Mitsubishi SRK100VNXWPZSX, Service Manual

Page: 45 / 202

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44
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'20 • PAC-SM-351
Outdoor air temp
erature
(
℃
)
［
Tho-A
］
Suction saturation temp
erature
(
℃
)
［
SST
］
-20
-25
-28.6
-30
-24
-15
-10
-8
-15 -10 -5 0 5 6 10 -20 -25
Defrost operation start temperature (Standard)
Defrost operation start temperature (SW3-1 ON)
-18
Defrost operation start
temperature zone
Model FDC100-140
Outdoor air temperature (
℃
)
［
Tho-A
］
-20
-25
-27
-30
-15
-10
-5
-6
-2
-15 -10 -5 0 5 6 10 -20 -25
Defrost operation start
temperature zone
Defrost operation start temperature (Standard)
Defrost operation start temperature (SW3-1 ON)
Outdoor heat exchanger temperature
(
℃
)
［
Tho-R
］
-18
Model FDC100-140
(5) Defrost operation
(a) Starting conditions
If all of the following defrost conditions A or conditions
B are satisfied, the defrost operation starts.
(i) Defrost conditions A
1) Cumulative compressor operation time after the
end of defrost operation has elapsed 37 minutes, and
the cumulative compressor operation time after the
start of heating operation (remote control ON) has
elapsed 30 minutes.
2) After 5 minutes from the compressor ON
3) After 5 minutes from the start of outdoor fan
4) After satisfying all above conditions, if temperatures
of the outdoor heat exchanger temperature sensor
(Tho-R1, R2) and the outdoor air temperature
sensor (Tho-A) become lower than the defrost
operation starting temperature as shown by the right
figure for 15 seconds continuously, or the suction
gas saturation temperature (SST) and the outdoor
air temperature (Tho-A), which are obtained from
the value detected by the low pressure sensor (LPT)
stay for 3 minutes within the range below the defrost
operation start temperature as shown by the right
figure.However, it excludes for 10 minutes after the
start of compressor and the outdoor air temperature
is as shown by the lower figure.
LPT detection
Outdoor air temperature (°C)
2 4
LPT invalid
(ii) Defrost conditions B
1) When previous defrost ending condition is the time
out of defrost operation and it is in the heating
operation after the cumulative compressor operation
time after the end of defrost operation has become
30 minutes.
2) After 5 minutes from the start of compressor
3) After 5 minutes from the start of outdoor fan
(b) Ending conditions
When any of the following conditions is satisfied, the
heating operation starts.
(i) When it has elapsed 13 minutes and 20 seconds after
the start of defrost operation.
(ii) When the outdoor heat exchanger temperatures (Tho-R1,
R2), whichever the lower, becomes 12°C or higher for 60
seconds continuously.