CKD EVD-1000 Series - Page 65

SM-A20758-A/3 5. TROUBLESHOOTING
57 2020-10-06
Problem
Cause
Solution
Primary side pressure is output as
it is.
There is a failure in EVD.
Make sure that there is no abnormality in piping and wiring
and then replace the product.
Pressure cannot be controlled.
Input signal is abnormal.
Check the Input signal type.
Check the Setting range.
(Refer to "On demand data")
There is a failure in pressure
sensor.
Replace the product.
Make sure that excessive pressure does not apply on the
secondary side due to pressure entering from other pipes.
Pressure is not output.
Primary side pressure is not
supplied.
Check that the primary side pressure is normal.
Wiring is abnormal.
Check that the wiring is normal.
In addition, check that the connector is properly connected.
Pressure does not reach set
pressure.
Primary side pressure is
insufficient.
Maintain the primary side supply pressure so that it is at
least the minimum working pressure.
Pressure does not drop.
Passage of exhaust port is
blocked.
Mount the product so that the air can be exhausted from
port R and the exhaust port.
Pressure is unstable.
Power supply voltage is unstable.
Use a stabilized power supply that satisfies the product
specifications.
Input signal is unstable.
Check whether the noise is affecting the signal.
Connect the shielded wires to the ground on the power
side.
Primary side pressure is unstable.
Install a regulator on the primary side of the EVD to
stabilize the primary side pressure.
There is leakage from piping.
Check leakage from piping on the primary side and
secondary side.
* Changing the proportional value ("Lower proportional
value") may stabilize the pressure (refer to "3.1.4
Proportional value change").
Note 1
Pressure oscillates.
Primary side pressure is too high
against control pressure.
Reduce the primary side supply pressure as much as
possible but maintain at least the minimum working
pressure.
Mismatched piping capacity,
leakage, or foreign matter
contamination on secondary side.
Oscillation may be avoided by changing the piping
condition. Reconsider the diameter of the piping, increase
or decrease the load capacity, or check leakage on the
secondary side.
* Changing the proportional value ("Lower proportional
value") may stabilize the pressure (refer to "3.1.4
Proportional value change").
Note 1