Toshiba RAS-4M23SACV-E, Service Manual, Page: 54 / 121

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Item
14. Pulse motor
valve (PMV)
control
Operation flow and applicable data, etc.
This function controls throttle amount of the
refrigerant in the refrigerating cycle.
According to operating status of the air conditioner,
this function also controls the open degree of valve
with an expansion valve with pulse motor.
Description
1) When starting the operation, move the
valve once until it fits to the stopper.
(Initialize)
* In this time, “Click” sound may be
heard.
2) Adjust the open degree of valve by super
heat amount. (SH control)
3) If the discharge temperature was exces-
sively up, adjust the open degree of valve
so that it is in the range of set tempera-
ture.
(Discharge temp. control)
4) When defrost operation is performed, the
open degree of valve is adjusted accord-
ing to each setup conditions during
preparation for defrost and during defrost
operation (4-way valve is inversed.).
5) To turn off the compressor while the air
conditioner stops by control of the
thermostat or by remote controller, adjust
the open degree of valve to the setup
value before stop of the compressor.
* SH = Ts – Tc or Te
(Super Heat value) =
(Temperature of suction pipe of the compressor) – (Heat exchanger temperature at evaporation side)
* PMV: Pulse Motor Valve
Starting up
Defrost
Initialize
Move to
initial position
PMV open degree control
SH control
Discharge
temp. control
Stop by
remote controller
Power OFF
Room temp. sensor
(Ta sensor) control
Compressor ON