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Posted by on June 28, 2007, 8:32 am
On Jun 28, 7:21 am, spamb...@milmac.com (Doug Miller) wrote:
tomme...@comcast.net wrote:
>
> [snip]
>
> >I currently have 150amp service. The meter and the load center are
> >separated by about 50-feet. The wiring from the meter to the load
> >center is 2/0 aluminum.
>
> That is the minimum size rated for 150A.
>
> >I work for a major residential electrical
> >equipment maker (starts with a "S" and ends with "iemens")...and our
> >construction sales people tell me that the latest version of NEC
> >requires 4/0 aluminum wiring for 200amp service.
>
> They're right, and not just the latest version, either.
>
> >What is up with 2 of these contractors telling me it is OK to upgrade
> >without replacing the existing 2/0 wiring?
>
> Either they're incompetent, or the wire is actually copper (doubtful). Per
> National Electrical Code, minimum size feeder for 200A service is 2/0 copper
> or 4/0 aluminum. [2005 NEC, Table 310.15(B)(6)]
>
> >Is there some sort of grandfather provision in this situation?
>
> Not relevant. Whatever Code provisions may have been in effect when your
> service was installed do not matter: upgrades must meet the Code that's in
> effect at the time of the upgrade, not the time of the original installation.
>
>
>
> >If the price difference wasn't so much it would be a no-brainer. But
> >at $3,500 vs. $750 it's a lot harder to go with the cadillac solution
> >simple because it is the cadillac solution....
>
> This isn't a Cadillac vs. Chevrolet situation -- more like Cadillac vs. rusty
> tricycle. 2/0 aluminum is neither adequate nor legal for a 200A service, pure
> and simple, and anyone who thinks it is should not be trusted to install a
> service entrance.
>
> The difference in price between 150' feet (50' run * 3 conductors) of 4/0 vs.
> 2/0 aluminum won't be much more than about a hundred bucks, if that.
>
> The difference between the $3500 quoted by the guy who says you need 4/0, and
> the $750 quoted by the guys who say 2/0 is acceptable, is at least in part the
> difference between a qualified electrician and a couple of incompetent hacks.
Yeah, I couldn't figure out how this huge price difference could be
attributed to replacing one 50 ft service run either.
>
> If you're uncomfortable with the $3500 price (which does seem a bit stiff to
> me), then solicit bids from other qualified electricians and compare.
>
>
>
> >Does anyone have any guidance on the issues and realities of this
> >situation?
>
> There's no "guidance" involved on the size of the service entrance. The
> reality is that using 2/0 aluminum for a 200A service is prohibited by the
> NEC. Period.
>
> --
> Regards,
> Doug Miller (alphageek at milmac dot com)
>
> It's time to throw all their damned tea in the harbor again.
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