2-17. OPERATION in EXTREME COLD. Continued.
b. Open shades and awnings to permit entry of direct rays of the sun, if appropriate.
c. Limit the amount of cold, outside air introduced thro ugh the fresh air damper to that needed for ventilation.
Do not perform the operational check in COOL mode until input power has been
supplied to the unit in accordance with the following:
Ambient (Outside) Temperature
Minimum Input Power Ti me
60 Degrees F
40 Degrees F
One (1) Hour
20 Degrees F
Two (2) Hours
Below 20 Degrees F
Four (4) Hours
Liquid refrigerant tends to migrate into the compressor and mix with the lubricating oil.
Since the refrigerant is heavier than the oil, it displaces the lubricating oil from the bottom
of the compressor well. The above sliding timetable for power input to Air Conditioner is
required to boil the liquid refrigerant out of the lubricating oil at the bottom of the
compressor well. This action is needed to prevent "slugging" of the compressor when the
Air Conditioner is started in cool mode and to prevent premature failure of the
Before starting the air conditioner in COOL mode, make sure that the fabric condenser
cover on the back of the condenser section is rolled up and secured and that all screens
and guards are in place and unobstructed. This action is needed to avoid damage to
2-18. OPERATION in DUSTY OR SANDY CONDITIONS . Dusty and sandy conditions can seriously reduce the
efficiency of the air conditioner by clogging the air filters which will restrict the volume of airflow. Accumulation of dust or
sand in the condenser coil and/or in the compressor compartment may cause overheating of the refrigeration system.
Dust or sand may also clog the condensate trap and water drain lines. When operating the air conditioner in these dusty
and sandy conditions, perform the following steps:
a. Frequent cleaning of filters and all other areas of dust and sand accumulation.
in extreme conditions, daily
cleaning of filters may be necessary.
b. Limit the amount of dusty or sandy outside air introduced through the fresh air damper to that essential for
c. Roll down and secure the fabric cover on the back of the cabinet during periods of shutdown.
2-19. OPERATION in UNUSUALLY WET CONDITIONS .
When operating the air conditioner in unusually wet
conditions, perform the following steps:
2-20 Change 1