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rowdy48 · 04-10-2010, 10:08 AM

When did the nec begin to require 240 breakers be located in the top of the panel with the 110 at the bottom. I assume its to place the larger amp breakers nearer the power "in" cables.

Thanks

Stuart

Nestor_Kelebay · 04-10-2010, 06:25 PM

Rowdy:

My understanding is that in most electrical panels ANY two adjacent breaker positions on the same side of the panel will give you 220 volts. I think it's just a well established convention to use the breaker positions at the top of the panel for the 220 volt loads like the stove and dryer (and maybe A/C).

Someone correct me if I'm wrong.

Nestor_Kelebay · 04-10-2010, 06:54 PM

JoeD · 04-11-2010, 08:35 AM

The NEC never 'required' it. It sounds like you might have a split bus panel.

**speedy petey** · 04-11-2010, 08:43 AM

Quote:

Originally Posted by Nestor_Kelebay

My understanding is that in most electrical panels ANY two adjacent breaker positions on the same side of the panel will give you 220 volts. I think it's just a well established convention to use the breaker positions at the top of the panel for the 220 volt loads like the stove and dryer (and maybe A/C).

Someone correct me if I'm wrong.

Two points:
"220" is an incorrect term. For many many years the nominal voltage has been 120/240v. Trivial I know, but I thought it was worth mentioning.

It is not at all a "well established convention" to place two-pole breakers at the top. At least not in my experience. There is simply no reason to go out of your way to do this. If that's how it lays out, fine.

ohmy · 04-19-2010, 12:26 PM

Quote:

Originally Posted by speedy petey

Two points:
"220" is an incorrect term. For many many years the nominal voltage has been 120/240v. Trivial I know, but I thought it was worth mentioning.

It is not at all a "well established convention" to place two-pole breakers at the top. At least not in my experience. There is simply no reason to go out of your way to do this. If that's how it lays out, fine.

If your in a residence in North America, 120/240 is normal. There are many places in throughout the US with 208, 220, 277, 480, etc.

JoeD · 04-24-2010, 07:07 AM

208,277,480 are three phase voltages that you will most likely never see in a residence. They are industrial voltages

Nestor_Kelebay · 04-24-2010, 11:03 AM

OK. 120 it is.

Can anyone in here explain the basis and origin of these different numbers?.

If I had to guess, I'd say 110 was the lowest voltage you'd typically expect to find in household wiring on any given day, 120 is the highest, and most of the time it's somewhere around 117. But, if I had to guess, I'd say that there's a slim chance of that guess being right.

Why can all three of these numbers claim to be the "true" voltage in household wiring?

triple D · 05-05-2010, 09:18 PM

depends on your location to serving substation, and neighbors sharing transformer with you. Your voltage should range from 119-124 or so. Breakers can go wherever you want. Just so happens that when making up a panel, good electricians will start at the top with 240 breakers and work their way down, but once in a while, when we think were done, someone ads a hot tub or something. Were not going to tear it all apart and start over, so then its at the bottom. Does'nt hurt a thing.

Nestor_Kelebay · 05-06-2010, 03:16 PM

Rowdy48:

One electrician says: "It is not at all a "well established convention" to place two-pole breakers at the top. At least not in my experience. There is simply no reason to go out of your way to do this. If that's how it lays out, fine."

And the other one says: "Breakers can go wherever you want. Just so happens that when making up a panel, good electricians will start at the top with 240 breakers and work their way down, but once in a while, when we think were done, someone ads a hot tub or something. Were not going to tear it all apart and start over, so then its at the bottom."

So there you have it. Put "240 breakers at top of panel" in the same bag as UFO's, the Burmuda triangle and crop circles.