Johnson Controls YORK YK MaxE, Operation Manual

Page: 24 / 184

JOHNSON CONTROLS
24
FORM 160.54-O1
freeze enabled) or 6ºF (brine). The offset being used is
displayed as “EFFECTIVE OFFSET”. With software
versions earlier than C.OPT.01.18.307, the value is
displayed as “Offset” and reflects the programmed
value only, not the offset being used. Refer to 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 “Offset” adjacent to this value.
prograMMaBLe
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 Temperature setpoint
above the operator programmed Base Setpoint (see
below). Programmable as 10, 20, 30 or 40ºF (software
version C.OPT.01.18.307 (or later); 10ºF or 20ºF with
earlier software versions). 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
Temperature setpoint over the range 45.0° - 55.0°F.
Local Leaving Chilled Liquid Temperature - Set -
point 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 to 20ºF above
the Base setpoint (see the Remote Leaving Chilled
Liquid Temperature Setpoint Range description above).
Additionally, 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 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 TEM-
PERATURE 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 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 (see below) is enabled, the threshold is
34.0°F for the next 10 minutes. After ten (10) minutes
have elapsed, the shutdown threshold becomes the pro-
grammed setpoint value.
With software version C.OPT.01.18.307 (or later), the
offset being used is displayed as “EFFECTIVE OFF-
SET” in the upper right area of the display. Usually, the
Offset 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 TEM-
PERATURE setpoint and the SHUTDOWN setpoint,
to prevent the leaving chilled liquid temperature from
going below the minimum allowed value: 36ºF (water),
34ºF (water with smart freeze enabled) or 6ºF (brine).
For example, if the leaving Chilled Liquid Temperature
setpoint is set to 45ºF (water) and the SHUTDOWN
setpoint is set to 4ºF, the Effective Offset is displayed
as 4ºF. If the leaving setpoint is lowered to 38ºF, the Ef-
fective Offset will change to 2ºF. If the leaving chilled
setpoint is raised back to 45ºF, the Effective Offset will
revert back to the SHUTDOWN setpoint. With software
versions prior to C.OPT.01.18.307, the value is displayed
as “Offset” and reflects the programmed value only, not
the offset being used.
optiView Control Center