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FORM 160.87-OM1
ISSUE DATE: 8/24/2018
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 from 10°F to 40°F, with
a default of 10°F, it is added to the BASE value to cre-
ate 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 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 (water).
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 creating an offset above
the operator programmed BASE Leaving Chilled Liq-
uid Temperature Setpoint. This offset may be defined
from to 10.0°F to 40.0°F above the BASE Setpoint
(refer to the Remote Leaving Chilled Liquid Tempera-
ture Setpoint Range description). Additionally, E-Link
or SC-EQ communications (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.
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 70°F below the setpoint, to a minimum cut-
JOHNSON CONTROLS
SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
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 threshold is 36.0°F
(water) or 6.0°F (brine) for the next ten (10) minutes. If
Smart Freeze 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.
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 programma-
ble over a range of 0°F to (80 - Local Leaving Chilled
Liquid Temp Setpoint). This allows 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.
Local Motor Current Limit
Access Level Required: OPERATOR
Allows the user to specify the maximum allowed mo-
tor current (as a percentage of FLA). Adjustable from
30% to 100%, Default = 100%. When the motor cur-
rent reaches this value, the Pre-Rotation Vanes will not
be permitted to open further. If the motor current rises
above this value, the Pre-Rotation Vanes will close to
reduce the current to this value.
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