Emerson Vission 20/20 Operation And Service Manual page 165

Appendix B • Vission 20/20 Application Procedures
CONTROL MODE DROPDOWN BOX
In Figure B-4, the Control Mode dropdown box allows
selection of the active setpoints.
To change from Setpoint 1 to Setpoint 2 being the active
setpoint, do the following:
• Select the Control Mode dropdown box, and then
select Setpoint 2.
• This can be done when the compressor is off or
running.
CAUTION
Please be aware that changing the active setpoint
while the compressor is running could end up shutting
the compressor off. A control setting (i.e. Auto-Cycle
Stop setpoint or Low Suction Pressure trip setpoint)
may shut the compressor down as soon as you make
the switch depending upon the setting of the new
active setpoint.
Figure B-4. Compressor Control Load Limit Setpoint 1 and Setpoint 2 Setup
Vission 20/20 • Operation and Service Manual •Vilter/Emerson • 35391SC 2.0
SAFETY SETPOINTS
In Figure B-5, the Alarm and Trip Safety setpoints also
have Setpoint 1 and Setpoint 2 settings. These should
be set up for proper operation when operating.
DIRECT I/O OPERATION AND SETPOINT 1 AND
SETPOINT 2 SELECTION
If the compressor is being operated in Direct I/O mode,
then selection of the active setpoint is accomplished
from an input module. Reference the wiring diagram to
identify the module. The Setpoint 1 / Setpoint 2 selec-
tion module will be recognized when the compressor is
placed in REMOTE mode (by pressing the Unit Start but-
ton and then the Remote button). When the input mod-
ule is energized, then Setpoint 2 is active. De-energizing
the module places the Vission 20/20 control panel into
Setpoint 1 mode.
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