Mitsubishi Electric PURY-P72 Service Handbook page 303

[ IX Troubleshooting ]
(5) In the case of SV5b (Bypass valve)
This solenoid valve closes when energized (when the relay is on).
This valve turns off for five minutes after the completion of the defrost cycle, or when SV9 is on turned ON and the value of
63HS1 is greater than 3.5 MPa [507psi] during Heating-only or Heating-main operation at the minimum frequency. The valve
position can be determined by measuring and monitoring the changes in the pipe temperature on the downstream of SV5b
while the unit is de-energized. When the valve is open, high-temperature gas refrigerant passes through the pipe. Do not at-
tempt to check the pipe temperature by touching the pipe.
(6) In the case of SV5c (Bypass valve)
This solenoid valve opens when energized (when the relay is on).
This valve turns on, depending on the operating conditions during Cooling-main, Cooling-only, and defrost (P120 and P144
models only). Check for proper operation on the LED and by listening for the operation sound of the solenoid valve.
(7) In the case of SV9 (Bypass valve)
This solenoid valve opens when energized (when the relay is on)
This valve turns on when the value of 63HS1 is greater than 3.5 MPa [507psi] during Heating-only or Heating-main operation
at the minimum frequency. The valve position can be determined by measuring and monitoring the changes in the pipe tem-
perature on the downstream of SV9 while the unit is energized. When the valve is open, high-temperature gas refrigerant
passes through the pipe. Do not attempt to check the pipe temperature by touching the pipe.
HWE09130 - 294 - GB