Amana ANX, Обслуживание и устранение неисправностей

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SYSTEM OPERATION
58
Expansion Valve/Check Valve Assembly In Cooling
Operation
Most expansion valves used in current Amana Heat Pump products use an internally checked expansion valve. This type
of expansion valve does not require an external check valve as shown above.
Restrictor Orifice Assy in Cooling Operation
In the cooling mode, the orifice is pushed into its seat,
forcing refrigerant to flow through the metered hole in the
center of the orifice.
Expansion Valve/Check Valve Assembly In Heating
Operation
Restrictor Orifice Assy in Heating Operation
In the heating mode, the orifice moves back off its seat
allowing refrigerant to flow unmetered around the outside
of the orifice.
SEQUENCE OF OPERATION
Refer to the installation instructions and wiring
diagrams provided with the MBR/AR*F for specific
wiring connections and system configuration.
MBR/AR*F With Single Stage Condensers
1.0 Cooling Operation
1.1 On a demand for cooling, the room thermostat
energizes “G” and “Y” and 24Vac is supplied to “Y” at the
condensing unit and the “G” terminal on the EBTDR board.
1.2 The compressor and condenser fan are turned on and
after a 7 second on delay, the relay on the EBTDR board is
energized and the blower motor starts.
1.3 When the cooling demand “Y” is satisfied, the room
thermostat removes the 24Vac from “G” and “Y”.
1.4 The compressor and condenser fan are turned off and
after a 65 second delay off, the relay on the EBTDR board
is de-energized and the blower is turned off.
2.0 Heating Operation
2.1 On a demand for heat, the room thermostat energizes
“W1” and 24Vac is supplied to heat sequencer, HR1, on the
heater assembly.
2.2 The contacts M1 and M2 will close within 10 to 20
seconds and turn on heater element #1. The normally
closed contacts on the EBTDR are also connected to
terminal M1. When M1 and M2 close, the blower motor
will be energized thru the normally closed contacts on the
EBTDR board. At the same time, if the heater assembly
contains a second heater element, HR1 will contain a
second set of contacts, M3 and M4, which will close to turn
on heater element #2.