Installation of the Avionics Equipment Ventilation Computer (AEVC)

TASK 21-26-34-400-001-A
Installation of the Avionics Equipment Ventilation Computer (AEVC)

ZONE: 128
FIN: 10HQ

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	ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
128	REAR AVIONIC COMPARTMENT
824

C. Referenced Information

REFERENCE	DESIGNATION
TASK 21-26-00-710-001-A	Operational Check of the Avionics Equipment Ventilation-System via MCDU
TASK 21-26-00-710-001-A-01	Operational Check of the Avionics Equipment Ventilation (without the CFDS)
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 52-41-00-410-002-A	Close the Avionics Compartment Doors after Access
Avionics Equipment Ventilation Computer (AEVC) ** ON A/C NOT FOR ALL
Avionics Equipment Ventilation Computer (AEVC) ** ON A/C NOT FOR ALL
Avionics Equipment Ventilation Computer (AEVC) ** ON A/C NOT FOR ALL

3. Job Set-up

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.

Subtask 21-26-34-860-050-A

A. Aircraft Maintenance Configuration
(1) Make sure that the ground service network is energized
(Ref. AMM TASK 24-42-00-861-001).

Subtask 21-26-34-865-051-A

B. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	AIR COND/AVNCS VENT/CTL	6HQ	D06
49VU	AIR COND/AVNCS VENT/CTL	5HQ	D05
122VU	AIR COND/AVNCS/VENT/MONG	3HQ	Y17

Subtask 21-26-34-010-051-A

C. Get Access
(1) Make sure that the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE is in position at the access door 824.
(2) Make sure that the access door 824 is open.

4. Procedure
Subtask 21-26-34-420-050-A

A. Installation of the AEVC
(1) Clean the component interfaces and the adjacent area.
(2) Do an inspection of the component interfaces and the adjacent area.
(3) Remove the CAP-BLANKING from each electrical connector and receptacle.
(4) Make sure that all the electrical connections are clean and in the correct condition.
(5) Install the AEVC (1) on its rack (3).
(6) Push the AEVC (1) on its rack (3) to connect the electrical connector (2).
(7) Engage the nut (4) on the lug (5) and tighten.

Subtask 21-26-34-865-052-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
122VU	AIR COND/AVNCS/VENT/MONG	3HQ	Y17

Subtask 21-26-34-710-050-A

C. Do an operational test of the ventilation system of the avionics equipment (Ref. AMM TASK 21-26-00-710-001).

NOTE: As an alternative procedure, you can do this operational test without the CFDS.

5. Close-up
Subtask 21-26-34-410-050-A

A. 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 21-26-34-862-051-A

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

[Rev.10 from 2021] 2026.04.02 06:11:03 UTC