Discharge Temperature Control; Pulse Motor Valve (Pmv) Control; High-Pressure Switch/Compressor Case Thermostat Control - Toshiba RAS-4M27U2AVG-E Service Manual

Item Operation flow and applicable data, etc.
8. Discharge
temperature
control
Td value
Judges as an error and stops the compressor.
120°C
Reduce the compressor speed.
115°C
Reduce slowly compressor speed.
111°C
Keeps the compressor speed.
108°C
If the operation is performed with lower speed than
one commanded by the serial signal, speed is slowly
raised up to the commanded speed.
101°C
Operates with speed commanded by the serial signal.
9. Pulse motor This function controls throttle amount of the
valve (PMV) refrigerant in the refrigerating cycle.
control
According to operating status of the air conditioner,
this function also controls the open degree of valve
with an expansion valve with pulse motor.
Move to initial position
∗ SH control
∗ PMV open degree control
Stop by
remote controller
Setup value
Power OFF
∗ SH (Super Heat amount) =
Ts (Temperature of suction pipe of the compressor) –
Tc or Te (Heat exchanger temperature at evaporation side)
∗ PMV: Pulse Motor Valve
10. High-pressure 1) When the high-pressure switch or the compressor case thermostat operates, the operation of
the compressor is terminated.
switch/
Compressor
2) The compressor restarts after 2 minutes 30 seconds using [1] as an error count.
case
After restart, the error count is cleared when operation continues for 10 minutes or more.
thermostat
control
3) An error is confirmed with the error count [10].
4) For the indicated contents of error, confirm using the check code table.
Control operation
Starting up
Initialize
Compressor ON
TD release control
Thermo. OFF Defrost
Setup value Setup value
1. Purpose
This function detects error on the
refrigerating cycle or error on the
compressor, and performs protective control.
2. Operation
• Control of the compressor speed
The speed control is performed as
described in the left table based upon
the discharge temperature.
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
excessively up, adjust the open degree of
valve so that it is in the range of set
temperature. (Discharge temp. control)
4) When defrost operation is performed, the
open degree of PMV is adjusted according
to each setup conditions during
preparation for defrost and during defrost
operation (4-way valve is inversed.).
5) When turning off the compressor by
thermo. OFF or STOP by remote
controller, the open degree of the PMV is
adjusted to the setup value.
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FILE NO. SVM-18052
Description