W DOC AIRBUS | TSM A320F

Intercell Transfer Valves (Left And Right Rear) - Fail To Close (Delatch)

TASK 28-15-00-810-814-A
Intercell Transfer Valves (Left And Right Rear) - Fail To Close (Delatch)

WARNING: OBEY THE FUEL SAFETY PROCEDURES.
WARNING: WHEN YOU DO WORK ON THE FUEL SYSTEM WIRING, YOU MUST USE TEST EQUIPMENT THAT IS APPROVED (REFER TO INTERNATIONAL OR NATIONAL SPECIFICATIONS FOR INTRINSICALLY SAFE TEST EQUIPMENT: EN50020, UL913 OR EQUIVALENT). TEST EQUIPMENT THAT IS NOT APPROVED CAN CAUSE FIRE OR AN EXPLOSION.
1. Possible Causes
  • FQIC [3QT]
  • aircraft wiring
2. Job Set-up Information
 A. Fixtures, Tools, Test and Support Equipment
REFERENCE
QTY
DESIGNATION
No specific
AR
MULTIMETER - STANDARD
 B. Referenced Information
REFERENCE
DESIGNATION
ESPM 2052210
ESPM 2052220
ESPM 2053210
ASM 281501
AIPC 28150802
AMM 28-42-34-000-001
Removal of the Fuel Quantity-Indicating Computer (FQIC)
AMM 28-42-34-400-001
Installation of the Fuel Quantity-Indicating Computer (FQIC)
AMM 28-46-34-000-001
Removal of the Fuel-Level Sensing Control-Unit (FLSCU)
AWM 930103
3. Fault Confirmation
Subtask 28-15-00-865-066-A ** ON A/C NOT FOR ALL
A. Table of the circuit breakers referred to in this procedure:
PANELDESIGNATIONFINLOCATION
** ON A/C NOT FOR ALL
49VUFUEL/FQI/CHAN/11QTA13
121VUFUEL/FQI/CHAN/22QTM27
Subtask 28-15-00-710-063-A ** ON A/C NOT FOR ALL
B. Test
   (1) In the forward avionics compartment, get access to the relay-box 103VU AMM 28-46-34-000-001 AWM 930103 AIPC 28150802.
   (2) Connect a MULTIMETER - STANDARD to the RELAY-L OR R REAR XFR VALVE OPEN LATCH (13QP) as follows:
  • the multimeter positive/high input to the relay terminal Z
  • the multimeter negative/low input to a suitable aircraft ground.
   (3) Do the power on BITE test (of the FQIC 3QT) and monitor:
  • the XFR Valve movement on the ECAM, FUEL System Display (lower ECAM DU)
  • the multimeter reading.
     (a) If the aircraft is already supplied with electrical power, reset the FQIC 3QT (to start a new test) as follows:
       1 Open the C/Bs 1QT and 2QT.
       2 Wait 5 seconds.
       3 Close the C/Bs 1QT and 2QT.
NOTE: The full FQIS BITE test (with ICTV movement) is done a short time after power on.
NOTE: The intercell transfer valves (ICTVs) are motor driven and the power for these circuits is supplied from the main power. The ICTVs will not operate if only battery power is available.
     (b) If during the power on BITE test the voltage reading on the multimeter:

  • changes from 0VDC to 28VDC (after an initial warm up period) and from 28VDC to 0VDC (when the transfer-valves have moved to the closed position), no troubleshooting work steps are necessary

  • stays at 0VDC or 28VDC, do Para. 4.A.
NOTE: In normal operation the rear ICTV delatch is set during a refuel. The FQIC 3QT open-circuits the pin 10B at 3QT-AB which causes the rear ICTVs to close ASM 281501.
4. Fault Isolation
Subtask 28-15-00-810-063-A ** ON A/C NOT FOR ALL
A. Procedure
   (1) Replace the FQIC [3QT] AMM 28-42-34-000-001 and AMM 28-42-34-400-001.
     (a) Do the test given in Para. 3.B.
   (2) If the fault continues:
     (a) Do a wiring check of the aircraft wiring ASM 281501 between the RELAY-L OR R REAR XFR VALVE OPEN LATCH (13QP), terminal Z and the FQIC connector 3QT-AB, pin 10B.
     (b) Do a wiring check of the aircraft wiring ASM 281501 between the RELAY-L WING TK LOW LEVEL CHANNEL A (5QP), terminal X2 and the RELAY-L OR R REAR XFR VALVE OPEN LATCH (13QP), terminal A.
     (c) Do a wiring check of the aircraft wiring ASM 281501 between the RELAY-R WING TK LOW LEVEL CHANNEL B (6QP), terminal X2 and the RELAY-L OR R REAR XFR VALVE OPEN LATCH (13QP), terminal B.
NOTE: A wiring check means that you test the wire(s) specified as follows:
These checks are necessary to find a possible short-circuit to ground in the latch hold-on (ground) wire. A short-circuit (as described) can cause the latch to stay on.
     (d) Repair all the unserviceable wiring and connectors ESPM 2053210.
     (e) Do the test given in Para. 3.B.
[Rev.8 from Aug 2018] 2026.04.04 04:28:29 UTC
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