220 vintage lathe wiring??

stratton

I have an older powerkraft metal lathe that has a belt driven 3/4H motor. The motor never had a ground on it. So I tried to wire the grounding plug to a motor bolt. But it would not run with it being grounded. So Now its just two hot wires going to the motor and a single pole switch. Is this safe? Why does my non-contact voltage detecor go off when i am anywhere near the lathe? Could it just be a small static reading? The lathe seems to work great. Just making sure this isnt a dumb mistake that I made. Any advice would be great. Oh my breaker is a 220v 30A. And i replaced the cord with the same 14G 2 wire that was previuosly on the lathe.

frenchelectrican

I will address one critcal item you can not use 30 amp breaker if the motor do not have thermal protetion there.

Now next step sound like you have issue with winding start to shorted to the frame what you need to do make sure the green wire is bolted on any part of motor frame and I know you did and it did make the motor not run so you have winding issue in the motor the surefire way is get ohm meter I know ohmmeter may not catch this but if show from line to ground if the meter show something then you have issue there.

Otherwise you can get other 3/4 HP motor if have standard mounting on it { this part I need to know what frame number it is }

Merci,Marc

oilseal

Are you sure that the wire in the plug actually goes to ground when plugged in? Explain what your "non-contact voltage detector" is. If your motor runs on 220V it should have a two pole switch.

stratton

My voltage detector is one of those that you can trace along a wire or get it near a plug and it will beep and light up. But it doesnt tell me how much voltage is there.

The way i have the motor wired now is, wire from the wall has black and white wire. black goes to motor wire, then other motor wire goes to switch, then switch goes to white wire from the wall plug.

when using a ground, the switch would only turn off half of the voltage. The motor would still run on 110v. Which i know is not safe. So when i bypassed the ground the switch then would cut total power. I am not sure why this works like it does.

I am just affraid that i am getting a reading on the detector because the voltage is trying to ground itself, And when i get near the lathe its reaching out to find its ground. If i lay the detector on the table and move my hand away from the area it will not beeb. Its just when i get close it it.

The guy at homedepot told me that 220v needs a neutral wire for it to work . And he didnt believe me that it would even work at all with only two wires coming in from the plug. What am I missing. The lathe works great with just two wires. Do i really need to be concerned. The original wire that was from the factory only had two.

InPhase277

Like Marc said, it sounds like a winding in the motor has shorted to the motor frame. This is not only inconvenient, it is dangerous. When the motor is running, the whole machine is energized. If you are touching the machine and are also grounded somehow, you will be shocked. Some people have been killed this way. You need to replace the motor before it kills you.

Also, the guy at Home Depot is an idiot. He is the last guy to get electrical advice from, seriously. Next time you need advice and can't log on here, stop and ask the drunk homeless guy under the overpass on the way to Home Depot before you ask the guy at HD.

stratton

Haha. Yeah I figured as much. Thanks for the heads up.