Mitsubishi Electric PURY-P72 Service Handbook page 144

[ VII Control ]
-7- Defrost Operation Control
(1) Starting the defrost operation
The defrost cycle starts when the pipe temperature (TH6), in the following table, or below has continuously been detected for
3 minutes after the integrated compressor operation time of 50 minutes have passed.
If 10 minutes have passed since compressor start-up or since the completion of defrost operation, forced defrost operation
will start by turning on the forced defrost switch (DIP SW2-7).
Even if the defrost prohibit timer is set to 90 minutes, the actual defrost prohibit time for the next operation will be 50 minutes
if defrosting took 12 minutes.
In the multiple-outdoor-unit system, all of the outdoor units that are in operation go into the defrost mode simultaneously. The
unit(s) that is stopped at the time defrost operation starts remains stopped.
Model
P72 model
P96 model
P120 model
(2) Defrost operation
Outdoou unit Compressor frequency
Outdoor unit fan
SV1a
SV2
SV5b
21S4a
SV9
BC controller LEV1
LEV3
SVM1
SVM2
SV B
SV A
HWE0803A
TH6
SW3 - 3 OFF
- 10°C [14°F]
- 8°C [18°F]
- 8°C [18°F]
Model
P72 model
P96 model
P120 model
G type: 4000, GA type: 6000
G type: 1000, GA type: 2000
GB, HB type: 60 (full closed)
Ports that are connected to the indoor units in cooling Thermo-ON
- 135 -
SW3 - 3 ON
- 5°C [23°F]
- 5°C [23°F]
- 5°C [23°F]
Compressor frequency
60 Hz
65 Hz
65 Hz
Stopped
ON (open)
ON (open)
ON (open)
OFF
OFF (closed)
ON
OFF
OFF
Other ports : OFF
GB