Replacement of the DC Fuse 4PB11(4PB21)

TASK 24-38-00-960-801-A
Replacement of the DC Fuse 4PB11(4PB21)

ZONE: 211
ZONE: 212

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 1M (3 FT)-ADJUSTABLE
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 1.1 and 0.9 m.daN (97.35 and 79.65 lbf.in )

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
211	COCKPIT
212	COCKPIT
121AL

C. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
12	DC FUSE	AIPC 24-38-08-01-120
4	DC FUSE	AIPC 24-38-08-01-120
12	DC FUSE	AIPC 24-38-88-01-080
4	DC FUSE	AIPC 24-38-88-01-080
FOR [4PB1] (HOLDER-BAT 1 FUSE)
FOR [4PB2] (HOLDER-BAT 2 FUSE)
3	FUSE	AIPC 24-38-08-01-120

D. Referenced Information

REFERENCE	DESIGNATION
TASK 24-38-51-000-001-A	Removal of the Battery
TASK 24-38-51-400-001-A	Installation of the Battery
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
DC Fuse 4PB11 (4PB21) ** ON A/C NOT FOR ALL
DC Fuse 4PB11 (4PB21) ** ON A/C NOT FOR ALL
FOR [2PB1] (BAT-1)
TASK 31-21-00-750-002-A	Procedure to Set the Clock
FOR [4PB1] (HOLDER-BAT 1 FUSE)
FOR [4PB2] (HOLDER-BAT 2 FUSE)
ESPM 2046200

3. Job Set-up
Subtask 24-38-00-010-053-A

A. Get Access
(1) Remove the Third Occupant seat (Ref. AMM TASK 25-11-41-000-001).
(2) On the bottom right side of rear panel 120VU, remove the access door (1).
(3) Put an ACCESS PLATFORM 1M (3 FT)-ADJUSTABLE in position at access door 121AL.
(4) Open access door 121AL.

Subtask 24-38-00-860-056-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) are in position on 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 control 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) 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).

Subtask 24-38-00-020-050-A

C. Disconnection of the Two Batteries
(1) Disconnect the connectors from the batteries, refer to (Ref. AMM TASK 24-38-51-000-001).

4. Procedure
Subtask 24-38-00-960-050-A ** ON A/C NOT FOR ALL

A. Replacement of the DC Fuse

DC Fuse 4PB11 (4PB21) ** ON A/C NOT FOR ALL

(1) FOR [4PB1] (HOLDER-BAT 1 FUSE), [4PB2] (HOLDER-BAT 2 FUSE)
(a) Loosen the nut (4) and remove and discard the DC fuse (3).
(b) Install the new AIPC 24-38-08-01-120 FUSE (3) to the terminals of the mount (2) as shown on Detail B and C.
(c) Tighten the nut (4) ESPM 2046200.

Subtask 24-38-00-960-050-B ** ON A/C NOT FOR ALL

A. Replacement of the DC Fuse

DC Fuse 4PB11 (4PB21) ** ON A/C NOT FOR ALL

(1) For DC Fuse 4PB11

NOTE: The 4PB1 label installed on DC-bus-1 contactor-module 13PN shows the location for the installation of DC fuse 4PB11.

(a) Remove the nut (9) and washer (8).
(b) Remove the screw (10) and washer (11).
1 Remove and discard the DC fuse (12).
(c) Install the new AIPC 24-38-08-01-120 DC FUSE (12) or AIPC 24-38-88-01-080 DC FUSE (12) to the terminals of the mount (5) as shown on Detail B.
(d) Install the washer (8) and nut (9).
1 TORQUE the nut (9) to between 1.1 and 0.9 m.daN (97.35 and 79.65 lbf.in )

.
(e) Install the washer (11) and screw (10).
1 TORQUE the screw (10) to between 1.1 and 0.9 m.daN (97.35 and 79.65 lbf.in )

.
(2) For DC Fuse 4PB21

NOTE: The 4PB2 label installed on DC-bus-1 contactor-module 13PN shows the location for the installation of fuse 4PB21.

(a) Remove the nut (7) and washer (6).
(b) Remove the screw (2) and washer (3).
1 Remove and discard the DC fuse (4).
(c) Install the new AIPC 24-38-08-01-120 DC FUSE (4) or AIPC 24-38-88-01-080 DC FUSE (4) to the terminals of the mount (5) as shown on Detail B.
(d) Install the washer (6) and nut (7).
1 TORQUE the nut (7) to between 1.1 and 0.9 m.daN (97.35 and 79.65 lbf.in )

.
(e) Install the washer (3) and screw (2).
1 TORQUE the screw (2) to between 1.1 and 0.9 m.daN (97.35 and 79.65 lbf.in )

Subtask 24-38-00-420-051-A

B. Connection of the Two Batteries
(1) Connect the electrical connectors to the batteries, refer to (Ref. AMM TASK 24-38-51-400-001).

Subtask 24-38-00-750-050-B

C. Adjustment of the Clock
(1) FOR [2PB1] (BAT-1)
Adjust the clock (Ref. AMM TASK 31-21-00-750-002).

5. Close-up
Subtask 24-38-00-410-053-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) On the bottom right side of rear panel 120VU, install the access door (1).
(3) Install the Third Occupant seat (Ref. AMM TASK 25-11-41-400-001).
(4) Remove the WARNING NOTICE(S).
(5) Close access door 121AL.
(6) Remove the access platform(s).

[Rev.10 from 2021] 2026.03.31 23:23:47 UTC