Installation of the Static Inverter Contactor

TASK 24-28-55-400-001-A
Installation of the Static Inverter Contactor

CAUTION: MAKE SURE THAT NO AC OR DC POWER IS CONNECTED TO THE AIRCRAFT ELECTRICAL CIRCUITS. THERE IS A RISK OF DAMAGE TO EQUIPMENT DURING ITS REMOVAL/ INSTALLATION IF THE AC OR DC POWER STAYS CONNECTED.

ZONE: 126
FIN: 2XB

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 2M (6 FT) - ADJUSTABLE
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 15.5808 and 13.0128 lbf.in (0.18 and 0.15 m.daN )

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
126	LATERAL AVIONIC COMPARTMENT
822

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-28-00-710-001-A	Operational Test of the Static Inverter when the Aircraft Electrical Circuits are Energized from the External Power
TASK 24-28-00-710-001-A-01	Operational Test of the Static Inverter when the Aircraft Electrical Circuits are Energized from the APU
Static Inverter Contactor

3. Job Set-up
Subtask 24-28-55-860-050-B

A. Aircraft Maintenance Configuration
(1) In the cockpit, on the overhead panel 35VU, make sure these pushbutton switches are released:

BAT 1, BAT 2,
GEN 1, GEN 2,
EXT A.

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

35VU (ELEC),
21VU (EMER ELEC PWR).

(3) Make sure that the external power connector is not connected to the aircraft receptable EXT PWR A.
(4) On the access door 121AL, make sure that the WARNING NOTICE(S) is in position to tell persons not to connect the external power connector.
(5) Make sure that the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE is in position at the access door 822.
(6) Make sure that access door 822 is open.
(7) In the avionics compartment, make sure that the access door from the panel 105VU is open.
(8) Make sure that the batteries are disconnected.

Subtask 24-28-55-865-051-A

B. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
105VU	ELEC/HOT BUS/702PP SPLY	5PB2	D02
105VU	ELEC/HOT BUS/701PP SPLY	5PB1	D01
105VU	ELEC/STAT INV/CNTOR/CTL	14XB	G02
106VU	CSM/G /EV/MAN/SPLY	6XE	B04
122VU	ELEC/REFLNG/ON/BAT	1PR	U28

4. Procedure
Subtask 24-28-55-420-050-B

A. Installation of the contactor
(1) Install the contactor (1) on the 6 tapped barrels (6) of the contactor base (7).
(2) TORQUE the six captive screws (4) to between 15.5808 and 13.0128 lbf.in (0.18 and 0.15 m.daN )

.
(3) Remove the CAP-BLANKING from each electrical connector and receptacle.
(4) Make sure that all the electrical connections are clean and in the correct condition.
(5) Connect the electrical connector (3).
(6) Connect the batteries:
(a) Put the connectors on the batteries.
(b) Tighten the knurled nuts by one quarter of a turn.

Subtask 24-28-55-865-052-A

B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
105VU	ELEC/HOT BUS/702PP SPLY	5PB2	D02
105VU	ELEC/HOT BUS/701PP SPLY	5PB1	D01
105VU	ELEC/STAT INV/CNTOR/CTL	14XB	G02
106VU	CSM/G /EV/MAN/SPLY	6XE	B04
122VU	ELEC/REFLNG/ON/BAT	1PR	U28

Subtask 24-28-55-710-050-A

C. Do an operational test of the static inverter (Ref. AMM TASK 24-28-00-710-001).

5. Close-up
Subtask 24-28-55-410-050-B

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the access door of panel 105VU.
(3) Close the access door 822.
(4) Remove the access platform(s).
(5) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.03.31 23:23:05 UTC