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No.VP500-OMZ0005
Trouble shooting
Problem
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
Operation
failure
Air is not
switched.
1) Operation failure or sticking of the main
valve.
●
Foreign matter from the piping and air source
got caught in the main valve of the valve,
causing a malfunction.
●
Malfunction occurred due to sticking such as
swelling of the rubber part of the main valve.
- Replace the valve.
- Clean the air supply.
- If incorrect oil has been used for lubrication,
remove the oil by air blow.
- If there is a large amount of condensate,
install an auto drain or a dryer.
2) Reduced pressure
Air source pressure is reduced and minimum
operating pressure of the valve was not reached,
causing an operation failure.
- Adjust the pressure within the specification
range for the valve.
3) Excessive oil supply
Due to excessive lubrication, oil accumulated
inside the valve, causing malfunction.
- Reduce the amount of lubrication to the
amount at which the oil does not splash
from the exhaust port [ 3(R), vent port].
1) Non-conforming of electric system
-
Incorrect wiring
- Fuse blown out, lead wire broken
- Incorrect contact at the contact and
connection
- Sequencer non-conforming
- Supply voltage insufficient
- Check all parts and replace the part,
if necessary.
- Check the supply voltage.
2) Drop of supply voltage
Operation failure of the valve due to voltage
drop.
- Check the supply voltage. Take corrective
action if voltage drop is confirmed.
3) Non-conforming of the installed pilot
valve
- Broken wire in the coil or burnout
(High supply voltage, incorrect coil specification,
entry of water)
- Replace the valve.
1) Leakage current
Operation failure of the valve occurred due
to residual voltage.
(Valve is not turned OFF)
Check the residual voltage.
Keep the residual voltage at 3% or less of
the rated voltage (DC coil).
2) Non-conformance of the installed pilot
valve
- Foreign matter is caught in the moving part
of the valve (or pilot valve).
- Swelling of rubber parts inside the valve
(or pilot valve)
- Clean the air supply.
- Eliminate foreign matter with air blow.
- Replace the valve when actions above do
not improve the condition.
The valve operate when
the manual override but-
ton is pushed?
No
Energized?
Is valve switched?
No
YES
YES
