In North America I know we use split-phase 220V power. I am wanting to purchase an industrial power supply that has an input rating 100-240VAC, and has 3 input terminals labeled ⏚, L, N. I know the N is for neutral, which would apply to most of the world which uses regular single-phase 220V. But can I plug split-phase power (with its two hots, 180 out of phase) into those two L, N terminals safely?

  • \$\begingroup\$ How many watts is this power supply? If it is only a few hundred watts, I would just run it off L & N (110 VAC). Really high power devices should be run L - L (220 VAC) to keep the two legs balanced. \$\endgroup\$
    – Mattman944
    Commented Jan 27, 2020 at 1:02
  • \$\begingroup\$ Its a mere 280W. I know supplying it with 110V is a sane option, but my question is more academic in nature. Although it would also save me from having to do any additional electrical wiring since there is already a 220V outlet where I need it. I am wiring a 220V VFD as well. \$\endgroup\$ Commented Jan 27, 2020 at 1:10
  • \$\begingroup\$ @SteveEasley In North America the very term split-phase means two hots (H1 and H2) and a neutral (N). That's why it is called split-phase -- to differentiate it from, for example, some EU countries that provide only single-phase 220. In North America, the N is also usually "grounded" using either a Ufer ground (20' of #4 bare copper or else 1/2" iron rebar in concrete) or else a fat, long copper stake in the ground near the home. Why do you imagine "no neutral" is implied by "split-phase" when exactly the opposite is the case? \$\endgroup\$
    – jonk
    Commented Jan 27, 2020 at 1:28
  • \$\begingroup\$ @jonk I think you are reading more into my question than I am asking. I know neutral is used in the North American systems. But I have a shop full of 220V equipment that don't use that neutral. My question is concerning that exact thing. \$\endgroup\$ Commented Jan 27, 2020 at 1:40
  • \$\begingroup\$ @SteveEasley The way I read what you wrote made me think you believed exactly "otherwise." I'll let it drop. You can hook up a 220 single-phase device (so long as it works with 60 Hz, obviously) across H1 and H2 and the device will run (it may need to be isolated from "earth," though.) Whether or not it is SAFE for a human to touch is yet another question. Does the equipment ground its chassis to one side? (I don't know what standards were used for your equipment and can't guess about it.) But if so, you probably need to disconnect that first. You don't want any metal-work to be at H1 or H2. \$\endgroup\$
    – jonk
    Commented Jan 27, 2020 at 1:48

1 Answer 1


First of all: 220V is very dangerous! Do not mess around without proper knowledge and safety procedures and equipment. Be sure to never wire things without being unplugged or with the breakers at off! Measure voltages at all times before wiring or touching power cables. If you aren't sure, call a professional electrician.

As for the question: the answer is yes, you can safely plug split-phase 220V into the L and N terminals safely. The ⏚ label indicates Ground, or Equipment Ground. This is usually a bare wire in 220V wiring.

By using this diagram as an example you can see why we call 110V with the labels Line and Neutral. There is 110V between any Line and the Neutral. There is 220V between any two Lines.

: enter image description here (oempanels.com)

To wire your power supply, simply connect the two Lines (Hot) to the L and N respectively. ex. Line 1 (usually red) goes to the L label of the power supply. Line 2 (usually black) goes to the N label of the power supply. The ⏚ label indicates earth ground. This is usually the bare/green wire in the middle of a 220V cable, or the wire connected to the metal casing of a 220V electrical box.

ex:(copyright MS Paint)

enter image description here

  • 1
    \$\begingroup\$ That picture isn't correct it's got plug ground going to l/h2 and plugs l/h2 going to ground \$\endgroup\$
    – Jacob
    Commented Dec 10, 2022 at 11:30

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