Vacuum Pumps The installation of a Variable Velocity Drive (VSD), sometimes called a variable frequency drive, usually saves between 50 and 65% in electrical power costs with the same or better regulation of vacuum. The number of energy savings could be from 30 to 80 percent. They may be adapted to blower or in some instances rotary vane type vacuum pumps. They work by changing the rate of the vacuum pump predicated on the reading from a pressure sensor that is mounted on the vacuum collection close to the receiver jar. The VSD is actually a dedicated pc with many adjustments therefore it may be possible to improve vacuum regulation over the typical pneumatic vacuum regulator that only includes a vacuum level adjustment. A VSD for vacuum pressure pump is usually economical for a dairy that milks a complete of 8 hours or even more per day. Energy-Conserving Vacuum Pump Typically a VSD will never be a cost-effective option for little dairies due to less milking time and therefore shorter vacuum pump run times but there are some other choices to save energy costs.