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9-2-2. Outline of Main Controls
1. Pulse Modulating V alve (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 103°C for SM562, SM802 and 92°C for SM1102, SM1402 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) 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
PMV control. It subdivides the frequency control
up to a unit of 0.6 Hz to stabilize the cycle.
2) When the discharge temperature is detected in an
abnormal stop zone, the unit stops the compres-
sor 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.
[°C]
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]
SM562 SM802 SM1102 SM1402
COOL HEAT COOL HEAT COOL HEAT COOL HEAT
10.1 12.0 12.2 14.0 18.9 19.7 19.7 19.7
SM562, SM802
SM1102, SM1402
abcde
117 107 103 100 93
111 106 100 95 90
a
b
c
d
e
TD [˚C]
Error stop ("P03" display with 4 times of error counts)
As command is
Frequency down
Frequency holding
Frequency slow-up
(Up to command)
I1
I1–0.5
Current [A]
Frequency down
Normal operation
Hold
Hold