Electric question, Amps on 2 legs of 220v

[ndemge]

I have a temp 50amp service into the shed for right now until I get the 100amp burried.<br /><br />Measureing the amperage on the 2 legs with everything running, getting 25amps on one, 20 on the other. (clamp meter)<br /><br />So is this 45 amps of the 50amp circuit?

 

[Paul Moir]

Re: Electric question, Amps on 2 legs of 220v

Nope, you're only using half that. You can use 50 amps per phase, or 100 amps at 120v total.<br /><br />That's the neat thing about having phases: if all your appliances were 120v, and so all that current would be going to the the neutral bus, it would still only be 50 amps going through the neutral wire maximum. And that would only happen if all the appliances on one phase were on and none of the other. Because if the appliances were running on the other phase, when one phase is dumping 50 amps into the neutral wire the other phase would be trying to take 50 amps out of it. So the current through the neutral wire would actually drop!<br /><br />This sort of thing gets even more ingenious with three phases. After that the law of deminishing returns hits hard.<br /><br />So whatcha got goin in the shed that needs 100 amps? Smelting furnace? Or is this a "gardening" shed?

 

[ndemge]

Re: Electric question, Amps on 2 legs of 220v

Wow, Sounds like I don't need 100 amps!<br /><br />With this pull I had on 220v AC, Air compressor, and a couple lights.<br /><br />Only thing not running was computer/Chopsaw/table saw<br /><br />The heater draws 18amps@220<br /><br />Welder would be the only other thing, but that is very seldom used, no big deal to make sure the compressor isn't running at the same time.