Tapping into AC power circuit???

[Dick Strauss]

Is it against the national code to tap into a 220V line for the AC system or is the line supposed to be a dedicated line?

I've got a 220 line that I'd like to tap into since it is right next to the garage. The AC circuit breaker is rated for 40A. I'd like to be able to power one 2HP (220V/10A) lathe and a 1/2HP 220V/2.5A) vacuum pump at present. I would be switching the AC off while I'm using the woodworking tools to make sure I don't overload the circuit. I may even add a panel in the garage at a lower rating (20-30A) just to add a layer of protection for the tools.

Tapping the AC circuit would save me from running 150-200 ft of copper to the garage. The line would have to go from the basement breaker to the second story and back down a story to the garage at the opposite end of the house.

Thanks in advance,
Dick

[Doug Shepard]

I dont know about the code issue or other electric issues, but in our area ACs have to be on a separate circuit (unless you pay top dollar rates) with a switch that is remotely controllable by the power company. The first thing they do during summer months at any hint of running low on power is shut off everyone's AC - which is going to shut down your WW tools if your setup is the same and you're tapped into that.

[Kermit Hodges]

I may even add a panel in the garage at a lower rating (20-30A) just to add a layer of protection for the tools.

Fuses and breakers protect the wire in the walls from overheating/overloading. Not the machines attached to them.

[Bob Smalser]

Is it against the national code to tap into a 220V line for the AC system or is the line supposed to be a dedicated line?



Usually. Code requires major appliances like hard-wired heat and A/C, washers and dryers to have their own seperate circuits. When I inspected houses that's the first thing I looked for....some Harry Homeowner cutting the dryer circuit to power a garage shop. The owners either had to hire somebody to bring the house back into code or drop a few grand from the asking price.

You need another circuit. There's probably room in both your box and your electrical load if you have 200 amp or higher service. Either hire and electrician to install one or get a book and do it yourself. It's not difficult, just make sure you shut off the main breaker into the house before opening the main panel. And by all means get both the box and wire gages right...that's the next thing I looked for in homeowner installations. When in doubt, bigger is better outlet boxes.

[Jim Becker]

You need another circuit. You can usually get away with multiple tools/outlets for your tools, but not when they involve hard-wired appliances. One appliance...one circuit...unshared.

[Al Willits]

Every A/C install I've heard of requires its own separate circuit, according to both the manufacture and Minn code.

Al

[Rick Christopherson]

Contrary to the other postings, if you install the subpanel as you describe, then your air conditioner will still be on its own circuit.

You will need to gather enough slack in the existing line to be able to feed it into the new subpanel and back out of the subpanel. If you can't do this, then you couldn't tap into it in any event. (Although you can put in a junction box nearby that would allow you to extend the wires.)

[Peter Stahl]

I vote for run another line if you have room in you breaker box.

[Bob Smalser]

Contrary to the other postings, if you install the subpanel as you describe, then your air conditioner will still be on its own circuit.



I don't see how.

X gage romex from a 40-amp breaker to a 40-amp load is still X gage romex from a 40-amp breaker to a 40-amp load. Adding 20 to 30 amps in the middle of that circuit....subpanel with more breakers or not.....still overloads the original circuit.

Codes don't buy into promises to not run the air conditioning while the lathe is running. But codes or not, subsequent owners of the house won't know that, and the proposed scenario is unwise.

[Dick Strauss]

Guys,
Thanks for all of the replies. My main breaker is rated for 200A. I also happen to have a pair of openings to handle the 220V circuit.

Can anyone give me a ballpark figure of what I might expect to pay an electrician or maybe what tricks to watch out for when interviewing a professional? I need to run it up one story from the drop-down basement ceiling, about 80 horizontal feet, and another 10 feet down the garage wall. How do electricians normally charge (if there is such a thing)? What is the hourly rate where you live?

Thanks in advance,
Dick

[Bob Smalser]

Can anyone give me a ballpark figure of what I might expect to pay an electrician...

All run lengths mean is a few more holes.

You'll need to know this anyway if you stay in the game and now's a good time to buy a book and learn how. Then you can hire a pro to come check your work. Or better yet, get a permit for the work if available. Most communities allow homeowners to do their own electrical work, and your county inspector gets paid to help you get it dine right.

[Art Mulder]

in our area ACs have to be on a separate circuit (unless you pay top dollar rates) with a switch that is remotely controllable by the power company. The first thing they do during summer months at any hint of running low on power is shut off everyone's AC

Did you forget to put a smiley face in this, or were you serious?

I have never, ever, heard of this before.

But it actually sounds like a good idea. But how do they differentiate between regular people and those people -- such as the elderly -- who are more prone to heat stroke who can't handle heat extremes?

How about only selling AC thermostats that won't let you set the A/C colder than 24c/75f ? That'd save electricity also.

and I'd better stop, as I'm going way OT to this thread.

[Al Willits]

Off peak as its sometimes called, is pretty common up here in Minn, the power company controls the 24 volt circuit (usually) that goes to your A/C unit and cycles the unit during peak demand times, maybe 15 mins off, 45 mins on, or whatever they chose.
Takes a bit of getting used to, but it can save ya some money as the power company changes less per killowatt.
They also can do that with elect water heaters and I believe some elect heating systems.

fwiw

Al

[Doug Shepard]

Did you forget to put a smiley face in this, or were you serious?
...


Totally serious. To be honest I dont recall all the details but it sounds exactly like Al described.

[Curt Harms]

.

Tapping the AC circuit would save me from running 150-200 ft of copper to the garage. The line would have to go from the basement breaker to the second story and back down a story to the garage at the opposite end of the house.

Thanks in advance,
Dick

I could dream up a possible means to to address this. The existing circuit would terminate with a transfer switch like generators use, a double pole double throw switch. The existing circuit goes to the center. Leads to the A/C unit attach to one side, leads to shop attach to the other. It would be impossible to power both the A/C and shop circuit. Would this meet code? I have no idea. Would it cost more than running another circuit? Probably. Would it work? Seems like it would. I need to go do something constructive.

Happy Holidays to all.

Curt

[Larry Halberstadt]

Your best bet is to install a new subpanel in the garage or other area you plan to use for your shop area. Since you already have room in your main panel, I'd recommend a 60 amp breaker feeding the subpanel. It sounds like you don't have an open basement space through which to run the wire. If you have an accessible attic, it may be quicker to run the wire through that space than the second floor. Since it sounds like you don't have any experience with electric wiring, I highly recommend you hire a professional or find a well qualified friend to help out. I'm not quite sure how much electricians charge. I'd expect it to be $60-$100 per hour and I could easily see at least a day to install a subpanel to the garage through finished construction as you describe.

[chris heinis]

You could buy the black and decker book on wiring at home depot and read it. it gives examples of how to wire subs. You could run 3/2 alum out to the garage and put a 100amp subpanel out there. After you read the book call your local inspector and clear things with hi first then wie it. It's not that expensie. Make sure you grease the connections with the special grease

[Ryan Lee]

On the power company note. Here in Jacksonville they use a timer on the electric waterheaters to shut them off during peak hrs. They give a discount on pwr if you have the timers. FYI