Installation of the AC Current Transformers

TASK 24-22-17-400-001-A
Installation of the AC Current Transformers

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.

ZONE: 131
ZONE: 133
ZONE: 212
FIN: 42XU1 ** ON A/C NOT FOR ALL
FIN: 42XU2 ** ON A/C NOT FOR ALL
FIN: 42XU3 ** ON A/C NOT FOR ALL
FIN: 42XU4 ** 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	1	ACCESS PLATFORM 1M (3 FT)-ADJUSTABLE
No specific	AR	WARNING NOTICE(S)
FOR [42XU1] (CT-AC, 1)
No specific	Torque wrench: range to between 0.70 and 0.52 m.daN (61.95 and 46.02 lbf.in )
FOR [42XU1] (CT-AC, 1)
FOR [42XU2] (CT-AC, 2)
FOR [42XU3] (CT-AC, 1)
FOR [42XU4] (CT-AC, 2)
No specific	AR	WARNING NOTICE(S)
FOR [42XU2] (CT-AC, 2)
No specific	Torque wrench: range to between 0.70 and 0.52 m.daN (61.95 and 46.02 lbf.in )
FOR [42XU3] (CT-AC, 1)
No specific	AR	TIE WRAP
No specific	Torque wrench: range to between 0.70 and 0.52 m.daN (61.95 and 46.02 lbf.in )
No specific	Torque wrench: range to between 1.1 and 0.90 m.daN (97.35 and 79.65 lbf.in )
FOR [42XU4] (CT-AC, 2)
No specific	AR	TIE WRAP
No specific	Torque wrench: range to between 0.70 and 0.52 m.daN (61.95 and 46.02 lbf.in )
No specific	Torque wrench: range to between 1.1 and 0.90 m.daN (97.35 and 79.65 lbf.in )

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
131	FORWARD CARGO COMPARTMENT
133	BAY UNDER FWD CAR COMPT FLOOR
212	COCKPIT
121AL
FOR [42XU1] (CT-AC, 1)
FOR [42XU2] (CT-AC, 2)
FOR [42XU3] (CT-AC, 1)
FOR [42XU4] (CT-AC, 2)
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 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 (42XU1, 42XU2) ** ON A/C NOT FOR ALL
AC Current Transformer (42XU1, 42XU2) ** ON A/C NOT FOR ALL
AC Current Transformer (42XU3, 42XU4) ** ON A/C NOT FOR ALL
AC Current Transformer (42XU3, 42XU4) ** ON A/C NOT FOR ALL
FOR [42XU1] (CT-AC, 1)
TASK 24-22-55-400-002-A	Installation of the Contactors
TASK 24-23-55-400-001-A	Installation of the APU GLC
FOR [42XU1] (CT-AC, 1)
FOR [42XU2] (CT-AC, 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)
FOR [42XU1] (CT-AC, 1)
FOR [42XU2] (CT-AC, 2)
FOR [42XU3] (CT-AC, 1)
FOR [42XU4] (CT-AC, 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)
FOR [42XU2] (CT-AC, 2)
TASK 24-22-55-400-002-A	Installation of the Contactors
TASK 24-23-55-400-001-A	Installation of the APU GLC
FOR [42XU3] (CT-AC, 1)
TASK 21-26-00-710-002-A	Operational Check of Override Function (BLOWER and EXTRACT)
TASK 24-22-55-400-002-A	Installation of the Contactors
TASK 24-24-00-710-001-A	Operational Check of Emergency Generating System
TASK 24-26-00-710-002-A	Operational Check of the Manual and Automatic Galley and Bus Shedding
TASK 24-32-00-710-001-A	Operational Test of the DC Generation Switching
TASK 28-21-00-710-001-A	Operational Test of the Wing-Tank Fuel Control
TASK 29-12-00-710-001-A	Functional Check of Blue Electrical Pump Pressure by Reading ECAM Indication
TASK 29-31-00-710-001-A	Functional Check of Reservoir Low Level Warning
TASK 30-31-00-710-001-A	Operational Test of the Probe Ice Protection
TASK 30-42-00-710-001-A	Operational Test of the Windshield Anti-Icing and Defogging
TASK 33-25-00-710-001-A	Operational Test of the Passenger Reading Light System
TASK 33-51-00-710-001-A	Operational Check of Emergency Power Supply Units by BITE-Check
FOR [42XU4] (CT-AC, 2)
TASK 21-26-00-710-002-A	Operational Check of Override Function (BLOWER and EXTRACT)
TASK 24-22-55-400-002-A	Installation of the Contactors
TASK 24-24-00-710-001-A	Operational Check of Emergency Generating System
TASK 24-26-00-710-002-A	Operational Check of the Manual and Automatic Galley and Bus Shedding
TASK 24-32-00-710-001-A	Operational Test of the DC Generation Switching
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 28-21-00-710-001-A	Operational Test of the Wing-Tank Fuel Control
TASK 30-31-00-710-001-A	Operational Test of the Probe Ice Protection
TASK 30-42-00-710-001-A	Operational Test of the Windshield Anti-Icing and Defogging
TASK 33-21-00-710-001-A	Operational Test of the General Illumination
TASK 33-25-00-710-001-A	Operational Test of the Passenger Reading Light System
TASK 34-11-00-710-001-A	Test of the Monitoring of the ADR/AOA 26VAC Power Supply

