Johnson Controls YORK OPTIVIEW CONTROL CENTER, Operation Manual

Page: 23 / 142

JOHNSON CONTROLS
23
SECTION 2 - OPTIVIEW OPERATION
FORM 160.10-O1
ISSUE DATE: 4/27/2018
2
ration temperature if the refrigerant temperature sensor
is disabled.
Leaving Chilled Liquid Temperature Setpoints
– Setpoint
This display indicates the present setpoint to which the
chiller is operating, whether controlled locally or re-
motely.
Leaving Chilled Liquid Temperature Setpoints
– Shutdown
This display indicates the leaving chilled liquid tem-
perature at which the chiller will shut down to avoid
over-cooling. The default value is 4.0°F below the
leaving chilled liquid temperature setpoint.
Leaving Chilled Liquid Temperature Setpoints
– Restart
This display indicates the leaving chilled liquid tem-
perature at which the chiller will restart after the chiller
has shut down due to over-cooling temperature. The
leaving chilled liquid temperature setpoint is the de-
fault value for this setting.
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 chill-
er. The temperature is programmable over the range of
38.0°F to 70.0°F (water) or 10.0°F to 70.0°F (brine).
The range is 36.0°F to 70.0°F (water) if Smart Freeze
is enabled (see below).
Local Leaving Chilled Liquid Temperature –
Range
Access Level Required: OPERATOR
This is the range that a remote device is able to adjust
the leaving chilled liquid temperature setpoint above
the temperature set locally at the OptiView. The range
setpoint is programmable to either 10°F or 20°F, with a
default of 20°F. This setpoint value is added to the lo-
cal leaving chilled liquid temperature (see above) val-
ue to create a range limit over which a remote device
can adjust the setpoint.
• For example, if the range is programmed for 10°F
and the locally programmed value of the chilled
liquid temperature is 45.0°F, then the remote de-
vice is able to change and set the leaving chilled
liquid temperature setpoint over the range 45.0°
- 55.0°F.
A remote device that provides an analog signal (0-
20mA, 4-20mA, 0-10VDC or 2-10VDC) in analog re-
mote mode or a PWM signal in digital remote mode
defines the setpoint change as an offset value.
• For example, if the setpoint is 45.0°F and the de-
sired setpoint is 50.0°F, then 5.0°F would be the
input on the remote device.
A MicroGateway (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 applied to the
leaving chilled liquid temperature setpoint value, but is
the programmed as the actual setpoint value.
Leaving Chilled Liquid Temperature Cycling
Offset – Shutdown
Access Level Required: OPERATOR
This value specifies the number of degrees below the
leaving chilled liquid temperature setpoint the chilled
liquid can reach before the OptiView performs a
“LEAVING CHILLED LIQUID – LOW TEMPERA-
TURE” cycling shutdown. This setpoint is program-
mable over a range of 1°F to 64°F (dependant on
setpoint temperature), to a minimum cutout of 36.0°F
(water), 34.0°F (water with Smart Freeze enabled) or
6.0°F (brine). This prevents over-cooling of the chilled
liquid.
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
ten minutes. After ten minutes have elapsed, the shut-
down threshold becomes the programmed setpoint
value.
Leaving Chilled Liquid Temperature Cycling
Offset – Restart
Access Level Required: OPERATOR
This value specifies the number of degrees above the
leaving chilled liquid temperature setpoint the chilled
liquid is permitted to reach before the chiller will re-
start after a “LEAVING CHILLED LIQUID – LOW
TEMPERATURE” cycling shutdown. The value is
programmable over a range of 0°F to 70°F (depen-
dant on setpoint temperature) above the chilled liq-