Fault Message:

GEN3 DRIVE SHAFT FAIL/INVALID % N2

Fault Code:

2423200LPS

Associated CAS:

GEN 3 FAIL
(Advisory)

Variable Frequency Generator (VFG) 3 has tripped off-line or will not come on-line.

• Variable Frequency Generator (VFG) 3 (G3)
• Generator Control Unit (GCU) 3 (A58)
• Associated Wiring

Advisory Wire/Service Bulletin:

• AW700-24-0598 - Variable Frequency Generator (VFG) GL511-1103-9 - Failure

Full Throttle Blog/Forum Articles/Infoservice/Newsletter:

• Reference Instruction Letter (RIL) GX-0198 - Return to service following VFG bearing failure and/or VFG housing rupture.

NOTES:

• Prior to T/S procedures, perform a visual of generator 3 for heat distress. Confirm if the heat exchanger is blocked  with FOD.
• A GCU patch cable (GSE REF # 24X-24-02) can be used to swap GCUs 1, 4 and 5 into position 2 or 3 (for troubleshooting only).

• The GCU NVMs can only be downloaded at position #2 or #3.

1. Access CAIMS and check if the following faults are active:

   • 2423126LPS - GEN3 OIL OVERTEMP FAULT
   • 2423124LPS - GEN3 [DIFF PROTECTION FEEDER]

   Inspect the VFG for the following:

   • VFG oil filter bypass indicator tripped, and/or
   • Metal particles in the oil lines, and/or
   • VFG end frame cracked or breached, and/or
   • Oil sight glass cracked

   1. If there is a combination of the listed CAIMS active fault and VFG condition(s) perform RIL GX-0198
   2. If there is NO combination, continue with next step.

2. Do a visual inspection of VFG 3. Is the drive shaft broken or sheared?

   1. if YES, investigate the cause and replace VFG 3.
   2. If NO, continue with next step.

3. Interchange GCU 3 with GCU 2 (physically or using the GCU patch cable).
   

   1. If system checks are good, replace GCU 3 and do close out.
   2. If fault remains, continue with next step.

4. Disconnect VFG 3 connector G3P1 and GCU 3 connector A58P1. Do a continuity check as follows:

   From	To	Result
   A58P1-E	Ground
   A58P1-F	Ground
   A58P1-G	Ground

   1. If there is continuity, repair defective wiring as required.
   2. If there is NO continuity, continue with next step.

5. Do continuity check between GCU 3 and VFG 3 as follows:

   From	To	Result
   A58P1 -E	G3P1-G
   A58P1-F	G3P1-C
   A58P1-G	G3P1-L

   1. If there is continuity, continue with next step.
   2. If there is NO continuity, repair defective wiring as required.

6. Disconnect connector ACPC (A54P3) and connector GCU 3 (A58P2). Perform wiring check between GCU 3 and ACPC as follows:

   From	To	Result
   A58P2-9	A54P3-a
   A58P2-15	A54P3-b

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

7. Replace VFG 3.
8. Do close out.