-
46
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2) Low pressure error detection
a) If either of the following conditions is satisfied, the compressor is stopped.
1
If the low pressure is 0.079 MPa or lower continuously for 15 seconds after the compressor starts.
2
If the low pressure is 0.15 MPa after 10 minutes have passed since the compressor started and superheating
at 30
°
C continues for 60 seconds.
b) Operation resumes automatically when the low pressure becomes 0.227 MPa or higher.
c) If the conditions in
1
or
2
of item a) above occur 3 times within 60 minutes or if the low pressure drops to
0.079 MPa or lower for 6 minutes or longer continuously, including when the compressor is stopped, the unit is
subjected to an abnormal stop (E49).
(iv) High pressure ratio protection control
During a heating operation, the compressor’s speed is controlled in accordance with the low pressure (LPT) and indoor
heat exchanger temperature (ThI-R1).
1) Start conditions
When all the following conditions are satisfied
a) 10 minutes have passed since the compressor started.
b) The outdoor unit fan is ON and 10 minutes have passed since the outdoor unit fan started.
c) 10 minutes have passed since defrosting ended.
d) When the low pressure and indoor heat exchanger temperature detected values are within the control region
shown in the following figure for 30 seconds.
2) Control contents
The compressor’s speed is lowered. 1 minute later, detection is repeated and if the conditions in item d) continue to
exist, the speed is lowered still further.
3) End conditions
When operation is outside the control region shown in item d) above for 6 minutes continuously.
( h) Inverter protection control
( i ) Current cut control
This prevents overcurrent at the inverter. If the current exceeds the set value, the compressor stops. It restarts automati-
cally 3 minutes later, but if the current is cut 4 times within a period of 30 seconds, an abnormal stop (E42) occurs.
(ii) Power transistor overheating protection
1) If the power transistor’s temperature rises to 110
°
C or higher, the compressor stops. If the temperature drops to 90ºC
or lower after 3 minutes, the compressor restarts automatically.
2) If this operation is repeated 5 times within 60 minutes, or the temperature rises to 110
°
C or higher for 15 minutes
continuously, an abnormal stop occurs.
( i)
Open phase protection
If the voltage of either the L1, L2 or L3 phase is 0 V for 5 seconds continuously after the power is turned ON, it is judged
that there is an open phase state in the power supply, and 1 second later, an abnormal stop (E34) occurs.
(j)
Temperature thermistor (outdoor heat exchanger, outdoor air, discharge pipe, suction pipe) and low pres-
sure sensor disconnection sensing
( i ) Outdoor heat exchanger temperature thermistor, outdoor air temperature thermistor, low pressure sensor
If the conditions on the following page are detected for 5 seconds continuously between 2 minutes to 2 minutes 20
seconds after the compressor goes ON, the compressor goes off. After a 3-minute delay, the compressor is restarted, but
if this state is detected 3 times within a 40-minute period, an abnormal stop occurs.
Note (1) This is not detected during defrosting and for 3 minutes after defrosting.
65
33
0.150
0.425
Low pressure (MPa)
Control domain
Indoor heat exchanger
temperature (˚C)