3. Job Set-up
Subtask 24-22-17-010-053-A ** ON A/C NOT FOR ALL

A. Get Access
(1) Make sure that the Third Occupant seat is removed (Ref. AMM TASK 25-11-41-000-001).
(2) On the left lower side of the rear panel 120VU, make sure that the access door (4) is removed.
(3) Make sure that the ACCESS PLATFORM 1M (3 FT)-ADJUSTABLE is in position at the access door 121AL.
(4) Make sure that the access door 121AL is open.

Subtask 24-22-17-860-050-A ** ON A/C NOT FOR ALL

B. Aircraft Maintenance Configuration
(1) Make sure that the external power connector is not connected to the aircraft EXT PWR receptacle.
(2) FOR [42XU1] (CT-AC, 1), [42XU2] (CT-AC, 2), [42XU3] (CT-AC, 1), [42XU4] (CT-AC, 2)
(a) 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 EXT PWR receptacle.
(3) In the cockpit, on the ELEC panel 35VU, make sure that these pushbutton switches are released:

BAT1, BAT2,
APU GEN,
GEN1, GEN2,
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 24-22-17-420-051-A ** ON A/C NOT FOR ALL

A. Installation of the AC Current Transformer

AC Current Transformer (42XU1, 42XU2) ** ON A/C NOT FOR ALL

(1) FOR [42XU1] (CT-AC, 1)
(a) Install the AC current transformer 1 (5) in correct position.
(b) Install the four washers (7) and screws (6) on the AC current transformer 1 (5) and tighten them.
(c) Remove the blanking cap from the electrical connector (8).
1 Make sure that the electrical connector (8) and electrical receptacle are clean and in the correct condition.
2 Connect the electrical connector (8) to the AC current transformer 1 (5).
(d) Connect the bars (3) to the contactor bases.
1 Install the six washers (2) and nuts (1) on the contactor bases and tighten them.
2 TORQUE the six nuts to between 0.70 and 0.52 m.daN (61.95 and 46.02 lbf.in )

.
(e) Install the BTC1 (Ref. AMM TASK 24-22-55-400-002) and the APU GLC (Ref. AMM TASK 24-23-55-400-001).
(2) FOR [42XU2] (CT-AC, 2)
(a) Install the AC current transformer 2 (5) in correct position.
(b) Install the four washers (7) and screws (6) on the AC current transformer 2 (5) and tighten them.
(c) Remove the blanking cap from the electrical connector (8).
1 Make sure that the electrical connector (8) and the electrical receptacle are clean and in the correct condition.
2 Connect the electrical connector (8) to the AC current transformer 2 (5).
(d) Connect the bars (3) to the contactor bases.
1 Install the six washers (2) and nuts (1) on the contactor bases and tighten them.
2 TORQUE the six nuts to between 0.70 and 0.52 m.daN (61.95 and 46.02 lbf.in )

.
(e) Install the BTC2 (Ref. AMM TASK 24-22-55-400-002) and the APU GLC (Ref. AMM TASK 24-23-55-400-001).

Subtask 24-22-17-420-052-A ** ON A/C NOT FOR ALL

B. Installation of the AC Current Transformer

AC Current Transformer (42XU3, 42XU4) ** ON A/C NOT FOR ALL

(1) FOR [42XU3] (CT-AC, 1)
(a) Put the disconnected cables through the AC current transformer 1 (5).

NOTE: Make sure that the location and the color of the cables of each bundle agree with those you recorded at the removal.

(b) Move the AC current transformer 1 (5) along the cable bundles.
(c) Install the two washers (6) and screws (7) on the AC current transformer 1 (5) and tighten them.
(d) Remove the blanking caps from the electrical connectors (8) and the electrical receptacle.
1 Make sure that the electrical connector (8) and the electrical receptacle are clean and in the correct condition.
2 Connect the electrical connector (8) to the AC current transformer 1 (5).
(e) Install new TIE WRAP.
(f) Connect the three electrical cables (3) to the studs of the contactor base.
1 Install the three washers (2) and nuts (1) on the studs of the contactor base and tighten them.
2 TORQUE the three nuts (1) to between 1.1 and 0.90 m.daN (97.35 and 79.65 lbf.in )

.
In the rear panel 120VU, connect the related cables to the pin 2 of the circuit breakers connected to the AC BUS 1 busbar 1XP.
(g) In the AC power center 123VU, connect the related cables to the pin 2 of the circuit breakers 11QA and 12QA.

