Slide Valve Troubleshooting Guide - Emerson Vilter Vission 20/20 Operation And Service Manual

Section 14 • Slide Calibration

Slide Valve Troubleshooting Guide

The Analog output card of the Vission 20/20 produces a 4–20mA signal to any attached devices. However, it is not
uncommon that small differences in the board components might result in small differences in the output. So this
screen offers the operator the ability to fi ne tune the upper and lower output values, see Table 14-2. Slide Valve
Troubleshooting Guide.
Problem
The actuator cannot be calibrated.
The actuator goes into calibration
mode spontaneously.
The actuator does not transmit the
correct position after a power loss.
There is a rapid clicking noise when
the motor is operating.
Vission 20/20 • Operation and Service Manual •Vilter/Emerson • 35391SC 1.9
Table 14-2. Slide Valve Troubleshooting Guide (1 of 2)
Dirt or debris is blocking one or both
optocoupler slots.
The photochopper fence extends
less than about half way into the
optocoupler slots.
The white calibrate wire in the grey
Turck cable is grounded.
Dirt and/or condensation on the
position sensor boards are causing it
to malfunction.
The calibrate button is stuck down.
The position sensor has failed.
Push button is being held down for
more that ¾ second when going
through the calibration procedure.
The white calibrate wire in the
grey Turck cable is grounding
intermittently.
A very strong source of electromag-
netic interference (EMI), such as a
contactor, is in the vicinity of the
actuator or grey cable.
The motor was manually moved
while the position sensor was not
powered.
The motor brake is not working
properly.
The position sensor's EEPROM
memory has failed.
The photochopper is misaligned
with the slotted optocouplers.
The motor brake is not working
properly.
Reason
Clean the optocoupler slots with a
cotton swab and rubbing alcohol.
Adjust the photochopper so that
the fence extends further into the
optocoupler slots. Make sure the
motor brake operates freely and
the photochopper will not contact
the optocouplers when the shaft is
pressed down.
Tape the end of the white wire in the
panel and make sure that it cannot
touch metal.
Clean the boards with an electronics
cleaner or compressed air.
Try to free the stuck button.
Replace the actuator.
Depress the button quickly and then
let go. Each ¾ second the button is
held down counts as another press.
Tape the end of the white wire in the
panel and make sure that it cannot
touch metal.
Increase the distance between the
EMI source and the actuator.
Install additional metal shielding ma-
terial between the EMI source and
the actuator or cable.
Recalibrate.
Get the motor brake to where it op-
erates freely and then recalibrate.
Replace the actuator.
Try to realign or replace the actuator.
Get the motor brake to where it op-
erates freely and then recalibrate.
Solution
14 – 5