Mitsubishi Electric PUHY-M200YNW-A1 Service Handbook page 145

[5-3 Hydro Unit Control ]
(4) Recovering from Defrost
The setting of the dip switch 001-10 determines the defrost method (bypass defrost or heat recovery defrost).
As shown in the following flow chart, the bypass defrost may be performed during the heat recovery defrost depending on the
operation status.
No
High pressure heat recovery defrost:
LEV1 = 3000
Pump = Always in operation
Indoor unit FCV during Thermo-ON = Fully open
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- chapter 5
Heating
Receiving
"Defrost" signal
from OC
Yes
Hydro unit
Dip switch
SW001-10
OFF
Water temp.<28°C
Yes
(DIP SW 002-10: OFF)
Water temp.<20°C
(DIP SW 002-10: ON)
No
Yes
Freezing is
suspected.
No
Receiving
No
"Defrost" signal
from OC
Yes
Recovering from Defrost
ON
No. of freezing
< 3 times
Yes
Lower the frequency,
count the No. of freezing.
No
Bypass defrost
BS_05_E