Mitsubishi SRK10CES, Technical Handbook

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(k) Cooling overload protective control
(i) Operating conditions: When the outdoor unit is operating with the speed of other than 0 rps, or when the outdoor air
temperature (detected by Th5) becomes 41ºC or over for 30 seconds continuously.
(ii) Detail of operation
1)
Outdoor fan is stepped up by 3 speed step.
2) The lower limit of control speed is set to 30 rps and even if the calculated result becomes lower than that after fuzzy
calculation, the speed is kept to 30 rps. However, when the thermo becomes OFF, the speed is reduced to 0 rps.
3) The upper limit of control speed is 96 rps.
(iii) Restoration condition: When the outdoor air temperature becomes 40ºC or less
(l) Freezing cycle system protective control
(i) Operating conditions:
When both of following conditions have continued for more than 5 minutes later than 5 minutes
after the start of operation.
1) Command speed is higher than 60 rps
2) During cooling, dehumidifying: Indoor heat exchanger temperature - Room temperature > – 4ºC
During heating: Indoor heat exchanger temperature - Room temperature < 6ºC
(ii) Detail of operation
The command speed repeats 30 minutes at 30rps
↔
2 minutes at 62 rps.
(iii) Restoration 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 40ºC at cooling and dehumidification operation and 0 to 40ºC at heating
operation.
(m) Compressor overheat protection
(i) Purpose:
It is designed to prevent deterioration of oil, burnout of motor coil and other trouble resulting from the compressor
overheat.
(ii) Detail of operation
1) Speeds are controlled with temperature detected by the sensor mounted on the discharge pipe.
Discharge pipe temperature (˚C)
Lower limit
(4)
After lapse of 3 min. or over
(3)
After lapse of 3 min. or over (3)
After lapse of 3 min. or over
(3)
4 rps
4 rps
(1)
0 rps
(Example) Fuzzy
80 90 110
Notes (1) When the discharge pipe temperature is in the range of 90 to 110ºC, the speed is reduced by 4 rps.
(2) When the discharge pipe temperature is raised and continues operation for 20 seconds without changing, then the speed is reduced again by 4 rps.
(3) If the discharge pipe temperature is still 80ºC or greater but less than 90ºC even when the inverter command speed is maintained for 3 minutes when
the temperature is 80ºC or greater but less than 90ºC, the speed is raised by 2 rps and kept at that speed for 3 minutes. This process is repeated until
the command speed is reached.
(4) Lower Limit Speed
Cooling Heating
SRK13ZEV-S 22 38
2) If the temperature of 110ºC is detected by the sensor on the discharge pipe, then the compressor will stop immediately.
When the discharge pipe temperature drops and the time delay of 3 minutes is over, the unit starts again within 1 hour but
there is no start at the third time.
(n) Serial signal transmission error protection
(i) Purpose:
Prevents malfunction resulting from error on the indoor
↔
outdoor signals.
(ii) Detail of operation: When the indoor unit controller
↔
outdoor unit controller signals cannot be received, the compressor
is stopped immediately. Once the operation stops, it does not start any more.
(TIMER light on the indoor unit flashing at the same time.)