Uh oh... Lathe problem

[brownsfn2]

So my Delta 46-460 lathe might be having a problem. 1 out of every 5 times I turn it off the GFI circuit pops that I ran for it. I hear a pop but it sounds like it is coming from the circuit box and not the GFI outlet. I am certainly no electrician but I checked the circuit and everything looks ok. I am now wondering if there is an issue with the lathe. Maybe a surge every time I turn it off.

Does anyone else have this issue with the Delta Lathe? Can anyone offer me some things to check? I am just not sure what to look at. Thanks!!

 

[bradh]

A GFI on the way out will pop too easily. It might be the GFI, do you have another GFI to try?

 

[monophoto]

I agree with Brad that the problem could be the GFI.

Why do you have a GFI on the lathe circuit? You absolutely MUST have one on outdoor circuits and on circuits that are close to water (bathrooms, kitchens, etc). But there is no requirement to have them on shop circuits.

GFIs rely on microelectronic circuits to perform their function, and your lathe is a variable speed machine that will inject harmonic currents back into the power system. That could be an unfortunate combination.

 

[brownsfn2]

Interesting. I thought that I needed gfi for a basement drop. I might just replace it. Any reasons why it would have taken almost a year for the problem to show itself?

 

[shull]

As to why the GFI took a year to give problems...GFIs and circuit breakers are spring loaded and mend to weaken somewhat over time. Additionally, the load may also increase due to wear and tear to the point that on a circuit that is borderline to begin with ithe added load could cause cause the breaker / GFI to pop.

As far as a GFI in the basement...not a bad idea if the basement tends to have high moisture levels or periodic water invasion. (hence the need for sump pumps in some areas.)

 

[ctubbs]

GFIs trip on a current imbalance of 4 to 6 ma between the neutral and line wires. When a motor shuts down, there is a reverse(not the correct term, but close) voltage generated that feeds back through the wires. This can cause false tripping of GFIs. Many GFIs just plain don't like motors very much and can cause false trips. I have a motor on my DC that hates GFIs. I have tested it seven ways from Sunday and can find nothing wrong with either it or the GFI it insists on tripping. I have even thrown it on a 1000v AC megger and can find no problem leakage. Sometimes some motors will not work on a GFI. As you are working in a basement, I would absolutely recommend the continued use of a GFI on your lathe. A 20% trip rate is a very small price to pay for preventing electrocution of yourself and or your family or friends. Been there, done that. Been hung and couldn't get off live circuits way too many times, twice on 480v. One of the luckiest people still alive, now one of the most cautious.

Around live power, always play it safe. When I first got into the apprenticeship program, I was told, "In the IBEW, we have old electricians and we have Bold electricians. WE ain't got no Old Bold electricians!"

Charles

 

[RetiredJake]

Where GFI's are required varies by state. In TN, you are required to have a GFI on all circuits in a garage, any circuit in a room with water, and all outdoor circuits. Everything I have in the garage is on a GFI, and yes, they do break down over time and have to be replaced periodically.

Jake

 

[brownsfn2]

I am pretty sure I am going to replace the GFI outlet since it is pretty cheap to do. I am pretty sure it is required by code in my area because the builder put one in originally with the house. I added my own.

I am also going to call CSUSA. Mike@CSUSA offered assistance from their lathe guy. I can't believe how helpful those guys are. I will always buy their products.

Thanks again for the advice guys!!

 

[EricJS]

GFI and Variable Speed Drives don't do well together. Even if you don't short the circuit or draw too many amps, the variable speed will still periodically cause the GFI to trip.