Mitsubishi Heavy Industries SRK60ZJX-S, Technical Manual

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142
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'10 • SR-T-091
(c) Defrosting operation
1)
Starting conditions (Defrosting operation can be started only when all of the following conditions are met.)
a) After start of heating operation
When it elapsed 45 (model 50 : 35) minutes. (Accumulated compressor operation time)
b) After end of defrosting operation
When it elapsed 45 (model 50 : 35) minutes. (Accumulated compressor operation time)
c) Outdoor heat exchanger sensor (TH1) temperature
When the temperature has been below –5ºC for 3 minutes continuously.
d) The difference between the outdoor air sensor temperature and the outdoor heat exchanger sensor temperature
¡
The outdoor air temperature ≧ 0°C ( model 50 : ≧ -2°C ) : 7°C or higher
¡
-15°C ≦ The outdoor air temperature ＜ 0°C (model 50 : ＜ -2°C) : 4/15 × The outdoor air tempe 7°C or
higher
¡
The outdoor air temperature < -15°C : -5°C or higher
e) During continuous compressor operation
In addition, when the speed command from the indoor controller of the indoor unit during heating operation has
counted 0 rps 10 times or more and all conditions of a), b), c) and e) above and the outdoor air temperature is 3°C or
less are satisfied (note that when the temperature for outdoor heat exchanger sensor (TH1) is -5°C or less: 62 rps or
more, -4°C or less: less than 62 rps), defrost operation is started.
2)
Ending conditions (Operation returns to the heating cycle when either one of the following is met.)
a) Outdoor heat exchanger sensor (TH1) temperature: 13ºC (model 50 : 10°C) or higher
b)
Continued operation time of defrosting → For more than 16 minutes and 50 seconds (model 50 : 18 minutes).
-20
-20 -15 -10 -5 0 5 10
-15
-10
-5
0
Outdoor air temperature (
℃
)
Outdoor heat exchanger temperature (
℃
)
-20
-20 -15 -10 -5 0 5 10
-15
-10
-5
0
Outdoor air temperature (
℃
)
Outdoor heat exchanger temperature (
℃
)
Defrost operation
start
Defrost operation
start
Defrost operation start temperature
Defrost operation start temperature
Models 20
～
35 Models 50, 60 Models 25,35 Models 50
Max. 16 minutes and 50 seconds
Heating operation
¡
Defrast operation
(Mode 50 Nax.18 minutes)
̪
Depends on an operation condition, the time can be longer than 7 minutes.
2~7 minutes ̪
Hot keep operation