background
x
loader
Troubleshooting
arrow By ATA By Message Color By Observed Faults By CAIMS By Tips

Select color for CAS message that you wish to troubleshoot

(WARNING)
RED MESSAGE (CAUTION)
AMBER MESSAGE (ADVISORY)
CYAN MESSAGE (STATUS)
WHITE MESSAGE Require immediate crew attention. These messages are accompanied by flashing master warning, triple chime attenson with or without voice message or dedicated tone. Require immediate crew awareness and future crew action may be required in the form of alternate system selection or performance limitation. These message are accompanied by flashing master caution and a single chime. Indicate safe or normal system operation which require crew awareness, over and above the dark cockpit philosophy. Indicate minor failures or reduction in systems capability, which require no crew action.

This page includes :

For AOG assistance contact:

CRC Montreal (YUL)
Quick Links

06/27/19

Message Overview:

Message Name:

APU GEN SHORTED MEF FAULT

Message Code:

2420099LPS

Associated CAS:

APU GEN FAIL
(Advisory)

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 ]



Message Description:

Auxiliary Power Unit Generator Control Unit (APU GCU) has detected a failure related to the generator shorted MEF (exciter field) wiring and consequently the Auxiliary Power Unit (APU) Generator trips off-line.

Possible Causes:

  • Auxiliary Power Unit (APU) Generator (A110)
  • Auxiliary Power Unit Generator Control Unit (APU GCU) (A109)
  • Associated Wiring

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 the GCU 1, the GCU 4 and the APU GCU into position 2 or 3 (for troubleshooting only). You can monitor the GCU fault in CAIMS via the active faults page.

Quick Links:

Removal of the APU Generator AMM 24-22-01-000-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Installation of the APU Generator AMM 24-22-01-400-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
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 ]
Wire Repair - Maintenance Practices - ALL SPM 20-12-10-02 [ Global Express ]  [ G5000 ]  [ Global XRS ]

Troubleshooting Recommendations:

  1. Swap the APU GCU with the GCU#2 (physically or using the GCU patch cable).

    1. If system checks are good, replace APU GCU and do close out.
    2. If fault remains, continue with next step.

  2. Disconnect connector A109P1 (APU GCU) and A110P1 (APU GEN).
  3. Perform wiring checks between A110P1-H, A110P1-B and ground.

    1. If wiring checks are not good, repair defective associated wiring and do close out.
    2. If wiring checks are good, continue with next step.

  4. Perform wiring checks between APU GCU (A109P1) and APU Generator (A110P1).

    1. If wiring checks are not good, repair defective associated wiring and do close out.
    2. If wiring checks are good, continue with next step.

  5. Replace APU Generator.
  6. Do close out.
    gcu

Registered and/or unregistered trademarks of Bombardier Inc. or its subsidiaries. © 2015 Bombardier Inc. All rights reserved.