We were discussing a #10 30A feed with 30A components. That is where the
price jump gets painful.
You also failed to include the wall outlet.
Carl
----- Original Message -----
From: "Martin A Flynn" <maflynn@att.net>
To: "Carl" <km1h@jeremy.mv.com>; "AMPS List" <amps@contesting.com>
Sent: Sunday, August 09, 2009 9:00 PM
Subject: Re: [Amps] 240V Outlet
> Martin Wrote:
>>> Paul,
>>> The breaker and device are the same rating. My comment was to state
>>> that his recommendation was to make the conductors and ground one wire
>>> gauge larger then NFPA 70 states it should be.
>>>
>>> Martin
>> That only makes sense if the I*R drop is excessive. Since the Invader
>> 2000 is only going to draw about half the ratings of #12 wire, then going
>> to #10 makes little sense on a basement long run. Going to #10 requires
>> all different plugs and outlets and the cost about goes thru the roof
>> compared to a 20A feed.
> The FPN notes in NFPA 70 (which is not part of the actual document)
> suggests no more then a 5% total drop between feeder and branch circuits.
> Here's the quote: (fair use excerpt)
>
> Art 210-19(A)(1), FPN No. 4: "Conductors for branch circuits as defined in
> Article 100, sized to prevent a voltage drop exceeding 3 percent at the
> farthest outlet of power, heating, and lighting loads, or combinations of
> such loads, and where the maximum voltage drop on both feeders and branch
> circuits to the farthest outlet does not exceed 5 percent, provide
> reasonable efficiency of operation.
>
> In the original case I commented on the run is ~50 feet, straight line
> distance. Service is 120/208 3 phase A licensed electrician made the
> calculations, presented them to the electrical inspector, and both agreed
> that the oversize wire was appropriate.
> I did the same at home. The difference in cost between #12 THHN and #10
> THHN was negligible. I used Square D breakers and Hubbell connectors.
> Since the wire clamp range on a Hubbell HBL2410 - 20 Amp twist lock is
> 18-10 AWG, and the 20 amp 2 pole QOB Square D breaker is 14-8 AWG, it
> fit together fine with no difference in cost other then the wire.
>
> Martin
>
>
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