NOTE: Make sure that the location and the color of the cables agree with those you recorded at the removal.

(h) Install the GLC1 (Ref. AMM TASK 24-22-55-400-002).
(2) FOR [42XU4] (CT-AC, 2)
(a) Put the disconnected cables through the AC current transformer 2 (5).

NOTE: Make sure that the location and the color of the cables of each bundle agree with those you recorded at the removal.

(b) Move the AC current transformer 2 (5) along the cable bundles.
(c) Install the two washers (6) and screws (7) on the AC current transformer 2 (5) and tighten them.
(d) Remove the blanking caps from the electrical connectors (8) and the electrical receptacle.
1 Make sure that the electrical connector (8) and the electrical receptacle are clean and in the correct condition.
2 Connect the electrical connector (8) to the AC current transformer 2 (5).
(e) Install new TIE WRAP.
(f) Connect the three electrical cables (3) to the studs of the contactor base.
1 Install the three washers (2) and nuts (1) on the studs of the contactor base and tighten them.
2 TORQUE the three nuts (1) to between 1.1 and 0.90 m.daN (97.35 and 79.65 lbf.in )

.
In the rear panel 120VU, connect the related cables to the pin 2 of the circuit breakers connected to the AC BUS 2 busbar 2XP.
(g) In the AC power center 123VU, connect the related cables to the pin 2 of the circuit breakers 11QA and 12QA.

NOTE: Make sure that the location and the color of the cables agree with those you recorded at the removal.

(h) Install the GLC2 (Ref. AMM TASK 24-22-55-400-002).

Subtask 24-22-17-420-051-B ** ON A/C NOT FOR ALL

C. Installation of the AC Current Transformer

AC Current Transformer (42XU1, 42XU2) ** ON A/C NOT FOR ALL

(1) FOR [42XU1] (CT-AC, 1)
(a) Install the AC current transformer 1 (5) in correct position.
(b) Install the four washers (7), screws (6), washers (8) and nuts (9) on the AC current transformer 1 (5) and tighten them.
(c) Remove the blanking caps from the electrical connector (10) and the electrical receptacle.
1 Make sure that the electrical connector (10) and the electrical receptacle are clean and in the correct condition.
2 Connect the electrical connector (10) to the AC current transformer 1 (5).
(d) Connect the bars (3) to the APU/EXT power-contactor module and the generator 1 contactor-module.
(e) Install the six washers (2) and screws (1) on the APU/EXT power-contactor module and the generator 1 contactor-module.
1 TORQUE the screws (1) to between 0.70 and 0.52 m.daN (61.95 and 46.02 lbf.in )

.
(f) Install the BTC1 (Ref. AMM TASK 24-22-55-400-002) and the APU GLC (Ref. AMM TASK 24-23-55-400-001).
(2) FOR [42XU2] (CT-AC, 2)
(a) Install the AC current transformer 2 (5) in correct position.
(b) Install the four washers (7), screws (6), washers (8) and nuts (9) on the AC current transformer 2 (5) and tighten them.
(c) Remove the blanking caps from the electrical connector (10) and the electrical receptacle.
1 Make sure that the electrical connector (10) and the electrical receptacle are clean and in the correct condition.
2 Connect the electrical connector (10) to the AC current transformer 2 (5).
(d) Connect the bars (3) to the APU/EXT power-contactor module and the generator 2 contactor-module.
(e) Install the six washers (2) and screws (1) on the APU/EXT power-contactor module and the generator 2 contactor-module.
1 TORQUE the screws (1) to between 0.70 and 0.52 m.daN (61.95 and 46.02 lbf.in )

.
(f) Install the BTC2 (Ref. AMM TASK 24-22-55-400-002) and the APU GLC (Ref. AMM TASK 24-23-55-400-001).

Subtask 24-22-17-420-052-B ** ON A/C NOT FOR ALL

D. Installation of the AC Current Transformer

AC Current Transformer (42XU3, 42XU4) ** ON A/C NOT FOR ALL

(1) FOR [42XU3] (CT-AC, 1)
(a) Put the disconnected cables through the AC current transformer 1 (1).

NOTE: Make sure that the location and the color of the cables of each bundle agree with those you recorded at the removal.

