Vfd to maintain a fixed.
Chilled water pump vfd.
Enable the primary chilled water pump when outside air temperature is above setpoint and at least 1 chilled.
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.
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.
The selection of this equipment is driven by the individual efficiencies at full and partial loads and also by how the system efficiency will respond to the building loads.
Water differential pressure transmitter near the end of the piping run varies the speed of the vfd.
Secondary pump in chilled water system is responsible to pump the chilled water to load end i e.
The building is a large distribution center that primarily uses chilled water for cooling.
Vfd technology is not new to the hvac industry.
With state of the art compressor technology and microprocessor based control systems manufacturers now offer variable frequency drives specially designed for centrifugal chillers.
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.
Variable frequency drives have been used extensively for air handling unit fans cooling tower fans and water pumps for a long time.
The three trane cvhe450 centrifugal chillers also had variable speed compressors.