ARMY TM 9-4120-380-14
AIR FORCE TO 35E9-136-21
5 19. PUMP DOWN-Continued
SERVICE - continued
g. Turn MODE SELECT switch to COOL mode
h. The compressor will operate until the low pressure cutout shuts off the compressor
i. The compressor will stand idle for a few minutes. During this time, pressure in the system may build up again
due to refrigerant remaining in the crankcase oil If the pressure builds up, let the compressor run to low pressure
cutout. Allow the compressor to pump down until the pressure no longer builds up.
J. Frontseat (clockwise) compressor discharge valve.
k. Turn MODE SELECT ACT switch to OFF.
Disconnect input power to the air conditioner before performing any internal
maintenance or adjusting thermostat. Voltages used can KILL. Shutting the unit off at
the control panel does not disconnect unit power.
1. Disconnect air conditioner input power at source.
m. Open manifold VPV and let remaining refrigerant escape.
Figure 5-10. Pump Down