TM 9-4520-271-14
0028 00
ADJUSTMENT
WARNING
FOR ARTIFICIAL RESPIRATION, REFER TO FM 4-25.11, FIRST AID.
Electrical high voltage cannot be seen but can kill you. Electricity is unlike most other dangerous things
you can come in contact with because it gives no warning and no symptoms to be wary of. Its effect is
immediate. It can kill you, render you unconscious, or severely burn you.
To ensure your safety and that of other maintenance personnel, always observe the following precautions:
DO NOT perform any maintenance on electrical equipment unless all power is removed.
BE CERTAIN that there is someone assisting you who can remove power immediately.
1.
Disconnect power cable (1) from power source.
2.
Remove return air hose assembly (2) from ASH.
3.
Open side rear door (3).
4.
If testing indicates air switch was closed, proceed as follows:
a. Remove cover (4) from air switch (5) and loosen locknut (6).
b. Turn adjustment screw (7) clockwise (in) until meter indicates 120 Vac. Turn adjustment screw (7) one-quarter turn
more.
c. Tighten locknut (6), install cover (4), and proceed to step 13.
5.
If testing indicated air switch is open, proceed to step 6.
6.
Remove cover (4) from air switch (5), loosen locknut (6), and turn adjustment screw (7) one-half turn counterclockwise
(out).
7.
Close rear side door (3).
8.
Connect power cable (1) to power source.
9.
Set MODE SWITCH (8) to VENT position and observe meter indication:
a. If air switch (5) closes (operating correctly), meter will indicate 0 Vac. Set MODE SWITCH (8) to OFF position and
proceed to step 10.
b. If air switch (5) does not close, meter will indicate 120 Vac. Repeat steps 1 thru 9.
c. If air switch (5) does not close after turning adjustment screw (7) completely clockwise (in), replace air switch.
10. Disconnect multimeter and close control panel (9) and control panel cover (10).
11. Open rear side door (3).
