Installation of the AC Current Transformer

TASK 24-23-17-400-001-A
Installation of the AC Current Transformer

WARNING: MAKE SURE THAT NO AC OR DC POWER IS CONNECTED TO THE AIRCRAFT ELECTRICAL CIRCUITS. THERE IS A RISK OF ELECTROCUTION IF THE AC OR DC POWER STAYS CONNECTED.

FIN: 42XS

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 18M (59 FT) - ADJUSTABLE
No specific	AR	TIE WRAP
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 0.19 and 0.17 m.daN (16.81 and 15.04 lbf.in )
No specific	Torque wrench: range to between 1.35 and 1.25 m.daN (119.47 and 110.62 lbf.in )

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
121AL

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-41-00-740-002-B	Operational Check of the GAPCU via the CFDS
TASK 24-41-00-740-004-A	Operational Check of the GPCU via the CFDS
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 25-11-41-000-001-A	Removal of the Third Occupant Seat
TASK 25-11-41-400-001-A	Installation of the Third Occupant Seat
AC Current Transformer - Block Diagram ** ON A/C NOT FOR ALL
AC Current Transformer ** ON A/C NOT FOR ALL
AC Current Transformer - Block Diagram ** ON A/C NOT FOR ALL
AC Current Transformer ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 24-23-17-010-051-A

A. Get access
(1) Make sure that the Third Occupant seat is removed (Ref. AMM TASK 25-11-41-000-001).
(2) On the rear panel 120VU, make sure that the panel which gives access to the AC power center 123VU is open.
(3) Make sure that the ACCESS PLATFORM 18M (59 FT) - ADJUSTABLE is in position at the access door 121AL.
(4) Make sure that the access door 121AL is open.

Subtask 24-23-17-860-050-A

B. Aircraft Maintenance Configuration
(1) Make sure that the external power connector is not connected to the aircraft external power receptacle.
(2) Make sure that the WARNING NOTICE(S) is (are) in position on the access door 121AL to tell persons not to connect the external power connector to the aircraft external power receptacle.
(3) In the cockpit, on the ELEC panel 35VU, make sure that these pushbutton switches are released:

BAT 1, BAT 2,
APU GEN,
GEN 1, GEN 2,
EXT PWR.

(4) In the cockpit, make sure that the WARNING NOTICE(S) is (are) in position to tell persons not to operate the pushbutton switches on these overhead panels:

21VU (EMER ELEC PWR section),
25VU (APU section),
35VU (ELEC).

4. Procedure
Subtask 24-23-17-420-050-A ** ON A/C NOT FOR ALL

A. Installation of the AC Current Transformer

AC Current Transformer - Block Diagram ** ON A/C NOT FOR ALL

AC Current Transformer ** ON A/C NOT FOR ALL

(1) Put the cables (6), (7) and (10) through the current transformer (1).

NOTE: Make sure that the location of the cables agrees with that you recorded at the removal.

(2) Move the current transformer (1) along the cables.
(3) Install the washers (2) and the screws (3) on the current transformer (1) and tighten them.
(4) Remove the CAP-BLANKING from each electrical connector and receptacle.
(5) Make sure that all the electrical connections are clean and in the correct condition.
(6) Connect the electrical connector (4) to the current transformer (1).
(7) Install new TIE WRAP.
(8) Install the cables (6) and (7), the washers (8) and the nuts (9) on the studs of the contactor (5) and tighten them.
(9) Install the cables (10), the washers (11) and the screws (12) on the studs of the contactor (5) and tighten them.

Subtask 24-23-17-420-050-B ** ON A/C NOT FOR ALL

A. Installation of the AC Current Transformer

AC Current Transformer - Block Diagram ** ON A/C NOT FOR ALL

AC Current Transformer ** ON A/C NOT FOR ALL

(1) Put the disconnected cables (6), (7) and (10) through the current transformer (1).

NOTE: Make sure that the location of the cables agrees with that you recorded at the removal.

