York YK Style H Operation Manual page 120

SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
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 signal (0 to 20
mA, 4 to 20mA, 0 to 10VDC or 2 to 10VDC) in Ana-
log Remote mode or a digital signal (PWM) in Digi-
tal Remote mode can reset the Leaving Chilled Liquid
Temperature Setpoint above the operator programmed
BASE Setpoint. 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 Liq-
uid Temperature Setpoint over the range of 45.0°F to
55.0°F.
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 72.0°F (water) or 10.0°F to 72.0°F (brine). If Smart
Freeze is enabled, the range is 36.0°F to 70.0° F (wa-
ter). The maximum allowed setpoint with Heat Pump
duty enabled is 86.0°F. A remote device can provide an
analog signal (0 to 20 mA, 4 to 20mA, 0 to 10VDC or 2
to 10VDC) in Analog Remote mode, or PWM signal in
Digital Remote mode that changes the setpoint by cre-
ating an offset above the operator programmed BASE
Leaving Chilled Liquid Temperature Setpoint. This
offset may be defined up to 10.0°F or 20.0°F above the
BASE Setpoint (refer to the Remote Leaving Chilled
Liquid Temperature Setpoint Range description). Ad-
ditionally, E-Link Gateway (in ISN Remote mode) can
define the setpoint through a serial data stream. In this
case, the incoming setpoint is not an offset that is ap-
plied to the locally programmed BASE Setpoint value,
but rather is the setpoint value itself.
120
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 Liquid
Temperature Setpoint. It is programmable over a range
of 1°F to 64°F below the setpoint, to a minimum cut-
out of 36°F (water), 34°F (water with Smart Freeze
enabled) or 6°F (brine). It establishes the minimum
allowed temperature for the Leaving Chilled Liquid
Temperature and prevents over-cooling of the build-
ing. Anytime the Leaving Chilled Liquid Temperature
Setpoint is increased, the shutdown temperature is in-
creased by 0.05°F/second to allow the chiller time to
unload to the new setpoint.
Leaving Chilled Liquid Temperature Cycling
Offset – Restart
Access Level Required: OPERATOR
This value allows the user to specify the Leaving
Chilled Liquid Temperature at which the chiller will
restart after a shutdown on a LEAVING CHILLED
LIQUID – LOW TEMPERATURE cycling shutdown.
This is done by defining an offset above the Leaving
Chilled Liquid Temperature Setpoint. It is program-
mable over a range of 0°F to 70°F above the setpoint,
to a maximum restart value of 80°F. The chiller will
automatically restart when this temperature is reached.
This setpoint can be used to reduce chiller cycling by
delaying the chiller restart until the cooling load has
increased.
Remote Analog Input Range
Access Level Required: OPERATOR
This setpoint defines, for the Control Center, the re-
mote signal range applied for remote reset of the Leav-
ing Chilled Liquid Temperature Setpoint and Current
Limit Setpoint in Analog Remote mode. If the remote
signal is 0 to 10VDC or 0 to 20mA, this setpoint must
be programmed for 0 to 10VDC. If the remote signal is
2 to 10VDC or 4 to 20mA, this setpoint must be pro-
grammed for 2 to 10VDC.
FORM 160.76-O2
issue date: 6/15/2015
JOHNsON CONtROLs