25
GB
2) LEV operation
When the power is turned on, a pulse signal of 2200 pulses 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
(a)
Close
(b)
Open
(c)
Fully open valve (2000 pulses)
(d)
No. of pulses
(e)
Extra tightening (80 - 100 pulse)
(f)
Valve opening degree
Symptom
Checking Criteria
Remedy
Circuit failure on
the microcomputer
Disconnect the connectors on the control board, and connect LEDs to test the cir-
cuit 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.
Replace the con-
troller board if
driving circuit fail-
ure is detected.
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.
Replace the LEV.
Disconnected or
shorted LEV motor
coils
Measure the resistance between the coils with a tester (red-white, red-orange,
brown-yellow, brown-blue). The normal range of resistance is 150
Ω
±10%
Replace the LEV.
(f)
(a)
(b)
(e)
(d)
(c)
6
5
4
3
2
1
1 k
LED
02_WT06728X03-body.fm 25 ページ ２０１３年１２月２５日 水曜日 午後１時２９分
