Danfoss Logo
Home Sitemap Worldwide
InfoEmail
HVACity
Drives Overview
Glossary
Technical Notes
Features
Fast Path
www.danfoss.com/drives

Primary Pumping - New Standard

Traditional solution | Application Description | Energy Savings 
Click here to read more about: AEO, PID Control, VVC plus

New Standard
Based on the size of the system, the energy consumption of the primary loop can be substantial. An adjustable frequency drive controlling the primary system pumps replaces the throttling valves and eliminates trimming the impellers. Decreasing the pumpís speed with a drive has the same effect as trimming the pump impeller, except it doesnít require any labor costs and the pumpís efficiency remains higher. The result is greater energy efficiency and reduced maintenance and operating expense.

Two drive control methods are common: One method uses a feedback signal from a flow meter. The desired constant-flow rate is known, a flow meter installed at the discharge of each chiller monitors the pump output. An adjustable frequency drive with a built-in PID controller maintains the appropriate flow rate, even compensating for scale buildup and for changing resistance in the primary loop as chillers and their pumps are staged on and off. This flow meter feedback application minimizes chiller low evaporator temperature safety trip-out and manual reset. More...


Click on graphic to animate!

Previous     Next