Mitsubishi Electric PURY-P200 Service Handbook page 180

Check whether the BC board output signal and the solenoid valve operation correspond.
Note1 SVA, SVB, SVC
SVA, SVB and SVC turn on or off according to the indoor unit operation mode.
Mode
Branch end
SVA
SVB
SVC
SVM1, SVM2 [P400-P550 types]
SVM1,SVM2 turns on or off according to the operation mode.
Operation mode Cooling-only
SVM1
SVM2
Note2 SVA, SVB, SVC
Measure the temperature of the piping 1-2 which is in front and behind the SVA.
Measure the temperature of the piping 1-3 which is in front and behind the SVB.
3
2
1
(4) BC controller transformer
BC controller control board
CNTR
Red White
Cooling
ON
OFF
ON
Cooling-main
Pressure difference
ON
control OFF or ON
OFF OFF
CN03
Red Red
Heating
OFF
ON
OFF
Heating-only Heating-main
OFF OFF
Pressure difference Pressure difference
control OFF or ON control OFF or ON
Normal
CNTR(1)-(3) about 58Ω
CN03(1)-(3)
about 1.6Ω
✻ Before measuring the resistance, pull out the connector.
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Stop Defrost
OFF OFF
OFF OFF
OFF OFF
Defrost
ON
OFF
Abnormal
Open-phase
or shorting
Stop
OFF
OFF