Mitsubishi Electric PURY-80TMU Service Handbook page 79

2 Solenoid Valve
Solenoid valve
troubleshooting
Operation OFF?
Check solenoid valve wiring
for incorrect connection, and
connector disconnection or
looseness.
No problem.
No
Operate cooler and heater for
the applicable solenoid valve's
refrigerant system only.
Note 1
Clicking noise
produced when working
timing?
Yes
Yes
Measure piping temperature
on both sides of solenoid
valve and check for following.
Solenoid valve ON:
no differential
Solenoid valve OFF:
differential
OK?
Yes
Solenoid valve
normal
Yes
Correct the problem.
No
Remove the coil and check for
a magnetic force.
Magnetic force
is OK?
Yes
Measure pipe temperature of
inlet and outlet sides of
solenoid valve.
No temperature differential: OK
Temperature differential: NG
OK?
Yes
No
No
Stop the unit.
Note 3
Disconnect solenoid valve
connector from the board and
check for a solenoid coil
conductance.
Conductance present?
No
Yes
With the solenoid valve con-
nector is disconnected from the
board, use remote controller to
turn on the unit and check the
output 208-230V from the con-
troller board.
208-230V output?
No
Change the control
board.
Solenoid valve
faulty
–78–
No
Yes
Change the
solenoid valve.