HFS and HFA (1934 to 1940)	Back	Up	Next
With the standardization of meters in 1934, the HC element was incorporated into the newly standardized housings. In addition to socket (HFS) and A-base (HFA) versions, two other versions were produced: the HFB and HFC. The HFB had a special 2-part terminal block that allowed testing of the meter in place, and the HFC has the HFB terminal block in an enclosure for outside mounting of the meter. Of the latter versions, GE was the only other company to make similar models: the I-20B and I-20C.	David Dahle collection