Failure of the Engine 1 Air Intake Anti-Ice Valve in the Closed Position

TASK 30-21-00-810-803-A
Failure of the Engine 1 Air Intake Anti-Ice Valve in the Closed Position

1. Possible Causes

VALVE-ENG AIR INTAKE ANTI ICE [4000DN]
defective muscle pressure tubes and hoses
P/BSW-ANTI ICE/ENG 1 [2DN1]
wiring between the engine 1 air intake anti-ice valve (4000DN) and the circuit breaker (1DN1)
C/B [1DN1]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 24-00-00-810-803-A	Circuit Breaker Tripped and/or C/B TRIPPED Warning
AMM 30-21-00-710-002	Operational Test of the Engine Air Intake Ice Protection (with the Engines in operation)
AMM 30-21-49-210-001	Visual Inspection of the Anti-Ice System Tubes, Ducts, and Hoses
AMM 30-21-49-210-040	Visual Inspection of the Anti-Ice System Hoses, Tubes and Ducts
AMM 30-21-51-000-040	Removal of the Engine Air-Intake Anti-Ice Valve
AMM 30-21-51-000-041	Removal of the Engine Air-Intake Anti-ice Valve
AMM 30-21-51-400-041	Installation of the Engine Air-Intake Anti-Ice Valve
AMM 30-21-51-400-042	Installation of the Engine Air-Intake Anti-ice Valve

3. Fault Confirmation
Subtask 30-21-00-710-050-A ** ON A/C NOT FOR ALL

A. Do the operational test of the engine air intake ice protection AMM 30-21-00-710-002.

4. Fault Isolation
Subtask 30-21-00-865-052-A ** ON A/C NOT FOR ALL

A. Table of the circuit breakers used in this procedure:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
122VU	ANTI ICE/ENG/1	1DN1	X10

Subtask 30-21-00-810-052-B ** ON A/C NOT FOR ALL

B. If the test confirms the fault:

do a check of the overpressure indicator on the air intake anti-ice valve (4000DN).

(1) If the overpressure indicator is extended:

replace the VALVE-ENG AIR INTAKE ANTI ICE [4000DN] AMM 30-21-51-000-040 and AMM 30-21-51-400-041.

(2) If the overpressure indicator is not extended:
(a) If the NAI valve operates correctly:

do a check of the defective muscle pressure tubes and hoses AMM 30-21-49-210-001.

(b) If the fault continues:

do a check of the status of the circuit breaker (1DN1).

1 If the circuit breaker is closed:

make sure that there is 28VDC at pin A/9 of the engine 1 air intake anti-ice valve (4000DN).

a If there is 28VDC:

replace the VALVE-ENG AIR INTAKE ANTI ICE [4000DN] AMM 30-21-51-000-040 and AMM 30-21-51-400-041.

b If there is no 28VDC:
- make sure that there is 28VDC at pin A/D2 of the ANTI ICE/ENG 1 pushbutton switch (2DN1).
. If there is no 28VDC:
- replace the P/BSW-ANTI ICE/ENG 1 [2DN1] .
. If there is 28VDC:
- do a check and repair the wiring between the engine 1 air intake anti-ice valve (4000DN) and the circuit breaker (1DN1).
2 If the circuit breaker (1DN1) is open:

Do the procedure (Ref. TSM TASK 24-00-00-810-803).

a If the fault continues:

replace the C/B [1DN1] .

Subtask 30-21-00-810-052-E ** ON A/C NOT FOR ALL