Brand New Nova Comet II Tripping GFCI

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indytruks138

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I bought a brand new Nova Comet II midi lathe and have been trying to break in the motor, but the lathe is tripping the GFCI in the garage anytime I turn up the speed and even at low speed it trips after 2-3 minutes. I can run Festool tools, a mini bandsaw, refrigerators, sanders, shop vacs, and all other sorts of tools without tripping the GFCI. Is this an issue with the lathe or is it pulling so much more power I need to get stronger outlets installed?
 
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pturley

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I've read several reports of the Comet II headstock getting very hot during break in. the build clearances are obviously very tight in this assembly!
This means friction and higher loads on the motor. Could be your's is too tight of assembly fits and is likely to get VERY hot during break in when you finally do get it going.
Lower speed actually means more AMP draw from the motor.

A lot of times, a number of additional outlets are ran in series from a GFCI downstream, providing protection without buying several GFCI outlets. If there are any other outlets going out when the GFCI trips, this is the case. Unplug everything else to reduce the amp load on the GFCI then try again.

Your GFCI outlet could be going bad as well.

Sincerely,
Paul Turley
 

indytruks138

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I've read several reports of the Comet II headstock getting very hot during break in. the build clearances are obviously very tight in this assembly!
This means friction and higher loads on the motor. Could be your's is too tight of assembly fits and is likely to get VERY hot during break in when you finally do get it going.
Lower speed actually means more AMP draw from the motor.

A lot of times, a number of additional outlets are ran in series from a GFCI downstream, providing protection without buying several GFCI outlets. If there are any other outlets going out when the GFCI trips, this is the case. Unplug everything else to reduce the amp load on the GFCI then try again.

Your GFCI outlet could be going bad as well.

Sincerely,
Paul Turley

Thank you for the response Paul, my house is a newly built home and it seems all outlets in the garage run to one actual GFCI outlet. Maybe I can take my lathe next door to my neighbor who has installed 20 amp GFCI in his garage to run the 45 minute break in, then hopefully the engine will be loose enough that it won't trip my outlets? Does that sound reasonable?
 

Charlie_W

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A documented issue with some lathes is that the harmonics from the variable speed control will trip GFCI outlets/breakers. Have you tried plugging your lathe into a non GFCI receptacle/circuit? Just run a cord from a circuit in the house to the lathe and give it a try. (Make sure the circuit is not GFCI protected.)

There was an issue with some of the Delta Midi lathes some years ago doing this. Currently, a friend has a Jet 1640 which is 120V and tripped the required GFCI in his shop. He ran a cord from a ceiling receptacle for his filter and the lathe runs fine all day long.

One solution I have read is to purchase a "Hospital Grade" GFCI receptacle. You can find them online or at an electrical supply house. They may not be at the big box stores. Apparently, these tolerant the harmonics from the lathe speed controller.

If the lathe bearings were tight, the headstock casting around the bearings would get hot. It should easily run with no load right out of the box without tripping. Note it is the GFCI that is tripping...not your electrical panel breaker...so I don't think it is a heavy load issue. Besides, the lathe doesn't pull many amps.

Hope this helps.
 

indytruks138

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Ok well both responses lead me to believe for now that I don't need to install a new outlet yet, but should try running it first without a GFCI plug (which will have to be from inside like suggested) and then maybe after break in I can try it back on the GFCI, and if that doesn't work I will try switching out the GFCI for a hospital grade GFCI. IF that doesn't work see if I can get a non-GFCI outlet. I just hate having this lathe and not being able to turn. Luckily I am a member of Dallas Makerspace so I can still turn there, just not the same as coming home from work and busting out a pen.
Thanks for the comments so far.
 

CaptainJane

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If you are using an extension cord, you need a heavier duty cord. Like others said, too many things on 1 circuit. I had to map which outlets fed which GFCI! And then plan. Your grinder, planer, or band saw don't run at same time as lathe, but your dust collector and lights do. Good luck..
 

