Toshiba RAV-SM1403AT-E1 service manual Outline of Main Controls Pulse Modulating Valve PMV control

7-1-2. Outline of Main Controls

1.Pulse Modulating Valve (PMV) control

1)For PMV 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 92°C for SM110, SM140 in both cooling and heating operations.

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 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)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 error counting is cleared when the operation continued for 10 minutes. If the error is detected by 4 times without clearing, the error is determined and restarting is not performed.

∗The cause is considered as excessively little amount of refrigerant, PMV error or clogging of the cycle.

3)For displayed contents of error, confirm on the check code list.

TD [˚C]

Abnormal stop

111

Frequency normal down

109

Frequency slow down

106

Frequency hold

103

Frequency slow up (Up to command)

96

As command is

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