Mitsubishi Heavy Industries SRK25GZ-L1 Handbook page 829

(d) Defrosting
(i) Conditions for starting defrosting
When all the following conditions are met, the defrosting operation will start:
1) The cumulative operating time of the compressor comes up to 48 minutes after completion of a defrosting operation, or it
comes up to 33 minutes after a heating operation starts (the remote controller is turned on).
2) Eight minutes has passed after the compressor was turned off and on.
3) Eight minutes has passed after end of outdoor unit fan motor control.
4) After all the above conditions have been met, the temperature of the heat exchanger thermistor (Th
defrosting start temperature for three minutes in succession.
(ii) Operation of functional components in defrosting
Frequency
CM2 OFF
CM2 ON
Outdoor unit fan
4-way
valve
Opener
SV1.2
or
Closed
Heating Output
(CnT-3)
(iii) Conditions for finishing Defrosting
When any of the following conditions is met, the defrosting finishing operation will start.
1) When the temperature of the heat exchanger thermistor (Th
2) When 12 minutes has passed after start of defrosting.
Outdoor air temperature (Th
Defrosting start
Heating
Designated Hz
40Hz
35Hz
10sec
OFF
ON
ON
5sec Opener or Closed
On
or
OFF
Heating Defrosting operation
R407C
-A)
O
20sec
Designated Hz
100Hz
65Hz
ON ON or OFF
ON
3min. or
ON
OFF
OFF
ON
OFF
ON
OFF
Heating
-R) increases adove 14˚C (R407C : 20°C)
O
FDC-HKX
-R) has been below the
O
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