Fault Message:

LH AFT XFER PUMP ELECT PWR/WRG

Fault Code:

2844624PK

Associated CAS:

AFT XFER FAIL
(Caution)

AFT XFER FAULT
(Advisory)

Fuel Management and Quantity Gauging Computer (FMQGC) computer senses that the Left AFT Transfer Pump has failed due to an Electrical Load Management System (LMS) failure.

• AC Power Center (ACPC)/Solid-State Power Controller (SSPC) 7 (A14)
• AC Power Center (ACPC) Secondary Logic Card (SLC)
• Left AFT Transfer Pump (B34)
• Fuel Management and Quantity Gauging Computer (FMQGC) (A47)
• Electrical Management System Control-and-Display Unit (EMS CDU) 1 (A94)
• Electrical Management System Control-and-Display Unit (EMS CDU) 2 (A91)
• Associated Wiring

Advisory Wire/Service Bulletin:

• AW700-45-0065 - CAIMS Nuisance Fault Messages

Forum Articles/Infoservice/Newsletter: None

1. Using CAIMS, verify if there are fault messages concerning the AC BUS 1 or ACPC shown:

   1. If YES, troubleshoot them first.
   2. If NO, continue with next step.

2. Select the ACPC A (B) LOAD STATUS LABEL 013, LOAD 1 (AFT TANK L PUMP, Phase A) page, via CAIMS. Set the AFT XFER swith to ON and monitor the results that follow:

   Reference	Status
   LOGIC EQUATION STATE (AFT TANK L PUMP)	ON
   VIRTUAL CIRCUIT BREAKER (SSPC CIRCUIT BREAKER)	IN
   VIRTUAL SWITCH (SSPC SW)	ON
   LOCK STATE	UNLOCKED
   VOLTAGE STATUS	PRESENT
   CURRENT STATUS	FLOWING
   TRIP STATUS (CIRCUIT BREAKER)	NOT TRIP
   FAIL STATUS (SSPC)	NOT FAILED

   1. If the above status are met, go to step 10.
   2. If one of the above status is not met, go to step 4.
      NOTE: Repeat this step by selecting LABEL 013 Load 2 (AFT TANK L PUMP, Phase B) and LABEL 014 Load 2 (AFT TANK L PUMP, Phase C).

3. An alternative way of monitoring the result is to select ACPC IN via EMS CDU1 or CDU2 Signboard Menu:

   	Left Column								Center Column
   Label 013	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14
   			1	1	1	1	1	1
   Reference	LOAD 2:AFT TANK L PUMP, PHASE B								LOAD 1:AFT TANK L PUMP, PHASE A
   Label 020	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14
   											1	1	1	1	1	1
   Reference									LOAD 1:AFT TANK L PUMP, PHASE C

   • Bit 14 or 22:LOGIC EQUATION STATE (AFT TANK L PUMP)
   • Bit 15 or 23:VIRTUAL CIRCUIT BREAKER (SSPC CIRCUIT BREAKER)
   • Bit 16 or 24:VIRTUAL SWITCH (SSPC SW)
   • Bit 17 or 25:LOCK STATE
   • Bit 18 or 26:VOLTAGE STATUS
   • Bit 19 or 27:CURRENT STATUS
   • Bit 20 or 28:TRIP STATUS (CIRCUIT BREAKER)
   • Bit 21 or 29:FAIL STATUS (SSPC)

   1. If the above status are met, go to step 10.
   2. If one of the above status is not met, continue with next step.

4. Perform wiring check (short to ground=fail) between the ACPC (A54P10) and left aft transfer pump (B34P1).

   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.

5. Perform a ground check at the left aft transfer pump (B34P1). Repair as required.

   1. If ground is not there, go to step 7.
   2. If ground is there, continue with next step.

6. Swap the left aft transfer pumps with right aft transfer pump.

   1. If system checks are good, replace left aft transfer pump and do close out.
   2. If fault remains, continue with next step.

7. Swap the ACPC/SSPC 7.

   1. If system checks are good, replace defective ACPC/SSPC 7 and do close out.
   2. If fault remains, continue with next step.

8. Swap the ACPC secondary logic card AC-2 (A12).

   1. If system checks are good, replace defective ACPC secondary logic card and do close out.
   2. If fault remains continue with next step.

9. Swap the EMS CDUs.

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

10. Replace FMQGC.
11. Do close out.