Fault Message:

CCBP AC BUS3 SHED RLYK1/DCPC RLYK14

Fault Code:

2460484DCP

Associated CAS:

ELEC SYS FAULT
(Advisory)

The DCPC detects a discrepancy between AC BUS 3 shed relay (K1) and its commanded state.

• AC BUS 3 Shed Relay (K1)
• Direct Current Power Center (DCPC) (A63)
• DC Power Center (DCPC) Relay (K14)
• DC Power Center (DCPC) Primary Logic Card (PLC) 1
• DC Power Center (DCPC) Primary Logic Card (PLC) 2
• DC Power Center (DCPC) Primary Logic Card (PLC) 3
• DC Power Center (DCPC) Battery/Ram-Air-Turbine (BATT/RAT) Card
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

NOTE: If you notice a TAT HTR 3 FAIL and L-R WINDSHIELD HT FAIL CAS messages, suspect a CCBP K1 stuck in shed position.

1. Remove power from the aircraft completely. Gain access to the CCBP and disconnect K1-X2 and K1-12.
2. Perform a continuity check on contactor K1 as follows:

   From	To	Result
   K1-11	K1-12

   1. If there is continuity, replace contactor K1 and do close out.
   2. If there is no continuity, continue with next step.

3. Perform a continuity check as follows:

   From	To	Result
   K1-11	Ground

   1. If there is no continuity, repair defective wiring as required and do close out.
   2. If there is continuity, continue with next step.

4. Apply External AC power to the aircraft. Perform a 115 VAC voltage check as follows:

   From	To	Result
   K1-X1	Ground

   1. If there is no 115 VAC, repair defective wiring as required and do close out.
   2. If there is 115 VAC, continue with next step.

5. Gain access to the DCPC logic assembly and remove all 3 PLCs.
6. Perform a continuity check as follows:

   From	To	Result
   K1-12	Ground

   1. If there is no continuity, go to step 9.
   2. If there is continuity, continue with next step.

7. Disconnect DCPC connector P2 and perform a continuity check as follows:

   From	To	Result
   K1-12	Ground

   1. If there is no continuity, replace the DCPC and do close out.
   2. If there is continuity, repair defective wiring as required and continue with next step.

8. Reconnect DCPC connector P2 and perform a continuity check as follows:

   From	To	Result
   K1-12	P110B-30
   K1-12	P210B-30
   K1-12	P310B-30

   1. If there is no continuity, repair defective wiring as required or replace DCPC if open circuit is located inside the DCPC and do close out.
   2. If there is continuity, continue with next step.

9. Perform a continuity check as follows:

   From	To	Result
   K1-X2	Ground

   1. If there is no continuity, go to step 13.
   2. If there is continuity, continue with next step.

10. Disconnect DCPC connector P2 and perform a continuity check as follows:

    From	To	Result
    K1-X2	Ground

    1. If there is continuity, repair defective wiring as required and do close out.
    2. If there is no continuity, continue with next step.

11. Disconnect Relay K14-B2. (You may consider disconnecting K14 only one pin at a time as this relay is soldered).
12. With DCPC connector P2 still disconnected, perform a continuity check as follows:

    From	To	Result
    K14-B2 (Aircraft side lead)	Ground
    K14-B2 (Relay side lead)	Ground

    1. If there is continuity on the aircraft side, replace the DCPC and do close out.
    2. If there is continuity on the relay side, replace K14 and do close out.
    3. If there is no continuity, continue with next step.

13. Apply Ground Service power to the aircraft and perform a continuity check to ground as follows (PLCs need to be installed for this test):

    From	To	Result
    K1-X2	Ground

    1. If there is continuity, make sure the fault message is no longer present and do close out.
    2. If there is no continuity to ground, continue with next step.

14. Gain access to the DCPC Logic assembly and remove all three PLCs.
15. Disconnect K14-X1 and K14-X2 and perform a continuity check as follows:

    From	To	Result
    K14-X2	P110C-15
    K14-X2	P210C-15
    K14-X2	P310C-15

    1. If there is continuity, replace the DCPC and do close out.
    2. If there is no continuity, continue with next step.

16. Apply EXT AC power to the aircraft and perform a 28 VDC voltage check as follows:

    From	To	Result
    K14-X1	Ground

    1. If there is 28 VDC, make sure the fault message is no longer present and do close out
    2. If there is no 28 VDC, continue with next step.

17. Replace the DCPC BATT/RAT Interface card.
18. Do close out.