Jolly Red

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If the other plugs "downstream" from that GFCI are regular plugs, you could switch the next plug with the GFCI and not have to worry about it. Don't know if this is acceptable to your electric code, so be sure to check that out.
 

cjester

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I'm with Charlie on this one. Variable speed and GFCI don't always play nicely together. My variable speed lathe trips GFCIs. My stand mixer in the kitchen does as well.
 

indytruks138

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Well I just ran the motor break in on an inside non-ggci outlet for an hour with no issue. Plug it back in to the gfci in the garage and it trips. So should I try the hospital grade gfci or hire an electrician to install a non-gfci outlet?
 

Charlie_W

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Well I just ran the motor break in on an inside non-ggci outlet for an hour with no issue. Plug it back in to the gfci in the garage and it trips. So should I try the hospital grade gfci or hire an electrician to install a non-gfci outlet?

The best answer to your question is...."It Dpends".

If the GFCI receptacle in the garage was the existing one with the house, most likely there are other regular receptacles being protected downline. If this is the case, all the other receptacles need to be protected( bathroom, outside, etc and the GFCI would need to be placed at the very next receptacle in the circuit.

In our house, the garage, one basement receptacle( unfinished basement), all 3 bathrooms, and two outdoor receptacles were all controlled by one GFCI on a 15A Circuit. Hair dryers, curling irons and outdoor Christmas lights easily overloaded the circuit tripping the breaker some houses had the GFCI locates in either the garage or master bathroom depending on the location of the electrical panel and which route used less cable.

Perhaps a better option long term is to have the electrician run new a circuit/s to the garage leaving the existing one alone. Your new circuit/s could be 20A for heavier tools. Your choice in the hospital grade GFCI receptacle for a new circuit or having a dedicated non GFCI receptacle.
However, one should always have everything electrical done to code whenever possible. Your homeowners insurance probably would not want to pay out for a fire resulting from a non code modification.

All this said, since you are not doing your own electrical work, talk to your electrician. If in doubt, call your local electrical inspector.
Any new work will require a permit and inspection.
 

JRK

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This is my understanding of GFCI breakers/outlets. They compare the voltage going out on the hot wire (black) with what is coming back on the neutral wire (white). If it detects a difference, it trips.

I am not an electrician, so that this for what it is worth. I think GFCI outlets are required by code in garages, outdoors, bathrooms, kitchens. So running a non GFCI outlet in the garage may violate electrical code.

Sometime GFCI outlets go bad and trip for no reason. I've had some that worked for a few days then went bad. Since you can run other tools with not problem, my suspicion is something about the lathe is causing your problem.

Just my .02

Jerry
 

donstephan

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GFCI protection in a garage is required by code to my knowledge - a concrete floor is on dirt and may have absorbed moisture from the ground underneath. It would seem the manufacturer would want their lathe to work in a garage on a concrete floor, so as suggested check with the manufacturer.
 

monophoto

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This is my understanding of GFCI breakers/outlets. They compare the voltage going out on the hot wire (black) with what is coming back on the neutral wire (white). If it detects a difference, it trips.

I am not an electrician, so that this for what it is worth. I think GFCI outlets are required by code in garages, outdoors, bathrooms, kitchens. So running a non GFCI outlet in the garage may violate electrical code.

Sometime GFCI outlets go bad and trip for no reason. I've had some that worked for a few days then went bad. Since you can run other tools with not problem, my suspicion is something about the lathe is causing your problem.


Jerry


That's a pretty comprehensive summary - - -


I see four potential causes for the problem:
1. There is a fault in the lathe drive such that there is leakage current returning through a path other than the neutral wire. That path could be the ground wire (uninsulated, or perhaps with green insulation) or through the frame of the lathe and into the floor. This would probably be a warranty issue on the lathe.

2. The GFCI is defective, and needs to be replaced.

3. Where is the GFCI? One of the fairly obscure issues with GFCI's is that wiring always has a small 'parasitic' leakage capacitance that results in naturally-occuring leakage current. As a result, if there is too much cable on the load side of the GFCI, the natural leakage current can approach the GFCI tripping threshold. Adding one additional device with a small incremental amount of leakage will then push things over the threshold and cause tripping even through the only thing that is 'wrong' is that there is a lot of wiring on the load side of the GFCI. When GFCI's were first introduced, manufacturers published maximum allowable circuit lengths, but that practice has faded into obscurity. If this is the problem, the solution is simple - run a new circuit from the house to the garage, and install a dedicated GFCI receptacle for the lathe.

