Emerson VILTER VSS Installation, Operation And Service Manual page 104

Section 6 • Troubleshooting
Table 6-1. Slide Valve Actuator Troubleshooting Guide (2 of 3)
Problem
The actuator goes into calibration mode
spontaneously.
The actuator goes into calibration mode
every time power is restored after a
power loss
The actuator does not transmit the cor-
rect position after a power loss.
There is a rapid clicking noise when the
motor is operating.
The motor operates in one direction only
6 – 2
VSS/VSR/VSM/VSH/VSSH Compressor • Installation, Operation and Service Manual • Emerson • 35391S
Reason
The white calibrate wire in the
grey Turck cable is grounding
intermittently.
A very strong source of
electromagnetic 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.
The position sensor's EEPROM
memory has failed
The motor was manually
moved while the position sen-
sor was not powered.
The motor brake is not work-
ing properly.
The position sensor's EEPROM
memory has failed
The photo-chopper is mis-
aligned with the slotted
optocouplers.
The photo-chopper is posi-
tioned too low on the motor
shaft.
A motor bearing has failed
There is a loose connection in
the screw terminal blocks.
There is a loose or dirty con-
nection in the yellow Turck
cable.
The position sensor has failed.
There is a broken motor lead
or winding
Solution
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.
Recalibrate.
Get the motor brake to where it
operates freely and recalibrate.
Replace the actuator.
Try to realign or replace the
actuator.
Adjust the photo-chopper so
that the fence extends further
into the optocoupler slots.
Replace the actuator.
Tighten
Clean an tighten
Replace the actuator.
Replace the actuator.