Operational Check of Integrated Drive Generator (IDG) Disconnect and Reconnect Function

TASK 24-21-00-710-805-A-01
Operational Check of Integrated Drive Generator (IDG) Disconnect and Reconnect Function

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.

ZONE: 435
ZONE: 445

1. Reason for the Job
Refer to the MPD TASK: 242100-23
OPERATIONAL CHECK OF INTEGRATED DRIVE GENERATOR (IDG) DISCONNECT AND RECONNECT FUNCTION.

NOTE: To do a check of the IDG disconnect system and the IDG reset system.

NOTE: This procedure is specially applicable for an IDG replacement. It is also applicable for an engine replacement.

2. Job Set-up Information
A. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
435	FAN AND ACCESSORY GEARBOX
445	FAN AND ACCESSORY GEARBOX
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL, 438AR
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR

B. Referenced Information

REFERENCE	DESIGNATION
TASK 24-21-51-000-806-A	Removal of the Integrated Drive Generator (IDG) - IDG 1(2)
TASK 24-21-51-400-806-A	Installation of the Integrated Drive Generator (IDG) - IDG 1(2)
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 31-60-00-860-001-A	EIS Start Procedure
TASK 31-60-00-860-002-A	EIS Stop Procedure
TASK 71-00-00-860-827-A	Start the Engine (Normal Automatic Start)
TASK 71-00-00-860-829-A	Engine Shutdown
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
IDG - Reset Ring

3. Job Set-up
Subtask 24-21-00-860-063-A

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits from the external power or from the APU (Ref. AMM TASK 24-41-00-861-002).
(2) Do the EIS start procedure (upper ECAM DU and lower ECAM DU only)
(Ref. AMM TASK 31-60-00-860-001).
(3) On the ECAM control panel, push the ELEC key.

On the lower ECAM DU, the ELEC page comes into view.

(4) Start engine 1(2) (Ref. AMM TASK 71-00-00-860-827).

Subtask 24-21-00-865-096-A

B. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
FOR FIN: 4000XU1 (IDGENG 1)
122VU	ELEC/GCU/1	2XU1	T26
122VU	ELEC/IDG1/DISC	1XT	T24
FOR FIN: 4000XU2 (IDGENG 2)
122VU	ELEC/GCU/2	2XU2	T27
122VU	ELEC/IDG2/DISC	2XT	T25

4. Procedure

CAUTION: DO NOT PUSH THE IDG DISCONNECT PUSHBUTTON SWITCH IF THE ENGINE SPEED IS LESS THAN IDLE SPEED. IF YOU DO, YOU WILL CAUSE DAMAGE TO THE JAW TEETH, AT ENGINE START.

CAUTION: DO NOT PUSH THE IDG DISCONNECT PUSHBUTTON SWITCH FOR MORE THAN 3 SECONDS. THERE MUST BE AT LEAST 60 SECONDS BETWEEN TWO OPERATIONS OF THE SWITCH. THIS IS TO PREVENT DAMAGE TO THE DISCONNECT SOLENOID WHICH WILL BECOME TOO HOT.

Subtask 24-21-00-720-065-A

A. Operational Test of the IDG Disconnect Function - Engine in Operation

NOTE: This test is for the system 1. For the other system(s), use the indications between the parentheses.

ACTION	RESULT
1.With engine 1(2) at idle speed, on ELEC control-panel 35VU: Lift the guard and push the IDG1(2) pushbutton switch.	On ELEC control-panel 35VU: The FAULT legend of the related GEN pushbutton switch comes on.
	On the lower ECAM DU, on the ELEC page: The load voltage of the related generator is zero. The frequency parameters of the related generator are amber crosses. The amber DISC indication comes into view below the IDG indication. The external power or the APU energizes the aircraft electrical circuits.
2.On ELEC control-panel 35VU: Release the GEN 1(2) pushbutton switch.	On ELEC control-panel 35VU: The FAULT legend of the related GEN pushbutton switch goes off. The OFF legend of the related GEN pushbutton switch comes on.
3.On ELEC control-panel 35VU: Lower the safety guard of the IDG1(2) pushbutton switch.

Subtask 24-21-00-720-066-A

B. Reset of the System
(1) Stop the engine (Ref. AMM TASK 71-00-00-860-829).

Subtask 24-21-00-010-135-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 24-21-00-720-067-A

D. Reset of the IDG 1(2) Disconnect System

CAUTION: MAKE SURE THE ENGINE IS STOPPED BEFORE YOU PULL THE DISCONNECT RESET RING. IF NOT YOU WILL CAUSE DAMAGE TO THE JAW TEETH.

CAUTION: MAKE SURE THAT THERE IS CORRECT RESET OF THE IDG DISCONNECT MECHANISM. IF THE RESET IS NOT CORRECT, YOU MUST REMOVE AND REPLACE THE IDG BEFORE THE NEXT FLIGHT.

(1) Slowly pull out the disconnect/reset ring (1) to the maximum limit of travel. Monitor the manual force that is necessary (you must not use too much force). The disconnect mechanism must move freely without hard points.

NOTE: The disconnect solenoid will make a click that you can feel in the disconnect/reset ring when the reset ring comes near the maximum travel limit.

(2) Let the disconnect/reset ring (1) go slowly back to the initial position.
(3) Again, slowly pull out the disconnect reset ring (1) to the full limit of travel.
Monitor the manual force that is necessary. If the reset of the disconnect mechanism is correct, this force will be much less than in Step (1). Also, there will be no indication of the reset of the disconnect mechanism.

NOTE: If you do not get a correct reset of the IDG 1(2), disconnect the mechanism after you obeyed the instructions given in Steps (1) thru (3), replace the IDG 1(2) (Ref. AMM TASK 24-21-51-000-806) and (Ref. AMM TASK 24-21-51-400-806).

NOTE: If IDG 1(2) was disconnected, the DISC indication on the ELEC page of the lower ECAM DU will go out of view at the next engine start.

NOTE: If you start the engine after the test, you must do a GCU 1(2) reset. To do this, release, then push the GEN 1(2) pushbutton switch.

5. Close-up
Subtask 24-21-00-410-131-A

A. Put the aircraft back to its initial configuration.
(1) Make sure that the work area is clean and clear of tools and other items.
(2) 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
(3) Remove the WARNING NOTICE(S).

Subtask 24-21-00-862-076-A

B. Put the aircraft back to its initial configuration.
(1) On the ELEC control-panel 35VU, push the GEN 1(2) pushbutton switch (the FAULT legend comes on).
(2) At the next engine start, make sure that:

The related electrical generation system operates correctly.
The amber DISC indication goes out of view.
The OFF legend of the IDG 1(2) pushbutton switch goes off.

(3) Do the EIS stop procedure
(Ref. AMM TASK 31-60-00-860-002).
(4) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.03.31 23:20:14 UTC