Section 10 • Compressor Sequencing; Overview; Pressure / Temperature Control Setpoints - Emerson Vilter Vission 20/20 Operation And Service Manual

Section 10 • Compressor Sequencing

Overview

Compressor sequencing screen is where more than one
Vission 20/20 panels can be sequenced in network using
Modbus TCP. These settings defi ne how the master com-
pressor should control sequenced Vission 20/20 panels.
This feature is enabled from the Confi guration Screen,
see Section 19 for Compressor Sequencing.

Pressure / Temperature Control Setpoints

Compressor Sequencing
those are used by master compressor for sequenc-
ing. For Pressure Control Setpoints see Figure 10-1, for
Temperature Control Setpoints see Figure 10-2.
Load Rate 2 offset (outer):
• Defi nes the outer pressure/temperature setpoint off-
set to monitor compressor load. If Suction pressure
/ process temperature surpasses Load Rate 1 offset
Vission 20/20 • Operation and Service Manual •Vilter/Emerson • 35391SC 1.9
screen defi nes settings
Figure 10-1. Compressor Sequencing Screen - Page 1
and goes beyond Load Rate 2 setpoint offset then se-
quencing decisions are made according to Load Rate
2 timer.
Load Rate 1 offset (inner):
• Defi nes the inner pressure/temp setpoint offset to
monitor compressor load. If Suction pressure / pro-
cess temperature goes beyond Load Rate 1 setpoint
offset then sequencing decisions are made according
to Load Rate 1 timer.
Suction Pressure/Process Temperature Control Setpoint:
• The target setpoints are read only values here.
These setpoints can be changed by logging on to
"Compressor Control" Screen.
Unload Rate 1 Offset (inner):
• Defi nes the inner pressure/temp setpoint to moni-
tor compressor load. If Suction Pressure/Process
Temperature Control drops below Unload Rate 1 set-
point offset then sequencing decisions are made ac-
cording to Unload Rate 1 timer.
10 – 1