Electrical Test of the Turbine Rear Frame Vibration Sensor [CFMB]

TASK 77-31-30-760-001-A
Electrical Test of the Turbine Rear Frame Vibration Sensor

FIN: 1000EM1 ** ON A/C NOT FOR ALL
FIN: 1000EM2 ** ON A/C NOT FOR ALL

1. Reason for the Job
To make sure of the serviceability of the Turbine Rear Frame (TRF) vibration sensor before fan trim balance or vibration check operation.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	ACCESS PLATFORM 1M(3 FT)
No specific	AR	MEGOHMMETER 100 MOHMS
No specific	AR	PLIERS - CONNECTOR, JAW, SOFT
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [1000EM1] (ENGINE-1)
437AL, 438AR, 451AL
FOR [1000EM2] (ENGINE-2)
447AL, 448AR, 461AL

C. Referenced Information

REFERENCE	DESIGNATION
TASK 71-13-00-010-040-B	Opening of the Fan Cowl Doors
TASK 71-13-00-410-040-B	Closing of the Fan Cowl Doors
TASK 77-31-30-000-002-A	Removal of the Turbine Rear Frame Vibration Sensor
TASK 77-31-30-210-002-A	Visual Inspection of the TRF Vibration Sensor
TASK 77-31-30-400-002-A	Installation of the Turbine Rear Frame Vibration Sensor
TASK 78-30-00-081-041-B	Make the Thrust Reverser Serviceable after Maintenance
TASK 78-30-00-481-041-B	Make the Thrust Reverser Unserviceable for Maintenance
TASK 78-36-00-010-040-B	Opening of the Thrust Reverser Doors
TASK 78-36-00-410-040-B	Closing of the Thrust Reverser Doors
Check of the TRF Vibration Sensor

3. Job Set-up
Subtask 77-31-30-941-055-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) On the center pedestal, on the ENG panel 115VU:
(a) Put a WARNING NOTICE(S) to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than 5 minutes before you do this procedure.
(3) On the overhead maintenance panel 50VU:
(a) Make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) to tell persons not to energize the FADEC 1(2).

Subtask 77-31-30-010-061-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-040):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Put the ACCESS PLATFORM 1M(3 FT) in position.

Subtask 77-31-30-040-054-A ** ON A/C NOT FOR ALL

C. Make the thrust reverser unserviceable (Ref. AMM TASK 78-30-00-481-041).

Subtask 77-31-30-010-062-A ** ON A/C NOT FOR ALL

D. Open the left thrust reverser door (Ref. AMM TASK 78-36-00-010-040):
(1) FOR [1000EM1] (ENGINE-1)
451AL
(2) FOR [1000EM2] (ENGINE-2)
461AL

4. Procedure
Subtask 77-31-30-760-050-A ** ON A/C NOT FOR ALL

A. Electrical Test of the TRF Vibration Sensor

NOTE: If the TRF vibration sensor is not serviceable at the end of this test, replace the TRF vibration sensor per (Ref. AMM TASK 77-31-30-000-002) and (Ref. AMM TASK 77-31-30-400-002).

(1) Disconnect the EVMU harness from the TRF vibration sensor connector at one o'clock. Use PLIERS - CONNECTOR, JAW, SOFT only if necessary.
(2) Visually inspect the TRF vibration sensor (Ref. AMM TASK 77-31-30-210-002).
(3) Measure the insulation resistance with a MEGOHMMETER 100 MOHMS set to the 50 volts DC scale between:

pins 1 and 2
pins 1 and 3
pins 2 and 3
pin 2 and connector body
pin 3 and connector body.
The insulation resistance must be higher than 20 megohms.

(4) Make sure that the connector and the receptacle are clean and clear of unwanted material.
(5) Connect the EVMU harness to the TRF vibration sensor connector. Fully tighten by hand. Use PLIERS - CONNECTOR, JAW, SOFT only if necessary.
(6) Make sure that the aircraft harness connector is fully engaged and does not move.

5. Close-up
Subtask 77-31-30-410-059-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the left thrust reverser door (Ref. AMM TASK 78-36-00-410-040):
(a) FOR [1000EM1] (ENGINE-1)
451AL
(b) FOR [1000EM2] (ENGINE-2)
461AL
(3) Remove the access platform(s).

Subtask 77-31-30-440-053-A ** ON A/C NOT FOR ALL

B. Make the thrust reverser serviceable (Ref. AMM TASK 78-30-00-081-041).

Subtask 77-31-30-410-060-A ** ON A/C NOT FOR ALL

C. Close Access
(1) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-040):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.02 06:37:44 UTC