Variable Speed Pump (CPO) - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 13.1

Controller Tool Help

Brand
Johnson Controls
Metasys
Product name
Controller Configuration Tool
Document type
User Guide
Document number
LIT-12011147
Version
13.1
Revision date
2019-12-04
Language
English

Variable Speed Primary Headered Chilled Water System

In a variable speed configuration, the appropriate number of pumps needed to supply the required chilled water flow are turned on. The pump speeds are modulated to maintain the differential pressure (dP) setpoint. As an option, the setpoint can be reset by either a second sensor that measures differential pressure near the end of the building’s chilled water loop, or by the valve positions of the main chilled water coils in the building. As the number of pumps and the speed of the pumps changes, chilled water flow through the chillers and building changes.

Variable Speed Primary Dedicated Chilled Water System

In a variable speed dedicated chilled water pump configuration, the pumps are interlocked to their dedicated chillers and the pumps modulate to control the building dP to the dP setpoint. As pump speed changes, the water flow through the chillers and building also changes. As an option, the setpoint can be reset by either a second sensor that measures dP near the end of the building’s chilled water loop, or by the valve positions of the main chilled water coils in the building. A bypass valve is available for chilled water minimum flow control.
Note: If primary pumps are variable speed, you cannot have a secondary chilled water loop.