Failure of the ELEC/GEN 1 Pushbutton Switch

TASK 24-22-00-810-827-A
Failure of the ELEC/GEN 1 Pushbutton Switch

1. Possible Causes

wiring
P/BSW-ELEC/GEN 1 [3XU1]
GCU-1 [1XU1]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
ASM 242202
AMM 24-22-34-000-001	Removal of the GCU-1(2)
AMM 24-22-34-400-001	Installation of the GCU-1(2)
AMM 24-41-00-740-002	Operational Check of the GAPCU via the CFDS

3. Fault Confirmation
Subtask 24-22-00-740-071-A ** ON A/C NOT FOR ALL

A. Test
(1) Do the BITE test of the GAPCU AMM 24-41-00-740-002.

4. Fault Isolation
Subtask 24-22-00-865-058-A ** ON A/C NOT FOR ALL

A. Table of the circuit breakers used in this procedure:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
122VU	ELEC/GCU/1	2XU1	T26

Subtask 24-22-00-810-082-A ** ON A/C NOT FOR ALL

B. If the BITE test gives the maintenance message PB SW ELEC GEN1 (3XU1)/ GCU1 (1XU1):

NOTE: After you do the trouble shooting for this fault, open and close the ELEC/GCU1 circuit breaker (2XU1) to remove all 28VDC power supply from the GCU 1.

do a check of the wiring of the ELEC/GEN 1 pushbutton switch (3XU1) ASM 242202 for an open circuit or a short to ground between:
. pin A/1C of the GCU 1 and pin A/D3 of the ELEC/GEN 1 pushbutton switch
. pin A/4E of the GCU 1 and pin A/D2 of the ELEC/GEN 1 pushbutton switch
. pin A/2G of the GCU 1 and pin A/D1 of the ELEC/GEN 1 pushbutton switch.

(1) If the wiring is not correct:

repair or replace as necessary.

(2) If the wiring is correct:

do a test of the contacts of the ELEC/GEN 1 pushbutton switch ASM 242202 for correct operation between:
. pins A/D3 and A/D2 (normally closed)
. pins A/D3 and A/D1 (normally open).

(a) If the test is not OK:

replace the P/BSW-ELEC/GEN 1 [3XU1] on the ELEC panel 35VU.

(b) If the test is OK:

replace the GCU-1 [1XU1] AMM 24-22-34-000-001 and AMM 24-22-34-400-001.

Subtask 24-22-00-740-072-A ** ON A/C NOT FOR ALL

C. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:26:38 UTC