York YT Millennium, Эксплуатация и техническое обслуживание

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FORM 160.55-O1 (920)
21
YORK INTERNATIONAL
PROGRAMMABLE
Local Leaving Chilled Liquid Temperature -
Range
Access Level Required:
OPERATOR
This is the range over which an analog (0-20mA or 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 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 Liquid Temperature
setpoint over the range 45.0° - 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 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
or 4-20mA, 0-10VDC or 2-10VDC) in Analog Remote
mode or PWM signal in Digital Remote mode that chang-
es the setpoint by creating 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 (see the Remote Leaving
Chilled Liquid Temperature Setpoint Range description
above). Additionally, 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 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). It
establishes the minimum allowable temperature for the
Leaving Chilled Liquid Temperature and prevents over-
cooling of the building. 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 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 programmable over a
range of 0°F to 70°F above the setpoint, to a maximum
restart value of 80°F. The chiller will automatically re-
start 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.
Brine Low Evaporator Cutout
Access Level Required:
SERVICE
This value is only available in Brine mode. It allows the
user to specify the Evaporator Pressure at which a safety
shutdown is initiated.
Sensitivity
Access Level Required:
SERVICE
This value allows the user to adjust the sensitivity of the
Leaving Chilled Liquid Temperature control.
Smart Freeze (Off / On)
Access Level Required:
SERVICE
This value is only available if the chiller is not in Brine
mode. It allows the user to enable the Smart Freeze Point
Operation which allows the chiller to run closer to the
freeze point without shutting down.
Refrigerant (Enabled / Disabled)
Access Level Required:
SERVICE
When an Evaporator Refrigerant Sensor has been installed
it must be enabled via this toggle before the system will
utilize the new, enhanced resolution input.
NAVIGATION
Home
Access Level Required: VIEW
Causes an instant return to the Home Screen.
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