Removal of the Thermocouple (APS 3200)

TASK 49-72-15-000-001-A
Removal of the Thermocouple (APS 3200)

WARNING: DO NOT TOUCH THE APU UNTIL IT IS SUFFICIENTLY COOL TO PREVENT BURNS WHEN YOU DO THE MAINTENANCE TASK(S).

1. Reason for the Job
Self explanatory
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	CAP - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
315AL, 316AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 29-00-00-864-001-A	Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action
TASK 52-41-00-010-001-A	Open the APU Doors for Access
Thermocouple

3. Job Set-up
Subtask 49-72-15-860-050-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) On the panel 25VU, make sure that the APU MASTER SW pushbutton switch is off.
(2) Put a warning notice in the cockpit to tell persons not to start the APU.
(3) Make sure that the hydraulic systems are depressurized
(Ref. AMM TASK 29-00-00-864-001).

Subtask 49-72-15-865-053-A ** ON A/C NOT FOR ALL

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	APU/APU/CTL	2KD	L42
121VU	APU/ECB/SPLY	1KD	L41

Subtask 49-72-15-010-052-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Put the ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE in position below the APU access doors 315AL and 316AR.
(2) Open the APU access doors 315AL 316AR (Ref. AMM TASK 52-41-00-010-001).

4. Procedure
Subtask 49-72-15-020-051-A ** ON A/C NOT FOR ALL

A. Removal of the Thermocouple

NOTE: There are two thermocouples. The procedure is the same for each of the thermocouples.
Long thermocouple TC1 P30 (1) is installed on the RH side (FD) of the APU and short thermocouple TC2 P31 (2) is installed on the LH side (FD) of the APU.

(1) Disconnect long thermocouple TC1 P30 (1) or short thermocouple TC2 P31 (2) from the mount bracket.
(2) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.
(3) Remove the bolts (4) to release the clamps (5) and (6) and remove the cables of the thermocouples from the clamp (5).
(4) Remove the bolt (3) and the short thermocouple TC2 P31 (2) or the long thermocouple TC1 P30 (1).

[Rev.10 from 2021] 2026.04.01 12:42:50 UTC