On Sep 21, 9:01*am, dpb wrote:
Aaron Fude wrote:
RBM wrote:
"Aaron Fude" wrote in message
...
Hi,

This is just a theoretical question to satisfy my curiosity.

A panel can be back-fed through a regular breaker. How is a main
breaker, then, different from a regular breaker? Or is it just a
breaker that doesn't give you an option of not having it?

Thanks,

Aaron

"Main breaker" is defining it's usage, not necessarily how it's built.
The same thing with a breaker used as a service disconnect. The
breaker is not necessarily different from a similar type breaker used
in the same panel, however when used as a service disconnect, it
requires a hold down method

Is there a technical reason why electrical panels with a main are so
much more expensive (at least at HD) than main lugs?

Yeah, that's how the catalog is printed...

In reality doesn't seem there should be as much differential as there
typically is other than that a 100 or 200A main is probably somewhat
more expensive to manufacture than the typical 50/60A I've seen in the
smaller subpanels.

(Maybe its my age and that we don't have any of the BORGs locally so
don't know what they're carrying but I haven't seen a full-blown 200A
panel w/o a traditional main--maybe they've started for the cheap/mass
market and I've just not paid attention, though, granted).

I would think that the main breaker would have a higher interrupt
current rating than a branch circuit breaker, just in case things go
really pear-shaped. (that is, if there's a *serious* issue, the main
breaker will provide protection in cases of overvoltages/dead shorts
that would just arc over an open branch circuit breaker.)

Now whether it works like that in practice, I don't know (IANAE)

nate