Sensor And Switch Operation - Toshiba HFC R407C Service Manual

Valve and sensor function and operation
Multi Controller sensor operation
Temperature According to a difference between the evaporator outlet temperature and
sensor (ThA, B, C, D) saturation temperature (ThX):
a. Performs superheat control.
b. Determines the degree of opening of PMV 2.
Outdoor unit sensor and switch operation
Discharge pressure
sensor
Suction temperature
sensor (ThS)
Discharge temperature Controls the degree of opening of PMV 1.
sensor (ThD1, ThD2)
Outdoor unit heat
exchanger sensor (TE) Controls the outdoor unit fan operation.
Heating operation
Outdoor temperature
sensor (ThO)
High pressure switch
Low pressure switch
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Sensor and switch operation

(cooling operation)
(cooling-dominant operation)
Determines the frequency of the inverter compressor and the ON/OFF status of
D.O.L. compressor.
Controls the outdoor unit fan operation.
Controls the hot gas bypass SV2.
Controls the changeover from outdoor unit main heat exchanger to sub heat
exchanger.
Controls the degree of opening of PMV 1.
Stops operation when ThS > 40°C for 10 minutes (Fault code [A7]).
Stops operation when the discharge temperature > 130°C (Fault code [A6]).
Controls the defrost operation.
Controls the high pressure release valve SV1.
Controls the hot gas bypass SV2.
Controls the outdoor unit fan operation.
Prevents heating operation when ThO > 25°C.
Stops operation when Pd > 30 kgf/cm
Stops operation when suction pressure < 0.25 kgf/cm
• After 30 seconds for cooling operation.
• After 10 minutes for heating operaton.
The low pressure switch is ignored during defrost operation.
2
G.
2 G: