AIR CONDITIONING (Cont) - TM-55-1905-223-24-170213

TM 55-1905-223-24-17

Table 4-1. Troubleshooting - CONT

Malfunction

Test or Inspection

Corrective Action

AIR CONDITIONING - CONT

(2)

Make sure both handwheels on the manifold are closed fully clockwise.

(3)

Start and run compressor for 5 minutes before continuing.

NOTE

The sight glass in the liquid line will show a stream of bubbles, or a foamy

appearance, when the system is low on refrigerant.

(4)

Open the valve on the refrigerant container counterclockwise.

(5)

Open the suction service valve on the compressor three turns clockwise.

(6)

Watch the sight glass and slowly crack open the gauge port handwheel on the

combination (suction) gauge momentarily for 1 to 2 seconds, adding a small

amount of refrigerant. Close handwheel and observe sight glass condition.

(7)

If bubbles are still present, repeat cracking and closing combination with gauge

handwheel until sight glass shows a clear condition. Do not continue to add

refrigerant once the sight glass has cleared.

(8)

When sight glass has cleared, close (back-seat) service valve fully

counterclockwise.

(9)

Close valve on refrigerant container fully clockwise.

(10) Shut down compressor and disconnect gauge manifold from refrigerant

container and suction service valve.

STEP 2.

Check for clogged suction strainer in semi-hermetic type compressor (A/C-2).

Remove and clean suction strainer (paragraph 4-19).

Compressor crankcase cold (sweating or frosting).

STEP 1.

Check to see if refrigerant is overcharged.

Remove excess refrigerant (Malfunction 3).

STEP 2.

Check to see if operating thermostat is set too low or is defective.

Adjust thermostat. Replace thermostat if defective (paragraph 4-14).

4-6