Electrical for a workshop/garage.

[EastTexFrank]

Lots of good advice here. The only thing I'll say is, "Put in plenty of outlets" and put in the 240 volts now. When I had the shop rewired I put in 240 volt outlets for a welder, window a/c, table saw and dust collector. The window a/c was already there and I have picked up the rest over the last 7 years.
That's good advice about the lights too. I had 3 lights installed, one at each end and one in the middle. I also put them on 2 different circuits. If you throw a breaker and a light goes out, you will still have one circuit operating and light to reset it. I did that after a friend ended up with 8 stitches and a concussion when he tripped over stuff on the floor when when the light breaker tripped in his shop at night when he was piddling.
By the way, if you do nothing else, put in a 50 amp, 240 outlet for a welder. I started with a 110v mig and while it is a good machine and does lots of things well, it is limited. It won't be long before you are wanting a bigger 240 volt machine.

 

[Cliff_Johns]

50 amps at 220 volts! Good grief. Welding is expensive, and I haven't even taken the class yet.

Cliff

 

[JeffRey30747]

All of this sounds like good advice to me. I can add:

More switched outlets in the ceiling. I use the 4' shop lights that you hang and plug in. If a ballast goes bad, you buy another light and plug it in where the old one used to be. You might even consider more than one switch. Half my lights are on one switch circuit and half on another.

Put your lights on a separate breaker circuit than your wall outlets. If your table saw trips a breaker, you won't be fumbling around in the dark to get everything back in service.

Jeff

 

[uhmgawa]

</font><font color="blue" class="small">( ..and put in the 240 volts now.)</font>

Assuming you are going to drop a subpanel in the new shop running a
240V lateral may be your only option. I don't believe I've ever seen a
120V panel nor would one make much sense. The intent is to distribute
the collective load over both poles of a service.

What you'll need is a main lug panel with as many breaker locations as
you can find. Don't scrimp here -- it pays to invest in the real estate for
future work. The panel cost will be trivial compared to the project
cost.

One important note is the subpanel needs to have a separate insulated
neutral bar in addition to the ground bar it will have by default.
The panel is then fed with a lateral consisting of four conductors (2 live,
1 neutral, 1 ground). You can typically buy the additional bar from
where you purchase the panel and just drop it in.

 

[rambler]

This is a really small shed, so we needn't get too carried away. It won't need _everything_.

Anytime you mention a welder or a real air compressor, you are talking at least 50 amp serive, 220. Anything less & you will be real sorry. Even if a small wire welder or compressor runs on 110, you make the lights dim if you don't have the 220 service to split from....

Since you need to hire it all done to be legal, there is only $200 difference in materials to go from a 20 amp 110 service to a good 100 amp 220 service. You'd be thick in the head to do anything less than the 100 amp 220 service! /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif

Not suggesting you avoid the legal regs, but once an electrician installs the basic 220 service & panel, most anybody can easily & without notice add more electrical outlets, lighting, etc. for the cost of materials & follow the code so it would pass any surprise inspection............

--->Paul

 

[Boondox]

Cliff -- Check on that prohibition on plastic. Most places allow either, though the metal boxes have to be grounded. I used plastic on my high amp circuits because the 10ga wire is a pain when it comes to multiple pigtails and the plastic boxes have greater volume. For the lower amperage circuits and those within chew range of the sheep I used metal. Nice installation, but not as easy to use as the plastic IMO.

I saved a small fortune by mounting the boxes/conduit and running the wires myself, then having a licensed electrician come in to make the connections and put his stamp of approval on everything. It didn't hurt that I got his blessing on the wiring diagram before the work started. He compared my work to the plan, grunted his approval, and spent less than an hour hooking everything up.

Good luck! Pete

 

[Lazy]

One important note is the subpanel needs to have a separate insulated
neutral bar in addition to the ground bar it will have by default

Hi could you give a reason why you need the insulated neutral bar?

Charlie

 

[Inspector507]

In a nut shell.........you are not permitted to ground anything with the "neutral conductor" beyond the main disconnect. Hence a 4-wire feed needs to be run to the separate building if you run 220 out there. The neutral and ground cannot be connected together.

 

[Lazy]

Hi
what NEC article covers that requirement? I'm still learning when it comes to the NEC.

Charlie

 

[johnday]

What you are winding up with is called a subpanel. You not only have to "debond" your nuetral from the panel, you also have to be sure to "bond" your grounding busbar to the panel. All the reasons for this were once known by myself, but I can't recall all of them[ getting old you know]. I'm a carpenter anyway and picked up electrical when I was an apprentice electrician.
In some jurisdications, an electrical permit cannot be refused a homeowner. That is generally true in Michigan. Unless there is an ordinance of some type. I do all my own wiring and also help out "good homeowner friends". I'll have them pull the permit since I'm not licensed and show them what needs to be done. It's too bad you don't have that luxery. Don't claim to know more than a journeyman, but the inspector doesn't make any more than two trips. One for rough and one for finish.
Good Luck, let us know how it tuns out.
BTW, there is an electrical inspector on this site that could maybe help you out. Inspector 507 I think.