Discussion, rules, and graphical representation of Extended Unloading and Minimum Capacity Timer.
EXV CONTROL MODE SWITCH CRITERION
(The image displays a graph showing the relationship between "EVAP TEMPERATURE CONTROL ERROR" and different control modes: SUPER HEAT CONTROL, HOLD LAST MODE, and EXTENDED UNLOADING.)
RULES:
SUPER-HEAT CONTROL:
HIGH LOAD AND LWT ABOVE SETPOINT
HIGH LOAD AND LWT AT SETPOINT
HIGH LOAD AND LWT BELOW SETPOINT
EXTENDED UNLOADING:
LOW LOAD AND LWT BELOW SETPOINT
TRANSITION LOAD AND LWT BELOW SETPOINT
LOW LOAD AND LWT AT SETPOINT
HOLD LAST MODE:
NO LOAD AND LWT ABOVE SETPOINT
TRANSIENT LOAD AND LWT AT SETPOINT
Additional Information...
Title: Information on RTHB's Minimum Capacity Timer.
Description: RTHB units have a built-in, Minimum Capacity Timer that will shut the unit off if the:
ActualEvaporatorDeltaT / DesignDeltaT < 0.15 for 15 continuous minutes.
Actual Evaporator Delta T = as measured by the Evaporator Entering and Leaving Water Temperature Sensors.
Design Delta T = programmed into the UCP2 controls (This should be based on achievable Full Load Delta T with present water flows.)
This feature cannot be disabled.
Additional details
Facts
RTHB
Water-Cooled Chiller (Pueblo) (RTHB)
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.
Issue:
Extended Unloading and Minimum Capacity Timer
Resolution:
RTHB Chillers:
Discussion, rules, and graphical representation of Extended Unloading and Minimum Capacity Timer.
Facts:
RTHB
Water-Cooled Chiller (Pueblo) (RTHB)
Document Identifier: DOC-97598
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.