59
Section C - Components, cont’d.
C22. Other
C22a.
Ambient Temperature
Running the air conditioner or heat pump at a temperature
below 75 degrees Fahrenheit may cause the inside coil
(evaporator) to freeze up in the cooling mode. The most
common time for this to occur is at night. Even after the
ambient temperature has gone up, the coils will remain fro-
zen. To assist the defrosting of the coil, turn the air condi-
tioner to HI FAN mode; set the temperature selector to a
higher setting and let the air conditioner or heat pump fan
run until the coils are defrosted. Temperatures below 24° F
(Comfort Control Center system) or 40° F (mechanical
changeover thermostat) will turn off the operation of the
heat pump system. It is recommended the auxiliary heat
(furnace) be used if the temperatures are subject to drop-
ping below this outdoor temperature. Running of the heat
pump in ambient temperature above 70° F will cause the
system amperage to increase. Popping of circuit breakers
or compressor cycling on overload would be common.
C22b.
Heat Gain
Heat gain can be caused by several factors; A hot, humid
and sunny day; a large number of people in the coach;
frequent opening of the door; excessive showering and
cooking, etc.
Other factors to be taken into consideration as possible
heat gain causes are the size of the air conditioner relative
to the size of the coach; the “R” factor of insulation; and the
size and placement of window. The manufacturer of the
RV should be consulted for recommendations.
C22c.
Loose Parts
Loose parts can cause the air conditioner to operate nois-
ily. Check for any loose bolts, any component rubbing
against its housing, or any plastic parts which might be
cracked. Repair or replace parts as necessary to correct
any noise problems.
C22d.
Tubing Vibration
If any of the copper tubing is rubbing against itself or any
other part, replace or position tubing as necessary.
C22e.
Condenser or Blower Fan/
Wheel
The blower motor will have either a squirrel-cage or blade-
type fan attached to it. Turn the air conditioner circuit breaker
to OFF. Adjust the component to make sure it is not rub-
bing against the bulkhead. If it is a blade-type fan, the blades
should be half through the opening for proper operation.
Replace the blade fan or squirrel-cage if necessary.
C22f.
Installation
The installation must be according to manufacturer’s in-
structions for the specific mode.
The air conditioner must not be installed in a valley on the
roof; water may pool around the drain holes and be drawn
into the air conditioner.
Make sure the air conditioner is tightened to the specifica-
tions. Overtightening can cause the unit to leak. Use cau-
tion not to damage the mounting gasket when placing the
air conditioner over the opening, as this can allow water to
leak into the coach.
The air conditioner may be installed across a roof seam,
but make sure this area is properly sealed to prevent leak-
age.
C22g.
Drain Pan
Some drain pan problems may be caused by a blockage
or restriction of the drain holes. This could be a piece of
styrofoam or dirt, etc., in or around a drain hole causing
water to accumulate in the drain pan and be sucked up into
the unit. Remove any blockage as necessary. Check for
water under the drain pan, this could indicate a bad seal
between the drain pan and metal base, or a problem in the
drain pan.
C22h.
Evaporator Bulkhead Leak
The rear section of the air conditioner which contains the
compressor, blower motor and condenser coil is designed
to dispose of any water which may enter.
C22i. Short Cycle
Air Distribution Box Installations
Short cycle is caused by cold air being drawn back into the
intake side of the air conditioner before it is mixed with the
warmer room air. This may cause the evaporator coil to
freeze up, causing the cold control or the thermostat to
open the circuit to the compressor. Cold discharge air that
enters into the return air portion of the air box can cause a
false temperature reading at the thermostat and shut down
the compressor.
Two possible causes of this condition are the air box and
the discharge duct. If the air box is not sealed tightly against
the ceiling template, it will allow cold air to cross over into
the return air portion of the air box. Also, if the discharge
duct is not installed properly, it can allow cold air to cross
over into the return portion of the air box. Make sure you
have the correct discharge duct for the thickness of the
roof. Seal all prob-
lem areas as nec-
essary. You may
need to use tape
to seal the dis-
charge duct. Also,
make sure the
discharge louvers
are not restricted.
FIG. C68
Manual
Compliments
of
Northwest
RV
Supply
Printed
From
http://www.nwrvsupply.com
