240V what a difference

[Woodwerker]

Moved into my current home in April and finally had a chance to tackle wiring the shop. My last house had a 28'x38' detached garage. The garage was bigger than the house
I had to reduce my "things" to fit into a standard two car garage.
The garage had no lights (garage door opener lights only) and only two outlets [:0]. I dropped 4 dedicated 20 amp lines wired 6 four foot fluorescent tube light and two 240V outlets. The 240V outlets are for my Jet 10" table saw and the 12" HF band saw. I did not try the band saw yet, but the table saw blade flies. I can not believe the difference.
Not sure why I waited so long.
Joe

[Ken Massingale]

I agree, Joe. I can't explain why, and don't really care. But, the ole Ridgid 3650 is definitely 'torkier' at 240.
ken

[onedash]

Based on everything I have read the motor produces NO MORE power at 240 than at 120. So if the power actually increases then its safe to say it must not have been getting full power when it was wired at 110.
Im guessing when someone upgrades to 240 the size of the wire usually gets bigger plus even the same size wire would then only have to supply 1/2 the amps. So a 15 amp 110 outlet that doesnt deliver a full 15 amps for whatever reason should better be able to deliver 7.5 amps once its 240. RIGHT?

[Tom Miller]

quote:Originally posted by onedash

Based on everything I have read the motor produces NO MORE power at 240 than at 120. So if the power actually increases then its safe to say it must not have been getting full power when it was wired at 110.
Im guessing when someone upgrades to 240 the size of the wire usually gets bigger plus even the same size wire would then only have to supply 1/2 the amps. So a 15 amp 110 outlet that doesnt deliver a full 15 amps for whatever reason should better be able to deliver 7.5 amps once its 240. RIGHT?

Yep, that analysis sounds about right. In addition, your motor is going to come up to (the same) speed faster. That could have a lot to do with it seeming "torkier", as Ken says.

Regards,
Tom
Oh, and congratulations on all your new electricity, Joe!

[JimD]

I am not sure what you guys are talking about. A 220V circuit is a phase to phase circuit. Totally different than a 120V circuit which is phase to neutral or phase to groud. If you are saying that you can get by with smaller wire to carry half as many amps then you are right. You can't turn a 120V circuit safely into a 220V circuit. You would have to put a phase wire on the white neutral conductor and I don't think that's safe. I haven't referenced my copy of the national electric code and I am not an electrician but it does not seem right to me.

If you have a BT3100 or similar saw on a 20 amp circuit and run a short 12 gauge extension cord, you won't gain anything by switching to 220V. If you run your 110V saw on a 15 amp circuit and are connected by a long and little extension cord, you need to do something different - 20 A 110 and bigger cord or 220V. The worst I have experienced was a 15 amp circuit in my last house that went from the circuit box in the basement, up to a second floor bathroom where the GUI was and then back to the basement. That was very incompatible with running a table saw.

Jim

[stewchi]

You can do it safely and it is done all the time by people using 12-2. The NEC requires that you re-label the white conductor to another color to identify it as a hot conductor. Of course this would not work for appliance that require 120v and 220v such as an electric oven with a clock timer or digital control that runs off 120v.

[MBG]

Found this:

Subject: Is it better to run motors at 110 or 220?
Theoretically, it doesn't make any difference. However, there is a difference is the amount of power lost in the supply wiring. All things being equal, a 110V motor will lose 4 times more power in the house wiring than a 220V motor. This also means that the startup surge loss will be less, and the motor will get to speed quicker with 220V. And in some circumstances, the smaller power loss will lead to longer motor life. This is usually irrelevant unless the supply wires are more than 50 feet long.