DOC AIRBUS | AMM A320FInstallation of the Loop-B Fire Harness
TASK 26-12-62-400-802-A
Installation of the Loop-B Fire Harness
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Work Zones and Access Panels
D. Referenced Information
3. Job Set-up
Subtask 26-12-62-861-051-A ** ON A/C NOT FOR ALL Subtask 26-12-62-941-053-A ** ON A/C NOT FOR ALL
Subtask 26-12-62-420-051-A ** ON A/C NOT FOR ALL
Subtask 26-12-62-410-051-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.03.31 23:43:29 UTC
Installation of the Loop-B Fire Harness
WARNING:
BE CAREFUL WHEN YOU DO WORK ON THE ENGINE AFTER SHUTDOWN. THE ENGINE CAN STAY HOT FOR A LONG TIME. IF YOU DO NOT OBEY THIS INSTRUCTION, INJURY CAN OCCUR.
WARNING:
WEAR APPLICABLE PERSONAL PROTECTIVE EQUIPMENT (PPE) WHEN YOU DO THIS TASK. BEFORE YOU USE PPE, READ, UNDERSTAND AND OBEY ALL INSTRUCTIONS FOR ITS USE. THESE INSTRUCTIONS INCLUDE INSTRUCTIONS FROM THE MANUFACTURER, YOUR EMPLOYER AND GOVERNMENT REGULATIONS. YOU CAN GET INJURED IF YOU DO NOT USE PPE. GET INSTRUCTIONS FROM YOUR EMPLOYER ON WHICH PPE IS NECESSARY.
1. Reason for the JobSelf explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.PU1-0001) | lint-free cotton cloth |
| (Material No.PU1-0006) | abrasive pad |
| (Material No.PU2-0001) | alcohol, isopropyl |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 450 | ENG 1 THRUST REVERSER & EXHAUST SECTION |
| 460 | ENG 2 THRUST REVERSER & EXHAUST SECTION |
| FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1) | |
| 437AL, 438AR, 451AL, 452AR | |
| FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2) | |
| 447AL, 448AR, 461AL, 462AR | |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 24-42-00-861-001-A | Energize the Ground Service Network from the External Power |
| TASK 24-42-00-862-001-A | De-energize the Ground Service Network Supplied from the External Power |
| TASK 26-12-00-710-001-A | Operational Check of Loop/Squib |
| TASK 31-60-00-860-001-A | EIS Start Procedure |
| TASK 31-60-00-860-002-A | EIS Stop Procedure |
| TASK 71-00-00-720-811-A | Test No. 3A - Idle Power Test |
| TASK 71-00-00-860-833-A | Procedure to Prevent Engine Motoring |
| TASK 71-13-00-010-802-A | Opening of the Fan Cowl Doors |
| TASK 71-13-00-410-802-A | Closing of the Fan Cowl Doors |
| TASK 73-21-00-710-806-A | Test No.7 - EEC Operation Test (Self Test) |
| TASK 78-30-00-040-805-A | Deactivation of the Thrust Reverser System for Ground Maintenance |
| TASK 78-30-00-440-805-A | Reactivation of the Thrust Reverser System after Ground Maintenance |
| TASK 78-36-00-010-802-A | Opening of the Thrust Reverser Cowl-Doors |
| TASK 78-36-00-410-802-A | Closing of the Thrust Reverser Cowl-Doors |
Loop-B Fire HarnessSubtask 26-12-62-861-051-A ** ON A/C NOT FOR ALL Subtask 26-12-62-941-053-A ** ON A/C NOT FOR ALL
B. Safety Precautions
(1) Make sure that you did the procedure to prevent engine motoring
(Ref. AMM TASK 71-00-00-860-833).
Subtask 26-12-62-865-054-A ** ON A/C NOT FOR ALL (1) Make sure that you did the procedure to prevent engine motoring
(Ref. AMM TASK 71-00-00-860-833).
C. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:
Subtask 26-12-62-010-056-A ** ON A/C NOT FOR ALL | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| FOR FIN: 4020KM1 (POWER PLANTDEMOUNTABLE, ENG 1) | |||
| 49VU | ENGINE/1/FIRE DET/LOOP A | 7WD1 | A06 |
| 121VU | ENGINE/ENG1/FIRE DET/LOOP B | 8WD1 | Q38 |
| FOR FIN: 4020KM2 (POWER PLANTDEMOUNTABLE, ENG 2) | |||
| 49VU | ENGINE/2/FIRE DET/LOOP B | 8WD2 | A07 |
| 121VU | ENGINE/ENG2/FIRE DET/LOOP A | 7WD2 | Q39 |
D. Get Access
(1) Make sure that the fan cowl doors are open (Ref. AMM TASK 71-13-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
447AL 448AR
Subtask 26-12-62-040-053-A ** ON A/C NOT FOR ALL (1) Make sure that the fan cowl doors are open (Ref. AMM TASK 71-13-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
447AL 448AR
E. Deactivation of the Thrust Reverser System for Ground Maintenance
Subtask 26-12-62-010-057-A ** ON A/C NOT FOR ALL WARNING:
YOU MUST DEACTIVATE THE THRUST REVERSER BEFORE YOU DO WORK ON OR AROUND IT. IF YOU DO NOT, THE THRUST REVERSER CAN OPERATE ACCIDENTALLY AND CAUSE AN INJURY AND/OR DAMAGE.
(1) Make sure that you did the deactivation of the thrust reverser system for ground maintenance (Ref. AMM TASK 78-30-00-040-805). F. Get Access
(1) Make sure that the thrust reverser cowl-doors are open (Ref. AMM TASK 78-36-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
461AL 462AR
(2) Make sure that the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE is in position.
4. Procedure(1) Make sure that the thrust reverser cowl-doors are open (Ref. AMM TASK 78-36-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
461AL 462AR
(2) Make sure that the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE is in position.
Subtask 26-12-62-420-051-A ** ON A/C NOT FOR ALL
A. Installation of the Loop-B Fire Harness
(2) Attach the Loop-B fire harness (1) to the spring clip on the PW support bracket.
(3) Put the INSTL REF band on the Loop-B fire harness (1) in the center of the spring clip.
(4) Attach the Loop-B fire harness (1) to the spring clip on the heatshield electrical bracket assembly.
(5) Put the clamps (17) on the Loop-B fire harness (1).
(6) Attach the Loop-B fire harness (1) and the three clamps (17) to the fuel return support bracket assemblies with the three bolts (15) and washers (16).
(7) Put the INSTL REF bands on the Loop-B fire harness (1) in the center of the clamps (17).
(8) Do not torque the bolts (15) at this time.
(9) Put the clamps (14) and (11) on the Loop-B fire harness (1).
(10) Attach the Loop-B fire harness (1) and the clamps (14) and (11) to the heatshield electrical bracket assembly with the bolts (12) and (9) and washers (13) and (10).
(11) Put the INSTL REF band on the Loop-B fire harness assembly (1) in the center of the clamp (11). Do not torque the bolts (12) and (9) at this time.
(12) Put the clamp (20) on the Loop-B fire harness (1).
(13) Attach the Loop-B fire harness (1) and the clamp (20) to the PW support bracket with the bolt (18) and washer (19). Do not torque the bolt (18) at this time.
(14) Put the clamp (8) on the Loop-B fire harness (1).
(15) Attach the Loop-B fire harness (1) and the clamp (8) to the heatshield electrical bracket and the aft fire/overheat detector bracket with the bolt (6) and washer (7). Do not torque the bolt (6) at this time.
(16) Put the clamp (28) on the Loop-B fire harness (1).
(17) Put the clamp (27) on the IDG-EDP-MON harness.
(18) Attach the Loop-B fire harness (1), IDG-EDP-MON harness, and clamps (27) and (28) together with the bolt (25), two washers (26) and nut (29).
(19) Do not torque the nut (29) at this time.
(20) Clean the screw (21) and washer (22) withPU2-0001 alcohol, isopropyl
(21) Rub the mating surface of the forward fire/overheat detector element with an abrasive pad (Material No.PU1-0006) .
(22) Clean the mating surface withPU2-0001 alcohol, isopropyl
(23) Remove the alcohol from the hardware and detector element with a clean, lint-free cotton cloth (Material No.PU1-0001) before it dries.
(24) Connect the Loop-B fire harness (1) ground lug to the forward fire/overheat detector element with the screw (21) and washer (22). Do not torque the screw (21) at this time.
(a) Measure the resistance between the ground lug of the Loop-B fire harness (1) and the forward fire/overheat detector element.
(b) Make sure that it is less than 0.0025 ohms.
(c) If the resistance is more than 0.0025 ohms, remove the hardware and repeat Steps 4.A.(19) thru 4.A.(23).
