Discharge Temperature Control; Pulse Motor Valve (Pmv) Control - Toshiba RAS-M10PKVP-E Service Manual

Item
14. Discharge
temperature
control
Td value
Judges as an error and stops the compressor.
117°C
Reduce the compressor speed.
112°C
Reduce slowly compressor speed.
108°C
105°C
Keeps the compressor speed.
If the operation is performed with lower speed than one
commanded by the serial signal, speed is slowly raised
98°C
up to the commanded speed.
Operates with speed commanded by the serial signal.
15. Pulse motor This function controls throttle amount of the refrigerant
valve (PMV)
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.
∗
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
Operation flow and applicable data, etc.
Control operation
Starting up
Initialize
Move to initial position
Compressor ON
TD release control
Thermo. OFF
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.
Defrost
Setup value
– 70 –
Description