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Item Operation fl ow and applicable data, etc. Description
13. Discharge
temperature
control
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.
•
Td value
117°C
112°C
108°C
105°C
98°C
Control operation
Judges as an error and stops the compressor.
Reduce the compressor speed.
Reduce slowly compressor speed.
Keeps the compressor speed.
If the operation is performed with lower speed than
one commanded by the serial signal, speed is slowly
raised up to the commanded speed.
Operates with speed commanded by the serial signal.
14. Pulse motor valve
(P.M.V.) control
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.
1) When starting the operation, move the
valve once until it fi ts 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.
Starting up
Initialize
PMV open degree control
SH control
Stop by
remote controller
Thermo. OFF Defrost
Setup value
Power OFF
Setup value Setup value
TD release control
Compressor ON
Move to initial position
∗ 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
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