Valve And Sensor Function And Operation - Toshiba HFC R407C Service Manual

Valve and sensor function and operation

Multi Controller - valve functions
Symbol Name of valve
PMV (A, B, C, D) Flow rate control valve
SVS (A, B, C, D) Suction gas valve
SVD (A, B, C, D) Discharge gas valve
SVSS Pressure reducing
solenoid valve
SVDD Pressure increasing
solenoid valve
SVH Superheat solenoid valve
Multi Controller - valve operation
Outdoor operation mode Indoor operation mode
Shutdown
During operation
Multi Controller
Shutdown, fan
Shutdown, fan
Cooling
Cooling thermo-control (@ setpoint) OFF
Heating
Heating thermo-control (@ setpoint) OFF
Description of function
This opens to the extent corresponding to the capacity
and performance required of each indoor unit.
Opens when commands from the indoor units require
cooling operation.
Opens when commands from the indoor units require
heating operation.
Opens when the number of units in heating operation
is reduced (heating to shutdown or cooling).
Opens when defrost operation starts.
Opens during oil retrieval control in cooling operation.
Opens when the number of units in heating operation
is increased (shutdown or cooling to heating).
Opens while control is performed to prevent liquid
in discharge pipe from being blocked.
Opens when unit in cooling operation is present.
SVD
OFF
OFF
OFF
OFF
ON
ON
SVS PMV
OFF Fully closed
ON Fully closed
ON Rated opening
ON Fully closed
OFF Rated opening
OFF Fully closed
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