Mitsubishi Electric CITY MULTI PEFY Series Technical & Service Manual page 22

[ VII Troubleshooting ]
2) LEV operation
(e)
♦ When the power is turned on, a pulse signal of fully open pulse + 10% pulse is output (valve closure signal), to bring the
valve to position A.
♦ When the valve is operating normally, it is free of vibration noise. If the valve locks or when it goes from point E to A in the
figure, it makes louder noise than would be heard when there is an open phase.
♦ Check for abnormal sound/vibration by placing the metal tip of a screwdriver against the valve and the handle side against
your ear.
3) Troubleshooting
Symptom
Circuit failure on Disconnect the connectors on the control board, and connect LEDs to test the
the microcomputer circuit as shown below.
Pulse signals are output for 10 seconds when the main power is turned on. If
there are LEDs that do not light up at all or remain lit after the pulses are turned
off, there is a problem with the driving circuit.
Locked LEV The motor will idle and make small clicking noise if it is run while the LEV is
locked. If this clicking noise is heard both when the valve is fully closed and while
it is being opened, it indicates a problem.
Disconnected or Measure the resistance between the coils with a tester (red-white, red-orange,
shorted LEV motor
Red-yellow, Red-blue). The normal range of resistance is 150 Ω)
coils
HWE1706A
(a)
(b)
(c)
(d)
(a) Close
(b) Open
(c) Fully open valve (2000 pulses)
(d) No. of pulses
(e) Extra tightening (41 pulses)
( f ) Valve opening degree
Checking Criteria
6
5
4
3
2
1
1 kΩ LED
- 17 -
Remedy
Replace the
indoor control
board if driving
circuit failure is
detected.
Replace the LEV.
Replace the LEV.
±
10%
GB