(25) Connect the Loop-B fire harness (1) STUD A lug (4002WD2A) to the terminal "A" of the forward fire/overheat detector element with the nut (23).
(26) Connect the Loop-B fire harness (1) STUD C lug (4002WD2C) to the terminal "C" of the forward fire/overheat detector element with the nut (24). Do not torque the nuts (23) and (24) at this time.
(27) Clean the screw (3) and washer (4) withPU2-0001 alcohol, isopropyl
(28) Rub the mating surface of the aft fire/overheat detector element with an abrasive pad (Material No.PU1-0006) .
(29) Clean the mating surface withPU2-0001 alcohol, isopropyl
(30) Remove the alcohol from the hardware and detector element with a clean, lint-free cotton cloth (Material No.PU1-0001) before it dries.
(31) Connect the Loop-B fire harness (1) ground lug to the aft fire/overheat detector element with the screw (3) and washer (4). Do not torque the screw (3) at this time.
(32) Measure the resistance between the ground lug of the Loop-B fire harness (1) and the aft fire/overheat detector element.
(a) Make sure that it is less than 0.0025 ohms.
(b) If the resistance is more than 0.0025 ohms, remove the hardware and repeat Steps 4.A.(26) thru 4.A.(31).
(33) Connect the Loop-B fire harness (1) STUD C lug (4001WD2C) to the terminal "C" of the aft fire/overheat detector element with the nut (5).
(34) Connect the Loop-B fire harness (1) STUD A lug (4001WD2A) to the terminal "A" of the aft fire/overheat detector element with the nut (2). Do not torque the nuts (2) and (5) at this time.
(35) Connection of the electrical connector
(a) Remove the CAP - PROTECTION from the Loop-B fire harness (1) connector (454VC-A) and the pylon interface. Connect the Loop-B fire harness assembly (1) connector to the pylon interface. Tighten the connector with your hands. Then tighten the connector 1/8 to 1/4 of a turn more with PLIERS - CONNECTOR, JAW, SOFT.
(b) Make sure that you cannot see the color band on the connector.
(36) Adjust the Loop-B fire harness (1) to make sure that there is a minimum load on the harness connector and lugs.
(37) Tighten the bolts, screws and nuts.
.
(b) TORQUE the screws (3) and (21) to between 35 and 31.5 lbf.in (0.40 and 0.36 m.daN ).
(c) TORQUE the nuts (2) and (24) on the harness lugs to between 55 and 50 lbf.in (0.62 and 0.57 m.daN ).
(d) TORQUE the nuts (5) and (23) on the harness lugs to between 45 and 40 lbf.in (0.51 and 0.45 m.daN ).
(e) TORQUE the nut (29) to between 35 and 30 lbf.in (0.40 and 0.34 m.daN ).
Subtask 26-12-62-865-055-A ** ON A/C NOT FOR ALL WARNING:
BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.
CAUTION:
WIPE CLEAN ALL PARTS AND TOOLS AS NECESSARY TO REMOVE UNWANTED DEBRIS AND PREVENT DAMAGE TO THE ENGINE.
CAUTION:
REMOVE THE PROTECTION COVERS FROM THE OPENINGS AS NECESSARY TO PREVENT ENGINE DAMAGE.
CAUTION:
DO NOT USE ELECTRICAL OR PNEUMATIC TOOLS TO LOOSEN OR TIGHTEN THE QUARTER-TURN FASTENER ON THE FIRE DETECTOR CLAMP. ONLY USE A MANUAL SCREWDRIVER. ELECTRICAL OR PNEUMATIC TOOLS WILL CAUSE THE FASTENER TO TURN TOO MUCH AND POSSIBLY TO BREAK.
CAUTION:
MAKE SURE THAT THE ELECTRICAL CONNECTORS ARE CLEAN BEFORE YOU DISCONNECT OR CONNECT THEM. CONTAMINATION ON THE ELECTRICAL CONNECTORS CAN CAUSE DAMAGE TO EQUIPMENT.
CAUTION:
USE TEFLON-JAWED PLIERS TO CONNECT ELECTRICAL CONNECTORS. DO NOT USE METAL-JAWED PLIERS. DAMAGE TO THE ELECTRICAL CONNECTORS COULD OCCUR.
(1) Make sure that you remove all the necessary COVER - PROTECTION to prevent damage to the engine. (2) Attach the Loop-B fire harness (1) to the spring clip on the PW support bracket.
