Emerson VSG & VSSG, Software Manual

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56
Slide Valve Actuator Troubleshooting Guide
The actuator cannot be cali-
brated
The actuator goes into cali-
bration mode spontaneously
The actuator goes into calibra-
tion mode every time power is
restored after a power loss
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 proce-
dure
The white calibrate wire in the grey
Turck cable is grounding intermit-
tently
A very strong source of electro-
magnetic interference (EMI), such
as a contactor, is in the vicinity of
the actuator or grey cable
There is an intermittent failure of
the position sensor
The motor brake is not work-
ing properly (see theory section
above.)
Clean the optocoupler slots with
a Q-Tip 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 electron-
ics 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
material between the EMI source
and the actuator or cable.
Replace the actuator.
Get the motor brake to where it
operates freely and recalibrate.
Replace the actuator.