Basic elctrical connections

[LaserImage]

OK, I am feeling really stupid this morning... I know enough about electrical stuff to get by with most things but something made me really question what I know, and don't know.

I am in the finishing stages of building my cnc router and am working on the controller box. I have a 24 volt power supply, 3 axis stepper driver board and a router speed controller from cnc4pc - the C19.

I don't want the speed controller outside the box, no need to have two separate boxes, right? So, I am mounting it inside the "main" controller box.

On a standard grounded outlet, US style, you have three connectors - hot, neutral and ground. I have wired many outlets and switches, this is not a foreign concept to me. I have always wired the switch on the hot side so when you switch it off, you don't have live wires at the other end. So far, so good.

When I went to feed the power to the C19 and my power supply, I noticed something that I thought was strange. The ground connection and the neutral were reversed on the C19. I did a triple-take and pulled out the ohm meter and verified that the connections were truly reversed. The hot went to "line", the neutral went to the "earth" and the ground went to the "neutral" on the C19. The board is screened with those designations, "line", "earth" and "neutral".

I reconnected them as I thought they should be but haven't plugged anything in to power yet. Am I thinking correctly or am I clueless? Does it matter where the "earth" and "neutral" wire go? I know they end up on the same bus in the breaker panel, but isn't there a reason they are wired as they are?

Thanks for not laughing...

Gary

[Al_The_Man]

What you should do is, with the three lines disconnected, check for continuity from the ground terminal to the neutral terminal.
According to the code, there should be no connection between ground and Neutral, except at the service entrance, the exception would be if you had an isolated 120vac supply, as in a local control circuits in your machine enclosure.
Then you can ground the new neutral at this point right at the transformer.
It is possible they have ground and neutral connected, which is a bit dangerous if you were to accidentally swap the hot and the neutral .
Al.