Topics include, Machine Tools & Tooling, Precision Measuring, Materials and their Properties, Electrical discussions related to machine tools, setups, fixtures and jigs and other general discussion related to amateur machining.
I'm sure this has already been answered somewhere, but I don't know what to look for. I'm wiring up a VFD to my Bridgeport Milling machine, and I'm a bit confused. I'm going from single phase 220v input, to a 220v 3 phase motor. The wires coming from the motor are Black, Red, White, Green. I know green is ground, and black and red are hot. I thought 3 phase generally doesn't have a neutral, so is the white also hot? Given the unusual configuration I can't figure out how to tell which is my L1, or if that even matters. Additionally, do I double up the ground from my input and the motor onto the same ground slot on the VFD?
You'll most likely benefit by waiting for a post by those who know better, but in the interim, look at your wires as the black being the A phase, the red being the B phase and the white being the C phase of the three phase circuit. Green, as you alluded, is ground. Red is typically the high leg of a three phase delta service, and is generally the center conductor of the panel.
Now to hear from those familiar with code and VFD's!
H
Wise people talk because they have something to say. Fools talk because they have to say something.
Forget the color of the wiring...look at the labels on the wires and terminals.
3 please motors also have grounds -> you should have UVW for power and a ground lug of some sort.vyour chart is tough to read but it looks like 1-2-3 for incoming power....across the bottom where it says LINE
Whoever wired your motor used 3 wrie with ground SJ cable which are the colors you have.
So use green for ground and do not worry about the colors for the other UVW connections...just 1-U. 2-V. 3-W and it will run.
It may run backwards, but that is quickly corrected
Agree, frequently, wire not suitable for the application is used. A proper cable might have had red, blue, black, and green conductors. Not quite as easy to come by as a scrap of common cable on hand.
There is nothing wrong with applying tape of the correct color over a conductor of the wrong color - so a bit of blue tape over the white wire would give the correct guidance to a future service person - just try to get both ends!
to confirm the above for peace of mind, use an ohm meter on the three hot wires; each pair should have the same resistance (within 10%).
And you can confirm that the green is connected to the case, and has near infinite resistance to the coils (hot wires).
