D4B switchboard (1968-1983)	Back	Up	Next
The D4B line of switchboard meters incorporated the same type of construction as the D4 line of polyphase meters. The photo shows the internal construction and the test switch in more detail (compare to the D2B photo). The cover for the D4B is similar to the D2B except the lower part of the cover is plain (no corrugations).	Photo by Ed Ranucci