More 240V wiring questions

[mike wacker]

So my buddy has this fantastic shop he/we/friends are building. 40x60 11 foot ceilings. I'm insanely jealous. Many wiring locations have been fed with 10 ga. wire in case "big" 240v power was needed. Single circuits to each outlet. The question/debate is what oulet to install in the boxes. I say put 6L30 twist locks in each one and change the plugs on any machines necessary. Put 30 amp breakers on each circuit and call it good. Breaker is to protect the wiring not the machine.

So, I'm looking for NEC Code book references as to whether this is safe/correct/to code, etc. This kind of response would be best, but safety/common sense thoughts are more than welcome.

[Wade Lippman]

:eek:
Where is the moderator when you need him?

[Pete Bradley]

:eek:
Where is the moderator when you need him?
Yeah, just kill this thread now...please.

Pete

[Rob Russell]

C'mon guys, there is no need to kill this thread. The fact that some folks got testy in another thread has no bearing on this one.

The question is "what outlets do we install?" The answer is pretty simple - whatever you need ... provided you (sort of) match the breaker to the outlet.

There is NOTHING in the NEC that prevents one from using #10 conductors for a 15 or 20 amp circuit. If you need a 30-amp circuit, then you need #10. Beyond that, you've just installed wiring that allows you to be flexible in what circuits you install.

If you have specific questions about what you want to do, that would be easier to respond to rather than explain what ALL of your options are. For example, if I were to choose a single set of outlets, it'd be 4-wire, 240v grounded, twistlock outlets. 30 amp receptacles require 30 amp circuits.

Rob
Addy protocol: unlicensed, homeowner electrician

[David Gunn]

One thing to consider is the twist-lock part. For plugs overhead and connectors, i.e. extentions cords they are good. But some people don't want twist-lock receptacles in case someone ever trips on a cord that is plugged into the wall. If you have a straight blade configuration, it will pull out and you may not fall, with a twist-lock, you will certainly trip. Not a big deal for some folks, but for others, it is.

[Steven Wilson]

Mike, if you're wiring up general purpose branch circuits (which it sounds like you are) then I would have the receptical match the breaker, not the wire guage. So, if you install 20A breakers with #10 wire I would go with a 20A twist lock recepticle.

[Mike Cutler]

Yeah, just kill this thread now...please.

Pete


It doesn't need to be killed per se, but folks have to understand that the NEC is not applied uniformally at every location, in every state and local munincipality in the United States, Additionally not all munincipalites throughout the US are even on the same version of the code.
Take into account the existing wiring,and the extent, and definition of the modifications and you can end up with a lot of different interpertations, very subtle in difference, but none the less subtle differences.

The advent of the DIY'r has also caused some munincipalities to be very conservative in the requirements in an attempt to mitigate the damage by someone modifying the electrical system of their home outside of the NEC or any inspection process.

The end result answer is always the same.
If you are going to get it inspected. The only person whose opinion matters is the inspector, or his supervisor.
If you are going it solo, and it's not going to be inspected. All bets are off. Better to log into Mike Holt's electrical forum and research the answer.

[Chuck Lenz]

This all should be answered by a electrician. Would you go to a Electrical forum website to ask about how to hanging cabinets ?

[glenn bradley]

Mike, if you're wiring up general purpose branch circuits (which it sounds like you are) then I would have the receptical match the breaker, not the wire guage. So, if you install 20A breakers with #10 wire I would go with a 20A twist lock recepticle.

I agree, match the outlet to the requirement and match the breaker to the outlet as long as it supercedes the wire limitation. If you run #10 and need to change that20a to a 30a, just change the breaker and outlet and rock on. . .. or you could run the minimum wire gauge required and re-wire it later when you need to change.

[Greg Funk]

I say put 6L30 twist locks in each one and change the plugs on any machines necessary. Put 30 amp breakers on each circuit and call it good. Breaker is to protect the wiring not the machine.
Nothing wrong with using 30A receptacles (with 30A breakers) but it seems like a hassle to have to cut off existing plugs and replace them with expensive L30 type plugs. If all your machines are 5HP that would be OK but for most equipment 3HP and under 20A receptacles (and breakers) would be more cost effective.

Greg

[scottj owen]

I wouldn't do anything at this point, loop the wire at the panel and leave a cover plate on the box, when the time comes put the appropriate end and breaker for the machine you will be using. No use putting in something that you might replace later. All the best

[Art Mann]

I am not an expert or even an electrician. I have, however, wired two houses and a stand alone shop that passed inspection. I have helped on several others. The inspector isn't going to find anything wrong with what you propose. Chances are, he won't even ask what you are going to plug in to the outlets. He will only verify that the receptacles match wire size and the rating on the breaker. Some inspectors won't even do that, depending on where you live. There are many other rules about installation methods, panel height and location and that sort of thing that he will be more concerned about. My experience has been that each guy has his own little subset of things he likes to look for.