Installation of the Relay Box [IAE]

TASK 71-51-49-400-010-A
Installation of the Relay Box

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

ZONE: 400
FIN: 4100KS ** ON A/C NOT FOR ALL

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 1M(3 FT)
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 19.8 and 16.2 lbf.in (0.22 and 0.18 m.daN )
No specific	Torque wrench: range to between 23.1 and 18.9 lbf.in (0.26 and 0.21 m.daN )
No specific	Torque wrench: range to between 45 and 36 lbf.in (0.51 and 0.41 m.daN )

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.V01-002)	cleaning fluid
(Material No.V02-159)	lacing tape
(Material No.14SBA1)	Textile-Lint free Cotton -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
400	POWER PLANT, NACELLES AND PYLONS
FOR [1000EM1] (ENGINE-1)
437AL, 438AR
FOR [1000EM2] (ENGINE-2)
447AL, 448AR

D. Referenced Information

REFERENCE	DESIGNATION
TASK 70-23-11-911-013-A	General Torque Tightening Techniques
TASK 71-13-00-010-010-A	Opening of the Fan Cowls 437AL(447AL),438AR(448AR)
TASK 71-13-00-410-010-A	Closing of the Fan Cowls 437AL(447AL),438AR(448AR)
TASK 73-22-11-710-040-A	Operational Test of the P2/T2 Probe Heater
TASK 74-00-00-710-041-A	Operational Test of the Ignition System with the CFDS
TASK 74-00-00-710-041-A-01	Operational Test of the ignition System without the CFDS
Relay Box

3. Job Set-up
Subtask 71-51-49-860-050-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) On the center pedestal, on the ENG panel 115VU, make sure that a WARNING NOTICE(S) is in position to tell persons not to start the engine.
(2) On the overhead maintenance panel 50VU, make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off. Make sure that a WARNING NOTICE(S) is in position to tell persons not to energize the FADEC 1(2).
(3) Make sure that the ACCESS PLATFORM 1M(3 FT) is in position.

Subtask 71-51-49-010-051-A ** ON A/C NOT FOR ALL

B. Make sure that the fan cowls are open: (Ref. AMM TASK 71-13-00-010-010)
(1) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(2) FOR [1000EM2] (ENGINE-2)
447AL 448AR

4. Procedure
Subtask 71-51-49-630-050-A ** ON A/C NOT FOR ALL

A. Remove the applicable covers/caps/plugs from the electrical connectors and the electrical receptacles.

Subtask 71-51-49-110-050-A ** ON A/C NOT FOR ALL

B. Clean the replacement parts and their interfaces.
(1) Use a clean Textile-Lint free Cotton - (Material No.14SBA1) , made moist with the cleaning fluid (Material No.V01-002) and clean the replacement parts and their interfaces.
(2) Use a clean dry Textile-Lint free Cotton - (Material No.14SBA1) and remove the dirty cleaning fluid from the parts while they are wet.

Subtask 71-51-49-420-050-A ** ON A/C NOT FOR ALL

C. Installation of the Relay Box and the Bonding Strap:
(1) Install the relay box

Relay Box ** ON A/C NOT FOR ALL

(a) Install the relay box on the mounting bracket with the four bolts (1) and washers (2).
(b) TORQUE the bolts (1) to between 45 and 36 lbf.in (0.51 and 0.41 m.daN )

(Ref. AMM TASK 70-23-11-911-013).
(2) Install the bonding strap.
(a) Clean the bonding strap connector and its mating faces on the bracket with cleaning fluid (Material No.V01-002) .
(b) Attach the bonding strap to the bracket with the bolt (3), the two washers (5) and the nut (4).
(c) Do a resistance check between the bonding strap and the bracket. The resistance must not be more than 5 milli ohms.
(d) Do a resistance check between the bracket and flange FB. The resistance must not be more than 5 milli ohms.
(e) If the bonding strap resistance check is not satisfactory, do step (a) again. Make sure the bonding strap is not damaged and is installed correctly.

Subtask 71-51-49-420-051-A ** ON A/C NOT FOR ALL

D. Connect the electrical connectors.

Relay Box ** ON A/C NOT FOR ALL

(1) Remove the V06-086 ties which attach the electrical harness/connectors 4100KS-B, 4100KS-C and 4100KS-D to the primary harness.
(2) Connect each electrical connector to the relay box receptacle.
(3) TORQUE the connectors to between 19.8 and 16.2 lbf.in (0.22 and 0.18 m.daN )

(Ref. AMM TASK 70-23-11-911-013).
(4) Remove the V06-086 ties which attach the electrical connectors 4100KS-A and 4100KS-E to the primary harness and mounting bracket.
(5) Connect each electrical connector to the relay box receptacle.
(6) TORQUE the connectors to between 23.1 and 18.9 lbf.in (0.26 and 0.21 m.daN )

(Ref. AMM TASK 70-23-11-911-013).
(7) Attach the electrical harness together with lacing tape (Material No.V02-159) .

5. Close-up
Subtask 71-51-49-410-050-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 fan cowls (Ref. AMM TASK 71-13-00-410-010)
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR.
(3) Remove the access platform(s).
(4) Remove the WARNING NOTICE(S).

Subtask 71-51-49-710-050-A ** ON A/C NOT FOR ALL

B. Do an operational test of the ignition system with the CFDS (Ref. AMM TASK 74-00-00-710-041).

Subtask 71-51-49-710-051-A ** ON A/C NOT FOR ALL

C. Do an operational test of the P2/T2 probe heater (Ref. AMM TASK 73-22-11-710-040).

[Rev.10 from 2021] 2026.04.01 02:30:46 UTC