06/20/19
Message Overview:
Fault Message:
APUGCU [GLCR/DRIVE CIRCUIT]
Fault Code:
2420179LPS
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:
Auxiliary Power Unit Generator Control Unit (APU GCU) has detected an internal failure related to the Generator Line Contactor Relay (GLCR) Drive Circuit, consequently resulting in APU Generator tripped off-line. GLCR/DRIVE Circuit is responsible to energize the Generator Line Contactor Relay, within the GCU. The GLCR, once energized, provide the 28 VDC to the Auxiliary Power Unit Line Contactor (APULC) located in the AC Power Center (ACPC).
Possible Causes:
- Auxiliary Power Unit (APU) Generator Control Unit (GCU) (A109)
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
The GCU NVMs can only be downloaded at position #2 or #3.
A GCU patch cable (GSE REF # 24X-24-02) can be used to swap GCU 1, GCU4 and APU GCU into position 2 or 3 (for troubleshooting only).
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:
- Replace APU GCU.
NOTE: Use PMAT to monitor the fault on GCU. - Do close out.