(1) If the circuit breaker trips:
 - disconnect the three unit below:
 FDU-ENG1 (2WD1)
 ENG/APU FIRE PNL (1WD)
 BOARD-ANN LT TEST & INTFC (18LP)
 - close the circuit breaker.
 (a) If the circuit breaker stays closed:
- connect the units one by one until the circuit breaker trips
- replace the defective unit: .for LRU 2WD1: (Ref. AMM TASK 26-12-34-000-001) and (Ref. AMM TASK 26-12-34-400-001) .for LRU 1WD: (Ref. AMM TASK 26-12-12-000-001) and (Ref. AMM TASK 26-12-12-400-001) .for LRU 18LP: (Ref. AMM TASK 33-14-33-000-001) and (Ref. AMM TASK 33-14-33-400-001).
(b) If the circuit breaker trips again:
 - do a check for a short to ground between the circuit breaker (8WD1) and the three units (2WD1, 1WD, 18LP) (Ref. ASM 26-12/01).
 1 If there is a short to ground:
_ - repair the defective wiring.
 2 If there is no short to ground:
_ - replace the C/B-ENGINE/ENG 1/FIRE DET/LOOP B (8WD1).
 「一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一1 EFF : ALL ∞∞26-12-00∞∞∞∞∞∞∞∞∞∞Page 260
 Feb 01/04R CES
 (2) Connect all the units.
 D. Do the test given in Para. 3.
 「一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一1 EFF : ALL ∞∞26-12-00∞∞∞∞∞∞∞∞∞∞Page 261
 Feb 01/04R
 CES  Loss of the Power Supply of the Engine 2 FDU (Loop A)
 1. Possible Causes
_______________
 - FDU-ENG2 (2WD2)
- ENG/APU FIRE PNL (1WD)
- BOARD-ANN LT TEST & INTFC (18LP)
- wiring of the 28VDC signal from the circuit breaker 7WD2 to the engine 2 FDU
- wiring of the ground signal at the engine 2 FDU
- C/B-ENGINE/ENG 2/FIRE DET/LOOP A (7WD2)
- short to ground between the circuit breaker (7WD2) and the three units (2WD2, 1WD, 18LP)
 2. Job Set-up Information
______________________
 A. Referenced Information
 -------------------------------------------------------------------------------REFERENCE DESIGNATION -------------------------------------------------------------------------------
AMM 26-12-00-710-001 Operational Check of Loop/Squib
 AMM 26-12-12-000-001 Removal of the ENG/APU Fire Panel (1WD)
 AMM 26-12-12-400-001 Installation of the ENG/APU Fire Panel (1WD)
 AMM 26-12-34-000-001 Removal of the Engine Fire-Detection Unit (FDU)
 (2WD1,2WD2) AMM 26-12-34-400-001 Installation of the Engine Fire-Detection Unit (FDU) (2WD1,2WD2) AMM 33-14-33-000-001 Removal of the Annunciator-Light Test and Interface-Board (1LP, 2LP, 3LP, 4LP, 5LP, 6LP, 7LP, R 8LP, 9LP, 10LP, 11LP, 12LP, 18LP, 19LP, 20LP) AMM 33-14-33-400-001 Installation of the Annunciator-Light Test and Interface-Board (1LP, 2LP, 3LP, 4LP, 5LP, 6LP, 7LP, R 8LP, 9LP, 10LP, 11LP, 12LP, 18LP, 19LP, 20LP) ASM 26-12/01
 3. Fault Confirmation
__________________
 A. Test
 (1) Do the operational test of the engine fire and overheat detection (loop/squib) (Ref. AMM TASK 26-12-00-710-001).
 (a) If the circuit breaker 7WD2 is open, refer to Para. 4.C.
 4. Fault Isolation
_______________
 A. Table of the circuit breakers used in this procedure:
 -------------------------------------------------------------------------------PANEL DESIGNATION IDENT. LOCATION -------------------------------------------------------------------------------
121VU ENGINE/ENG2/FIRE DET/LOOP A 7WD2 Q39
 B. If the circuit breaker 7WD2 is closed, and if the FIRE legend of the ENG 2 annunciator and the DISCH legend of the ENG 2/AGENT 2 pushbutton switch on the ENG/APU FIRE panel do not come on:
 - do a check for 28VDC at the pin A/A of the engine 2 FDU.
 (1) If there is 28VDC:
- replace the FDU-ENG2 (2WD2) (Ref. AMM TASK 26-12-34-000-001) and (Ref. AMM TASK 26-12-34-400-001).
(2) If there is no 28VDC:
 - do a check of the wiring of the 28VDC signal from the circuit breaker 7WD2 to the engine 2 FDU (Ref. ASM 26-12/01).
 (a) If there is no continuity:
- repair the above wiring.
(b) If there is continuity:
 - do a check of the wiring of the ground signal at the engine 2 FDU pin B/B (Ref. ASM 26-12/01).
 1 If there is no continuity:
_ - repair the above wiring.
 2 If there is continuity:
_ - replace the C/B-ENGINE/ENG 2/FIRE DET/LOOP A (7WD2).
C. If the circuit breaker (7WD2) is open: 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址:A320 Trouble Shooting Manual 排故手册 FIRE PROTECTION 防火(50)