SMC Networks VQC4000, Operation Manual

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No.VQC4000V-OMX0001
Trouble
When the valve is failing, use this flow chart to
clarify the cause of the failure and take
countermeasures appropriate for the cause.
Possible cause Countermeasures
Operating
failure
The air
supply
does not
switch the
valve
.
1) Sliding failure or stick of
main valve.
A foreign material included in
supplied air is caught by main
valve and makes the main
valve unable to slide smoothly
or sticky.
•
Replace with new valve.
•
Clean the supplied air.
2) Pressure drop.
The pressure of supplied air
lowers the valve which can
operate the valve (min.
operating pressure). Raise the pressure of supplied air up
to operating pressure of the valve.
1) Failure of electrical system
•
Incorrect wiring
•
Blow of fuse and breakage of
lead wire.
•
Poor contact at contactor wire
or connection part
•
Failure of sequencer
•
Lack of supply voltage
Check these items and replace part
and re-wire positively.
1) Voltage drop
Even if the indicator light keeps
turning on, the valve can’t be
operated due to the voltage
drop.
•
Check the voltage and if it is not
enough to operate the valve, take
appropriate measures.
2) Leakage current
When the power turns off, the
valve can’t be switched due to
residual voltage.
•
Confirm the residual voltage is
follows.
•
DC is 3% or less of rated voltage.
3) Failure of pilot valve
•
Foreign matter caught in
core of pilot valve.
•
Disconnection coil
wire of pilot valve
•
Swelled out poppet
of pilot valve
•
Burnt coil of pilot valve
(Higher voltage or wrong coil
used, Coil splashed by
water)
•
Replace part or re-wire positively.
•
Check voltage. Replace valve.
(Pilot valve)
•
Replace valve (pilot valve). Protect
the valve so that water does not
splash the coil.
Response
failure
The
operation
of the valve
is delay.
1) Current leakage
When the power turns off, the
valve can be switched late due
to residual voltage.
•
Confirm the residual voltage is
follows.
•
DC is 3% or less of rated voltage.
2) Clogging of filter element of
manifold.
•
Clean the element or replace with
new element.
3) Sliding failure or stick of
main valve.
A foreign material included in
supplied air is caught by main
valve and makes the main
valve unable to slide smoothly
or sticky.
•
Replace with new valve.
•
Clean the supplied air.
Can manual
override move the
valve
NO
YES
Does the indicator
light keep turning on
during
energization?
NO
YES