Outline Of Main Controls - Toshiba RAV-GP1101AT8-E Service Manual

7-2. Outline of Main Controls

1. PMV (Pulse Motor Valve) control
1) PMV is controlled between 30 and 500 pulses during operation.
2) In cooling operation, PMV is usually controlled with the temperature difference between TS sensor and
TC sensor aiming 1 to 4K as the target value.
3) In heating operation, PMV is usually controlled with the temperature difference between TS sensor and
TE sensor aiming –1 to 4K as the target value.
4) When the cycle excessively heated in both cooling and heating operation, PMV is controlled by TD
sensor. The target value is usually 91°C in cooling operation and 96°C in heating operation.
REQUIREMENT
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 trouble in the resistance
value or the refrigerating cycle of each sensor after repair and then start the operation.
2. Discharge temperature release control
1) When the discharge temperature did not fall or the discharge temperature rapidly went up by PMV
control, this control lowers the operation frequency. It subdivides the frequency control up to 0.6Hz to
stabilize the cycle.
2) When the discharge temperature detected an abnormal stop zone, the compressor stops and then
restarts after 2 minutes 30 seconds.
The trouble counting is cleared when the operation continued for 10 minutes. If the trouble is detected by
4 times without clearing, the trouble is determined and restarting is not performed.
" The cause is considered as excessively little amount of refrigerant, PMV trouble or clogging of the cycle.
3) For displayed contents of trouble, confirm on the check code list.
TD [˚C]
111
Frequency normal down
109
Frequency slow down
106
103
Frequency slow up
(Up to command)
96
Abnormal stop
Frequency hold
As command is
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