Elektronika SCM60ZD-S Manual page 31

(e) Defrosting
(i) When the following conditions are met, the defrosting operation will start.
1) During normal operation
a) When 40 minutes has passed since the start of heating or 40 minutes after the last defrosting (based on cumulative
operation time of compressor).
b) When the outdoor heat exchanger sensor (Tho-R) temperature is –2 °C or less for 3 continuous minutes after 37
minutes have passed.
c) Outdoor temperature sensor (Tho-A) – outdoor heat exchanger sensor (Tho-R) temperature > = 0.44 × outdoor
temperature sensor (Tho-A) temperature + A °C or more.
A = Outdoor temperature > = – 2 °C: 4, outdoor temperature < – 2 °C: 6.
d) When the compressor is operating.
u Or, during heating, defrosting will start when the decision speed counts zero (0) rps for 10 times or more and
all conditions in a), b) and d) have been satisfied.
2) During defrosting acceleration
a) When 40 minutes has passed since the last defrosting (based on cumulative operation time of compressor).
b) When the compressor is operating.
u Or, during heating, defrosting will start when the decision speed counts zero (0) rps for 10 times or more and
all conditions in a) and b) have been satisfied.
Note (1) Defrosting acceleration is when the finishing of the previous defrosting is according to the defrosting conditions of the 10 minutes
that have passed.
3) Operation of function component in defrosting
After compressor software
Outdoor unit speed
Outdoor unit fan
4-way valve
Electronic expansion
valve EEV
(Operating unit)
Electronic expansion
valve EEV
(Stopped unit)
Start of defrost operation
100 sec.
R1rps
Decision rps
has started
0rps
F1
According to rps
OFF
ON
OFF
470 pulse
fully opened
X1 pulse
250 pulse
EEV control
50 sec.
Opening in
relation to
conditions
0 pulse
Defrost operation
Defrost end condition
120 sec.
R2rps
Decision rps
F1
Notes (1)
300 pulse
X2 pulse
EEV control
Opening in relation to conditions
Defrost end operation
Indoor unit fan is
in response to Hot
Keep.
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