Shopsmith Forums

I need to run a new 240V 20a circuit about 25 to 30 feet long. It will terminate into a 6-20 receptacle. This is for a new piece of equipment I am about to acquire.

I have room in my panel and have some 10-2 with ground romex that I am planning to use. Is this adequate and are there any got-yas I'm not thinking about? (I will remember to cut power before making connections.)

10-2 should handle about 40 amps 220. Make sure you carry a ground most 10-2 romex has a ground but if for some reason yours does not make sure you carry one. Also if any thing on the new piece of equipment needs 110 (like a shop light) you will need an additional wire. 10-3 with ground works great. By law you can not use the ground wire for the return leg of a 110 circuit.

I recently did something similar so I would be prepared for using my PowerPro upgrade on 240 V. I used an existing dedicated 110 volt 15 amp wall outlet. I had an electrician change out the receptacle and rewire the line at the circuit breaker panel. 14 guage wire is just fine for 15 amp regardless of the voltage. 12 guage wire is fine for 20 amp regardless of the voltage assuming you are under 600 volts.

Thanks for the confirmations that I should be OK with my plan. I decided to use the 10-2 since I already have it.

Thanks for the heads up ED, but I won't need 110v for anything on the equipment so I should be good.

#10 is 'overkill' for that short of a run. So use what ya got!!!!

Attaching the wire to the receptacle may be a challenge!

Make sure you install a 2 pole breaker(20A or 30A)

FWIW I would go bigger wire for 40A.(#8))

Watch your local electrical codes and national codes as well. Newer convention requires four wire hookups for 240 volt appliances. The stove in my house has a 4 wire configuration.
Bill V

wa2crk wrote:Watch your local electrical codes and national codes as well. Newer convention requires four wire hookups for 240 volt appliances. The stove in my house has a 4 wire configuration.
Bill V

For a 20A branch?

Again a matter of 115v loads. That requires two 'hot', one neutral and one ground. That be 4 wires.

YES
When I removed the stove from this house there was a 4 wire configuration. Red, Black, White and an insulated Green lead connected to the frame of the stove.

The old stove on the other house only had three wires on the terminal block, red, black and white. This house was about 9 years older than mine. So the standards have changed.

Bill

tdubnik wrote:Thanks for the confirmations that I should be OK with my plan. I decided to use the 10-2 since I already have it.

Thanks for the heads up ED, but I won't need 110v for anything on the equipment so I should be good.

My new circuit is now complete and working properly.Measures 238v on my voltmeter and the ground proves to be grounded.

As it turned out I did things a little differently than planned. I went with my 20a circuit breaker but decided to use 12-2 with ground instead of the 10-2. I had no particular reason except that I thought 10-2 was overkill for a 20a circuit and a machine that draws 15a at full load.

The run length turned out to be about 40 feet by the time I ran the wire up walls and through ceiling joists and at somewhat of an angle across my basement. This is still well within the recommendations to avoid a voltage drop.

When you measured the 238 vac, was the circuit loaded (power tool plugged in and running)?

If not, I suggest that you do that. With no load, there will be MINIMAL (if any) LINE LOSS.