Mitsubishi Heavy Industries FDTC40ZHXV Technical Manual page 174

12) Serial signal transmission error protection
a) Purpose: Prevents malfunction resulting from error on the indoor ↔ outdoor signals.
b) Detail of operation: If the compressor is operating and a serial signal cannot be received from the indoor control
13) Rotor lock
If the motor for the compressor does not turn 1/12 revolution 0.044 seconds after it has been started, it is determined that
a compressor lock has occurred and the compressor is stopped.
14) Outdoor fan motor protection
If the outdoor fan motor has operated at 75 rpm or under for more than 30 seconds, the inverter and fan motor are
stopped.
15) Outdoor fan control at low outdoor temperature
◆
Cooling
a) Operating conditions: When the ambient air temperature (Th5) is 22ºC or lower continues for 30 seconds while
b) Detail of operation: After the outdoor fan operates at A speed for 60 seconds; the corresponding outdoor heat
1 Outdoor heat exchanger temperature = < 21ºC
After the outdoor fan speed drops (down) to 1 speed for 60 seconds; if the outdoor heat exchanger temperature
is lower than 21°C, gradually reduce the outdoor fan speed by 1 speed. (Lower limit 1st speed)
2 21ºC < Outdoor heat exchanger temperature = < 38ºC
After the outdoor fan speed maintains at A speed for 20 seconds; if the outdoor heat exchanger temperature is
21°C~ 38°C, maintain outdoor fan speed.
3 Outdoor heat exchanger tempeature > 38ºC
After the outdoor fan speed rises (up) to 1 speed for 60 seconds; if the outdoor heat exchanger temperature is
higher than 38°C, gradually increase outdoor fan speed by 1 speed. (Upper limit 3rd speed)
c) Reset conditions: When either of the following conditions is satisfied
1 The ambient air temperature (Th5) is 25ºC or higher.
2 The inverter command speed is 0 rps.
◆
Heating
a) Operating conditions: When the ambient air temperature (Th5) is 4ºC or lower continues for 30 seconds while
b) Detail of operation: The outdoor fan is stepped up by 2 speed step at each 20 seconds. (Upper limit 8th speed)
c) Reset conditions: When either of the following conditions is satisfied
1 The ambient air temperature (Th5) is 6ºC or higher.
2 The inverter command speed is 0 rps.
with outdoor control having serial signals continues for 7 minute and 35 seconds, the com-
pressor is stopped.
After the compressor has been stopped, it will be restarted after the compressor start delay if
a serial signal can be received again from the indoor control.
the inverter command speed is other than 0 rps.
exchanger temperature shall implement the following controls.
¡ Value of A
Ambient temperature > 10˚C
Ambient temperature _ 10˚C
the inverter command speed is other than 0 rps.
167
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Outdoor fan
2nd speed
1st speed