Airxcel 45000 Series, Installation, Operation And Maintenance Instructions

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IX. OPERATION AND MAINTENANCE
INSTRUCTIONS FOR 45000 SERIES
ROOF TOP HEAT PUMPS AND CEILING PLENUMS
i. GENERAL INFORMATION
NOTE: An optional auxiliary electric resistance
heating assembly can be installed to take the chill
out of the indoor air when the Heat Pump can no
longer operate. The Heat Pump will shut down at
conditions which would cause outdoor coil freeze-
up, generally near freezing temperatures.
IMPORTANT
The electric resistance heating assembly cannot be added to
the rooftop unit that does not use a standard ceiling assembly.
This roof mount Heat Pump is designed to operate from
a 115 VAC, 60 HZ, 1 Phase power supply. A qualified
technician should verify that the Heat Pump is receiving
the proper power.
The ability of the Heat Pump to maintain the desired
inside temperature depends on the heat gain or heat
loss of the recreational vehicle. All sizing considerations
should be based on the cooling load desired. The Heat
Pump should be considered a cooling unit which also
provides heat at outdoor temperatures above freezing.
The size of the vehicle, amount of window area, amount
of insulation, direct exposure to the sun, outside
temperature and the number of people in the recreational
vehicle may increase the heat gain to such an extent that
the capacity of the Heat Pump is exceeded.
As a general rule, air entering the Heat Pump will be
cooled about 15 to 20 degrees, depending on the outside
temperature and humidity conditions.
For example, if the air entering the return air grilles in the
Heat Pump is 80 degrees F., the air leaving the discharge
grilles in the Heat Pump will be 60 to 65 degrees F.
As long as this temperature difference is being
maintained between the return air and discharge air, the
Heat Pump is operating at its capacity. If the desired
inside temperature (normally 80 degrees F) cannot be
maintained, then the heat gain of the RV is too great for
the capacity of the Heat Pump.
Parking the vehicle in a shaded area, keeping windows
and doors shut and avoiding the use of heat producing
appliances in the vehicle will help to reduce the heat
gain. When possible, the addition of insulation and
tinted glass (especially in uninsulated vans) should be
considered.
R410A Roof Top Heat Pumps
High Pressure Switch Lockout Circuit
Heat pumps using R410A refrigerant may utilize a
factory installed High Pressure Switch Safety Circuit. In
the event of an abnormal condition (failure of fan motor,
dirty condenser coil, dirty filters), the high pressure
switch will prevent the compressor from continuing to
run. Once the high pressure switch has tripped, this
safety circuit will “Lock Out” the compressor preventing
it from trying to restart or run until the 115 VAC supply
power has been turned off and then back on to reset the
High Pressure Switch Safety Circuit. If repeated trips of
the high pressure switch lock out occur, then you must
have the unit serviced by a qualified technician.
ii. CONTROL PANEL
If your RV Heat Pump is operated from the control panel
located in the ceiling assembly, then there are three
controls on the ceiling assembly that help you control the
Heat Pump. They are as follows:
A. The Selector Switch – The selector switch
determines which mode of operation the Heat
Pump will be in. By rotating the selector switch, the
operator can obtain any system function desired.
System functions vary depending upon options of
both the roof top unit and ceiling assembly. Figure 1
shows selector switch location and lists all available
functions by model.
The “Operation” section explains the operational
characteristics of each mode of operation.
B. The Thermostat (temperature control) – In the
cooling mode, the thermostat regulates the “ON” and
“OFF” temperature setting at which the compressor
will operate.
C. Louvers – The louvers are located at both ends
of the ceiling assembly shroud and are used in
directing the discharge air from the unit.
FIGURE 1
LOUVER
CONTROLS
SELECTOR SWITCH
COOLER
WARMER
THERMOSTAT
HIGH
FAN
OFF
LOW
COOL
HIGH
COOL
LOWFAN
LOW
FAN
HIGH
FAN
OFF
LOW
COOL
HIGH
COOL
LOW
HEA
T
LOW
FAN
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