jwelectric
Senior Member
- Location
- North Carolina
Re: Spare capacity in panelboards
Well just for those who don?t know.
This misconception of extra breakers came about by a bunch of idiots who install commercial and industrial systems. I have always said that a good residential man that learns to bend pipe can install commercial and industrial systems but a commercial or industrial man knows nothing about residential.
A lighting and appliance panel board can have no more than 14 three phase breakers because they are manufactured to hold only 42 circuits. Try and fill this same panel board with two pole breakers and you will have one left on each side.
General contractor asks the electrician what are these two spaces for and the idiot answers SPARES.
Now we have the concept started that we are to have spares because the idiot electrician didn?t take one of MY classes so he would know that they are supposed to use a three phase breaker on the bottom of both sides to prevent these free spaces.
Some will find this explanation logical while others will think of it as a total line of anal secretion. Personally I think it is pretty good until someone comes up with something better.

Well just for those who don?t know.
This misconception of extra breakers came about by a bunch of idiots who install commercial and industrial systems. I have always said that a good residential man that learns to bend pipe can install commercial and industrial systems but a commercial or industrial man knows nothing about residential.
A lighting and appliance panel board can have no more than 14 three phase breakers because they are manufactured to hold only 42 circuits. Try and fill this same panel board with two pole breakers and you will have one left on each side.
General contractor asks the electrician what are these two spaces for and the idiot answers SPARES.
Now we have the concept started that we are to have spares because the idiot electrician didn?t take one of MY classes so he would know that they are supposed to use a three phase breaker on the bottom of both sides to prevent these free spaces.
Some will find this explanation logical while others will think of it as a total line of anal secretion. Personally I think it is pretty good until someone comes up with something better.