Power

[Dave Novak]

First off let me thank all of you for providing me countless hours of informative enjoyable reading. I only recently stumbled into this website and I'm addicted. My boss hates you.

I'm really not much of an electrician, so any help you guys can offer would be very much appreciated. I recently bought a Laguna LT16HD bandsaw. I only have 1 220v circuit in my house, it's 30 amp (at least that's what it says on the breaker) and it's running to the laundry room. Lucky for me, my garage shop shares a wall with the laundry room. I tapped into it to add a 220v outlet in the garage. I assumed I could splice into the wire I ran across the garage attic to add more outlets as necessary.

My next purchase is going to be a Dust collector (reading these forums has me convinced I need an Onida and a second job) and most of the better units also require 220v. My initial reaction was no problem, I'll just run another outlet into the garage. But will I be able to run both my bandsaw and a DC at the same time on the same circuit? What if the wife happens to be using the dryer? Will i be able to run either unit? Thanks in advance for your thoughts!

[Jim Becker]

Dave, it's not really kosher to "spice into" your dryer circuit. Not only can you not run your tool(s) when the dryer is in operation, you may have a problem with code.

You really should have two 240v circuits (minimum) added to your shop...one for the DC and one for the tool being used. The Oneida and other similar machines should be on their own circuit, IMHO. My suggestion is to have a sub-panel brought into your shop for tool circuits. Talk with a licensed electrician about that to be sure you can do that with your present service and to find out the cost.

[Brian Tuftee]

What are the nameplate amperage draws on your DC, bandsaw, etc. Is the dryer electric or gas? Add up all of the loads, if you're close to 30A, you'll probably see nusiance tripping on that circuit. If you have open space in your breaker box, why not just run a feeder to a 60A subpanel in your garage? That's what I'd do, instead of leeching power from other circuits in your house - you'll have enough power that you'll never worry about it again.

Also, I think under the NEC that a laundry circuit 'technically' needs to be dedicated, i.e. share no other outlets or receptacles in other rooms, but I'd have to pull up the code and double check that.

*edit* Yep, you're not supposed to splice into a dedicated laundry circuit. NEC 2005, 210.11. Just do a subpanel instead.

[Dave Novak]

That's what I was afraid of. I'll probobly just hold off on dust collection for a while. I need a little time to financially recouperate from the saw purchase, and having electricians over for a wiring party would surely sink me. Thanks for the quick response!

[Brian Tuftee]

You may want to check out this article at Hammerzone.com, on installing a subpanel. The hardest part of this job is actually fishing the wire from the main panel to your garage. If you can manage that, the rest is easy.

http://www.hammerzone.com/archives/e...1/overview.htm

Once you have the subpanel in your garage, you can install dedicated 240V and 120V circuits for your equipment, and never worry about tripping a breaker.

[Dave Novak]

I believe you, but it doesn't really make sense that you can't splice into an existing circuit to add another outlet. There's only one outlet on that circuit now, and it's only used when the dryer is running. Everywhere else in the house there are many outlets and maybe even lighting on single circuits. As long as the total amps running at one time are below 30 or what ever the breaker limit is, it would seems to be ok. I know the code says otherwise, I'm just wondering if the code isn't at least partially designed to keep electricians employed.

[Dave Novak]

Thanks for the link to the artical. Before I finished off my basement I had electricians run three additianal 30 amp 110v circuits to the garage. At the time I didn't envision ever requiring 220v. What an idiot I feel like now, as that was only 4 years ago, and with the basement finished running wires from the brewaker box to the garage would be quite a chore.

[Brian Tuftee]

Nah, the code is there just because most people would burn their house down in ten minutes, if given free reign over their electrical systems. Ok, that's an exaggeration, but electricity (unlike, say, plumbing), is life or death - no one ever got killed from a leaky toilet.

In some cases, code requirements can be a little hard to understand. In cases with dedicated branch circuits (laundry, bathroom, and kitchen small-appliance circuits), I suppose the rationale is to avoid nuisance trips. Not a straightfoward safety issue. I agree that if the branch circuit wiring is properly sized, with the appropriate breaker, there should be no safety difference than any other circuit in the house.

Total cost of materials to do this is pretty low, I'd guesstimate around a hundred bucks (depends a lot on the length of cable you need). If you feel comfortable with installing outlets and whatnot, you might want to give this a try. Pull a permit, get a book or two, ask questions in here, and you'll almost certainly pass inspection.

[Pete Brown]

I believe you, but it doesn't really make sense that you can't splice into an existing circuit to add another outlet. There's only one outlet on that circuit now, and it's only used when the dryer is running. Everywhere else in the house there are many outlets and maybe even lighting on single circuits. As long as the total amps running at one time are below 30 or what ever the breaker limit is, it would seems to be ok. I know the code says otherwise, I'm just wondering if the code isn't at least partially designed to keep electricians employed.