(3) Put the INSTL REF band on the Loop-B fire harness (1) in the center of the spring clip.
(4) Attach the Loop-B fire harness (1) to the spring clip on the heatshield electrical bracket assembly.
(5) Put the clamps (17) on the Loop-B fire harness (1).
(6) Attach the Loop-B fire harness (1) and the three clamps (17) to the fuel return support bracket assemblies with the three bolts (15) and washers (16).
(7) Put the INSTL REF bands on the Loop-B fire harness (1) in the center of the clamps (17).
(8) Do not torque the bolts (15) at this time.
(9) Put the clamps (14) and (11) on the Loop-B fire harness (1).
(10) Attach the Loop-B fire harness (1) and the clamps (14) and (11) to the heatshield electrical bracket assembly with the bolts (12) and (9) and washers (13) and (10).
(11) Put the INSTL REF band on the Loop-B fire harness assembly (1) in the center of the clamp (11). Do not torque the bolts (12) and (9) at this time.
(12) Put the clamp (20) on the Loop-B fire harness (1).
(13) Attach the Loop-B fire harness (1) and the clamp (20) to the PW support bracket with the bolt (18) and washer (19). Do not torque the bolt (18) at this time.
(14) Put the clamp (8) on the Loop-B fire harness (1).
(15) Attach the Loop-B fire harness (1) and the clamp (8) to the heatshield electrical bracket and the aft fire/overheat detector bracket with the bolt (6) and washer (7). Do not torque the bolt (6) at this time.
(16) Put the clamp (28) on the Loop-B fire harness (1).
(17) Put the clamp (27) on the IDG-EDP-MON harness.
(18) Attach the Loop-B fire harness (1), IDG-EDP-MON harness, and clamps (27) and (28) together with the bolt (25), two washers (26) and nut (29).
(19) Do not torque the nut (29) at this time.
(20) Clean the screw (21) and washer (22) with
(21) Rub the mating surface of the forward fire/overheat detector element with an abrasive pad (Material No.PU1-0006) .
(22) Clean the mating surface with
(23) Remove the alcohol from the hardware and detector element with a clean, lint-free cotton cloth (Material No.PU1-0001) before it dries.
(24) Connect the Loop-B fire harness (1) ground lug to the forward fire/overheat detector element with the screw (21) and washer (22). Do not torque the screw (21) at this time.
(a) Measure the resistance between the ground lug of the Loop-B fire harness (1) and the forward fire/overheat detector element.
(b) Make sure that it is less than 0.0025 ohms.
(c) If the resistance is more than 0.0025 ohms, remove the hardware and repeat Steps 4.A.(19) thru 4.A.(23).
(25) Connect the Loop-B fire harness (1) STUD A lug (4002WD2A) to the terminal "A" of the forward fire/overheat detector element with the nut (23).
(26) Connect the Loop-B fire harness (1) STUD C lug (4002WD2C) to the terminal "C" of the forward fire/overheat detector element with the nut (24). Do not torque the nuts (23) and (24) at this time.
(27) Clean the screw (3) and washer (4) with
(28) Rub the mating surface of the aft fire/overheat detector element with an abrasive pad (Material No.PU1-0006) .
(29) Clean the mating surface with
(30) Remove the alcohol from the hardware and detector element with a clean, lint-free cotton cloth (Material No.PU1-0001) before it dries.
(31) Connect the Loop-B fire harness (1) ground lug to the aft fire/overheat detector element with the screw (3) and washer (4). Do not torque the screw (3) at this time.
(32) Measure the resistance between the ground lug of the Loop-B fire harness (1) and the aft fire/overheat detector element.
(a) Make sure that it is less than 0.0025 ohms.
(b) If the resistance is more than 0.0025 ohms, remove the hardware and repeat Steps 4.A.(26) thru 4.A.(31).
(33) Connect the Loop-B fire harness (1) STUD C lug (4001WD2C) to the terminal "C" of the aft fire/overheat detector element with the nut (5).
(34) Connect the Loop-B fire harness (1) STUD A lug (4001WD2A) to the terminal "A" of the aft fire/overheat detector element with the nut (2). Do not torque the nuts (2) and (5) at this time.
