Wiring new machine

[Logan Y]

Originally Posted by Jim Becker

This was the point I was making. The breaker "should" trip if the current draw of the device exceeds the rating, but given breakers are never perfect, using a higher rated termination on a lower rated circuit "could" cause a dangerous situation, but mostly gives the visual impression that there's a higher rated circuit than there is and someone could easily plug in a device that requires, say 50 amps, but can't get it from that circuit. Code isn't going to be copacetic with that, either.

And if you go to an RV park all of these rules go out the window. Almost every person you'll meet at an RV park carries a variety of dogbones that allow them step down to lower rated circuits. The connections rely on the breakers to trip whenever the requested load is too high (which happens all the time).


Agreed that you should use a dedicated circuit for your machine. There are enough electrical gremlins to deal with, putting anything else on a circuit with the CNC isn't worth the headache.

[Racegrafix]

The amp plug should make zero difference, as long as its not too low.

You could use a 5000 amp plug on a 50a circuit. The wire itself is rated at over 50 amps, so a good connector is no different than an uncut wire. An overly efficient/ load carrying connector is not a bad thing unless you are counting on the connector to fail. I will rely on breaker. Its not going to be running on its own anyway.

[Jim Becker]

Yes, you "can" do that...put a beefier termination on the circuit for a given machine. But that's not a necessarily a "best practice" nor will code look with favor on it.