Why are non restriceive twin breakers made if you can't use them to over fill a panel box. The only panels that can exept twins have the notch in them. What the dilio???

Older load centers did not have notched stabs but many were approved for use with twin breakers in the positions shown on the wiring diagram. The problem was people were installing these breakers in any position and in panels that were not approved for twin breakers so they had to come up with a CTL design. They still make the breakers for use in older panels without the notches but usually cost quite a bit more.

Curt

That is one of my pet peeves. When I go on an inspection and I see twin breakers, I have to look at the wiring diagram and/or the panel model number. Some panels like the ITE (Siemans) 20-20 panel means that it can handle 20 full size breakers only. No twins. Then the contractor usually argues with me that panels can haold up to 42 circuits. Well that is true, however the manufacture of a certain panel only wants a certain number of breakers in that panel. I wish that the manufactures all had seperate configurations for their own equipment and not let everyone elses in there. It might be so much easier.