(35) Connection of the electrical connector
(a) Remove the CAP - PROTECTION from the Loop-B fire harness (1) connector (454VC-A) and the pylon interface. Connect the Loop-B fire harness assembly (1) connector to the pylon interface. Tighten the connector with your hands. Then tighten the connector 1/8 to 1/4 of a turn more with PLIERS - CONNECTOR, JAW, SOFT.
(b) Make sure that you cannot see the color band on the connector.
(36) Adjust the Loop-B fire harness (1) to make sure that there is a minimum load on the harness connector and lugs.
(37) Tighten the bolts, screws and nuts.
CAUTION:
WHEN YOU TORQUE THE NUTS, MAKE SURE THAT THE TERMINAL LUGS OF THE LOOP-B FIRE HARNESS BELOW THE NUTS DO NOT MOVE. IF YOU DO NOT OBEY THIS INSTRUCTION, YOU CAN PULL THE PART OF THE LUGS BELOW THE NUTS AWAY FROM THE OTHER PART OF THE LUG. THIS CAN CAUSE DAMAGE TO THE HARNESS ON THE LOOP-B FIRE HARNESS.
(a) TORQUE the bolts (6), (9), (12), (15) and (18) to between 35 and 31.5 lbf.in (0.40 and 0.36 m.daN ) . (b) TORQUE the screws (3) and (21) to between 35 and 31.5 lbf.in (0.40 and 0.36 m.daN )
. (c) TORQUE the nuts (2) and (24) on the harness lugs to between 55 and 50 lbf.in (0.62 and 0.57 m.daN )
. (d) TORQUE the nuts (5) and (23) on the harness lugs to between 45 and 40 lbf.in (0.51 and 0.45 m.daN )
. (e) TORQUE the nut (29) to between 35 and 30 lbf.in (0.40 and 0.34 m.daN )
. B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
Subtask 26-12-62-860-053-A ** ON A/C NOT FOR ALL Subtask 26-12-62-710-051-A ** ON A/C NOT FOR ALL | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 49VU | ENGINE/2/FIRE DET/LOOP B | 8WD2 | A07 |
| 49VU | ENGINE/1/FIRE DET/LOOP A | 7WD1 | A06 |
| 121VU | ENGINE/ENG2/FIRE DET/LOOP A | 7WD2 | Q39 |
| 121VU | ENGINE/ENG1/FIRE DET/LOOP B | 8WD1 | Q38 |
D. Do this test:
(1) On the upper ECAM DU, make sure that the FIRE ENG1(2) LOOP A (B) FAULT message is out of view.
(2) Do an operational test of the engine fire detection system (Ref. AMM TASK 26-12-00-710-001).
Subtask 26-12-62-720-051-A ** ON A/C NOT FOR ALL (1) On the upper ECAM DU, make sure that the FIRE ENG1(2) LOOP A (B) FAULT message is out of view.
(2) Do an operational test of the engine fire detection system (Ref. AMM TASK 26-12-00-710-001).
E. Tests
(1) If you disconnected an oil or fuel tube or manifold, do test No. 3 (Ref. AMM TASK 71-00-00-720-811), if not included in the test that follows.
(2) If you disconnected an electrical harness connector, do the FADEC system static test (Ref. AMM TASK 73-21-00-710-806).
Subtask 26-12-62-860-054-A ** ON A/C NOT FOR ALL 5. Close-up(1) If you disconnected an oil or fuel tube or manifold, do test No. 3 (Ref. AMM TASK 71-00-00-720-811), if not included in the test that follows.
(2) If you disconnected an electrical harness connector, do the FADEC system static test (Ref. AMM TASK 73-21-00-710-806).
Subtask 26-12-62-410-051-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) Close the thrust reverser cowl-door (Ref. AMM TASK 78-36-00-410-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
461AL 462AR
Subtask 26-12-62-440-051-A ** ON A/C NOT FOR ALL (1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the thrust reverser cowl-door (Ref. AMM TASK 78-36-00-410-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
461AL 462AR
B. Do the reactivation of the thrust reverser system after ground maintenance (Ref. AMM TASK 78-30-00-440-805).
Subtask 26-12-62-410-052-A ** ON A/C NOT FOR ALL C. Close Access
(1) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
447AL 448AR
(2) Remove the access platform(s).
(3) Remove the WARNING NOTICE(S).
Subtask 26-12-62-862-050-A ** ON A/C NOT FOR ALL (1) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
447AL 448AR
(2) Remove the access platform(s).
(3) Remove the WARNING NOTICE(S).