Table of Contents
Advertisement
7-1. Outline of Main Controls
1. Pulse Modulating Valve (PMV) control
1) For PMV : 30 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 : 91°C 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 compressor 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.
7. OUTDOOR CONTROL CIRCUIT
TD [˚C]
Abnormal stop
a
Frequency normal down
b
Frequency slow down
c
Frequency hold
d
Frequency slow up
(Up to command)
e
As command is
a
GV160
111
b
c
d
e
109
106
103
96
- 36 -
Advertisement
Table of Contents
Troubleshooting
