VFD Router Problem Solved

I just received my VFD router and installed it. Installation was easy. Using Carbide Motion, I ran through all the setup processes. When I went to the MDI tap and put in the code to run the spindle, it would always trip my ground fault. I gave up for the day. Next day I was able to get the spindle to run first time with the code. I them used M5 to stop the spindle and it immediately triped the ground fault. Reset everything and couldn’t get it to run again. I switched over to a non ground fault receptical and it has been running perfectly. Ran a few jobs, no problem at all. Ill keep everyone posted if something changes.

I noticed the other day when I ordered one (just arrived still in the box) they say it will not work with GFIC


The VFD controller cannot run on a GFCI (ground fault) outlet. If you have a GFCI outlet, the VFD will not function properly. This is not a limitation of our particular VFD, it is a limitation of all VFDs.

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VFD’s do appreciate GFI’s

If you do not have a regular receptical to replace that one, in a pinch you can override the wiring in a GFI. However, thats in a pinch. Best to simply replace.
Depending on your load wire, a 20 amp receptical may be wise as well. (Wire must be 12/2 or greater for 20amp, if the wire is 14/2 a normal receptocal is sufficient). Do not add a 20 amp breaker to a 14/2 wire

My Jet 12-21 Variable Speed Lathe trips GFCI outlets. I was able to replace the outlet because it was the only thing on that circuit. I put the GFCI outlets on the first outlet on my electrical install. At the time the only GFCI breakers were double size and took up two spots in my electrical breaker cabinet. For my living areas I put in GFCI/Arc Fault breakers but for the shop I just put the GFCI in the first outlet and that protects all the remaining outlets on that run.

The latest electrical code requires GFCI basically everywhere and especially in areas that might get wet like a garage and/or shop area. The living areas require GFCI/AFCI combo breakers or the first outlet on a run. The Arc Fault circuit interpreter is when you plug in something and it arcs it is supposed to shut down the circuit to prevent fires. An outlet under curtains could catch on fire so that is why they are required in living spaces.

So VFD spindles and variable speed controllers tend to feed back electricity to neutral and that is what a GFCI is monitoring for and trips.

Requesting an opinion from someone who understands the magical pixie dust that is electricity better than me… but is it possible that by using a (good) uninterruptable power supply you can still use a GFI plug and the Carbide 3D VFD? Or did I just somehow just get lucky, because my entire CNC setup including the dust collection is powered from a single socket in my garage.

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The reason the Drive will cause this tripping of the GFCI is the Common Mode Current or Common Mode Noise (CMNoise) that the VFD is producing. The Common Mode Noise is the current that appears on a conductor with respect to ground. This Common Mode
Noise can and will travel throughout the ground system and even beyond. This Common
Mode Noise can affect the operation of the application, and other equipment on the panel by interfering with signals from sensors, computers, PLC’s, telephone and radio. The VFD does provide ground fault protection on the output of the VFD. Your apllication seems to be grounded well and my thought is that you are diffusing the CMN throughout your set up just enough to not interfere with the GFI.

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When I lived in Kingwood Texas I had a 2 car garage shop. There was a single outlet in the back of the garage. I moved my shop into the garage and the electrical panel was in the garage. I added a 220VAC circuit for my table saw but was busy moving into the house and fixing it up for living.

I went to the garage and turnedon the table saw on its own outlet and fired up the dust collector and the overhead lights and maybe a few more things. I had just finished a cut on the table saw and it was running when bam the garage went dark. The circuit breaker went and the garage was black as a cave but the 220VAC 3HP table saw was still running because it was on a different circuit.

That was a scarry moment but other than being in the dark I was safe. I reached down and turned the table saw off and found my way out and fixed the breakder.

I went to the store and bought an emergency light that goes on when the electricity goes off. Then the next day I added a couple of circuits in the shop so I would not be in the dark any more.

If you are running your whole shop on a single outlet that could happen to you. For me luckily I was not running something through the table saw at the moment the lights went out because that could have been a disaster.


that’s so clean, I just starting pondering last night where the VFD will go in my setup

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