Vacuum Pumps The installation of a Variable Velocity Drive (VSD), Energy-Conserving Vacuum Pump sometimes called a adjustable frequency drive, usually saves between 50 and 65% in electrical power costs with the same or better regulation of vacuum. The range of energy savings can 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 acceleration of the vacuum pump predicated on the reading from a pressure sensor that is installed on the vacuum collection close to the receiver jar. The VSD is basically a dedicated pc with many adjustments so it might be possible to improve vacuum regulation over the normal pneumatic vacuum regulator that only includes a vacuum level adjustment. A VSD for a vacuum pump is usually cost-effective for a dairy that milks a complete of 8 hours or even more each day. Typically a VSD will not be a cost-effective option for little dairies because of less milking period and thus shorter vacuum pump run times but there are several other choices to save energy costs.