Functional Test of Ionic Smoke Detector Sensitivity

TASK 26-15-00-720-001-A
Functional Test of Ionic Smoke Detector Sensitivity

1. Reason for the Job

NOTE: Make sure that the detector is not dirty.

NOTE: This task is applicable only on aircraft with ionic smoke detector installed.

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
35M5M01130000	1	TEST SET-SMOKE DETECTOR

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
824

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
TASK 24-42-00-862-001-A	De-energize the Ground Service Network Supplied from the External Power
TASK 26-15-00-710-001-A	Operational Test of the Avionics Smoke Detection
TASK 26-15-15-000-001-A	Removal of the Smoke Detector - Avionics Compartment
TASK 26-15-15-400-001-A	Installation of the Smoke Detector - Avionics Compartment
TASK 52-41-00-410-002-A	Close the Avionics Compartment Doors after Access

3. Job Set-up
Subtask 26-15-00-861-050-A

A. Energization

CAUTION: USE ONLY THE GROUND SERVICE NETWORK TO SUPPLY ELECTRICITY BECAUSE THE AVIONICS VENTILATION SYSTEM IS NOT SERVICEABLE. IF YOU ENERGIZE THE AIRCRAFT ELECTRICAL CIRCUITS WITHOUT THE VENTILATION SYSTEM YOU WILL CAUSE DAMAGE TO ELECTRICAL EQUIPMENT.

(1) Energize the ground service network (Ref. AMM TASK 24-42-00-861-001).

Subtask 26-15-00-865-058-A

B. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	AIR COND/AVNCS VENT/CTL	6HQ	D06
49VU	AIR COND/AVNCS VENT/CTL	5HQ	D05

Subtask 26-15-00-010-050-A

C. Get Access
(1) Put the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position at the access door 824.
(2) Open the access door 824.

Subtask 26-15-00-480-050-A

D. Connection of the Tooling
(1) Disconnect the electrical connector 1WA-A from the smoke detector 1WA.
(2) Connect the electrical connector of the 35M5M01130000 TEST SET-SMOKE DETECTOR to the connector of the smoke detector 1WA ; the voltage of the electrical power supply is 28V, supplied by the test set.

4. Procedure
Subtask 26-15-00-720-050-A

A. Functional Test of Smoke Detector Sensitivity

ACTION	RESULT
1.On the test set :	On the test set :
Set the ammeter sensitivity switch to 400 mA.
Set the SELECTOR switch to 28V
Set the A.L switch to ON
Read the stable voltage U1.	U1 is between 2V and 4V.
Push the TEST 28V pushbutton switch
When the value is stable, read the voltage U2.	U2 is between 8V and 10V.
	The detector sensitivity is : Delta U = U2-U1 = 6V (plus or minus 1V). If the smoke detector sensitivity is out of tolerance (sensitivity less than 5V or more than 7V) the smoke detector is dirty. You must remove it (Ref. AMM TASK 26-15-15-000-001) and (Ref. AMM TASK 26-15-15-400-001).

5. Close-up
Subtask 26-15-00-080-050-A

A. Disconnection of the Tooling
(1) Disconnect the electrical connector from the test set.
(2) Connect the electrical connector 1WA-A to the smoke detector 1WA.

Subtask 26-15-00-865-059-A

B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	AIR COND/AVNCS VENT/CTL	6HQ	D06
49VU	AIR COND/AVNCS VENT/CTL	5HQ	D05

Subtask 26-15-00-710-051-A

C. Do the operational test of the avionics smoke detection system from the Multipurpose Control and Display Unit (MCDU) (Ref. AMM TASK 26-15-00-710-001).

Subtask 26-15-00-410-050-A

D. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the access door 824 (Ref. AMM TASK 52-41-00-410-002).
(3) Remove the access platform(s).

Subtask 26-15-00-862-050-A

E. De-energize the ground service network (Ref. AMM TASK 24-42-00-862-001).

[Rev.10 from 2021] 2026.03.31 23:43:44 UTC