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9-2-2. Outline of Main Controls
1. Pulse Modulating Valve (PMV) control
1) For PMV, SM560 is controlled with 45 to 500 pulses and SM800 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 105°C for SM560 and 100°C for SM800 in both cooling and heating opera-
tions.
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 fre-
quency control up to a unit of 0.6Hz to stabi-
lize the cycle.
2) When the discharge temperature is detected
in an abnormal stop zone, the unit stops the
compressor 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.
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.
SM560
SM800
abcde
117 112 108 105 98
111 106 100 95 90
[°C]
Objective
model
I1 value [A]
SM560
COOL HEAT
10.22 10.35
SM800
COOL HEAT
13.00 14.43
* For the cooling only models, only COOL is
objective.
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
1–0.5
[A]
Frequency down
Normal operation
Hold
Hold