12 amp wire size

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I was wondering what cable size to use for wiring a 125V 12 amp fan that is 100 feet away from the breaker panel.
Thanks.
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Henry wrote:

http://www.wiktel.com/standards/wiresize.htm
Rich
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Henry wrote:

You should be able to use 14 gauge wire.
It'll drop about 4 volts at 12 amps over that length, but that shouldn't worry a fan much.
HTH,
Jeff
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You could use #14, but there will be a lot of VD at startup, which won't be too good for the fan. #12 isn't all that much more expensive.
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Toller wrote:

How did you determine that, and how much, specifically, are you thinking is "a lot" for a fractional hp fan motor???

That's true, certainly, and I have pretty much quit using 14, but if it's a dedicated circuit I don't think there's a chance in the world the difference would make any practical difference at all.
If, otoh, there's a chance of wanting something else, that would necessitate it in all likelihood.
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On Mon, 09 Jul 2007 17:10:50 -0500, dpb wrote:

Not to nitpick but wouldn't a motor drawing 12 running amps (if the OP is correct) be in the realm of a couple hp? If I recall my 5 hp compressor motor draws around 12.

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Not at 120V it don't. A "true" 5HP motor will draw somewhere around 40A on 120V, or 20A on 240V. (On motors >= 1HP, count on approximately 900-1000W/HP because of inefficiencies. Yes, I know, the exact conversion is 746W/HP, but no motor is 100% efficient)
At 120V, a standard 12A motor is probably between 3/4 and 1HP, tho possibly as low as 1/2HP. Not lower unless it's a real lousy or poorly spec'd motor. (Serious fan in any case...)
A 12A motor can draw well over three (or even five) times that much during startup. 12V or more drop (assuming the previous math was right) at 100'. That's a significant amount, and will significantly prolong startup and produce more heat, and ultimately shorten the fan motor's lifetime. Perhaps by not much, but perhaps by quite a bit.
This is a good place to go up a wire size. It's cheap.
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On Mon, 09 Jul 2007 22:43:51 +0000, Chris Lewis wrote:

I used to work with Baldor repulsion/induction motors in the oilfield. There were all 240v, 15 hp. If memory serves, on the well upstroke they drew around 30 amps and otherwise around 18.
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240V at 30A is 7200W, which means that during the upstroke those motors were delivering somewhere around 6-8 HP. Conservative motor selection, given that weather/rig conditions etc could cause the motor to need more.
It would have been interesting to compare that with the motor plate ratings, or know what size the fuses/breakers were.
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On Tue, 10 Jul 2007 17:40:08 -0000, snipped-for-privacy@nortelnetworks.com (Chris Lewis) wrote:

Don't let that theoretical 800w per HP confuse you. Motors never get close to that efficiency. A typical 1HP motor will pull more like 12-13a @ 120v (my C/H compressor) and some cheap ones will be more like 15-16a.
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On Tue, 10 Jul 2007 15:25:35 -0400, snipped-for-privacy@aol.com wrote:

Lowe's claims to have a 3HP electric chain saw, that still works on a 15A receptacle.
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Assuming it's not simply a baldfaced lie, that is an intermittent rating. As in "if you load this motor with a brake to the point where it produces maximum output in overload, it's producing 3 HP - until the circuit breaker trips or the motor burns up, whichever comes first".
The rating might actually make a bit of sense for a chainsaw, where hitting a hard spot *will* cause the motor to put out more power temporarily, and where you're comparing against gas-powered motors where the HP rating is the maximum HP available.
But it's not comparable to induction motor ratings, where "1 HP" generally means it will deliver 1 HP all day, and nearly 2 HP momentarily when overloaded.
Rating continuous-running things like shop vacs and air compressors in "peak HP" is completely bogus, of course.
    Dave
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Yes. It's an instantaneous max HP, rather than a safe continuous rating. Shop vacuums and routers are infamous for using these inflated figures. Instantaneous max HP is a useful measure on a router or chain saw in some cases, but is useless to a shop vacuum.
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In case it wasn't clear, I wasn't confused ;-)

Once you get into multi-horsepower industrial-grade motors, rule-of-thumb is about 1000 watts per HP. At 1-2HP and below, they're not as efficient and 12-13A/HP is a reasonable ballpark at the high end. Once you get to 1/4HP and below, motors can be stupidly inefficient. Eg: the 1/4HP motor I saw whose label said 10A.
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Don't know who you are; I have you blocked for the stupid things you have said in the past. For good reason, here is one more! 12a is not a fractional hp motor. Don't you even bother to read the posts?
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How do they rate air compressors at 5HP when they have a 3/4 or 1 HP motor driving it?

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wrote:

They lie. Campbell Hausfeld lost a class axction suit over it. I ended up with a sheet metal nibbler out of it.
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kool wrote:

AFAIK that's some a not very useful rating called "peak horsepower" which I believe is the horsepower which can be delivered for a VERY brief time if the motor is up to speed and you suddenly apply a heavy torque load to it.
I think the energy must come from inertial storage in the rotating parts, but it gets "used up" pretty quickly and the motor HAS to slow down (and burn up?)
If someone has a better explanation, or a cite to an industry standard definition, I'm all ears.
Jeff
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Toller wrote:

You're correct about that, and using 12 gauge might be a wise investment.
Currently Lowes' price for 100 ft of 14 gauge is $36.00 vs. $52.50 for 12 gauge.
Jeff
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52.50? that sounds like a 200' price to me.
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"Jeff Wisnia" < snipped-for-privacy@conversent.net> wrote in message
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