Mitsubishi SRK63ZEA-S1, Technical Manual

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(12) Freezing cycle system protective control
(a) Operating conditions: When both of following conditions have continued for more than 5 minutes later than 5 minutes
after the start of operation.
1) Inverter command speed is higher than 60 rps
2) During cooling, dehumidifying: Indoor heat exchanger temperature–Room temperature > –4°C
During heating: Indoor heat exchanger temperature–Room temperature < 6°C
(b) Detail of operation:
The inverter command speed repeats 30 minutes at 30rps
↔
2 minutes at 62 rps.
(c) Reset conditions: When the condition becomes outside of either conditions 1) or 2) shown above
Note (1) This control is valid when the room air temperature is in the range of 10 to 40°C at cooling and dehumidification operation and 0 to 40°C at heating
operation.
(13) Prevention of continuous low speed operation: For oil return to compressor
(a) Operating conditions:
When inverter command speed of less than 20 rps continues for 60 minutes
(b) Detail of operation: The unit is operated at inverter command speed of 30 rps forcibly for 15 seconds. (The indoor and
outdoor fans are not changed.)
Note (1) When the inverter command of exceeding 30 rps is directed during 30 rps forced operation, the unit follows it.
(14) Current cut
(a) Purpose: Inverter is protected from overcurrent.
(b) Detail of operation: Output current from the converter is monitored with a shunt resistor and, if the current exceeds the
setting value, the compressor is stopped immediately. Operation starts again after a delay time of 3
minutes.
(15) Outdoor unit failure
This is a function for determining when there is trouble with the outdoor unit during air conditioning.
The compressor is stopped if any one of the following in item 1), 2) is satisfied. Once the unit is stopped by this function, it is not
restarted.
1) When the input current is measured at 1 A or less for 3 continuous minutes or more.
2) If the outdoor unit sends a 0 rps signal to the indoor unit 3 times or more within 20 minutes of the power being turned on.
(16) Current safe
(a) Purpose: Current is controlled not to exceed the upper limit of the setting operation current.
(b) Detail of operation: Input current to the converter is monitored with the current sensor fixed on the printed circuit board
of the outdoor unit and, if the operation current value reaches the limiting current value, the outdoor
unit speed is reduced.
If the mechanism is actuated when the speed of outdoor unit is less than 20 rps, the compressor is
stopped immediately. Operation starts again after a delay time of 3 minutes.