The BA and BB Series transient surge suppressors are heavy-duty industrial metal-oxide varistors (MOVs) designed to provide surge protection for motor controls and power supplies used in oil-drilling, mining, transportation equipment and other heavy industrial AC line applications. These UL-recognized varistors have similar package construction but differ in size and ratings.The BA models are rated from 130 to 880VM(AC) . The BB models from 1100 to 2800VM(AC) . Both the BA and BB Series feature improved creep and strike capability to minimize breakdown along the package surface, a package design that provides complete electrical isolation of the disc subassembly, and rigid terminals to insure secure wire contacts. See BA/BB Series Device Ratings and Specifications table for part number and brand information.