Mitsubishi Electric PURY-P72TYJMU-A Service Handbook page 157

[ VII Control ]
(2) Defrost operation
Outdoou unit Compressor frequency
Outdoor unit fan
SV1a
SV2
SV5b
SV5c
21S4a, 21S4b
SV9
BC controller LEV1
LEV3
SVM1
SVM2
SVM1b
SVM2b
SV B
SV A
(3) Stopping the defrost operation
ŒThe defrost cycle ends when 12 minutes have passed since the beginning of the cycle, or when the pipe temperature (TH3)
is 10°C[50°F] or above has been continuously detected for 2 minutes.
ŒThe defrost cycle does not end for 2 minutes once started unless the pipe temperature exceeds
25°C ( = Outdoor temperature(TH7) - 25)°C
ŒIn the multiple-outdoor-unit system, defrosting is stopped on all units at the same time.
(4) Problems during defrost operation
ŒIf a problem is detected during defrost operation, the operation will be stopped, and the defrost prohibition time based on the
integrated compressor operation time will be set to 20 minutes.
(5) Change in the number of operating indoor units during defrost operation
ŒEven when there is a change in the number of operating indoor units during defrost operation, the operation will continue, and
an adjustment will be made after the completion of the defrost operation.
ŒDefrost operation will be continued, even if the indoor units stop or under the Thermo-OFF conditions until it has run its course.
HWE0913A
Model
P72 model
P96 model
P120, P144 models
Stopped
ON (open)
P72, P96 models
P120, P144 models
ON (open)
P72, P96 models
P120, P144 models
OFF (closed)
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
Other ports : OFF
5°C [77°F ( = Outdoor temperature(TH7) - 45)°F
- 148 -
Compressor frequency
60 Hz
65 Hz
65 Hz
ON (open)
N/A
OFF (closed)
ON (open)
OFF
ON
OFF
ON
OFF
OFF
below within 2 minutes.
41°F]
GB