Future-proofing wiring

[bigbucky]

I will be putting in a bunch of new circuits for my garage remodel. Several 110v and two 20Amp 220v circuits. My tools all will run on those fine but I'm not sure about when I upgrade the compressor, dust collector, etc. May also get a welder. However I don't know ahead of time if that will be 30amp or 40amp, etc. So do I just guess? Can I put in a 40 amp breaker/wire and change the outlet to 30amp if that's what I end up needing?

Also, people have suggested running extra conduit if I need to run line in the future. Do you just terminate that in an empty box? Otherwise how do you get to it?

 

[wyliesdiesels]

Is this garage attached or detached?

No u cant put a lower rated outlet on a higher rated circuit with a few exceptions...

Motor equipped devices will change the circuit requirements. If u size a circuit for a 3hp compressor(by guessing as u suggested) and then get a 5hp compressor, the circuit is useless for the 5hp unit...

 

[Stuff]

If you install a 40 amp breaker/wire/receptacle then when you go to a 30 amp receptacle just downsize the breaker at that time. If you check breaker specs they accept a range of wire sizes. Also, big compressors tend to be hard wired which can have other issues.

 

[Speedy Petey]

Why guess at anything? Just run what you need when you need it.

 

[hh76]

Why guess at anything? Just run what you need when you need it.

I agree a little. It's good to plan ahead, but chances are things will change, and that planning will have been for nothing.

If you know your welder or compressor will always be in the same spot, you can run heavier wire, but protect with breaker currently needed.

 

[CNGsaves]

Planning ahead is a good thing OP. Layout garage as to WHERE you would want those big circuits for welder, compressor, etc. No harm in putting IN WALL conduit (up into attic accessible later) that would make it easy to pull proper wire later from breaker panel. Installing empty box in wall also a good idea. These ideas presume that you'll be installing sheetrock for wall covering.

Others have opted for wall covering of OSB, steel, etc. that is much easier to remove and make changes for wire runs later.

Only real killer for planning ahead is committing to spray foam insulation AND sheetrock walls without any clue where you will be putting those circuits !

 

[bigbucky]

Why guess at anything? Just run what you need when you need it.

because the cost to have the electrician run another line now is small compared to the hassle of having to fish wire and cut drywall later. You all raise valid points about plans changing. But it would be annoying to finish everything only to end up tearing up drywall in a year if I decide to upgrade.

Thanks Stuff, that's what I thought. Seems like I should be able to downsize breaker and outlet if needed.

 

[theoldwizard1]

IMHO. the "best" future-proofing is run oversized conduit. Swap in new conductors as needed.

 

[sberry]

Ideally some planning would help but runs are often short in a small garage so the cost of some extra materials is not a deal stopper. Cant hurt to run a chunk of 8 to a recept or deep box. It covers pretty much everything in common garage class.
My tech and I having coffee here now and I mention,, can think of only one machine I got that cant run from a 10 wire and that's a 300 tig. I am a farmer. Most home brew applications cant apply the load. Welders for this market have got more plentiful but generally smaller.
Even a common buzz box has a 12 cord and only 28A comps overload a 10 romex. Only fac pac cord machine that would tax a 10 wire would be a 250 mig running in current ranges not normally used in small garages.
They do sell a cord with 8 with welder ends and that's why. A 211 that uses the same end runs fine from a 12.
I only say this because I have been on both ends, I have some parked wiring, maybe someday I will be glad its there but 10 yrs later it sits not handling a watt.

 

[sberry]

Some means for a raceway at the business end of a shop is not a bad idea. My neighbor used a section of wood in place of drywall screwed in place next to the panel. I added a recept for a bud the other day in the same bay below the panel for a welder, couldn't get easier.

 

[justsam]

What is the high level electrical plan? A sub panel in the garage to feed these current and future circuits?

If the garage is detached, there must be a subpanel, if attached these can be fed from main if it would make sense to do so. (I prefer the flexibility of a subpanel even if not required).

Sounds like you have hidden wiring in mind. Some desire the "industrial" look of exposed conduit and that of course can impact future planning.

There is no harm in oversizing the wiring, (except to your wallet), as long as breaker is appropriate to protect wiring. Receptacles can not be undersized for the circuit they are attached to.

Assuming you want hidden wiring, I would just use PVC conduit large enough to accommodate future wire size in those locations I was not certain of. Given sockets, such as those above a work bench will no doubt not change and they can be wired without conduit, assuming drywall covered.

 

[Falcon67]

I ran 12 gauge to my 3.5HP compressor because I don't ever see needing anything larger. If I had any thoughts of a bigger compressor, then I'd have run #10. For a welder circuit, I'd run 10 because I'll never need anything more than a 210MVP and 10 should be plenty for that. Since the 10 requires a specific outlet, then I'd make a patch cord to mate the appliance to the outlet. 210MPV for example shows 24A @ 240 max draw. Over that, you'd be doing some pretty serious welding IMHO. Same with the compressor - 5HP compressor good for painting lots of cars - if you're not painting cars on the weekends, then you're just bench racing compressor power

 

[sberry]

Put the welder recept on the wire, no need for a patch cord.