110 or 220?

I am picking up a Table Saw and it comes prewired for 110, but have been told it can be switched over to 220.

Right now I do not have a 220 line in the Garage, but am thinking of having an electrician come out to put in the line. Is it worth it? What are the benefits of going 220?

I probably need a line run anyway as I keep tripping the circuit breaker with a few things running at the same time.

Thanks,

Adam

Reply to
Airedale
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I would run a line for a subpanel box. It greatly simplifies wiring in the shop.

The best part about 220 is that it is needed for many tools. And if you are like most of us, you will acquire more tools in the future. Particularly if you ever decide to do some welding.

Reply to
Lee Michaels

Well - it's a no brainer then. If you're tripping breakers with what you currently have, you need more circuits. Go ahead with the 220 line while you're at it. Any additional cost will be negligible. Your saw motor will run cooler and you'll be well positioned for other tools that run better on

220. Be sure to run at least a 60A service (sub-panel) out there.
Reply to
Mike Marlow

Sounds like you have your answer. More circuits. Not much advantage to going to the 240 as far as the saw's concerned, due to the way the majority of the dual voltage motors are wired. What should be a saving in less length of wire (parallel windings) is taken away when the 240 connects them in series. Won't hurt, certainly, and you don't have to run as high gage wires, due to lower amperage draw.

Reply to
George

In my garage I have a 20 amp circuit. I cannot run 2 big tools at the same time. In my basement where I have my woodworking tools I have a few 20 amp circuits. Vacuum/dust collector is on a different circuit from the saws or planer.

I second the subpanel in the garage. More circuits of 120 and 240 are possible at a lower cost.

Reply to
Jim Behning

I'm not seeing the original post so replying here.

Other than being able to run tools that aren't available in 110 versions, the major benefit is that the current draw and thus IsquareR losses in the wiring are cut in half. Thus, for example, my band saw instead of taking a minute and a half to come to speed and popping the breaker half the time instead comes up to speed in a few seconds.

I agree that a subpanel for the garage is the way to go. If code allows you to do your own wiring, once the box is in place adding additional circuits becomes much easier than running them to the main breaker panel. You can also kill all power in the garage from the main breaker panel if you need to.

Reply to
J. Clarke

Yeah the subpanel sounds like a good idea, though I doubt I will need any more lines and I am thinking there is even more of a cost for that subpanel. I have been quoted many different prices and it is rather disconcerting to think about spending even more money on a subpanel out in the garage.

I just spoke with an electrician and he thinks I can use the existing conduit to add in another line if it is just 110. The 220 they are guessing will require a brand new run of conduit. Since my basement is already finished, it would mean a lot of holes I think to run that pipe...

Reply to
Airedale

You have alot of pretty good suggestions about the subpanel, etc., but I don't think anyone has yet answered your original question.

The basic reason for running 220 volt vs 110 volts would be to decrease the amperage load. For example: If you were running a tool that draws close to 10 or 12 amps on normal run time, the amperage would increase on start-up (initial load/torque) and if the tool was put under a heavy load (like ripping on table saw or taking the maximum cut on a planer) the amperage would also increase, relative to the load placed on the tool. If plugged into a standard 15 amp line, you'd most likely trip the breaker. But even if not, you'd be pulling enough amps through the standard 14 guage wire as to risk overheating it. (14 guage wire is rated for 15 amps and 12 guage wire is rated at 20 amps.) You must also have the proper receptacle for whatever you are going to use... 110 volt/15 amp, 110 volt/20 amp, 220 volt, etc.)

Basic electricity (Ohm's Law) dictates that as voltage capacity increases, the amperage decreases. So, a 15 amp load at 110 volts would decrease by half at 220 volts... which would be 7.5 amps.

I run mine on 220, but I really can't tell much difference in the performance of the saw. I have had it wired both ways, and it doesn't seem to change the power of the saw. (Of course, I would have to have two identical saws and try them side by side with the different voltages to really compare.)

Reply to
Robert Allison

I'm pretty sure the gozinta equals the gozouta (watts) regardless of whether it's wired for 120V or 240V. Parallel vs series doesn't affect that at all. See Kirchoff.

I'm always amused by this particular point. If smaller wires is the goal then there's no point in wiring for 240V at all. Usually the need for 240V (other than supplying 240V Only tools) arises from the 120V wiring being inadequate in the first place. By going to 240V, the current draw is cut in half, thus reducing the voltage drop (loss). That solves the inadequacy part, but then turning around and saying, "and, you can run smaller wires..." utterly negates the benefits, putting one back to square one.

