Circuit Configuration And Control Specifications; Indoor Control Circuit - Toshiba RAV-SM562MUT-E Service Manual

8. CIRCUIT CONFIGURATION AND CONTROL SPECIFICATIONS

8-1. Indoor Control Circuit

8-1-1. Outline of Main Controls
1. Pulse Motor Valve (P.M.V.) control
1) PMV is controlled with 50 to 500 pulses during operation, respectively.
2) In cooling operation, PMV is controlled with the temperature difference between TS sensor and TC
sensor.
3) In heating operation, PMV is controlled with the temperature difference between TS sensor and TE
sensor.
4) For the temperature difference in items 2) and 3), 1 to 5K is aimed as the target in both cooling and
heating operations.
5) When the cycle excessively rose in both cooling and heating operations, PMV is controlled by TD sensor.
The aimed value is usually 105°C for SM562 in both cooling and heating operations.
A sensor trouble may cause a liquid back-flow or abnormal overheat resulting in excessive shortening of the
compressor life. In a case of trouble on the compressor, be sure to check there is no error in the resistance
value an the refrigerating cycle of each sensor after repair and then start the operation.
2. Discharge temperature release control
1) This function controls the operation frequency,
that is, lowers the operation frequency when
the discharge temperature has not lower or
the discharge temperature has rapidly risen
during P .M.V. control.
It subdivides the frequency control up to a unit
of 0.6Hz to stabilize the cycle.
2) When the discharge temperature is detected
in an abnormal stop zone, the unit stops the
compressor and restarts after 2 minutes 30
seconds.
The error counter is cleared when it has
continued the operation for 10 minutes.
If the abnormal stop zone has been detected
by 4 times without clearing of counter, an
error "P03" is displayed.
* The cause is considered as excessively little
amount of refrigerant, defective PMV, or
clogging of cycle.
a b
SM562 117 112
3. Current release control
The output frequency and the output voltage are controlled by AC current value detected by T02 on the
outdoor P .C. board so that input current of the inverter does not exceed the specified value.
Objective
model
I1 value [A]
CAUTION
[°C]
c d e
108 105 98
SM562
COOL HEAT
9.22 11.93
TD [˚C]
Error stop ("P03" display with 4 times of error counts)
a
b
c
d
e
As command is
[A]
I1
1–0.5
* For the cooling only models, only COOL is objective.
– 33 –
Frequency down
Frequency holding
Frequency slow-up
(Up to command)
Frequency down
Hold
Normal operation
Hold