I want to use a monophasic 230/240 volts chainsaw coming from Europ in USA. I have biphasic 240 Volt outlet in my new US house. Can I just connect the two 125 volts phases to get a 240 volts monophasic? On the chainsaw there are two wires: one is phase and the other is neutral. Thank you for your help.

Thank you for your answers. I have been using electric chain saws for more than 20 years as a non professionnel. Less maintenance and less noise.

Of course I would use proper outlets for the connections. My questions are: 1- Is there a risk that I damage any part of the installation or switches panel if I connect the two phases together in a European female plug in order to plug in my chainsaw? 2- Do I risk to damage the chainsaw if I plug it in that female plug and start it? Thank you again for your help.

  • This isn't meant to be advice, exactly; rather a pointer that might help you with more research. In the UK, they make 110v site power by combining two 55v legs from a center tapped transformer. Most North American 110v tools (ie, universal motor based ones) work fine on that power. It may or may not be important to note the 50Hz in Europe/ 60Hz difference. Oct 24, 2015 at 15:18
  • US home power distribution is Split-Phase, not Two-Phase or Biphasic with the 240 volt power being Single-Phase and 120V developed between each transformer secondary leg and the secondary center tap. Oct 24, 2015 at 17:51
  • Please use the edit link directly underneath the question to update it. Do not post your update as an answer. Thanks!
    – Niall C.
    Oct 25, 2015 at 14:02

2 Answers 2


The two 120V legs of household wiring are 180 degfees out of phase with each other, which is how we get 240V for stoves and workshops and the like. Yor really (REALLY!) should have a proper 240V outlet installed for that tool to plug into, preferably with a 240V GFCI since you will presumably be working outside.

Remember that an electric chainsaw is just as dangerous as a gas chainsaw, plus the risk of cutting the power cord. Proper safety equipment and training is essential.


In the US, with the split-phase system, you are correct that you wouldn't be supplying a current-carrying conductor with a voltage close to ground. It would supply two AC voltages both centered around the ground, where the voltage between them is about 240 V.

If the chainsaw uses a two-wire cable (without a ground), then the chainsaw will be unable to tell the difference between the two situations. Safety-wise, using the US power supply may be slightly safer because the voltage will always be closer to ground (Since it is +/- 120 V, instead of +/- 240 V).

If the chainsaw has a three-wire cable (with a ground), then the chainsaw could be able to tell the difference (because the neutral won't be close to the same voltage as the ground). But, the chainsaw's case should be isolated from the neutral and line (to reduce the safety risk of when the neutral and line are accidentally swapped).

In the US, in order to produce the "proper" neutral and line, you would need to use a transformer. Its windings would need to have a 1:1 ratio because the primary and secondary voltages are the same. It would need to be able to handle the current requirements of the saw. Also, you would connect the chainsaw's "neutral" (one of the outputs on the secondary side) to the neutral or ground on the primary side. This sort of transformer is called an isolation transformer. The transformer would likely be slightly expensive, and probably is unneeded.

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