Vacuum Pumps Installing a Variable Energy-Conserving Vacuum Pump Velocity Drive (VSD), 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 function by changing the rate of the vacuum pump predicated on the reading from a pressure sensor that is mounted on the vacuum series close to the receiver jar. The VSD is actually a dedicated pc with many adjustments therefore it may be possible to boost vacuum regulation over the normal pneumatic vacuum regulator that just has 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 more per day. Typically a VSD will not be an economical option for little dairies due to less milking time and thus shorter vacuum pump run times but there are several other choices to save energy costs.