_
2.
If the reference pressure is still under 12 psig
_
then replace the HPC, (AMM 36-11-06/401).If the HPSOV did not fully open, do these steps: 1) Check the fittings and tubing between the HPC and HPSOV for
leaks with a soap solution and repair as necessary. 2) If no leaks are found, do these steps: a) Increase the supply pressure to a maximum of 20 psig or when the reference pressure reads 12 psig.
b) If the reference pressure is less than 12 psig and the ECS maintenance page shows the HPSOV is open, replace the HPSOV (AMM 36-11-05/401).
c) If the reference pressure is less than 12 psig and the ECS maintenance page shows the HPSOV is closed, replace the HPC (AMM 36-11-06/401).
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
36-00-22
ALL ú ú 01 Page 510 ú Feb 18/02
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
(q)
Use the 'HIGH PRESSURE SUPPLY' gauge on the test box.
(r)
Increase the supply pressure to 95 psig and slowly thereafter to 110 psig.
(s)
Make sure the HPSOV closes completely by 110 psig. 1) Make sure the HPSOV is closed by visually inspecting the position switch on the valve. 2) Make sure the HPSOV shows CLOSED on the ECS maintenance page.
3) If the valve is closed but does not indicate CLOSED on the ECS maintenance page, troubleshoot the position switch and/or wiring.
(t)
Make sure the reference pressure is equal to or less than 2 psig. 1) If the reference pressure is greater than 2 psig, replace
the HPC (AMM 36-11-06/401).
(u)
If the HPSOV does not close, do these steps: 1) If the reference pressure is equal to or less than 2 psig, replace the HPSOV, (AMM 36-11-05/401)
2) If the reference pressure is greater than 2 psig, replace the HPC (AMM 36-11-06/401).
(v)
Reduce the supply pressure to zero.
S 715-038
(6)
Test the HPC shutoff solenoid.
(a)
Increase the supply pressure to 50 psig.
(b)
Make sure the HPSOV opens.
(c)
Select the Bleed switch on the overhead panel to OFF
(d)
Make sure the HPSOV closes.
(e)
If the HPSOV does not close, do these steps: 1) Remove the electrical connector on the HPC. 2) Measure the voltage across pins 7 and 8 while the Bleed
switch is changed to the OFF position.
NOTE: The 28 VDC "pulse" can only be measured while
____ the switch is changed from ON to OFF. You should use an analog meter to see the pulse.
3) If the voltage is 28VDC, replace the HPC (AMM 36-11-06/401). 4) If the voltage is not 28 VDC, troubleshoot the wiring between the HPC and the ASCTU.
(f) Decrease the supply pressure to zero.
S 845-039
(7)
Put the Airplane Back to Its Usual Condition.
(a)
Remove the fittings and replace the connections.
NOTE: Make sure the anti-seize compound is applied to all
____ the male threads before connecting the pneumatic control/supply lines.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
36-00-22
ALL ú ú 01 Page 511 ú Feb 18/02
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
(b) Visually inspect all pneumatic lines and fittings to and from the HPC and HPSOV. 1) If loose or damaged, repair or replace as necessary.
I. Pressure Regulating Valve (PRV) and PRV Controller Test (Fig. 503)
S 415-040
(1)
Open the thrust reverser halves and find the PRV and PRV controller (AMM 06-09-09/201)
S 215-041
(2)
Make sure the PRV is closed.
中國航空網 www.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：747-400 AMM 飛機維護手冊 氣動系統 PNEUMATIC SYSTEM(13)
