From: clewis@ferret.ocunix.on.ca (Chris Lewis)
Newsgroups: misc.consumers.house
Subject: Re: 12 gauge vs 14 gauge wiring price
Date: 8 Sep 92 02:19:26 GMT
Organization: Elegant Communications Inc., Ottawa, Canada

In article <1992Sep4.215428.23716@porthos.cc.bellcore.com> patter@dasher.uucp (24224-guthrie) writes:
>And for the person who said you can fill up a panel with as many breakers
>as it will hold regardless of size, don't try that in Maplewood, NJ.
>According to the fellow that put in my brother's new service wiring, the
>code there is very simple; your total breaker load on each side may not
>exceed the main breaker size. The electrician who gave me an estimate
>for a new service last year told me that my area (Franklin township) has
>the same regulation. Franklin uses one of the nationally accepted codes,
>but I can't remember the name (something like BOCA).

It ain't the NEC.

That was me.  How bizarre.  Haven't they ever heard of service factors?
Conceptually, circuit interrupters are rated to protect the wiring "downstream"
of them.  The panel main breaker protects the service wiring and panel,
and the individual breakers protect the wiring in the circuit itself.

If the breakers add up to more than the main, it just means that the main
will trip before all of the circuits are running at their maximum rated
load simultaneously.  Which is perfectly acceptable.  After all, electrical
codes place all sorts of requirements on circuits - one for a fridge (only
600W), one for a furnace blower (probably only 800W) etc. - they're running
at a fraction of the circuit's rating - and non-continuous to boot.

The main breaker is selected to limit the current draw of your whole
house in total, the individual breakers are simply protecting the
individual circuit wires.

If the breaker total was constrained to total less than the main,
that would mean that a 60A service could have three circuits: stove,
fridge, and furnace fan.  Somebody with a 125A could barely fulfill
the NEC requirements for *just* the kitchen (in actuality, 125A or
150A is the size that *most* new houses get - 200A is for electric
heat).  You'd have to have 200A before you could have a dryer.

The CEC *mandates* 40-slot panels for 200A services (only 32 if there's an
electric furnace).  Fully stuffed with minimum size breakers makes 300A/side.

In point of fact, my panel adds up to 520A or thereabouts *per* side.
And we've never lost our main.  Everything is perfectly legal.

The NEC and CEC rules are designed differently:

	- there's a wattage assessment for house area.
	- there's a increment for the appliances most places have
	  (stove, dryer etc.)
	- optional increment for electric heat
	- other major uses.

These numbers (some of the numbers are discounted for continuous/cycling/
or interlock (you don't have to add the electric heat together with A/C))
are added up to find your service size.  That gives you a panel size.
Then the rules tell you how many circuits you need based on what they're
supplying.

Frankly, I think that "fellow" is badly mistaken, or was trying to snow
your brother into a larger panel than he needed so he could make a little
more money off the job.

Or, he was simply stating the truism that the calculated house load must
be smaller than the service and it got garbled in translation - the breaker
total has relatively little to do with the calculated house load - except
that it must be *higher* (obviously).

>You can certainly fill up the panel with all the breakers it will hold,
>but you might as well quit paying for insurance if you do.

Not here nor under NEC.
-- 
Chris Lewis; clewis@ferret.ocunix.on.ca; Phone: Canada 613 832-0541
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