Cabin Recirculation Fault (Fan 2 / Supply)

TASK 21-21-00-810-803-A
Cabin Recirculation Fault (Fan 2 / Supply)

1. Possible Causes

RECIRC FILTER CARTRIDGE 2 [4013HM]
P/BSW-VENTILATION/CAB FANS [4HG]
RELAY-FAN FAULT SUPPRESS [16HG]
RELAY-R FAN POWER [6HG]
RELAY-R FAN CONTROL [8HG]
RELAY-R FAN FAULT [9HG]
RECIRC FAN 2 [14HG]
wiring

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 21-21-00-710-001	Operational Test of the Cabin Recirculation Fans
ASM 212101
AMM 21-21-41-000-001	Removal of the Recirculation Filter
AMM 21-21-41-400-001	Installation of the Recirculation Filter
AMM 21-21-51-000-001	Removal of the Cabin Recirculation Fans
AMM 21-21-51-400-001	Installation of the Cabin Recirculation Fans
ASM 216301

3. Fault Confirmation
Subtask 21-21-00-710-056-A

A. Do the operational test of the cabin recirculation fans 14HG and 15HG AMM 21-21-00-710-001.

4. Fault Isolation
Subtask 21-21-00-810-054-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message RECIRC FAN 2 OR SPLY:

make sure that the recirculation filter (4013HM) housing and the adjacent area is clean.
remove the RECIRC FILTER CARTRIDGE 2 [4013HM] AMM 21-21-41-000-001.

(1) If the recirculation fan (14HG) operates correctly:

do a check of the recirculation filter (4013HM) for contamination.

(a) If the filter is clogged:

replace the RECIRC FILTER CARTRIDGE 2 [4013HM] AMM 21-21-41-000-001 and AMM 21-21-41-400-001.

(b) If the filter is not clogged:

install the RECIRC FILTER CARTRIDGE 2 [4013HM] AMM 21-21-41-400-001.

(2) If the recirculation fan (14HG) does not operate:

do a check of the P/BSW-VENTILATION/CAB FANS [4HG] and replace it if necessary ASM 212101.

(a) If the fault continues:

do a check of the RELAY-FAN FAULT SUPPRESS [16HG] and replace it if necessary ASM 212101.

(b) If the fault continues:

do a check of the RELAY-R FAN POWER [6HG] and replace it if necessary ASM 212101.

do a check of the RELAY-R FAN CONTROL [8HG] and replace it if necessary ASM 212101.

(d) If the fault continues:

do a check of the RELAY-R FAN FAULT [9HG] and replace it if necessary ASM 212101.

(e) If the fault continues:

replace the RECIRC FAN 2 [14HG] AMM 21-21-51-000-001 and AMM 21-21-51-400-001.

(f) If the fault continues:

do a check and repair the wiring ASM 212101 and ASM 216301 from:
the FAN (14HG) to the CB (3HG),
the FAN (14HG) to the CB (11HG),
the FAN (14HG) to ground,
the RELAY (8HG) to the RELAY (6HG),
the RELAY (8HG) to ground,
the RELAY (9HG) to the RELAY (6HG),
the RELAY (9HG) to ground,
the RELAY (9HG) to the ZC (8HK),
the RELAY (16HG) to the SW (4HG) and,
the RELAY (16HG) to ground.

Subtask 21-21-00-810-054-B ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message RECIRC FAN 2 OR SPLY(14HG):

make sure that the recirculation filter (4013HM) housing and the adjacent area is clean.
remove the RECIRC FILTER CARTRIDGE 2 [4013HM] AMM 21-21-41-000-001.