Chilled Water Pump Vfd

The existing chilled water system consisted of two variable flow primary chilled water pumps three variable speed cooling fans and three constant volume condenser water pumps.

Chilled water pump vfd. Vfd to maintain a fixed. Vfd technology is not new to the hvac industry. Variable frequency drives have been used extensively for air handling unit fans cooling tower fans and water pumps for a long time. Actually vfd normally used in secondary pump but in some diagram it shows in primary pump so please clarify what is role of vfd in chilled water system and where it used.

Control question added by rashid ali abdul haque senior mechanical engineer bureau veritas. With state of the art compressor technology and microprocessor based control systems manufacturers now offer variable frequency drives specially designed for centrifugal chillers. Secondary pump in chilled water system is responsible to pump the chilled water to load end i e. Enable the primary chilled water pump when outside air temperature is above setpoint and at least 1 chilled.

The building is a large distribution center that primarily uses chilled water for cooling. The single primary pump pumps water through the chiller and to the coils. The three trane cvhe450 centrifugal chillers also had variable speed compressors. Vfd s variable frequency drives are usually employed to serve the purpose of feeding electrical power to pump motors as these provide a good control over speed of motor which in turn changes the gpm s gallon per minutes being supplied to load end.