Failure of the Smoke Detector

TASK 21-26-00-810-811-A
Failure of the Smoke Detector

1. Possible Causes

DET-SMOKE, AVNCS COMPT [1WA]
RELAY-SMOKE WARNING, AVNCS COMPT (2WA)
AEVC [10HQ]
C/B-AIR COND/AVNCS VENT/CTL [5HQ]
wiring between pin A/A of the smoke detector (1WA) and the circuit breaker (5HQ)

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 21-26-00-710-001	Operational Check of the Avionics Equipment Ventilation-System via MCDU
ASM 212603
AWM 212606
AWM 212608
AMM 21-26-34-000-001	Removal of the Avionics Equipment Ventilation Computer (AEVC)
AMM 21-26-34-400-001	Installation of the Avionics Equipment Ventilation Computer (AEVC)
AWM 261501
AMM 26-15-15-000-001	Removal of the Smoke Detector - Avionics Compartment
AMM 26-15-15-400-001	Installation of the Smoke Detector - Avionics Compartment
AMM 31-50-00-710-001	Ground Scanning of the Central Warning System

3. Fault Confirmation
Subtask 21-26-00-710-073-A

A. Test
(1) Do the operational test of the avionics equipment ventilation from the Multipurpose Control and Display Unit (MCDU) AMM 21-26-00-710-001.

4. Fault Isolation
Subtask 21-26-00-865-052-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	AIR COND/AVNCS VENT/CTL	5HQ	D05

Subtask 21-26-00-810-062-A

B. If the test gives the maintenance message SMOKE DETECTOR 1WA:

Do a check of the status of the circuit breaker (5HQ).

(1) If the circuit breaker (5HQ) is closed:

Do a check for a ground signal at pin AB/7D of the AEVC (10HQ) ASM 212603.

(a) If there is a ground signal:

Do a check for 28VDC at pin A/X1 of the smoke warning relay (2WA) AWM 261501.

1 If there is 28VDC:

Replace the DET-SMOKE, AVNCS COMPT [1WA] AMM 26-15-15-000-001 and AMM 26-15-15-400-001.

2 If there is no 28VDC:

Replace the RELAY-SMOKE WARNING, AVNCS COMPT (2WA)

a If the fault continues:

Do a check and repair the wiring between the smoke warning relay (2WA) and the AEVC (10HQ), pin A/A1 and pin AB/7D ASM 212603 AWM 261501 AWM 212606.

b If the fault continues:

Replace the AEVC [10HQ] AMM 21-26-34-000-001 and AMM 21-26-34-400-001.

(b) If there is no ground signal:

Do a check for a ground signal at pin A/A2 of the smoke warning relay (2WA).

1 If there is a ground signal:

Do a check for 28VDC at pin A/X1 of the smoke warning relay (2WA).

a If there is 28VDC:

Replace the RELAY-SMOKE WARNING, AVNCS COMPT (2WA).
* If the fault continues:
* - Do a check and repair the wiring between the smoke warning relay (2WA) and the smoke detector (1WA), pin A/X1 and pin A/D ASM 212603 AWM 261501.

b If there is no 28VDC:

Do a check for 28VDC at pin A/A of the smoke detector (1WA).

* If there is 28VDC:
* - Replace the DET-SMOKE, AVNCS COMPT [1WA] AMM 26-15-15-000-001 and AMM 26-15-15-400-001.

* If there is no 28VDC:
* - Replace the C/B-AIR COND/AVNCS VENT/CTL [5HQ] .

** If the fault continues:
** - Do a check and repair the wiring between pin A/A of the smoke detector (1WA) and the circuit breaker (5HQ) ASM 212603 AWM 212608 AWM 261501.

Subtask 21-26-00-710-074-A

C. Do the operational test given in Para. 3.

Subtask 21-26-00-865-055-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	FWS/FWC1/SPLY	3WW	F01
121VU	EIS/FWC2/SPLY	2WW	Q07

Subtask 21-26-00-710-112-A

E. Test
(1) Reset of the FWC1 and FWC2

NOTE: The reset of the FWC will clear the latched condition of the AVIONICS SMOKE ECAM warning. Then, no unwanted LAND ASAP message will show.

NOTE: It is necessary to open the circuit breakers for a minimum of five seconds before they are closed.

(a) Open this(these) circuit breaker(s):
1 2WW
2 3WW.
(b) Close this(these) circuit breaker(s):
1 2WW
2 3WW.
(2) Do the ground scanning of the central warning system AMM 31-50-00-710-001.

[Rev.8 from Aug 2018] 2026.04.04 04:24:37 UTC