No. Major appliances - stoves, dryers, AC, etc. all need dedicated circuits. In fact, even your Microwave should have a dedicated circuit, as it has become a fixed appliance in most homes. You should never go above 80% load for a circuit, IIRC, as most motors spike on startup.

If you run your 240v saw while someone runs the dryer, you may be screwed. Do you have a magnetic starter on your saw? If not, you'll need to remember to turn if off or else you'll have a real mess when you power back up.

How did you "splice in" to the circuit? Is the wiring all sized appropriately and did you do everything inside an appropriate wiring box?

If you go to sell your house, you will have problems with the inspection. If you have a fire right now, you will have problems with insurance. I suggest following Jim's advice and breaking out a subpanel for the garage and running the wiring back to your main panel. Nuke the splice.

There are a lot of things I'll mess with in my house. Electricity isn't one of them. If you're going to do that in your house, make sure you get some good books on the subject so you can do your best to do it correctly.

Pete

[Pete Brown]

Nah, the code is there just because most people would burn their house down in ten minutes, if given free reign over their electrical systems. Ok, that's an exaggeration, but electricity (unlike, say, plumbing), is life or death - no one ever got killed from a leaky toilet.

I don't know about that. You should have been here when they pumped the septic right after we moved in. The toilet downstairs "burped" and I thought for sure I'd pass out

On the nuisance trips bit: it becomes a safety issue if it happens often. Circuit breakers have a limited lifetime based on how often they trip. That's why (unless rated to do so), they can't be used as regular switches. They will eventually fail if they trip too many times. I have no idea how many that is - it is likely more than any of us will ever run into, but it is still a possiblity.

Pete

[Rod Sheridan]

Hi Dave, as long as the 30 Ampere, 120 volt circuit isn't used for anything else, you can convert it to 240 volt by replacing the single pole 30 A breaker with a 2 pole (I'd go with 20A) and use it for your dust collector.

The #10 wire is oversized, however that's a good thing.

You could convert the other 30A circuit to 240 V for all your 240 volt tools and still have one remaining 30 Ampere 120 volt circuit for other stuff.

P.S. the code requirement for nothing else on a dryer circuit is due to demand loading limits on the circuit. The electrical code gets updated on a scheduled basis, many of the updates are due to fires or fatalities in the past. Not following code is illegal, and just plain iresponsible.

Regards, Rod.

[Justin McCurdy]

I just went through this a couple of weeks ago. I had no 240 in the garage, a laundry room with a shared wall to the garage, and only 1 space( instead of the necessary 2) left in the main house panel. After much debate, I ended up with a sub-panel in the garage. I don't know what length of wire you need, but here were my costs:

Panel: $38 ( 16 breaker Siemens )
Main Wire: 125 ft. of 10 -3 (which is 3 conductor and a ground) for around $130. I only needed 10-2 but I listened to the guy at Home Depot, now I want to kick myself.
Extension Wire: 30 ft. of 10-3 wire (this time, because it is SJOO or SOO, the ground is part of the wiring designation) $50
Breakers: $8 each

So, for under $250, I was able to power anything I could ever want in my garage (that is not 3 phase).


Figure that $250 vs. the cost of accidentally ruining a motor or causing a house fire and it is a no-brainer. Sometimes it is better to bite the bullet than cause yourself more worries in the end.

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On the other side, if you are absolutely positive that you will only need a couple 240 outlets in the garage, buy a couple 1/2 space breakers and put them in your main panel. If you buy enough of these ($15), you should be able to free up enough room for a double pole breaker.

My 2 cents.

Justin

[Pete Brown]

Hi Dave, as long as the 30 Ampere, 120 volt circuit isn't used for anything else, you can convert it to 240 volt by replacing the single pole 30 A breaker with a 2 pole (I'd go with 20A) and use it for your dust collector.

You'd need to also mark the neutral (white) wire with black or red tape to indicate that it is hot. I don't recall the code requirement here, but it is one of those colors. Do that at both ends, and make sure you have the formerly-neutral wire connected to the circuit breaker and not to neutral in the panel.

Pete

[Brian Tuftee]

I take it back, re-identifying the white conductor as a hot wire would be acceptable here, so long as it's done in a permanent manner, and at each point where the conductor is visible or accessible, including the two terminated ends. Normally, black and red are the two colors of choice for hot conductors in a 240V circuit.

*gotta read the NEC closely...*

This would allow a much easier creation of a 240V circuit to the garage, though he'll still need space in the breaker panel to do it.

[Pete Brown]

On the other side, if you are absolutely positive that you will only need a couple 240 outlets in the garage, buy a couple 1/2 space breakers and put them in your main panel. If you buy enough of these ($15), you should be able to free up enough room for a double pole breaker.

Just make sure the panel 1. allows for the half-space breakers and 2. doing this doesn't go over the limit for the panel.

There are lots of places to screw up when you mess with wiring

In my county in MD, homeowners are not allowed to do any wiring themselves. If you did some and there's a problem with your house after you sell it, the new owners can still sue you.

Pete