Specifications

145
(h) Current safe control
1) When the converter input current detected by the current sensor (CT) exceeds the set value, the frequency is reduced by
2 Hz. Checks are performed every second following this and if the current still exceeds the setting, the frequency is
reduced by another 2 Hz.
2) When the frequency is 30 Hz or less, this control will operate four in one hour and then perform an abnormal stop. At the
same time, LED 5 on the printed circuit board for the outdoor unit will flash 3 times at 0.5 second intervals every 8
seconds. Note that on the first operation, the unit can be restarted after setting the compressor to stop mode.
(i) Inching protection control
1) When the detected outdoor air temperature (detected by Tho-A) before the compressor stop is 22°C or less for the
cooling operation and 0°C or less for the heating operation for 1 continuous minute, following control is executed in
order to prevent the dilution of the refrigerant oil due to the dissolved refrigerant caused by the frequent start/stop of the
compressor during the therm operation.
2) Restoration is made when the outdoor air temperature thermistor detects a temperature of 24°C or more during cooling
or a temperature of 2°C or more during heating.
Outdoor frequency
Hot Standby
Decision frequency
0 Hz
ON
OFF
Stop mode
1 minute
1 minute 55 seconds
(j) Discharge pipe thermistor interrupt protection
After 10 minutes from the compressor operation start other than 0 Hz of outdoor unit, when the temperature of discharge
pipe thermistor detected the open circuit signal for 10 seconds (less than 7°C), the stop mode is performed immediately
and then the unit is re-started.
(This is detected only once at the compressor ON condition.)
If abnormality occurred 4 times in succession, the abnormal stop is performed and the re-start is not performed. At the
same time, the LED 5 on the printed circuit board of the outdoor unit will be lit for 4 seconds and lit off for 4 seconds.
(The timer lamp on the indoor unit flashes twice.)
(k) Power transistor overheat protection
If the thermal switch inside the power transistor is activated, the compressor is stopped immediately. While the unit can be
restarted once temperature of the power transistor has gone down and/or after the 3-minute delay has finished, it cannot be
started a third time if there is an abnormal stop of a restart within 1 hour. At the same time, LED 5 on the printed circuit board
for the outdoor unit will flash 4 times at a 0.5 second interval every 8 seconds. (The timer lamp on the indoor unit will flash
4 times.)
Set value: 110 ± 10°C open / 90°C close
(l) Compressor overheat protection control
1) When the discharge pipe thermistor temperature is 125°C for 5 continuous seconds, the inverter is stopped. If the
temperature becomes 90°C after stop mode, the inverter is re-started.
2) If the inverter stop occurs 4 times within 1 hour, the abnormal stop is performed and the re-start is not performed.
(The LED5 on the printed circuit board of the outdoor unit will flash 5 times every 8 seconds at a 0.5 second's interval
for 5 times. The timer lamp on the indoor unit will flash 5 times.)
3) When the detected temperature is 105°C, the following frequency control is performed.
Notes (1) If the discharge pipe temperature is 105°C, the frequency is lowered 4 Hz.
(2) After 40 seconds, if the discharge pipe temperature is lower than the previous temperature, the frequency is lowered 2 Hz; if it is higher, the
frequency is lowered 4 Hz.
(3) If the discharge pipe temperature is 95°C or more and less than 105°C and the inverter frequency is maintained and/or the unit operates at the
same frequency for 6 minutes or more, compressor overheat protection control is cancel and the unit returns to normal operation.
Decision frequency
Inverter
6 minutes or more has passed
(3)
6 minutes or more has passed
(3)
6 minutes or more has passed
(3)
95 105 125
Lower limit 30 Hz
4 Hz
4 Hz or 2 Hz
(2)
4 Hz or 2 Hz
(2)
0 Hz
Dischar
g
e pipe temperature (°C)