Vission 20/20 Compressor Sequencing Setup - Emerson Vilter Vission 20/20 Operation And Service Manual

Appendix B • Vission 20/20 Application Procedures

Vission 20/20 Compressor Sequencing Setup

SCOPE
Vission 20/20 programs – version 1.6.4550.1 and later.
OVERVIEW
Compressor sequencing in the Vission 20/20 panel is
carried out by utilizing the Ethernet communication
port using Modbus TCP protocol.
Compressor sequencing is accomplished by the master
compressor, monitoring its own control parameter (ei-
ther suction pressure, process temperature or discharge
pressure). As its control parameter changes value, it
will make decisions to start, stop, load and unload slave
compressors as needed, to maintain the control setpoint
which is defined in the master compressor sequencing
screen.
The master compressor will ALWAYS be priority #1
Figure B-6. Master Compressor Loading, Unloading and Auto-cycle Setpoints Setup
B - 14
NOTE
compressor – and act as the trim compressor. So this
must be taken into account when deciding which
compressor is to act as the master compressor.
The following discussion assumes that the physical
Ethernet Network has been installed between all Vission
20/20 control panels.
Vission 20/20 • Operation and Service Manual • Emerson • 35391SC 2.7