York YK Style H Operation Manual page 43

FORM 160.76-O2
issue date: 6/15/2015
setpoint is 90°F, the remote device can set the Leaving
Condenser Liquid Temperature Setpoint over the range
of 90 to 80°F.
Leaving Condenser Liquid Temperature
Cycling Offset – Shutdown
Access Level Required: OPERATOR
This setpoint allows the user to specify the Leav-
ing Condenser Liquid Temperature at which the Heat
Pump will shutdown on LEAVING CONDENSER
LIQUID – HIGH TEMPERATURE cycling shutdown
in Heating mode. This is done by defining an offset
above the Leaving Condenser Liquid Temperature
Setpoint. The offset is programmable over the range
of 1 to 59°F (default 1) above the setpoint, to a maxi-
mum of 125°F. Anytime the Leaving Condenser Liq-
uid Temperature Setpoint is decreased, this shutdown
threshold becomes 125°F for the next 10 minutes. Af-
ter 10 minutes, the shutdown threshold becomes the
programmed setpoint offset value.
The actual offset being used is displayed as Effective
Offset on this screen. Usually, the offset that is used
is the same as the programmed value. However, the
setpoint used can change automatically to prevent the
Leaving Condenser Liquid temperature from going
above the maximum allowed temperature of 125°F.
For example, if the offset is set to 6°F but the Leav-
ing Condenser Liquid Temperature Setpoint is set to
120°F, the Effective Offset used will be 5 because 6
would allow it to exceed the maximum of 125.
Leaving Condenser Liquid Temperature
Cycling Offset – Restart
Access Level Required: OPERATOR
This setpoint allows the user to specify the Leav-
ing Condenser Liquid Temperature at which the Heat
Pump will restart after a shutdown on a LEAVING
CONDENSER LIQUID TEMPERATURE – HIGH
TEMPERATURE cycling shutdown in Heating mode.
This is done by defining an offset below the Leaving
Condenser Liquid Temperature Setpoint. It is program-
mable over a range of 0 to 67°F (default 0) below the
Leaving Condenser Liquid Temperature Setpoint, to a
minimum of 55°F. The chiller will automatically re-
JOHNSON CONTROLS
SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
start when this temperature is reached. This setpoint
can be used to reduce chiller cycling by delaying the
Heat Pump restart until the heating load has increased.
Heating LCHLT Shutdown
Access Level Required: OPERATOR
In Heating mode, the existing LEAVING CHILLED
LIQUID TEMPERATURE – LOW TEMPERATURE
cycling shutdown logic will include an additional
check to its existing logic that will cause a shutdown in
Heating mode. This setpoint allows the user to specify
the Leaving Chilled Liquid Temperature at which the
Heat Pump will shut down on LEAVING CHILLED
LIQUID – LOW TEMPERATURE cycling shutdown
when the Heat Pump is operating in Heating mode.
The low limit for this setpoint is the higher of (Leaving
Condenser Liquid Temperature Setpoint minus 71°F)
or (Cooling mode Leaving Chilled Liquid Tempera-
ture Shutdown Temperature). The high limit for this
setpoint is the Leaving Condenser Liquid Temperature
Setpoint. The default is (Leaving Condenser Liquid
Temperature Setpoint minus 60°F).
The Heat Pump will restart when the Leaving Chilled
Liquid Temperature exceeds this shutdown tempera-
ture by 5°F.
NAVIGATION
Home
Access Level Required: VIEW
Returns user to HOME Screen
Evaporator
Access Level Required: VIEW
Returns user to EVAPORATOR Screen
Condenser
Access Level Required: VIEW
Returns user to CONDENSER Screen
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