Emerson Vilter Vission 20/20, Operation And Service Manual

Page: 251 / 338

B - 33
Appendix B • Vission 20/20 Application Procedures
Vission 20/20 • Operation and Service Manual • Emerson • 35391SC 2.7
81
82
Figure B-22. Analog Output card wiring to VPLUS VFD controller
VPLUS (AC Motor) Setup Procedure for 20/20
Panel
INTRODUCTION
This document provides guidelines to setup AC Motor
VPLUS oil cooling system control on the Vission 20/20
panel. Further information can be found in the VPLUS
IOM manual (#35391XA).
SCOPE
Vilter
TM
AC VPLUS oil cooling system utilizes a PID algo-
rithm in the Vission 20/20 panel to control the speed of
the VPLUS motor. The motor speed controls the amount
of liquid refrigerant being injected into the compressor
which is used for oil cooling. Motor speed is based on
discharge temperature. As the discharge temperature
varies from the liquid injection control setpoint, a modu-
lating 4-20ma signal wired to the AC motor VFD will ad-
just the speed of the motor.
This document provides instructions to help setup the
Vission 20/20 for VPLUS (AC Motor) control.
ADDITIONAL HARDWARE
In order to control the VPLUS pump motor VFD, an ana-
log output card is required. The 4-20ma signal from the
card will be wired to the VFD and will vary the speed of
the VPLUS motor - thereby increasing and decreasing
the amount of liquid refrigerant that will be injected into
the compressor to provide oil cooling.
HARDWARE WIRING
The analog output card needs to be wired to the VPLUS
VFD, see Figure B-22 and Figure B-23.
The VPLUS VFD needs to be wired to the VPLUS Motor,
see Figure B-23.
The digital output card needs to wired to the VPLUS liq-
uid injection solenoid, see Figure B-24.
A control relay must also be installed for the VPLUS VFD
Start, see Figure B-23 and Figure B-24. The control relay
is not supplied by Vilter
TM .
VPLUS VFD Settings
In order to achieve a stable liquid injection control, the
VPLUS VFD “Maximum Frequency” setting should be set
to 38 Hz. This setting is arrived at by matching the his-
torical setting for the DC VPLUS system which used a DC
voltage motor controller board to control the speed of a
DC motor. On the DC VPLUS system, the DC VPLUS mo-
tor had a 90vDC armature. The motor controller board
was then set so that the maximum DC voltage to the
DC motor was 57 volts DC. This number was arrived at
through empirical testing, which provided stable liquid
injection control. Translating this to the AC VPLUS sys-
tem then, the maximum frequency setting on the VFD
should be (57/90 x 60 Hz = 38 Hz).