin 100-24-20 - DC Power Center (DCPC) System - Inspection and Replacement of Internal Fuses in the L/H and R/H DC Power Center (DCPC)
Forum Articles/Infoservice/Newsletter: None
Quick Links:
| Removal of the Main Generator | AMM 24-31-05-000-801 |
| Installation of the Main Generator | AMM 24-31-05-400-801 |
| Removal of the APU Generator | AMM 24-31-09-000-801 |
| Installation of the APU Generator | AMM 24-31-09-400-801 |
| Removal of the Generator Control Unit (GCU) - Primary | AMM 24-31-13-000-801 |
| Installation of the Generator Control Unit (GCU) - Primary | AMM 24-31-13-400-801 |
| Removal of the Auxiliary Generator Control-Unit | AMM 24-31-17-000-801 |
| Installation of the Auxiliary Generator Control-Unit | AMM 24-31-17-400-801 |
| Removal of the Generator Power Module | AMM 24-31-21-000-801 |
| Installation of the Generator Power Module | AMM 24-31-21-400-801 |
| Removal of the Auxiliary Generator Power-Module | AMM 24-31-25-000-801 |
| Installation of the Auxiliary Generator Power-Module | AMM 24-31-25-400-801 |
| Removal of the Auxiliary Power Center (Aux DCPC) | AMM 24-64-01-000-801 |
| Installation of the Auxiliary Power Center (Aux DCPC) | AMM 24-64-01-400-801 |
| Wiring - Maintenance Practices - ALL | SPM 20-12-00-02 |
| Wire Repair - Maintenance Practices - ALL | SPM 20-12-10-02 |
| Electrical Connectors - Maintenance Practice - ALL | SPM 20-20-00-02 |
Troubleshooting Recommendations:
- Spin the APU Generator (G3) shaft by hand through the opening of the cooling ports. Does it spin freely?
- If YES (the shaft is sheared), replace the defective Generator.
- If NO (some friction could be felt), continues with next step.
- Do wiring check of the following wires:
From To Results APU GEN conn. G3P1 - pin A AUX DCPC conn. A196P1 - pin G APU GEN conn. G3P1 - pin B AUX DCPC conn. A196P1 - pin F APU GEN conn. G3P1 - pin G AUX DCPC conn. A196P1 - pin AA APU GEN conn. G3P1 - pin D AUX DCPC conn. A196P1 - pin K APU GEN conn. G3P1 - pin F AUX DCPC conn. A196P1 - pin h APU GEN conn. G3P1 - pin E AUX DCPC conn. A196P1 - pin H APU GEN conn. G3P1 - pin L AUX DCPC conn. A196P1 - pin JJ APU GEN conn. G3P1 - pin M AUX DCPC conn. A196P1 - pin z APU GEN conn. G3P1 - pin H AUX DCPC conn. A196P1 - pin D APU GEN conn. G3P1 - pin J AUX DCPC conn. A196P1 - pin d APU GEN conn. G3P1 - pin K AUX DCPC conn. A196P1 - pin E - If wiring check is satisfying, continue with next step.
- If wiring check is not satisfying, repair the defective wire.
- Swap the APU Generator with one of the Main Generator. Is the fault message still present?
- If YES, continue with next step.
- If NO, replace the defective Generator.
- Swap the Auxiliary Generator Power-Module PCB10 with the Right Generator Power Module PCB8 or the Left Generator Power Module PCB7. Is the fault message still present?
- If YES, continue with next step.
- If NO, replace the defective Auxiliary Generator Power-Module.
- Swap the Auxiliary Generator Control Unit (PCB9) with the Right or Left Generator Control Unit (PCB6 or PCB5). Is the fault message still present?
- If YES, continue with next step.
- If NO, replace the defective Generator Control Unit.
- Replace the AUX DCPC.
- Do close out.