Fig. 25 - Setpoints Screen - York YT Millennium Operating & Maintenance

OptiView Control Center
FIG. 25
OVERVIEW
This screen provides a convenient location for program-
ming the most common setpoints involved in the chiller
control. This screen also serves as a gateway to a subscreen
for defining the setup of general system parameters.
DISPLAY ONLY
Leaving Chilled Liquid Temperature - Setpoint
Displays the present setpoint to which the chiller is oper-
ating whether controlled remotely or locally. This value
could come from a 0-20mA, 4-20mA, 0-10VDC or 2-
10VDC input in Analog Remote mode, PWM signal in
Digital Remote mode, MicroGateway interface in ISN
mode or a locally programmed value.
Leaving Chilled Liquid Temperature Cycling - Shut-
down
Displays the Leaving Chilled Liquid Temperature at
which the chiller will shut down to avoid over-cooling
the building. This value is calculated by subtracting the
Leaving Chilled Liquid Temperature Cycling Offset
– Shutdown from the Leaving Chilled Liquid Tem-
perature Setpoint. If this value is below the absolute
minimum allowed shutdown temperature the minimum
value is displayed.
Leaving Chilled Liquid Temperature Cycling – Re-
start
Displays the Leaving Chilled Liquid Temperature at which
58
SETPOINTS SCREEN
the chiller will restart after it has shut down due to over-
cooling temperature. This value is calculated by adding
the Leaving Chilled Liquid Temperature Cycling Offset
– Restart to the Leaving Chilled Liquid Temperature
Setpoint.
Current limit Setpoint
Displays the active Current Limit setpoint. In Local
mode, this is the locally programmed Current Limit
setpoint. In ISN remote mode, this is the setpoint re-
ceived from the MicroGateway interface. In Analog re-
mote mode, this is the setpoint received via 0-10VDC,
2-10VDC, 0-20mA or 4-20mA input. In Digital remote
mode, this is the Pulse Width Modulation input.
PROGRAMMABLE
Local Leaving Chilled Liquid Temperature -
Range Access Level Required: OPERATOR
This is the range over which an analog signal (0-20mA, 4-
20mA, 0-10VDC or 2-10VDC) in Analog Remote Mode
or a digital signal (PWM) in Digital remote mode can reset
the Leaving Chilled Liquid Temperature setpoint above
the operator programmed Base Setpoint (see below).
Programmable as either 10°F or 20°F, with a default
of 20°F, it is added to the BASE value to create a range
over which the remote device can reset the setpoint. For
example, if this setpoint is programmed for 10°F and
the operator programmed value is 45°F, then the remote
device can set the Leaving Chilled Liquid Temperature
setpoint over the range 45.0° - 55.0°F.
FORM 160.55-O1 (920)
00364VIP
YORK INTERNATIONAL