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What type of wire for dedicated 20A AC lines?

I’m about to have two 20A dedicated lines installed. What type of wire should I use? I know there are differences of opinion on whether to use 10 AWG or 12 AWG, however the link below makes a great case for using even 8 AWG solid core copper on longer runs like mine will be (50 ft), to ensure a lower resistance, lower voltage drop over the long run, and therefore more access to instantaneous current for my Gryphon Diablo 300. The wire would need to be stepped down to 10 AWG to connect with the receptacle. The article actually states that the thickness of the wire is more important than the fact that it is dedicated…

Assuming I want to follow this advice, which again makes sense to me, where would I find such wire to give to my electrician?

 

nyev

Showing 5 responses by cleeds

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cleeds
5,941 posts
 

twoleftears

If you’re putting in a dedicated 20amp line, or even 2 or 4 of them, and if there are no free spaces on the main breaker box panel that you currently have, do you also end up putting in a new larger panel? Does a sub-panel solve that?

A sub-panel is one solution. The less complicated solution is a tandem breaker, which many panels accept.

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cleeds
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bigtwin

12/2  NM Copper Wire.  Available at any DIY store.  All you will ever need to meet code and run 20 Amps. 

That is mistaken. What is the length of the run? Is it in conduit? Depending on the answers, 12/2 may not meet local code, which always takes precedence.

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cleeds
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andybflo

8AWG will give you no more current than 12AWG of the amp doesn’t need it

Not necessarily. If you have voltage drop (because of the length of the run, or heat build-up in a conduit), the 8 gauge will be able to deliver more current.

Nothing sold 120v in the US exceeds 15A draw.

Completely false. Further, a 20A line is advantageous if you are using it for multiple components.

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cleeds
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audioguy85

why make life diffucult restling with 10 gauge....code for 20 Amp is the yellow romex 12 gauge. The 10 is overkill.

Depending on the length of the run and whether it is in conduit, 12 AWG may not meet local code for a 20A line.

In any event, consider that NEC sets only minimum standards. There’s more than one good reason to use 10AWG on a 20A line.

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cleeds
5,941 posts
 

Any electrical supply house will have 10 AWG solid core. Home Depot, too, I'm sure.

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