Emerson Vilter VSS Installation, Operation & Maintenance Manual page 244

Appendix F • Hand-Held Slide Valve Calibration Tool
Hand-Held Slide Valve Calibration Tool
By Vilter™
The Slide Valve Calibration Tool allows the operator to
perform the calibration procedure of Vilter´s slide valve
actuators (VPN 25972D) single-handedly, while stand-
ing at the actuator, without multiple trips to the panel
screen, or the need of another person at the panel.
How It Works
The calibration tool replaces the power cable that feeds
the actuator during normal operation, and provides 115
volts to the actuator motor using the CW and CCW push
buttons. The regular control cable which provides 24
volts DC to the actuator must be connected at all times.
The greatest advantage from this set up is that the op-
erator can perform the whole calibration procedure in
front of the compressor, and therefore can easily detect
if the actuator is driving the slide valves up against the
mechanical stop inside the compressor.
Calibration Procedure
1. Look for the motor control cable on the actuator
(connector J2), and disconnect it. Connect the cali-
bration tool´s turck connector to the actuator.
2. Remove the screws securing the actuator cover to
the actuator assembly, and carefully lift the actuator
cover and tilt it towards connectors. Raise the cover
high enough to attain access to the blue calibration
button and be able to see the red LED on the top of
assembly.
3. Press "CW" or "CCW" on the calibration tool to move
the slide valve and check for the correct rotation, see
the Increase Direction for Single Screw Compressors
Table on the next page to establish which one is the
increase button and which one the decrease button
for your compressor model.
Red LED
Blue
Calibrate
Button
F − 2
VSS/VSM/VSH/VSSH • Installation, Operation and Maintenance Manual • Emerson • 35391SD
For use in non-hazardous locations
Features
The calibration procedure may be performed directly
at the actuator, so the operator can immediately de-
tect when the actuators start to slow down and reach
the mechanical stop
Using this tool bypasses the standard calibration
procedure which requires several trips between the
actuator and the control panel, or to have two opera-
tors available
Electrical Rating of 125V and 5A (not fuse protected)
Light and easy to move around the compressors room
Pendant switch for easy access and comfortable
handling
4. Quickly press and release the blue push button on the
actuator once. This places the actuator in calibration
mode. The red LED will start flashing rapidly.
5. Use the decrease button on the calibration tool to
drive the slide valve to its minimum "mechanical
stop" position. Release the decrease button when
the slowing of the motor rotation and a winding
sound from the actuator motor is noted.
6. Press and hold down on the photo-chopper shaft to
disengage the brake slowly, releasing tension from
the motor mount. Use the increase button to pulse
the actuator to where the slide is just off of the me-
chanical stop and there is no tension on the motor
shaft.