Fault Message:

LH CTR XFER PUMP ELECT PWR/WRG

Fault Code:

284461EPK

Associated CAS:

CTR FUEL XFER FAIL
(Caution)

CTR XFER FAULT
(Advisory)

Left Center XFER Pump failed on or off due to:

• A failure of the Pump command signal from the Fuel Management Quantity and Gauging Computer (FMQGC) to the Electrical System, OR
• A failure of the Electrical System to power up or down the Pump when commanded by the FMQGC, OR
• A failure of the Electrical System to provide Pump power status feedback to the FMQGC

• Electrical Management System Control-and-Display Unit (EMS CDU) 1 (A94)
• Electrical Management System Control-and-Display Unit (EMS CDU) 2 (A91)
• AC Power Center (ACPC) (A54)
• Solid-State Power Controller (SSPC) 2 (A3)
• AC Power Center (ACPC) Microprocessor Card
• AC Power Center (ACPC) Supervisor Card
• Data Acquisition Unit (DAU) 1 (A17)
• Data Acquisition Unit (DAU) 2 (A18)
• Associated Wiring

1. Go to CENTER TRANSFER TEST page via PMAT to turn on Left Center Transfer Pump.
2. Check L TRANSFER REQUEST command discrete input at EMS CDU as follows:

   1. In PMAT, select CH24-00 - Electrical Power.
   2. Select EMS CONT DISPLAY UNIT #1A.
   3. Select LTR TEST.
   4. Select DISCRETE INPUTS to display data.
   5. Ensure LEFT TRANSFER REQUEST command is ON.

3. Repeat step 2 for EMS CONT DISPLAY 1B, 2A and 2B.

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

4. Check L CTR XFER PUMP command signals from the FMQGC to EMS CDU 1 and 2 (Two signal grounds at: A94P1-67 and A91P1-67).

   1. If checks are good, go to step 9.
   2. If fault remains, continue with next step.

5. Perform wiring checks between FMQGC to Fuel Panel as follow:

   From	To	Result
   A47AP1-K15	AP5P1-2
   A47DP1-H13	AP5P1-3

   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.

6. Perform wiring checks between Fuel Panel to EMS CDU 1 and EMS CDU 2 as follow:

   From	To	Result
   AP5P1-9	A94P1-67
   AP5P1-4	A91P1-67

   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. Perform wiring checks inside the Fuel Panel as follow:

   From	To	Result
   AP5P1-2	AP5P1-9
   AP5P1-3	AP5P1-4

   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.

8. Replace EMS CDU as required (CDU 1 for 1A and 1B command failure, CDU 2 for 2A and 2B command failure).

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

9. Check L CTR XFER PUMP load status from SSPC to EMS CDU as follows:

   1. In PMAT, select CH24-00 - Electrical Power.
   2. Select ACPC POWER CENTER ACPC A.
   3. Select LTR TEST.
   4. Select ACPC A, LOAD STATUS LABEL 002-007
   5. Select Label 003 load 2 - L CTR XFER PUMP Phase A.
   6. Ensure the following status are met.

      Reference	Status
      LOGIC EQUATION STATE (L TRANSFER REQUEST)	ON
      VIRTUAL CIRCUIT BREAKER	IN
      VIRTUAL SWITCH (SSPC SW)	ON
      VOLTAGE STATUS	PRESENT
      TRIP STATUS (CIRCUIT BREAKER)	NOT TRIP
      FAIL STATUS (SSPC)	NOT FAIL

10. Repeat step 9 for phase B and phase C of the pump by selecting label 004 Load 1 (L CTR XFER PUMP Phase B) and label 004 Load 2 (L CTR XFER PUMP Phase C).

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

11. Check L CTR XFER PUMP feedback status from ACPC to EMS CDU 1 and CDU 2 as follows:

    1. Using EMS CDU 1 and CDU 2 Signboard Menu to select ACPC IN.
    2. Check L CTR XFER PUMP status, Label 276 Bit15 - Bit 18.

       	Left Column								Center Column
       Label 276 L Ctr Xfer Status	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14
       	X	X	X	X	X	X	X	X	X	X	X

       Bit 14-15
       X	=	Ignore the values in the position shown by X
       0000	=	Pump OFF
       0001	=	Pump ON (V&I<20%)
       0011	=	Pump ON (V&I>20%)
       X1XX	=	SSPC TRIP
       1XX0	=	SSPC FAILED OFF
       1XX1	=	SSPC FAILED ON

12. Does EMS CDU 1 agree with CDU 2 that L CTR XFER PUMP (ACPC IN) is Pump ON (V&I>20%)-(0011)?

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

13. Check L CTR XFER PUMP feedback status from EMS CDU 1 and CDU 2 to DAU 1 and DAU 2 as follows:

    1. Using EMS CDU 1 and CDU 2 Signboard Menu to select DAU OUT.
    2. Check L CTR XFER PUMP status, Label 276 Bit15 - Bit 18.

14. Does EMS CDU 1 agree with CDU 2 that L CTR XFER PUMP (DAU OUT) is Pump ON (V&I>20%)-(0011)?

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

15. Replace defective DAU.
16. Do close out.