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Joined: Feb 2003
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I need to run 115 to a motor rated at 10.6 amps that is about 250 ft from the main service. The motor is the only thing on the circuit. Is 12 guage wire sufficient or should a smaller guage be used?
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Joined: Jan 2003
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Using a voltage drop calculator I got on the Web and the info you gave you will have voltage drop of 10.5 volts or 9.2% if you use #12
#10s would be 5.5% drop or 6.3 volts #8s would be 3.5% drop or 4.0 volts #6s would be 2.2% drop or 2.2 volts
Bob Badger Construction & Maintenance Electrician Massachusetts
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Not wanting to throw a wrench in the gears, remember that for motors, one needs to also consider starting voltage drop. A rule of thumb for starting is 15% maximum. This is why 230 and 460V motors become attractive.
{Note that starting voltage drop is not a Code requirement, or even an FPN. Overlooking it can cause problems, and is commonly part of the commercial and industrial design process.}
[This message has been edited by Bjarney (edited 03-09-2003).]
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Joined: Jan 2003
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Bjarney, not a wrench in the gears but do you apply the 15% to the FLC, so 10.6 x 1.15 = 12.19 amps and then apply the voltage drop calcs. And does 15% work for all voltages.
Bob
Bob Badger Construction & Maintenance Electrician Massachusetts
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Joined: Dec 2002
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Check to see if you can wire it to 240 Volt If you can then use 240 Volt connections and use 8 AWG wires.
Edward
Thanks Edward
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Joined: Feb 2003
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ok i look at my electican calculator and for 115 volts appactions for that kind of distance i recomoned #10 is minumin wire size other wise if the moter can change to 230 volts. if so all by the mean go for 230 volts and i got one note from power company say any electric moter over 1 1/2 hp will like to keep on high side (voltage) due less stress at the transformer and line effcts and btw most motors dont like to start when voltage get too low ( i have alot of sevrvice call with waterwell pumps and came with way too small a wire size )
merci marc
Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)
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Joined: Apr 2002
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iwire — Sorry for the slow follow-up. Motor starting current is usually something like 6xFLC.
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Tom
Shinnston, WV USA
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Joined: January 2001
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