Reply to
LRod

Add the 220 and you will probably never have voltage drop problems using

220. Many stationary planers and larger band saws, jointers, etc run on 220.
Reply to
Leon

Concur on the subpanel. I had to take two house breakers out of the main panel and move them to the sub to open up a spot for a 100amp breaker to the sub. The minor inconvenience of this is that I can't cut power to the whole shop without killing the lights to swmbo's office (she doesn't like that). The *major* convenience is that every machine has its own breaker. Another benefit is that the circuit that has both the ceiling lights and wall receptacles (which are two different circuits) are still in the main panel. That way, if ever a situation arises that the 100amp breaker to the sub trips (I can't imagine why), I'll still have lights on.

I've not tripped a single breaker since going to this arrangement.

jc

Reply to
Joe

How many horsepower does the table saw generate? Another way of asking is how many amps does the table saw draw at 110 volts, both on start up and under load?

If you were looking at a 1.5 HP table saw, or the amps are at 15 or under, you'd probably be OK with a 110 volt circuit, 20 amp circuit breaker, 12 gauge wire.

At 2 HP or more, or over 15-18 amps current draw, you really are going to want a 220 volt circuit, as the alternative is a 30 amp 110 volt circuit and 10 gauge wire, which doesn't make a lot of sense to put in.

Regardless you want to dedicate this circuit to the table saw.

If you ever want a dust collector for your saw, or other heavy duty tools, the subpanel others have suggested is going to save a lot of money over time.

Reply to
Jim Weisgram

Airedale wrote in news: snipped-for-privacy@s19g2000prg.googlegroups.com:

*snip*

Think about it this way: What's going to happen in the future? If you spend all this money on running a new line out to the garshop, then find you could use that extra capacity later, you've got to spend all that money again. If you run a proper subpanel out there, and find you need a new line, the subpanel's already out there.

When you're ready for 220V, you can take it off the subpanel and put on matching plugs. As I understand it, there's several styles of plugs for

220, so you need to make sure they match up.

When you're getting quotes, make sure to ask for a couple variations. You may find that an upgrade doesn't cost as much as you thought.

Puckdropper

Reply to
Puckdropper

LRod wrote in news: snipped-for-privacy@4ax.com:

*snip*

With high enough voltage, shouldn't we be able to use 24 gauge wire to run our table saws? LOL Danger, 1.5 MILLION VOLTS!

Puckdropper

Reply to
Puckdropper

"Puckdropper" wrote

Also, if you are trying to save money and don't want to do the actual wiring, Buy the subpanel and run the wires. Leave room at the ends for the electricial to make the connections. Install any boxes needed and run tnose wires as well.

This is commonly done in areas where it is illegal to do do the wiring itself. So people do everything except the connections. That way a licensed electrican can sign off ont the job.

Reply to
Lee Michaels

See resistance.

What's so amusing? Run 20 amps at 240 on the same wires you can run 20 at

120, right? Sounds like a correct statement to me.
Reply to
George

This question comes up at least every other week.

Yes, you need 240V in the shop if you are going to do any serious work involving stationary power tools.

To do the job so that you get the biggest bang for the buck, install a

2P-60A sub feeder in the house panel, a 12/24 ckt, 125 MLO sub panel with a 2P-60A main, in the garage and #4 feeder wire in a new conduit. (1-1/2" plastic will make pulling the wire a lot easier).

(Yes you can save a couple of $'s with #6AWG, but I like #4AWG, especially when you only do this job once)

Find an electrican who wants to pick up a few extra $'s and work with them.

You do the grunt work under their direction, they make the hook ups.

Have fun.

Lew

Reply to
Lew Hodgett

Advantage of 220: Less voltage loss in the circuitry. Thus more of the power that are buying (at a not so cheap price these days) gets wasted heating the wiring.

Disadvantage of 220: Costs lots to install in old work. But only an electrician would know how much more (depends on whatever else needs to be done at \the very least..

Jim

Reply to
Jim

See parallel resistance vs series resistance. Again, Kirchoff.

Yes, in isolation that statement is correct. You said, however, "...and you don't have to run as high gage wires..."

Where the amusement comes in is that in most cases someone is contemplating switching to 240V supply because the tool in question is having trouble ramping up to speed smartly, is dimming the shop lights, or some other symptom of undersized feed for the load at hand. The obvious and correct answer is to switch to 240V, because with only half the current draw, the I^2*R losses are reduced to the point that the capacity of the feed is no longer the issue that it was at 120V.

Then someone always follows such a recommendation with the news that with 240V you can run smaller wire. Smaller wire was the problem in the first place (at 120V). If you run smaller wire at 240V, you have essentially put yourself right back into the same circumstance you were before.

Reply to
LRod

Look at it this way: To get the same behaviour at 120 that you get at 240 with (forex AWG12), you'd need to go to AWG10 on the 120 circuit (and possibly a 30a current interrupting device, to boot).

So, you can use smaller wire with 240 than with 120 _performance being equal_.

I do understand your point, however.

scott

Reply to
Scott Lurndal

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