220 wiring; why isn't a neutral necessary?

Hello ... probably the only thing I don't understand is how a neutral is NOT required on a 220V line to operate at 220.

A normal 110 circuit terminates at the panel with white to common and black (hot) to breaker. When a motor is turned on, I understand current *flows* from neutral to hot (even though it's AC, it flips 60 times a second; not dealing with AC?) I assume this is just boilerplate.

I have a 220V air compressor (2 hots, 1 ground) and it has no return, which is OK since there's no device requiring 110 (one leg). How can current flow with just 2 hot wires? I assume the 2 incoming "hot bars" (from outside) are in sync. Both bars are either positive or negative. So, when the "negative" phase occurs, where does the current drain? I can see how the ground will work... and maybe it *IS* used.

Can someone clarify?

Thanks a lot! I greatly appreciate it.

Mike

Reply to
Mike
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Thanks Mark (or Sue?), by clarifying the hot bars are not ever the same polarity, current can flow between both breakers. So at any given time, either are + or -, correct?

Thanks again.

Mike

Reply to
Mike

Generally you have 3 wires coming into your home, one of which is neutral. Across either of the other 2 wires to neutral is ~120 VAC. But between the 2 hots is ~240 VAC. So be careful about connecting one hot to another hot, because if they are different hots, it could be a 240 volt short.

So yes you do have 2 hots with 220/240 V and neither of them should be grounded. But at an given instant (except in middle of AC cycle) they are opposite polarities, so current will flow between them.

Reply to
David Efflandt

quoting:

AC reverses polarity 120 times per second. So for 1/120th of a second, one wire is +, and the other is -. I like to think of it as the "push-pull" effect. At any givin half-cycle, one is pushing(+), and the other is pulling(-).

With one hot wire to ground, only that one wire pushing or pulling on it's own at any givin half-cycle. When the circuit is closed, the ground or neutral is sorta forced into push/pull action, except it isn't really pushing/pulling it's own electricity on it's own, so the voltage is half, or

120 volts.
Reply to
JM

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