Failure of the 212XP and 216XP Busbars in Normal Flight Configuration

TASK 24-50-00-810-813-A
Failure of the 212XP and 216XP Busbars in Normal Flight Configuration

1. Possible Causes

wiring
C/B-BUS 2/212XP/SPLY [10XN]
CNTOR-AC SVCE BUS NORM SPLY [12XN]
RELAY-GND/FLT SELECT CTL [7XX]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 24-00-00-810-803-A	Circuit Breaker Tripped and/or C/B TRIPPED Warning
AMM 24-41-00-861-002	Energize the Aircraft Electrical Circuits from the External Power
AMM 24-41-00-862-002	De-energize the Aircraft Electrical Circuits Supplied from the External Power
ASM 244201
ASM 245103
AMM 24-51-55-000-001	Removal of the AC Service Bus Normal Supply Contactor
AMM 24-51-55-400-001	Installation of the AC Service Bus Normal Supply Contactor

3. Fault Confirmation
Subtask 24-50-00-860-072-A

A. Job Set-up
(1) Aircraft Maintenance Configuration
(a) Energize the aircraft electrical circuits AMM 24-41-00-861-002.

Subtask 24-50-00-710-074-A

B. Test

ACTION	RESULT
1.On the forward attendant panel 120RH, push the CABIN WDO and CABIN CLG pushbutton switches.	the ceiling forward and aft lights (L side) do not come on the window forward and aft lights (R side) do not come on.

4. Fault Isolation
Subtask 24-50-00-810-062-A ** ON A/C NOT FOR ALL

A. If the test confirms the fault:

Do a check of the status of the circuit breaker (10XN).

(1) If the circuit breaker is closed:

Do a check for 115VAC on the pins A/D, A/E and A/F of the contactor (12XN) ASM 245103.

(a) If there is no 115VAC:

Do a check of the wiring between the circuit breaker (10XN) and the contactor (12XN) ASM 245103.

1 If there is no continuity:

Repair the wiring .

2 If there is continuity:

Replace the C/B-BUS 2/212XP/SPLY [10XN] .

(b) If there is 115VAC:

Replace the CNTOR-AC SVCE BUS NORM SPLY [12XN] AMM 24-51-55-000-001 and AMM 24-51-55-400-001.

1 If the fault continues:

Do a check of the wiring between pins A/N, A/P and A/R of the contactor (12XN) and the busbars 212XP and 216XP ASM 244201.

a If there is no continuity:

Repair the wiring .

b If there is continuity:

Replace the RELAY-GND/FLT SELECT CTL [7XX] .

c If the fault continues:

Do a check and repair the wiring :
. from the circuit breaker (3XX) to the pin B/3 of the contactor (12XN).
. from the pin B/5 of the contactor (12XN) to the first terminal block ASM 245103.

(2) If the circuit breaker is open:

Do the procedure (Ref. TSM TASK 24-00-00-810-803).

(a) If the fault continues:

Replace the C/B-BUS 2/212XP/SPLY [10XN] .

Subtask 24-50-00-810-062-B ** ON A/C NOT FOR ALL