BITE Test of the APU Fire and Overheat Detection System

TASK 26-13-00-710-002-A
BITE Test of the APU Fire and Overheat Detection System

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. 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 31-32-00-860-005-A	Procedure to Get Access to the SYSTEM REPORT/TEST FIRE PROT Page

3. Job Set-up
Subtask 26-13-00-861-051-A

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

Subtask 26-13-00-865-053-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/APU/CTL	2KD	L42
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 26-13-00-710-053-A

A. BITE Test of the APU Fire and Overheat Detection System

NOTE: If you do the BITE test when the APU operates, the APU shuts down

(1) On one Multipurpose Control and Display Unit (MCDU) get the SYSTEM REPORT/TEST/FIRE PROT Page (Ref. AMM TASK 31-32-00-860-005).
(2) Do this test:

ACTION	RESULT
1.On the MCDU: Push the line key adjacent to the FDU APU indication.	On the MCDU: The FDU APU page comes into view.
2.On the MCDU: Push the line key adjacent to the TEST indication.	On the MCDU: On the FDU APU page the TEST WAIT message comes into view. After 90 seconds the TEST WAIT message goes out of view and this message comes into view: TEST OK
3.On the MCDU: Push the line key adjacent to the RETURN indication.	On the MCDU: The MCDU MENU page comes on.

5. Close-up
Subtask 26-13-00-869-054-A

A. Put the aircraft back to its initial configuration.
(1) On the MCDU set the BRT button to OFF.

Subtask 26-13-00-862-051-A

B. De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.03.31 23:43:37 UTC