(2) Move the current transformer (1) along the cables.
(3) Install the washers (2) and the screws (3) on the current transformer (1) and tighten them.
(4) Remove the blanking caps from the electrical connector (4) and the electrical receptacle.
(5) Make sure that all the electrical connections are clean and in the correct condition.
(6) Connect the electrical connector (4) to the current transformer (1).
(7) Install new TIE WRAP.
(8) Connect the cables (6) and (7), to the studs of the module 29XN.
(9) Install the washers (8) and the nuts (9) on the studs of the module 29XN.
(10) TORQUE the nuts (9) to between 1.35 and 1.25 m.daN (119.47 and 110.62 lbf.in )

.
(11) Connect the cables (10) to the studs of the module 29XN.
(12) Install the washers (11) and the screws (12) on the studs of the module 29XN.
(13) TORQUE the screws (12) to between 0.19 and 0.17 m.daN (16.81 and 15.04 lbf.in )

Subtask 24-23-17-860-051-A

B. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits from the APU (Ref. AMM TASK 24-41-00-861-002).

Subtask 24-23-17-865-050-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
122VU	ELEC/GALLEY/CNTOR	7MC	S28
122VU	ELEC/GALY & CAB/CTL	1XA	S26
** ON A/C NOT FOR ALL
123VU	AFT GALLEY/FEEDER A	3MC	AF04
** ON A/C ALL
123VU	FWD GALLEY/FEEDER F	16MC	AC10
123VU	AFT GALLEY/FEEDER E	14MC	AF09
** ON A/C NOT FOR ALL
123VU	AFT GALLEY/FEEDER B	12MC	AD09
123VU	FWD GALLEY/FEEDER D	2MC	AD04
123VU	FWD GALLEY/FEEDER C	1MC	AE10
** ON A/C NOT FOR ALL
123VU	FWD GALLEY/FEEDER D	2MC	AE02

Subtask 24-23-17-710-050-B ** ON A/C NOT FOR ALL

D. Operational test
(1) Do this test:

ACTION	RESULT
1.On the ECAM control panel: Push the ELEC key to get the ELEC page	On the lower ECAM display unit: The ELEC page comes into view.
2.On the ELEC panel 35VU: Push the GALY & CAB pushbutton switch.	On the panel 35VU: The OFF legend of the GALY & CAB pushbutton switch goes off.
3.In the FWD and/or AFT galleys: Energize all the items of equipment.	On the lower ECAM display unit: Make sure that the electrical parameters (load, voltage and frequency) of the APU GEN are correct.
4.On the MCDU: Do the operational check of the GPCU with the CFDS (Ref. AMM TASK 24-41-00-740-004).	On the MCDU, on the AC GEN page: The TEST OK message comes into view (after some seconds).

Subtask 24-23-17-710-050-C ** ON A/C NOT FOR ALL

D. Operational test
(1) Do this test:

ACTION	RESULT
1.On the ECAM control panel: push the ELEC key to get the ELEC page	On the lower ECAM display unit: the ELEC page comes into view.
2.On the ELEC panel 35VU: push the GALY & CAB pushbutton switch.	On the panel 35VU: the OFF legend of the GALY & CAB pushbutton switch goes off.
3.In the FWD and/or AFT galleys: energize all the items of equipment.	On the lower ECAM display unit: make sure that the electrical parameters (load, voltage and frequency) of the APU GEN are correct.
4.On the MCDU: do the operational test of the Ground And Auxilary Power Control Unit (GAPCU) (Ref. AMM TASK 24-41-00-740-002).	On the MCDU, on the AC GEN page: the TEST OK indication comes into view (after some seconds).

Subtask 24-23-17-860-052-A

E. Aircraft Maintenance Configuration
(1) De-energize the aircraft electrical circuits supplied from the APU (Ref. AMM TASK 24-41-00-862-002).

Subtask 24-23-17-410-050-A

F. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) On the rear panel 120VU, close the panel which gives access to the AC power center 123VU.
(3) Install the Third Occupant seat (Ref. AMM TASK 25-11-41-400-001).
(4) Remove the WARNING NOTICE(S).
(5) Close the access door 121AL.
(6) Remove the access platform(s).

[Rev.10 from 2021] 2026.03.31 23:22:25 UTC