York OPTIVIEW Operation Manual page 24

SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
Leaving Chilled Liquid Temperature Setpoints
– Restart
Displays the Leaving Chilled Liquid Temperature at
which the chiller will restart after it has shutdown on
LEAVING CHILLED LIQUID – LOW TEMPERA-
TURE cycling shutdown. This temperature is set as
an offset using the LEAVING CHILLED LIQUID
TEMPERATURE CYCLING OFFSET – RESTART
setpoint, displayed as "Offset" adjacent to this value.
Leaving Chilled Liquid Temperature Setpoints
– Remote Range
Displays the temperature range proportional to a re-
mote analog input as selected according to the pro-
grammable values description below.
Leaving Chilled Liquid Temperature Setpoints
(Shutdown) – Effective Offset
Displays the present value of the leaving chilled liquid
temperature shutdown offset in effect.
Leaving Chilled Liquid Temperature Setpoints
(Restart) – Offset
Displays the value set for leaving chilled liquid tem-
perature restart offset.
Evaporator Saturation Temperature
Displays the present saturation temperature in the
evaporator, determined from evaporator pressure.
Chilled Liquid Flow Switch (Open/Closed)
Displays whether the liquid flow is present in the evap-
orator.
Chilled Liquid Pump
Displays the command presently sent by the control
center to the Chilled Liquid Pump run contacts (RUN
or STOP).
Evaporator Refrigerant Temperature
Displays the temperature of the refrigerant in the evap-
orator, if the sensor is enabled.
24
PROGRAMMABLE
Local Leaving Chilled Liquid Temperature -
Setpoint
Access Level Required: OPERATOR
This value allows the user to define the Leaving
Chilled Liquid Temperature that is to be maintained by
the chiller. It is programmable over the range of 38.0°F
to 70.0°F (water) or 10.0°F to 70.0°F (brine). If Smart
Freeze (see below) is enabled, the range is 36.0°F to
70.0°F (water). A remote device can provide an analog
signal (0-20mA, 4-20mA, 0-10VDC or 2-10VDC)
in Analog Remote mode, or PWM signal in Digital
Remote mode that changes the setpoint by creating an
offset above the operator programmed Base Leaving
Chilled Liquid Temperature setpoint. This offset may
be defined as 10, 20, 30, or 40ºF above the Base setpoint
(see the Remote Leaving Chilled Liquid Temperature
Setpoint Range description above). Additionally,
E-Link Gateway (in BAS (ISN) Remote mode) can
define the setpoint through a serial data stream. In
this case, the incoming setpoint is not an offset that is
applied to the locally programmed Base setpoint value,
but rather is the setpoint value itself.
When the chiller is running, performing capacity con-
trol, any change to the active LCHLT setpoint results
in a ramp from the old value to the new value at the
programmed LCHLT setpoint ramp rate.
Local Leaving Chilled Liquid Temperature -
Range
Access Level Required: OPERATOR
This is the range over which an analog (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 Tempera-
ture setpoint above the operator programmed Base
Setpoint (see below). Programmable as 10, 20, 30 or
40ºF. 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 Tem-
perature setpoint over the range 45.0 - 55.0°F.
FORM 160.78-O2
ISSUE DATE: 5/22/2017
JOHNSON CONTROLS