4. As Charlie noted, GCFI's are susceptible to harmonics. In fact, some GFCI's actually induce a small harmonic voltage between the neutral (white wire) and ground (bare wire), and if the neutral (white wire) is inadvertently connected to ground, a harmonic current will flow. Since the neutral is not supposed to be grounded anywhere other than at the source (or the service panel), then the GFCI can detect that incorrect (or inadvertent) connection. However, if there is a load such as a variable speed drive that naturally injects harmonic currents back into the grid (the reason that happens is too complicated to explain here), then the GFCI will mistakenly confuse those harmonic currents for the currents that would flow if the neutral is grounded, and therefore trip. Using a different GFCI might solve this problem.
 

indytruks138

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Welp, I called Teknatool and spoke to their electrician. He was very nice but unfortunately did not have a solution. He advised using a surge protector but did not think that would solve this problem. He took down my name and number as he knows one person did find a GFI that worked with the lathe but he was going to have to search for it. He said he had heard of this problem before but wasn't really sure why it was happening. I told him the manual even recommends using a GFI which surprised him.
I think it is quite a bad practice to sell a product that trips GFI as a somewhat known issue and then recommend using a GFI in your manual. The lathe works great on a non-GFI, but I don't know that I can recommend this lathe to anyone else with this known issue.
 

Terredax

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Looking at the manual real quick, it requires a 15 amp circuit. I couldn't find the start-up amp draw, but in all of my cases, if it requires a 15 amp circuit, it usually has a 12 amp start-up draw. So, if there is anything else on that circuit, it will trip.
If you have a breaker panel in the garage, it's easy enough to run a dedicated circuit for the lathe. All it requires is a 20 amp breaker, 12/2 wgr romex, and a 20 amp GFCI.
If you are not comfortable connecting power, hire an electrician.
I run 20 amp on all circuits for 120v machines.
 

Charlie_W

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The manual also says the average motor output is 550 watts. If this is the motor draw in the circuit, at 120 volts, that would be 4.6 amps. The 15 amp circuit should be more than adequate.
About 18 months ago, we did an onsite turning project for two dozen scouts. We had 8 mini/midi lathes and a grinder on three circuits. We calculated the amps per lathe and mapped out the circuits and divided them up accordingly.....All was fine...never tripped a breaker. We had 24 scout's with ice cream scoops by the end of the day.
 

indytruks138

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The electrician at Teknatool said that lathe should only draw 8 amps I believe. And the machine will turn on without tripping, but depending on the speed of the lathe it will trip the GFI somewhere between 15 second and 2 minutes later.
I believe running a non-GFI plug is my best option at this point, just not sure if that is up to code in a garage in my city. I don't feel qualified to do it myself, but I don't mind paying an electrician. I'm afraid if I pay to install the 20 amp GFI the same thing would happen.
 

ed4copies

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Call a licensed electrician for an opinion. He will know code in your area.


Here, in Wis, I had to run conduit in the garage. I did the work, the electrician came in to hook it all up and check for code compliance--very reasonable cost and completely code compliant.
 

Terredax

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After reading on the subject, GFCI is a problem for VFD.
It's a known problem for many manufacturers. Most people don't run on GFCI, and some use the hospital grade GFCI.

Also, reading the NEC, a dedicated circuit for an appliance in a garage, doesn't require GFCI, or any circuit located in the ceiling. Contact a local electrician, and see how that affects your situation.
 

rholiday

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I'm running a Nova Comet II lathe on a 20 amp circuit in my garage.
That circuit is protected by a 20 amp GFCI outlet. The lathe is plugged into an outlet downstream from the actual GFCI outlet, (which is immaterial since the lathe is still protected by that GFCI outlet). The GFCI has not tripped. It is a standard GFCI outlet. Wiring was installed by licensed electricians.

