Toshiba CARRIER RAV-SP300AT2-UL User Manual

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7-2. Outline of Main Controls


1. PMV (Pulse Motor Valve) control

1) PMV is controlled between (20 to 500) pulsed during operation.
2) In cooling operation, PMV is usually controlled with the temperature difference between TS sensor and

TC sensor aiming (2 to 5K) as the target value.

3) In heating operation, PMV is usually controlled with the temperature difference between TS sensor and

TE sensor aiming (–2 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 213.8°F (101°C) for 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 or the refrig-

erating 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 A minutes. If the error is detected by

B 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.






Frequency normal down

Frequency slow down

Frequency hold

Frequency slow up

(Up to command)

As command is

Abnormal stop

TD ˚F (˚C)

242.6 (117)

224.6 (107)




215.6 (102)

199.4 (93)