Table 33: Display only fields
Field/LED name
Description
[Evaporator (Cooling)] Active
Setpoint
Displays the active temperature setpoint to which the chiller is set to control liquid
leaving the evaporator. The Active Setpoint is a target to the Local, Remote or BAS
LCHLT programmed setpoint, depending on the control source selected. When the
chiller is not running, the Active Setpoint is set to Entering Chilled Liquid Temperature
- LCHLT Setpoint Start Offset When the VSD starts, the Active LCHLT Setpoint is ramped
to the programmed LCHLT Setpoint at the programmable LCHLT Setpoint Ramp
Rate. When the chiller is running, performing capacity control, any change to the
programmed LCHLT setpoint results in a ramp from the old Active Setpoint value
to the new LCHLT setpoint value at the programmed LCHLT Setpoint Ramp Rate.
Displayed when the unit is cooling or cooling/heating.
[Evaporator (Cooling)]
Delta T
Displays the difference between the temperature of the chilled liquid leaving the
evaporator and the Leaving Chilled Liquid Active Setpoint. Only displayed when the
unit is cooling or cooling/heating.
Control State
Displays the present source controlling the command to the capacity control devices.
Control state
Condition
Inactive
Capacity Control is not active
Cooling Control
Capacity Control is active with no overrides acting.
Heating Control
Capacity Control is active with no overrides acting.
Input Current
Input Current Override is in control
Motor Current
Motor Current Override is in control.
Condenser Pressure
Condenser Pressure Override is in control.
Evaporator Pressure
Evaporator Pressure Override is in control.
Low LCHLT
LCHLT low temperature Override is in control
Discharge Superheat
Low Discharge Superheat Override is in control
High LCLT
High Leaving Condenser Liquid Temperature
Override is in control
Load Limit
Displays if any load limiting control is acting on the temperature control output to the
capacity control devices. The field indicates the following:
•
Inactive - Capacity Control is not active
•
None – No limit is in effect
•
Input Current
•
Motor Current
•
Condenser Pressure
•
Evaporator Pressure
•
Discharge Superheat
Head Pressure
Displays the difference between condenser refrigerant pressure and evaporator
refrigerant pressure.
[Condenser] Entering Liquid
Displays the temperature of the condenser liquid as it enters the condenser.
[Condenser] Leaving Liquid
Displays the temperature of the condenser liquid as it leaves the condenser.
Capacity Control Output Devices
Displays the following for each of the devices that is available: VSD (Variable Speed
Drive), PRV (Pre-Rotation Vanes) or HGBP (Hot Gas Bypass Valve):
•
Active Output (LED): Indicates which device is currently selected by the control
for manipulation.
•
Command: Displays the output command from the control to the device in Hertz
to the VSD or in percent of full open to the PRV or HGBP valve.
•
Feedback: Displays the present speed feedback from the VSD or present
position feedback from the PRV.
•
Active Min: Displays the prevailing minimum value to which the control to the
device is limited, based upon surge controls or operating limits.
•
Control State: Displays whether the device is under Automatic or Manual
control.
53
Model YK Style H Centrifugal Liquid Chillers with OptiView Control Center
