Deactivation of the CPC1

TASK 21-31-00-040-007-A
Deactivation of the CPC1

Task Summary

Access	Test	Specific Tools	Mhr	E/T	Nb Men
NO	NO	NO	0.5	0.5	1

1. Reason for the Job
MMEL 21-31-01A
AUTOMATIC CABIN PRESSURE CONROL SYSTEM (CPC, OUTFLOW VALVE AUTO CHANNEL) (FAA ONLY)
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 34-10-00-860-002-A	ADIRS Start Procedure

3. Job Set-up
Subtask 21-31-00-861-069-A

A. Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).

Subtask 21-31-00-865-076-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	AIR COND/CAB/PRESS/CTL1	1HL	D09
** ON A/C NOT FOR ALL
122VU	RPCU	4HL	X23

Subtask 21-31-00-860-073-A

C. Aircraft Maintenance Configuration
(1) Do the EIS start procedure (upper ECAM DU and lower ECAM DU only)
(Ref. AMM TASK 31-60-00-860-001).
(2) On the ECAM control panel do the steps necessary to get the CAB PRESS page to show on the lower ECAM display unit.
(3) On the AIR COND panel 30VU make sure that:

the PACK 1 and the PACK 2 pushbutton switches are in the off position (the OFF legends are on) and,
the RAM AIR pushbutton switch is in the off position (the ON legend is off).

(4) Do the ADIRS start procedure (Ref. AMM TASK 34-10-00-860-002).

4. Procedure
Subtask 21-31-00-710-069-A

WARNING: MAKE SURE THAT THE TRAVEL RANGES OF THE OUTFLOW VALVES ARE CLEAR. MOVEMENT OF THE OUTFLOW VALVES CAN CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT.

A. Verification Test of the Pressure Control and Monitoring Indications

ACTION	RESULT
1.On the overhead panel 25VU push the MODE SEL pushbutton switch to MAN.	On the lower ECAM display make sure that: the differential pressure, the cabin vertical speed, the cabin altitude indications and the outflow valve position show.
2.On the overhead panel 25VU put the MAN V/S CTL switch to the DN position.	On the lower ECAM display make sure that: the outflow valve position indicator moves in a downwards direction.
3.On the overhead panel 25VU put the MAN V/S CTL switch to the UP position.	On the lower ECAM display make sure that: the outflow valve position indicator moves in an upwards direction.
4.On the overhead panel 25VU push the MODE SEL pushbutton switch to AUTO.	On the lower ECAM display make sure that the outflow valve position indicator moves to the open position.
5.On the ECAM status page make sure that no FCU messages are shown.

5. Close-up
Subtask 21-31-00-865-079-A

A. 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
122VU	RPCU	4HL	X23

Subtask 21-31-00-862-065-A

B. Do the EIS stop procedure (Ref. AMM TASK 31-60-00-860-002).
(1) Put a temporary placard in the cockpit that tells persons that the automatic cabin pressure control system 1 is not in operation.
(2) Make an entry in the aircraft technical log book to tell the crew that the cabin pressure control system 1 is not in operation.
(3) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.04.02 06:11:13 UTC