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Electrical Wiring FAQ (Part 1 of 2)
Section - What size wire should I use?

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	For a 20 amp circuit, use 12 gauge wire.  For a 15 amp circuit,
	you can use 14 gauge wire (in most locales).  For a long run,
	though, you should use the next larger size wire, to avoid
	voltage drops.  12 gauge is only slightly more expensive than
	14 gauge, though it's stiffer and harder to work with.

	Here's a quick table for normal situations.  Go up a size for
	more than 100 foot runs, when the cable is in conduit, or
	ganged with other wires in a place where they can't dissipate
	heat easily:

		Gauge		Amps
		14		15
		12		20
		10		30
		8		40
		6		65
	
	We don't list bigger sizes because it starts getting very dependent
	on the application and precise wire type.

User Contributions:

Dev
Report this comment as inappropriate
Dec 21, 2011 @ 12:00 am
In a fire protection circuit, circuts are shown witha no example 6,8,4etc. what it mean?these circuits are connected between smode detector,junction box etc
kevin
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Dec 24, 2011 @ 12:12 pm
My daughter dropped a small necklace behind her dresser. The necklace crossed a plug terminal and shorted the receptacle.
I bought a new receptacle and installed the same. I still have no power I suspect there could be a bigger problem,this is aluminum wiring.
I've killed the breaker and call an electrician but am curious as to what happened.P.s. there is a dimmer switch on the same circuit.
dennis
Report this comment as inappropriate
Feb 24, 2012 @ 11:11 am
Regarding new construction wiring and running 12/2 and 14/3 wire in the same box.

I have multiple switches to lights. Ran 12/2 and 14/3 into switch box and inspector wrote correction needed.

What should I have done instead?

thank you
dennis
Robert
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Nov 26, 2012 @ 9:21 pm
Does a grounding electrode facilitate the operation of a OCPD, to clear a ground fault ?
@dennis
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Mar 18, 2013 @ 10:10 am
Assuming you are installing two switches in a two switch box, you probably should have used 14/2 and 14/3 instead of replacing 14/2 with 12/2. If you are only installing one switch in a one switch box, you should only have one cable in the box.
P k
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Jan 26, 2014 @ 10:10 am
I prefer to use nothing smaller than12 awg /the smallest sized wire on a circuit determines the allowable ampacity
Ex: 15 amp-14awg. 12awg-20amp only rule for thumb other factors such as continuous load,heating and others if you do not know the safe NEC rules then please call a qualified journeyman Electrician better be safe

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Top Document: Electrical Wiring FAQ (Part 1 of 2)
Previous Document: Breakers? Can't I use fuses?
Next Document: Where do these numbers come from?

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Last Update March 27 2014 @ 02:11 PM