Mitsubishi Electric PURY-EP200YLM-A, Service Handbook, Page: 151 / 434

[5-2 Outdoor Unit Control ]
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HWE1314A GB
(2) Defrost operation
* When PWFY-AU model units are connected, SVA and SVC on the BC should be set to ON.
* Outdoor air temperature (TH7) < -10°C and SVA and SVB are ON when PWFY-AU is not connected
(3) Stopping the defrost operation

The defrost cycle ends when 12 minutes have passed since the beginning of the cycle, or when the pipe temperatures (TH3
and TH6) have been continuously detected for 4 minutes (when SW4 (916) is set to OFF) or 2 minutes (when SW4 (916) is
set to ON) that exceeds the values in the table below.

The defrost cycle will not end for two minutes once started unless one of the following conditions is met : Pipe temperature
reaches 25°C [77°F] and SW4 (916) is set to OFF OR α
*1
=25°C+TH7°C [77°F+TH7°F] and SW4 (916) is set to ON.
*1 (5°C [41°F] ≤ α ≤ 25°C [77°F]).

In the multiple-outdoor-unit system, defrosting is stopped on all units at the same time.
(4) Problems during defrost operation

If 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

Even 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.

Defrost operation will be continued, even if the indoor units stop or under the Thermo-OFF conditions until it has run its course.
Outdoou unit Compressor frequency Model Compressor frequency
(E)P200, (E)P250 models 79Hz
(E)P300, (E)P350, P400 models 107Hz
EP400, (E)P450, (E)P500 models 112Hz
Outdoor unit fan Stopped
SV1a ON (open)
SV5b ON (closed)
21S4a, 21S4b OFF
SV9 OFF (closed)
BC controller LEV1 G type: 4000, GA type: 6000, HA type: 8000 (60 or 41)
LEV3 G type: 1000, GA type: 2000, HA type: 2000 (60)
GB, HB type: 60 (full closed)
SVM1 ON
SVM2 ON
SVM1b ON
SVM2b OFF
SVB OFF
SVA Ports that are connected to the indoor units in cooling Thermo-ON
Other ports : OFF
Model
TH3 and TH6
SW4 (916) OFF SW4 (916) ON
(E)P200 model 7°C [45°F] 12°C [54°F]
(E)P250 model 7°C [45°F] 12°C [54°F]
(E)P300 model 7°C [45°F] 12°C [54°F]
(E)P350 model 7°C [45°F] 12°C [54°F]
(E)P400 model 7°C [45°F] 12°C [54°F]
(E)P450 model 7°C [45°F] 12°C [54°F]
(E)P500 model 7°C [45°F] 12°C [54°F]