Operational Check of Low Pressure Indicating Circuit

TASK 26-22-00-710-003-A
Operational Check of Low Pressure Indicating Circuit

WARNING: BE VERY CAREFUL WHEN YOU MOVE A FULL FIRE EXTINGUISHER BOTTLE. A SUDDEN OR HEAVY SHOCK TO A FULL BOTTLE CAN CAUSE UNWANTED DISCHARGE AND INJURY TO PERSONS.

ZONE: 210

1. Reason for the Job
Refer to the MPD TASK: 262200-05
OPERATIONAL CHECK OF LOW PRESSURE INDICATING CIRCUIT
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE
No specific	AR	ALLEN KEY 3/32 IN
No specific	1	BOOMSET 600 OHMS
No specific	1	FLASHLIGHT
No specific	AR	HEADSET 600 OHMS
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
210	CKPT,FWD COMPT BHD TO FLT COMPT BULKHEAD
314AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 23-51-00-710-001-A	Operational Test of the Audio Management Unit (AMU)
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
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-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
TASK 52-41-23-010-801-A	Opening of Access Door 314AR
TASK 52-41-23-410-801-A	Closing of Access Door 314AR
CHECK OF THE PRESSURE SWITCH

3. Job Set-up
Subtask 26-22-00-860-054-A

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002) or (Ref. AMM TASK 24-41-00-861-002).
(2) Energize the audio integrating system (Ref. AMM TASK 23-51-00-710-001).
(3) On the CAPT jack panel, connect the HEADSET 600 OHMS to the related connector.
(4) On the overhead panel 50VU, make sure that the ON legend on the SVCE INT OVRD pushbutton switch is off.

Subtask 26-22-00-865-062-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
121VU	APU/APU/CTL	2KD	L42
121VU	APU/ECB/SPLY	1KD	L41

Subtask 26-22-00-010-053-A

C. Get Access

WARNING: BEFORE YOU START WORK, YOU MUST PUT ON A SAFETY HARNESS AND ATTACH IT TO THE ACCESS PLATFORM. WITHOUT A SAFETY HARNESS, YOU CAN FALL. THIS CAN KILL YOU OR CAUSE YOU INJURY.

(1) Put on and attach a safety harness before you start work in the work area
(2) Put the ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE below the access door 314AR.
(3) Open access door 314AR and safety it in the open position.
(Ref. AMM TASK 52-41-23-010-801).
(4) If necessary, use a FLASHLIGHT.
(5) In Zone 314, connect the BOOMSET 600 OHMS to the service interphone jack.

4. Procedure
Subtask 26-22-00-710-056-A

A. Test

NOTE: For this procedure we recommend that a minimum of two persons are in contact with each other with the audio integrating system. One person must monitor the cockpit APU panel 20VU and the other person does the test in the zone 314.

ACTION	RESULT
1.On the APU fire extinguisher bottle: put the ALLEN KEY 3/32 IN (1) into the pressure switch hexagon test-socket (2). Slowly turn the Allen Key clockwise or counterclockwise approx. 10 degrees.	On the APU FIRE panel 20VU: the DISCH legend in the AGENT pushbutton switch comes on.
2.On the APU fire extinguisher bottle: release the Allen Key.	On the APU FIRE panel 20VU: the DISCH legend in the AGENT pushbutton switch goes off. NOTE: The pressure effect must send the Allen Key back to the initial position.
3.On the APU fire extinguisher bottle: remove the Allen Key from the test socket.

5. Close-up
Subtask 26-22-00-410-054-A

A. Close Access
(1) Disconnect the BOOMSET 600 OHMS from the service interphone jack.
(2) Make sure that the work area is clean and clear of tools and other items.
(3) Close access door 314AR (Ref. AMM TASK 52-41-23-410-801).
(4) Remove the access platform(s).

Subtask 26-22-00-865-063-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
121VU	APU/APU/CTL	2KD	L42
121VU	APU/ECB/SPLY	1KD	L41

Subtask 26-22-00-860-055-A

C. Put the aircraft back to its initial configuration.
(1) Remove the HEADSET 600 OHMS from the CAPT jack panel.
(2) De-energize the audio integrating system (Ref. AMM TASK 23-51-00-710-001).
(3) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002) or (Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.04.01 04:27:01 UTC