(b) Move the AC current transformer 1 (1) along the cable bundles.
(c) Install the two washers (2) and screws (3) on the AC current transformer 1 (1) and tighten them.
(d) Remove the blanking caps from the electrical connector (5) and the electrical receptacle.
1 Make sure that the electrical connector (5) and the electrical receptacle are clean and in the correct condition.
2 Connect the electrical connector (5) to the AC current transformer 1 (1).
(e) Install new TIE WRAP.
(f) Make sure that the three electrical cables (7) and (6) are clean and in the correct condition.
1 Connect the three electrical cables (7) and (6) to the generator 1 contactor-module.
2 Install the three washers (8) and screws (9) on the generator 1 contactor-module.
3 TORQUE the three screws (9) to between 0.70 and 0.52 m.daN (61.95 and 46.02 lbf.in )

.
In the rear panel 120VU, connect the related wires to pin 2 of the circuit breakers connected to the AC BUS 1 busbar 1XP.
(g) In the AC power center 123VU, connect the related wires to pin 2 of the circuit breakers 11QA and 12QA.

NOTE: Make sure that the location and the color of the cables agree with those you recorded at the removal.

(2) FOR [42XU4] (CT-AC, 2)
(a) Put the disconnected cables through the AC current transformer 2 (1).

NOTE: Make sure that the location and the color of the cables of each bundle agree with those you recorded at the removal.

(b) Move the AC current transformer 2 (1) along the cable bundles.
(c) Install the two washers (2) and screws (3) on the AC current transformer 2 (1) and tighten them.
(d) Remove the blanking caps from the electrical connector (5) and the electrical receptacle.
1 Make sure that the electrical connector (5) and the electrical receptacle are clean and in the correct condition.
2 Connect the electrical connector (5) to the AC current transformer 2 (1).
(e) Install new TIE WRAP.
(f) Make sure that the three electrical cables (7) and (6) are clean and in the correct condition.
1 Connect the three electrical cables (7) and (6) to the generator 2 contactor-module.
2 Install the three washers (8) and screws (9) on the generator 2 contactor-module.
3 TORQUE the three screws (9) to between 0.70 and 0.52 m.daN (61.95 and 46.02 lbf.in )

.
In the rear panel 120VU, connect the related wires to pin 2 of the circuit breakers connected to the AC BUS 2 busbar 2XP.
(g) In the AC power center 123VU, connect the related wires to pin 2 of the circuit breakers 11QA and 12QA.

NOTE: Make sure that the location and the color of the cables agree with those you recorded at the removal.

Subtask 24-22-17-860-054-A ** ON A/C NOT FOR ALL

E. Aircraft Maintenance Configuration
(1) FOR [42XU1] (CT-AC, 1), [42XU2] (CT-AC, 2)
Energize the aircraft electrical circuits from the external power (Ref. AMM TASK 24-41-00-861-002).

Subtask 24-22-17-860-057-B ** ON A/C NOT FOR ALL

F. Aircraft Maintenance Configuration
(1) FOR [42XU3] (CT-AC, 1)
Do these tests:

(2) Energize the aircraft electrical circuits from the external power (Ref. AMM TASK 24-41-00-861-002).

Subtask 24-22-17-860-058-B ** ON A/C NOT FOR ALL

G. Aircraft Maintenance Configuration
(1) FOR [42XU4] (CT-AC, 2)
(a) Do these tests:

(b) Energize the aircraft electrical circuits from the external power (Ref. AMM TASK 24-41-00-861-002).

Subtask 24-22-17-865-050-A ** ON A/C NOT FOR ALL

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

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

Subtask 24-22-17-710-050-B ** ON A/C NOT FOR ALL

I. 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 24-22-17-710-050-D ** ON A/C NOT FOR ALL

I. 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 GAPCU with the CFDS (Ref. AMM TASK 24-41-00-740-002).	On the MCDU, on the AC GEN page: The TEST OK message comes into view (after some seconds).

Subtask 24-22-17-860-056-A ** ON A/C NOT FOR ALL

J. Aircraft Maintenance Configuration
(1) FOR [42XU1] (CT-AC, 1), [42XU2] (CT-AC, 2), [42XU3] (CT-AC, 1), [42XU4] (CT-AC, 2)
De-energize the aircraft electrical circuits supplied from the external power (Ref. AMM TASK 24-41-00-862-002).

5. Close-up
Subtask 24-22-17-410-051-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) Remove the WARNING NOTICE(S).
(3) Install the access panel (4) on the rear panel 120VU.
(4) Install the third occupant seat (Ref. AMM TASK 25-11-41-400-001).
(5) Close the access door 121AL.
(6) Remove the access platform(s).

[Rev.10 from 2021] 2026.03.31 23:21:59 UTC