Mitsubishi Heavy Industries SRK25GZ-L1 Handbook page 1039

(11) Defrosting
(a) 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 45 minutes after completion of a
defrosting operation, or it comes up to 30 minutes
after a heating operation starts (the remote controller
is turned on).
2) Five minutes has passed after the compressor was
turned off and on.
3) Five 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 sensor (Th
has been below the defrosting start temperature
for three minutes in succession.
(b) Operation of functional components in defrosting
Outdoor unit fan ON
4-way valve
(20SL,SS)
Solenoid valve
(SV ,SV
L
[Indoor unit electronic
expansion valve (EEV)]
Heating unit
(include, pause)
COOL, DRY unit
(include, pause)
FAN unit,
Stop unit and COOL, DRY unit
Output of heating
(c) 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 sensor (Th
2) When 12 minutes has passed after start of defrosting.
R)
O-
Defrosting start
1 min.
Designated Hz
Frequency
0
or
OFF
5 sec.
ON
ON
or
)
S
OFF
to Hz
<Pause, stop>
(Open of about
7%)
to Hz
<Pause, 0>
Closed, 0
ON
or
OFF
Heating
-2°C
-5°C
-10°C
-15°C
-20°C
-20°C -15°C -10°C
Outdoor air temperature (Th
Defrosting
Finishing of
defrosting,
Finishing of
start defrosting
defrosting
1 min. 4 min.
95Hz
65Hz
65Hz
0
1'45" 1'45"
5 sec.
ON
Full open
Full open
Closed
Full open
Defrosting operation
R) increases adove 20°C
O-
FDC-HKXR
Zone for initiate temp. of defrost
-5°C 0°C 5°C
)
O-A
Heating
Target Hz
ON
or
OFF
ON
or
OFF
ON
or
OFF
to Hz
<Pause, stop>
(Open of about 7%)
to Hz
<Pause, Closed>
Closed
ON
or
OFF
Heating
10°C
1037