Monaco 2002 Diplomat, Service Manual

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The motorhome is equipped with two independent 13,500 BTU roof air
conditioners. The roof air conditioners operate from 120 Volts AC only, either
from shore power or from the on-board generator. Operations are controlled by
the 12 Volt DC comfort control. The electronics in the comfort control use a
telephone type patch cord to send a low voltage signal to the roof air condi-
tioner's circuit board. The circuit board controls the desired roof air functions
and/or LP-Gas furnace operations. The refrigerant operation principal of the
roof air conditioner is the same as the dash air conditioner or a household type
refrigerator. The function is that of an enclosed system. The compressor draws
refrigerant into it. A high-pressure vapor is then sent to a condenser where the
heat is expelled into the atmosphere. The vapor leaves the condenser as a high
pressure liquid. This liquid is forced into a metered capillary tube and then into
the evaporator or low side pressure. The refrigerant then changes from liquid
form to vapor as heat extracts. The vapor then draws back into the compressor
to start the cycle again. When operating the roof air conditioners in heat pump
mode, the principals of air conditioning reverse. The refrigerant flow reverses,
blowing heated air into the interior of the motorhome.
NOTE: The air conditioning system will freeze the moisture
in the air depending on the humidity content. Under high
humidity conditions it is recommended to set the blower fan
speed to High.
NOTE: There are ambient temperature limitations of the
Heat Pump mode. The roof air conditioner will not operate
in Heat Pump mode with ambient temperatures at or below
30º F.
Aux. Heat Mode:
When selecting the HEAT PUMP mode, or if operating in HEAT PUMP
mode and ambient temperatures are approximately 30° F, the air conditioner
will stop the Heat Pump operation and begin Aux. Heat operations. Automatic
selection of an auxiliary heat (the furnace) becomes the primary heat source
and furnace operations begin. The
AUX. HEAT mode is due to refrigerant
characteristics in cold temperatures. The furnace remains the primary heat
source until ambient temperatures rise above 42º F. When ambient temperatures
are between 30-42º F., the Defrost cycle initiates approximately every 40
minutes of compressor operation. The blower motor will stop for five minutes
and the comfort control displays
DEFROST . After the defrost cycle Heat
Pump operation will resume.
Appliances
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DIPLOMAT 4 • 1 1 9
AIR CONDITIONER
- ROOF