Is there a code reference regarding federal pacific split bus panels. If there is I cant find it in the nec. In my area I run across them quite frequently.

See 408.16(A) Exception #2. The handbook has a couple of diagrams with more detail on this exception. ( I am assuming that they are the same type of panel you are talking about. One shows a top bus with 2 breakers feeding a middle and a bottom bus. The other shows a top bus with 6 breakers. 5 feed other loads, and the 6th feeds a bottom bus.)

Steve

are you talking about the 2002 code, because I have the 99 code and it goes from article 402 fixture wires to article 410 light fixtures and lamps. Thanks for the reply.

Yes, that was the 2002 NEC. For the 96 (which should have the same number at the 99 code) the reference is 384-16 Exception #2.

The handbook commentary:

"The phrase "for existing installations" in Exception #2 means the existing panelboard. It is not intended that a split bus panelboard used in an individual dwelling occupancy be replaced if a circuit is added to the existing panelboard. It does mean, however, that for installation of new panelboards in new or existing residential occupancies, a split-bus six-disconnect panelboard (with more than two circuit breakers or sets of fuses protecting the panelboard ) is not permitted for the service equipment.
Etc.

STeve