York YK Style H Operation Manual page 28

SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
Leaving Chilled Liquid Temperature Setpoints
– Shutdown
Displays the Leaving Chilled Liquid Temperature at
which the chiller will shutdown on Leaving Chilled
Liquid – Low Temperature. This temperature is en-
tered as an offset with the Leaving Chilled Liquid Tem-
perature Cycling Offset – Shutdown Setpoint below.
Although the offset setpoint is changed manually, the
offset being used can change automatically to prevent
the Leaving Chilled Liquid Temperature from going
below the minimum allowed value: 36°F (water), 34°F
(water with smart freeze enabled) or 6°F (brine). The
offset being used is displayed as Effective Offset. Re-
fer to the setpoint description below.
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 OFF-
SET adjacent to this value.
For fields requiring access level of SER-
VICE. Service Technicians refer to the
OptiView Control Center - Service Instruc-
tions (Form 160.76-M1) for operation
instructions and explanation of all pro-
grammable setpoints and displayed values.
PROGRAMMABLE
Local Leaving Chilled Liquid Temperature –
Range
Access Level Required: OPERATOR
This is the range over which an analog (0 to 20mA, 4 to
20mA, 0 to 10VDC or 2 to 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. Programmable as 10°, 20°, 30° or 40°F. It is
added to the BASE value to create a range over which
the re-mote device can reset the setpoint. For example,
if this Range setpoint is programmed for 10°F and the
operator programmed BASE value is 45°F, then the
remote device can set the leaving chilled Liquid Tem-
perature Setpoint from 45 to 55°F.
28
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 (refer to Page 29) is enabled, the range is 36.0°F
to 70.0°F (water). The maximum allowed setpoint with
Heat Pump duty enabled is 86.0°F. A remote device
can provide an analog signal (0 to 20mA, 4 to 20mA, 0
to 10VDC or 2 to 10VDC) in Analog Remote mode, or
a 1 to 11 second 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 to 20°F above the BASE Setpoint (refer to the Leav-
ing Chilled Liquid Temperature Setpoints – Setpoint
on Page 27 description). Additionally, an E-Link
Gateway in ISN (BAS) 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
BASE setpoint value, but rather is the communicated
setpoint value itself.
Leaving Chilled Liquid Temperature Cycling
Offset – Shutdown
Access Level Required: OPERATOR
This value allows the user to specify the Leaving
Chilled Liquid Temperature at which the chiller will
shut down on a LEAVING CHILLED LIQUID – LOW
TEMPERATURE cycling shutdown. This is done by
defining an offset below the Leaving Chilled Liq-
uid Temperature Setpoint. It is programmable over
a range of 1°F to 64°F below the setpoint, to a mini-
mum cutout of 36°F (water), 34°F (water with Smart
Freeze enabled) or 6°F (brine). Anytime the Leaving
Chilled Liquid Temperature Setpoint is increased, the
shutdown threshold is 36.0°F (water) or 6.0°F (brine)
for the next ten (10) minutes. If Smart Freeze (refer to
Page 29) is enabled, the threshold is 34.0°F for the
next 10 minutes. After ten (10) minutes have elapsed,
the shutdown threshold becomes the programmed
setpoint value.
The offset being used is displayed as Effective Offset
in the upper right area of the display. Usually, the Off-
set used is the same as the value programmed for the
Shutdown Setpoint. However, the Offset being used
will automatically change based on the values pro-
grammed for the Leaving Chilled Liquid Temperature
Setpoint and the Shutdown Setpoint, to prevent the
FORM 160.76-O2
issue date: 6/15/2015
JOHNsON CONtROLs