06/21/19
Message Overview:
Fault Message:
APUGCU [VOLTAGE REGULATOR]
Fault Code:
2420247LPS
Associated CAS:
| Reporting LRU: | Auxiliary Power Unit Generator Control Unit (APU GCU) |
| System Description: | 24-22-00 |
| Schematic Diagram: | 24-22-00 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Wiring Diagram: | 24-22-01 [ Global Express ] [ G5000 ] [ Global XRS ] |
Fault Description:
An internal Generator Control Unit (GCU) Voltage regulator fault, detected by continuous monitoring, has caused the Generator output voltage to exceed 120 VAC while remaining below the Generator trip threshold. This fault should be evident on the AC synoptic page while active.
Possible Causes:
- Auxiliary Power Unit Generator Control Unit (APU GCU) (A109)
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
A GCU patch cable (GSE REF # 24X-24-02) can be used to swap GCU 1, GCU 2, GCU 3, GCU 4 and the APU GCU into a different position (for troubleshooting only). You can monitor the GCU faults in CAIMS via the active faults page.
Quick Links:
| Removal of the Generator Control Units (GCU) | AMM 24-24-01-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of the Generator Control Units (GCU) | AMM 24-24-01-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
Troubleshooting Recommendations:
- Remove power from the A/C completely. Apply power to the A/C. Is the fault still present?
- If NO, monitor for failure and do close out.
- If YES, continue with next step.
- Replace APU GCU.
- Do close out.