HELP me Split 240 to 120

[sglaab]

OK so I think this can be done quite simply I just need to be positive. I have an unused 240V stove plug (the 3 pronged triangle shaped) I would like to use this power to hook up a home vacuum system. I want to split the 240V line into a 120V outlet for the vacuum itself and the other line for the outlets at each conection (one on each floor) for the power for the tools & attachments. I believe I can connect the red white to the outlet for the vacuum in a junction box and the white and black to a new wire out to the outlets at each connection. OK so far?

The double breaker in the box says 40 on both connected breakers. Are they both

20A then? Can I leave this together and use this breaker? Am I OK here. Thanks for the help.

[RBM]

Your circuit breaker is 40 amps per leg. If you plan to use 12 ga wire, replace the breaker with 20 amp. Since you mention red, black, and white wires, I'll assume you have a bare ground or steel cable as a ground, make sure your new cables are connected to the ground wire or junction box ground screw

[Kevin Ricks]

No the 40 amp means 40amp on each wire. Since the 2 poles are alternating (sine wave) you will never have more than 40 amps at the appliance. When one side is drawing 40 the other side is at 0. When one is at 30 the other is

10 etc.

Does your stove outlet have 4 wires. Red, Black, White, Ground? The ground may be attached to the box. If not I would not try to convert it. I would run new wires from the panel. Some 240V outlets have red, black ground (no neutral). Some have neutral but no ground. Newer 240V outlets are required to be 4 wire.

In general this is not a good idea. but do this safely you would need to replace your 40A with a 20 amp double pole. Or two 20 amps breakers with the handles tied together. (That is if you are using 12 ga wire) If you did not change the breaker then you would have to keep using the larger wire (6ga?) on the entire circuit.

A better idea is to make a sub panel at the stove outlet with 2 - 20 amp breakers there. In that case you would leave the 40 amp breaker in the main panel. You couldn't do this though if you don't have the 4 wire circuit with a properly sized ground wire.

Kevin

[Mark Lloyd]

That's not right. The 2 phases are opposite. The peaks occur at the same time (just opposite polarities). During that time, each side is drawing 40A. 1/240 second later, each is drawing 0A. The currents will always be equal and opposite.

It will never total more than 40A because the sides are at opposite polarities.

The difference between ground and neutral has to do with current flow. it you have a dedicated (currently with no load connected) 240V circuit, how would you know which you have?

You couldn't use 4 (2 for each side) 20A receptacles?

I've seen 240V circuits split for holiday lights.

[Doug Miller]

Code violation. Breakers are not permitted to be connected in parallel.

[homersimpson]

Wrap about 600 to 800 feet of insulated wire around your neck and connect each of the ends to the plug on your vacuum. Put on some well insulated rubber boots and stand where you dont touch any grounded metal objects. Grab one of the 240 V wires in your left hand and the other wire in your right. Turn on the breaker and you will have 120 volts going to the vacuum from the inductance of the coil of wire around your neck.

Note: You might experience heart failure from doing this, but thats a small price to pay for progress and technology. Better yet, if you do survive, you will know you have a strong heart and can save a doctor bill for cardiac testing.

[Mark Lloyd]

And why would I have suggested such a thing?

[Doug Miller]

Sorry, misread your post. My bad.

[Mark Lloyd]

I'm actually considering a similar thing (as I originally said). Specifically, using a 240V 30A circuit to 4 GFCI receptacles.