Operational Test of the APU Fire-Extinguishing Loop/Squib

TASK 26-22-00-710-001-A
Operational Test of the APU Fire-Extinguishing Loop/Squib

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER

B. Referenced Information

REFERENCE	DESIGNATION
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
TASK 31-60-00-860-001-A	EIS Start Procedure
TASK 31-60-00-860-002-A	EIS Stop Procedure
TASK 33-14-00-710-001-A	Operational Check of the Light Test System

3. Job Set-up
Subtask 26-22-00-860-050-A

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(2) Do the EIS start procedure (upper ECAM DU and lower ECAM DU only)
(Ref. AMM TASK 31-60-00-860-001).
(3) Do the operational test of the annunciator light test system in the cockpit (Ref. AMM TASK 33-14-00-710-001).

Subtask 26-22-00-865-053-A

B. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
121VU	APU/FIRE AND OVHT/DET/LOOP B	2WG	L44
121VU	APU/FIRE AND OVHT/DET/LOOP A	1WG	L43
121VU	APU/ECB/SPLY	1KD	L41
121VU	APU/FIRE/EXTIG/SQUIB/B	2WF	L39
121VU	APU/FIRE/EXTIG/SQUIB/A	1WF	L38
121VU	APU/FIRE/LP VALVE/NORM	4WF	M42
121VU	APU/FIRE/LP VALVE/STBY	3WF	M41

4. Procedure
Subtask 26-22-00-875-050-A ** ON A/C NOT FOR ALL

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	APU/AUTO/EXTIG/GND/TEST	30WF	L40

Subtask 26-22-00-710-052-A ** ON A/C NOT FOR ALL

B. Operational Test of the APU Fire-Extinguishing Loop/Squib

Make sure that circuit breaker APU AUTO EXTIG GND TEST 30WF (L40) on panel 121VU is open.

NOTE: You can open circuit breaker APU AUTO EXTIG GND TEST 30WF (L40) to prevent an unwanted automatic fire-extinguisher discharge during the test.

ACTION	RESULT
WARNING: DO NOT PUSH THE APU FIRE/TEST PUSHBUTTON SWITCH FOR MORE THAN 3 SECONDS. IF YOU PUSH IT FOR MORE THAN 3 SECONDS, THERE IS A RISK THAT IT WILL CAUSE THE DISCHARGE OF THE APU FIRE-EXTINGUISHER BOTTLE. 1.On APU FIRE panel 20VU: Push and hold the APU FIRE/TEST pushbutton switch for not more than 3 seconds.	On APU FIRE panel 20VU: The APU FIRE light in the APU FIRE pushbutton switch comes on. The DISCH and SQUIB legends in the AGENT pushbutton switch come on.
	On glareshield panels 130VU and 131VU: The MASTER WARN lights flash. You hear a continuous repetitive chime.
	On the ECAM upper display unit: The warnings that follow come on: APU FIRE APU FIRE P/B....PUSH.
2.On APU FIRE panel 20VU: Release the APU FIRE/TEST pushbutton switch.	On APU FIRE panel 20VU: The APU FIRE light in the APU FIRE pushbutton switch goes off. The DISCH and SQUIB legends in the AGENT pushbutton switch go off.
	On glareshield panels 130VU and 131VU: The MASTER WARN lights go off. The continuous repetitive chime stops.
	On the ECAM upper display unit: The warnings that follow go off: APU FIRE APU FIRE P/B....PUSH.

Subtask 26-22-00-710-052-B ** ON A/C NOT FOR ALL

B. Operational Test of the APU Fire-Extinguishing Loop/Squib

ACTION	RESULT
WARNING: DO NOT PUSH THE APU FIRE/TEST PUSHBUTTON SWITCH FOR MORE THAN 3 SECONDS. IF YOU PUSH IT FOR MORE THAN 3 SECONDS, THERE IS A RISK THAT IT WILL CAUSE THE DISCHARGE OF THE APU FIRE-EXTINGUISHER BOTTLE. 1.On APU FIRE panel 20VU: Push and hold the APU FIRE/TEST pushbutton switch for not more than 3 seconds.	On APU FIRE panel 20VU: The APU FIRE light in the APU FIRE pushbutton switch comes on. The DISCH and SQUIB legends in the AGENT pushbutton switch come on.
	On glareshield panels 130VU and 131VU: The MASTER WARN lights flash. You hear a continuous repetitive chime.
	On the ECAM upper display unit: The warnings that follow come on: APU FIRE APU FIRE P/B....PUSH.
2.On APU FIRE panel 20VU: Release the APU FIRE/TEST pushbutton switch.	On APU FIRE panel 20VU: The APU FIRE light in the APU FIRE pushbutton switch goes off. The DISCH and SQUIB legends in the AGENT pushbutton switch go off.
	On glareshield panels 130VU and 131VU: The MASTER WARN lights go off. The continuous repetitive chime stops.
	On the ECAM upper display unit: The warnings that follow go off: APU FIRE APU FIRE P/B....PUSH.

Subtask 26-22-00-875-051-A ** ON A/C NOT FOR ALL

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	APU/AUTO/EXTIG/GND/TEST	30WF	L40

5. Close-up
Subtask 26-22-00-860-051-A

A. Put the aircraft back to its initial configuration.
(1) Do the EIS stop procedure
(Ref. AMM TASK 31-60-00-860-002).
(2) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.03.31 23:45:29 UTC