TM 9-4120-407-14
2-7. OPERATING PROCEDURES. (Cont)
(7) Turn the MODE selector rotary switch to COOL position. If the TEMPERATURE /PRESSURE
FAULTS indicator light continues to come on, notify Unit Maintenance.
NOTES
The evaporator fan motor will continue to operate when the
TEMPERATURE potentiometer cut-out setting is reached.
The evaporator fan motor will cycle off when the TEMPERATURE
potentiometer cut-in setting is reached and start up again with the
The motor controller will delay equipment re-start for
approximately 30 seconds, then it will take approximately two
seconds to bring the equipment from start to full power.
(8) If the air conditioner was returned to the cooling mode, the temperature should soon stabilize and
the air conditioner will begin to cycle the equipment on and off. If the desired temperature is not
maintained, adjust the TEMPERATURE knob slightly toward WARM or COOL as necessary until
it does.
Do not operate the air conditioner in the COOL mode if the
refrigerant condition color indicator has turned yellow or if numerous
bubbles appear in the liquid sight indicator. Equipment damage can
result.
(9) When the desired temperature has been reached and the air conditioner is cycling, observe the
NOTE
The liquid sight indicator shows the liquid refrigerant flowing from
the condenser coil to the evaporator metering device.
(a) The liquid sight indicator should be full. No bubbles or an occasional flash of bubbles or foam
should be observed. Rechecked after four hours of operation to insure that the condition has
not become worse. If there is a constant flow of bubbles or foam, shutdown the air conditioner
and disconnect power. Notify supervisor.
Figure 2-16. Liquid Sight Indicator
2-26