Modification of the Ignition 1 and 2 Systems Routing to Return to the Normal Configuration [CFML]

TASK 74-31-00-440-804-A
Modification of the Ignition 1 and 2 Systems Routing to Return to the Normal Configuration

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE PARTS AFTER THE ENGINE SHUTDOWN. USE APPLICABLE THERMAL GLOVES. THE ENGINE PARTS CAN STAY HOT FOR ONE HOUR AFTER SHUTDOWN AND CAN BURN YOU.

WARNING: BEFORE YOU START WORK ON THE IGNITION SYSTEM, MAKE SURE THAT THE IGNITION EXCITERS ARE DE-ENERGIZED FOR A MINIMUM OF FIVE MINUTES. ALSO DO NOT TOUCH THE ELECTRICAL CONTACTS. THE IGNITION SYSTEM VOLTAGE IS VERY HIGH, AND THE IGNITION EXCITERS CAN HAVE AN ELECTRICAL CHARGE EVEN WHEN NOT ENERGIZED. IF YOU DO NOT OBEY THESE PRECAUTIONS, INJURY CAN OCCUR.

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

ZONE: 400

1. Reason for the Job
MMEL 74-31-01A
IGNITION SYSTEM A (FAA ONLY)
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	PLIERS - NOSE, SOFT, LONG
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 59 and 51 lbf.in (0.67 and 0.58 m.daN )

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.CP2442)	engine oil

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
400	POWER PLANT, NACELLES AND PYLONS
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL, 438AR, 452AR
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR, 462AR

D. Referenced Information

REFERENCE	DESIGNATION
TASK 71-13-00-010-803-A	Opening of the Fan Cowl Doors
TASK 71-13-00-410-803-A	Closing of the Fan Cowl Doors
TASK 74-00-00-710-803-A	Ignition Test (Menu Mode)
TASK 78-30-00-040-809-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-30-00-440-809-A	Reactivation of the Thrust Reverser System after Ground Maintenance
TASK 78-36-00-010-806-A	Opening of the Thrust Reverser Cowl Doors
TASK 78-36-00-410-806-A	Closing of the Thrust Reverser Cowl Doors
Ignition Exciter

3. Job Set-up
Subtask 74-31-00-941-058-A

A. Safety Precautions
(1) On the center pedestal, on ENG panel 115VU:
(a) Make sure that the ENG/MODE selector switch is in the NORM position.
(b) Make sure that the ENG/MASTER 1(2) control switch was in the OFF position not less than five minutes before you do this procedure.
(c) Put WARNING NOTICE(S) in position to tell persons not to operate:

The ENG/MODE selector switch
The ENG/MASTER 1(2) control switch.

(2) On the ENG section of maintenance panel 50VU:
(a) Make sure that the ON legend of the FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) in position to tell persons not to energize FADEC 1(2).

Subtask 74-31-00-865-066-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	ENGINE/1 AND 2/IGN/SYS A	1JH	A03
FOR FIN: 4020KM1 (POWER PLANTDEMOUNTABLE, ENGINE 1)
121VU	ENGINE/IGN/ENG1/SYS B	3JH1	P41
FOR FIN: 4020KM2 (POWER PLANTDEMOUNTABLE, ENGINE 2)
121VU	ENGINE/IGN/ENG2/SYS B	3JH2	P42

Subtask 74-31-00-010-058-A

C. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR

Subtask 74-31-00-040-056-A

D. Deactivation of the Thrust Reverser System for Maintenance

WARNING: YOU MUST DEACTIVATE THE THRUST REVERSER BEFORE YOU DO WORK ON OR AROUND IT. IF YOU DO NOT, THE THRUST REVERSER CAN OPERATE ACCIDENTALLY AND CAUSE AN INJURY AND/OR DAMAGE.

(1) Do the deactivation of the thrust reverser system for ground maintenance (Ref. AMM TASK 78-30-00-040-809).

Subtask 74-31-00-010-059-A

E. Get Access
(1) Open the right thrust-reverser cowl-door (Ref. AMM TASK 78-36-00-010-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
462AR

4. Procedure
Subtask 74-31-00-020-055-A

A. Removal of the Exciter Box Shroud Lid
(1) Get access to the ignition exciter located at 6 o'clock position in the core compartment.
(2) Remove the four bolts (5) that attach the exciter box shroud lid (4) to the exciter box shroud (3).
(3) Remove the exciter box shroud lid (4) from the exciter box shroud (3).

Subtask 74-31-00-040-057-A

B. Swap of the Two Ignition-Exciter Electrical Connectors to Return to the Normal Configuration

CAUTION: DO NOT TWIST OR BEND THE ELECTRICAL HARNESS WHEN YOU DISCONNECT/CONNECT THE ELECTRICAL CONNECTOR. IF YOU DO, YOU CAN CAUSE DAMAGE TO THE HARNESS AND THUS CAUSE ELECTRICAL CIRCUIT DEFECTS.

(1) Disconnect electrical connector (7) P24B (red harness) from ignition exciter 2 (2) (upper ignition exciter). If necessary, use the PLIERS - NOSE, SOFT, LONG.
(2) Disconnect electrical connector (6) P24A (blue harness) from ignition exciter 1 (1) (lower ignition exciter). If necessary, use the PLIERS - NOSE, SOFT, LONG.
(3) Swap and connect the electrical connectors to the opposite ignition exciters.
(4) Tighten the coupling ring. If necessary, use the PLIERS - NOSE, SOFT, LONG.

NOTE: Normal configuration:

Upper ignition exciter 2 (2) with P24A connector (blue harness).
Lower ignition exciter 1 (1) with P24B connector (red harness).

Subtask 74-31-00-420-051-A

C. Installation of the Exciter-Box Shroud Lid
(1) Apply an engine oil (Material No.CP2442) to the threads and the friction surfaces of the four bolts (5).
(2) Put the exciter-box shroud lid (4) in position.
(3) Install the four bolts (5) that attach the exciter-box shroud lid (4) to the exciter box shroud (3).
(4) TORQUE the four bolts (5) to between 59 and 51 lbf.in (0.67 and 0.58 m.daN )

Subtask 74-31-00-865-068-A

D. 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	ENGINE/1 AND 2/IGN/SYS A	1JH	A03
FOR FIN: 4020KM1 (POWER PLANTDEMOUNTABLE, ENGINE 1)
121VU	ENGINE/IGN/ENG1/SYS B	3JH1	P41
FOR FIN: 4020KM2 (POWER PLANTDEMOUNTABLE, ENGINE 2)
121VU	ENGINE/IGN/ENG2/SYS B	3JH2	P42

Subtask 74-31-00-710-058-A

E. Do an ignition test (menu mode) on FADEC channel A and channel B (Ref. AMM TASK 74-00-00-710-803).

5. Close-up
Subtask 74-31-00-410-058-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the right thrust-reverser cowl-door (Ref. AMM TASK 78-36-00-410-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
462AR

Subtask 74-31-00-440-058-A

B. Do the reactivation of the thrust reverser system after ground maintenance (Ref. AMM TASK 78-30-00-440-809).

Subtask 74-31-00-410-059-A

C. Close Access
(1) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR
(2) Remove the WARNING NOTICE(S).
(3) Make an entry in the logbook to record that the ignition 1 and 2 systems routing was returned to the normal configuration.

[Rev.10 from 2021] 2026.04.01 03:09:04 UTC