Do not put a 20 amp GFCI outlet on a 15 amp circuit. I don't believe this would be code compliant.

The current NEC states that all outlets in the garage, including dedicated ones and the outlet for the garage door opener must be protected by GFCI. I believe the NEC changed in 2008 in this regard. The newer versions of the NEC are not always adopted immediately by all municipalities. Also, local municipalities can revise some aspects of the NEC. The code office or officer of the municipality, or a licensed electrician for that area will be able to tell you what 'code' is for your area. Also, a licensed electrician will not install a non GFCI outlet in an area the requires a GFCI outlet.

For the GFCI protected outlet for the garage door opener, some electricians are putting a 'dead front GFCI' by the light switches for the garage and letting that GFCI device protect a standard outlet in the ceiling. A dead front GFCI is a device that has the test and reset buttons and the GFCI circuitry but no place to actually plug in a cord.

And to round this out -- I am not an electrician so please contact a licensed electrician that is familiar with your local codes.

Bob
 

indytruks138

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Can I buy the hospital grade gfci outlet and just swap the main gfci in the garage? The plug I am using for the lathe is down line but still protected by the main gfci. Is it as easy as just swapping the outlet? Anything special about it? I see 15A hospital grade gfci outlets on amazon.
 

Charlie_W

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Can I buy the hospital grade gfci outlet and just swap the main gfci in the garage? The plug I am using for the lathe is down line but still protected by the main gfci. Is it as easy as just swapping the outlet? Anything special about it? I see 15A hospital grade gfci outlets on amazon.

I would say the answer is yes....and no.
If you are electrically handy, comfortable with wiring, and have changed out switches and outlets, etc, it should be a easy. If not, hire an electrician.
It is imperative that the line and load are connected correctly for the GFCI to function properly....and do not let the neutral and ground touch when installed in the box.
If you purchase the new receptacle and have the electrician install it....and something is bad with the receptacle itself, it is your problem $$.
If you have an electrician install, have them provide the device. If there is a problem, it is their problem.
 
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Terredax

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Do not put a 20 amp GFCI outlet on a 15 amp circuit. I don't believe this would be code compliant.
Bob


It doesn't meet code. 15 amp circuits utilize 14/2 romex, and 20 amp requires 12/2 romex. Of course, a matching 20 amp breaker would be necessary.

If the receptacle is a single outlet, a dedicated circuit, or a circuit on the ceiling that can't be touched while standing on the ground (grounded surface), it isn't required to be GFCI. The NEC states this is utilized for lighting, refrigerators and freezers. These are known to trip GFCI's. This is according to an electrician friend.

Of course, consult an electrician in your municipality.
 

JRK

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I am not an electrician, I do have a friend who is and I ask his advice on all things electrical.

The amperage of the breaker (not the outlet) determines the thickness of the wire that must be used. A 15amp breaker requires 14 gauge wire, a 20amp break requires 12 gauge wire. Wire gauges decrease with thickness, so a 12 gauge wire is thicker than a 14 gauge wire.

Using a 14 gauge wire with a 20amp breaker is a recipe for a electrical fire.

I am not sure if the amperage rating of the outlet really matters. I would probably match it to the breaker to be safe.

Jerry
 

indytruks138

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I'd be installing a new 15A hospital grade outlet on 14 gauge wire and a 15A breaker. I'm just planning to replace the 15A standard GFI with a 15A hospital grade GFI.
 

JRK

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I'd be installing a new 15A hospital grade outlet on 14 gauge wire and a 15A breaker. I'm just planning to replace the 15A standard GFI with a 15A hospital grade GFI.

Sounds like a good plan. I was not aware of hospital grade GFCI until I read this thread.

I hope it solves your problem.

Jerry
 

indytruks138

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I'm overjoyed to say that my lathe is running like a champ on my newly installed hospital grade gfci. No trips after hours of turning. I switched it myself which is painfully easy. Thank you a million times over to everyone who responded and gave suggestions. I'm so happy a $25 gig upgrade solved this problem. I will call the electrician at Teknatool and let him know so hopefully this will help others in the futute.
 
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