magnetrip zinsco panels

[lawrence kany]

the older panels with no main breaker had up to 12 breakers-
in what year did the six breaker maximum or a main c/b come into effect
in the NEC

 

[satcom]

I can't tell you when it first went in, but i know it has been at least 35 years, and i can't recall 12 breakers without a main ever being acceptable, there were a lot of installations, where they just filled up main lug panels, used for a service.
Stand by, there will be plenty of replys comming, and might be someone, has the date it was included.

 

[77401]

I think(guessing) the code had something about "up to six breakers" to turn everything off.
Older Zinsco panels had no main but like about 5 - 2pole breakers & a 2pole sub main that turns off the single pole breakers below.
Was it called a Split Buss panel?

 

[dlhoule]

It has been that way since I got started in contracting in '65. Some of the old timers can probably give you a date.