I-30S and I-30A (1937 to 1954)	Back	Up	Next
The I-30 meter was similar to the previous I-20 but used a new stator that had increased overload capacity and improved compensation. There were two major changes that were made early in the I-30's production span. First, the chrome steel magnets (which had been used since the I-16) were replaced in 1938 with an Alnico I magnet assembly that was more resistant to loss of magnet strength from lightning or power surges. After WWII, the cast iron internal frame was replaced with one made from a lighter aluminum alloy. I-30A meters made during WWII have almost no aluminum in them (which was needed for the war effort) - they have steel alloy bases, iron internal frames, brass registers, and cardboard nameplates. The I-30S used a compression-molded insert in the base instead of individual bushings. Wartime units are similar to the pre-war and postwar units except for the cardboard nameplates. Although this meter was superseded in 1948 by the I-50, it continued in production until GE stopped making meters at its original plant in Lynn, MA in 1954 (moving all watthour meter production to a plant GE opened in Somersworth, NH in 1948).	David Dahle collection