Dedicated power

Most, if not all, new receptacles have terminals that accomodate 14, 12 and 10 wire. Even the 15-amp 5-15R. The limiting factor is not the wire but the circuit breaker. The breaker must not pass more current than the wire ampacity that's it's connected to. So you could put a set of 500MCM wires on a 20-amp breaker feeding a 15-amp receptacle (that's not physically possible, I'm making a point). In your case, #10 wires are good for 30-amps but when used for a branch receptacle circuit, the breaker can only be 20-amps max. When the breaker limits the current, a larger wire size is not an issue. Correct wire sizes are equivalent to steel beam sizes - you can go bigger than what's needed to do the job if you don't care about money.

Where and why #10 instead of #12 when a 20-amp breaker is the most permitted? When voltage drop is a concern. Generally, #10 is used when there is a 50 foot or more total wire length from panel to receptacle. Less than that, you are wasting money as #12 is more than adequate.

Also keep in mind that any 115 volt device with a UL label can be safely be put on a 15-amp circuit. That's where the confusion lies over 15-amp receptacle with 20-amp breakers. The circuit will never draw the 20-amps as you are limited by code to size your system based on a ten receptacle maximum on a circuit, each one 180 VA, or 1,800 VA (15-amps) total.

Overheating a circuit is an end-user created problem (power strips and extension cords). It's your choice for the wire sizes, #10 will work and fit properly.

Thanks guys for all your input. I have learned a great deal about running these dedicated lines that I didn't know. Especially that the wire lengths used must be the same to avoid a ground differntial between my pieces of equipment. This site is a really great resource for all of us!!

Mark

One more thing to keep in mind is something I've picked up on this forum as I too am installing dedicated lines (Thanks again Gs5556). The #/2 or #/3 represents how many hot leads are in the wire. A 12/2 for example in a standard Romex includes an individually jacketed black wire which is the "Hot", an individually jacketed white wire which is the "neutral" and a bare/wrapped in loose - paper-only copper wire which is the ground wire. On a standard outlet receptacle the black goes to the brass screw, the white to the silver looking screw and the bare copper goes to the green painted screw usually located below and to one side. I have taken the advice of several people and am going with a 12/3 arrangement because these contain 2 hot leads (both are jacketed) and because I want to use a jacketed ground wire instead of bare I will label one of these black hots with green tape and use it as a ground wire to connect to that green ground screw on the terminal. In this case the bare copper wire is simply ignored/unused. This facilitates using Isolated Grounding schemes from whichever outlets you want to run an I/G ground system with. As far as I've been told this is supposedly an acceptable practice but the I/G outlets must run their grounding wires to a separate isolated grounding bar and ultimately out to a buried grounding rod. Does this still sound legitimate to you Gs5556? P.S. My distance from breaker box to outlets is less than 30' each and therefore I'm choosing the much easier to work with 12G instead of the 10G... I hope there's no possibility of audible difference at any time? Good lick with your project.

Lissnr, I would suggest you consult an electrician. Isolated grounds are a little more complicated than what you outline above. Perhaps you left some things out for brevity.

With an isolated ground, you typically run the white wire from the silver screw on the receptacle to the neutral bus bar at the panel. You run the black wire from the brass screw on the receptacle to a GFCI breaker at the panel. You code the red wire green and run it from the green screw on the receptacle to the grounding bus bar on the panel. The bare copper wire goes from the grounding screw in the receptacle box to the grounding bus bar on the panel.

An isolated ground receptacle does not need a separate isolated gorunding bar. It uses the grounding bar in the panel. It's just that the isolated ground receptacle does not share a common grounding path back to the ground.

I've been told this is supposedly an acceptable practice but the I/G outlets must run their grounding wires to a separate isolated grounding bar and ultimately out to a buried grounding rod.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>.

Dangerous and in violation of NEC code.

Works great for hunting fish worms though....
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