Lavatory Smoke Detection Fault

TASK 26-17-00-810-801-A
Lavatory Smoke Detection Fault

1. Possible Causes

lavatory smoke detector

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 26-17-00-710-001	Operational Test of the Lavatory Smoke-Detection System
AMM 26-17-15-000-001	Removal of the Lavatory Smoke Detector
AMM 26-17-15-400-001	Installation of the Lavatory Smoke Detector

3. Fault Confirmation
Subtask 26-17-00-865-050-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
49VU	AIR COND/SDCU/CHAN1	11WQ	C06
122VU	AIR COND/SDCU/CHAN2	12WQ	T18

Subtask 26-17-00-710-050-A ** ON A/C NOT FOR ALL

B. Test
(1) Open the circuit breakers 11WQ and 12WQ.
(a) After 60 seconds, close the circuit breakers 11WQ and 12WQ.
(b) After one more minute, start the subsequent test.
(2) Do the operational test of the lavatory smoke-detection system AMM 26-17-00-710-001.

4. Fault Isolation
Subtask 26-17-00-810-062-A ** ON A/C NOT FOR ALL

A. If the test gives a different maintenance message:

Do the trouble shooting procedure related to the maintenance message.

Subtask 26-17-00-810-063-A ** ON A/C NOT FOR ALL

B. If the test gives the maintenance message TEST OK, no other maintenance action is necessary.

Subtask 26-17-00-810-050-A ** ON A/C NOT FOR ALL

C. If the test gives the maintenance message SMOKE DET LAV X (YWQ):

NOTE: X/Y shows the related lavatory location.

replace the related lavatory smoke detector
AMM 26-17-15-000-001 and AMM 26-17-15-400-001.

Subtask 26-17-00-710-051-A ** ON A/C NOT FOR ALL

D. Do the test as given in the Para. 3.

5. Close-up
Subtask 26-17-00-860-050-A ** ON A/C NOT FOR ALL

A. Put the aircraft back to its initial configuration.

[Rev.8 from Aug 2018] 2026.04.04 04:27:19 UTC