DIYbanter - View Single Post - Main breaker inside vs. outside the house?

wrote:
In article ,
Jeffrey J. Kosowsky wrote:

In upgrading our electrical we have the choice of either keeping the
main breaker inside the house or locating it outside as part of a
combo unit with the meter?
[Note we need a separate main breaker since the main panel is about 20
feet away from where the meter is and the supply enters the house]

Locating the main breaker outside would save a little money since we
avoid the need for a separate breaker box inside.

Are there any disadvantages (or advantages) to having the main breaker
outside?

(note we still will be able to shut off power inside at the main
panel, I assume)

I'm not sure I understand. As someone else already said: You need to
have a main shutoff for the whole house outside (for the fire
department to kill power to a burning house quickly, without going
in), which has to be within 10' of the meter. So the main breaker
(which nearly always is the main shutoff for a residential system)
will go outside, whether you like it or not. So I fail to see how the
main breaker could possible be inside. It is theoretically possible
that your local area has modified the standard electrical code to
allow the main shutoff to be inside, but I find that unlikely.

But you also say that you will be able to shut off power inside (which
I think is an excellent idea, I'd hate to have to go outside anytime a
breaker trips or I want to kill a particular circuit), *** but you say
at the main panel *** (which has to be outside, so how could this
work)?

The only way this makes sense is if you are asking the following
question: Given that the main breaker will be outside, does it make
sense to have two panels: One outside, with just a main breaker to cut
power to the whole house, feeding nothing but one big wire that goes
to a single subpanel inside, with lots of little breakers in it, and
from where power is distributed? I'm all in favor of that, and that's
exactly how our house is wired: Outside is just a meter and a 200A
breaker. and located in the basement in a central location (from where
all wire runs are reasonably short) is a big subpanel with all the
breakers. Cost is a little higher (two panels), but not terribly
much, because the outside panel can be a reasonable small one with
very few breaker slots.

The way I look at this is: You save a lot of money by doing the
electrical installation yourself. We decided to take some of those
savings, and plow them into having a better electrical system, by
upgrading things all over the place: Two separate panels in convenient
locations, use a more expensive but easier to work in large panel (we
have a 40-slot panel for a 1700 sqft house, without use of tandem
breakers), divide the house into more circuits than one would usually
do (to modularize wire runs), use heavier gauge wire, put some runs
into conduit to allow future upgrades without having to fish wires,
and use better outlets and more dimmers. This also left us much room
for expansion, which has really paid off this year when finishing the
basement, and adding a 100A subpanel for the woodshop.

Only some local building codes require a shut off outside the house.
There is no such requirement in the US NEC. You appear to be confusing
the main panel which is a term of art with the National Electric Code
Service Disconnecting Means which is a national standard regulatory term.

The NEC defines panels in two categories. These are Lighting and
Appliance and Power. A lighting and appliance branch-circuit panelboard
is one having more than 10 percent of its overcurrent devices protecting
lighting and appliance branch circuits.

A lighting and appliance branch circuit is a branch circuit that has a
connection to the neutral of the panelboard and that has overcurrent
protection of 30 amperes or less in one or more conductors.

A service disconnecting means can take many forms of which a panel
mounted breaker is but one. Some of the others are fused & unfused
disconnects, Fused pull outs, enclosed circuit breakers, and in the case
of the Grounded Current Carrying Conductor a lug or terminal.
--
Tom H