ARTC-SVX007A-EN
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The Hand/Off/Auto function has 3 modes:
• Off – no function. Compressors are off and remain so
regardless of loop temperatures. All display functions
work as normal. Chiller Enable is White and OFF. If
pumps are controlled by the chiller and they are
configured to Cooling Enable, the pumps will not be
enabled.
• Hand – the chiller controls the compressors based on
(by default) achieving setpoint on leaving chilled water
temperature. Chiller Enable displays Red and Hand. If
connected, pumps will be enabled.
• Auto – this mode requires an external (hardwired)
signal providing Chiller Enable; otherwise, Chiller is Off.
Once Chiller Enable signal is provided, chiller controls
compressors according to setpoint. Chiller Enable
displays White and Auto.
Chiller Setpoint Control
Multiple chiller setpoint control modes are available. These
are:
• User Setpoint
• Digital Offset
• Remote Setpoint
• Remote Offset
The chiller ultimately works with one value for setpoint, this
value is always displayed on the Main Screen in the
Evaporator Section, labeled SET POINT:
Figure 13. Main screen
User Setpoint
To Access the Chiller Setpoint control screen, select the
setpoint indicator from the Main Screen or the Chiller
Control screen. See the following figure:
Figure 14. Chiller setpoint control
To change the setpoint, touch User Setpoint. A keyboard
appears and allows you to enter a new value.
Note: In user setpoint mode Actual Setpoint equals User
Setpoint.
Digital Offset
This feature requires a parameter and a digital input. The
parameter, Digital Offset is exposed to the HMI on the
Chiller Control Setpoint screen:
Operating Procedures
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