# Ever Heard of a GFCI Tripping Due To Line Side Problem?



## swimmer (Mar 19, 2011)

A DVD dispenser company asked me to look into a problem where the GFCI cord, attached to the DVD dispenser, trips intermittently. The GFCI is integral to the power cord and is part of the DVD dispenser. Here is a link. Note that it is automatic set. 

https://www.hubbell.com/hubbell/en/...ring-Devices/GFCI/Portables/GFP15LA/p/1726153

I am an electrician so I'm looking into facility issues. I am working along side an equipment tech who is looking into equipment issues. So my task is to identify any facility electrical issues that would cause the GFCI to trip. I can't think of any. Though there are dozens of reasons for power loss from the facility, I can't think of any way for the facility wiring to cause the GFCI to trip. Note that the GFCI is protecting only this single piece of equipment. No facility wiring is connected to the load side of the GFCI. I've checked voltage Line to Neutral, Line to Gnd and Nuetral to Gnd. Plug tester lights look good. The tech has already replaced the GFCI power cord and the UPS that it feeds. The wiring looks good. 

So my main questions are: 
1. Has anyone seen a GFCI trip due to LINE side issues.
2. If this is an equipment problem then there will be a 5mA difference between Load Hot and Load Neutral. Is there a meter or technique anyone knows to do this? I don't want to connect 2 meters because there may be differences in their readings.


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## macmikeman (Jan 23, 2007)

Gfi's are designed to save peoples lives. I just tell the customer's that. Lady calls me about her new house recently that I wired. Complaining that the poolside gfi keeps tripping. I asked what she is has plugged into it. Oh, she was given a small refrigerator for free and decided to put it out by the pool so she can keep drinks cold out there. So guess what I told her over the phone? Yep, the gfi just saved her life. 


Have the equipment checked out by the factory that makes it. You could also replace the gfi as a matter of course, but if the machine keeps tripping it , you know what you should do then.........


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## macmikeman (Jan 23, 2007)

My extra two cents: The equipment probably runs fine when connected to a non gfi protected outlet. The gfi is saving somebody's life. EVEN IF IT IS NOT.

It's a legal thing. Don't be the stupid guy who foolishly removes gfi protection and somebody get's nailed later on. They will send Frenchy all the way from the Philippines to get to the bottom of it and he will nail your ass to the cross. Don't do it. Tell management to buy a new machine.


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## brian john (Mar 11, 2007)

https://www.instrumart.com/products...L6bEE5Ue9enSUzGvglQt9tuoWV7gZmKIaApmZEALw_wcB

And to answer your question No.


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## frenchelectrican (Mar 15, 2007)

swimmer said:


> A DVD dispenser company asked me to look into a problem where the GFCI cord, attached to the DVD dispenser, trips intermittently. The GFCI is integral to the power cord and is part of the DVD dispenser. Here is a link. Note that it is automatic set.
> 
> https://www.hubbell.com/hubbell/en/...ring-Devices/GFCI/Portables/GFP15LA/p/1726153
> 
> ...



I dont know if you did ran a megger test to make sure the supply line is not comperised ?

what I heard but it may sound little far feteched but did someone have pretty strong two way radio near by that area ? I have ran into that at least couple time over the years. 

The other option is run the data logger sometime you may catch something on the line side. 

Normally if the conductors are very good shape and passed the megger then it should NOT affect the GFCI operation on line side but load side yuh I can understand it . 

Have that tech guy run couple more test or replace the DVD vending machine and have that bad unit back to factory so they can able take a look to figure it out. 

Did that machine use WIFI or direct internet connection ?


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## CoolWill (Jan 5, 2019)

Plug it into a GFCI receptacle and see if that trips.


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## splatz (May 23, 2015)

brian john said:


> https://www.instrumart.com/products...L6bEE5Ue9enSUzGvglQt9tuoWV7gZmKIaApmZEALw_wcB


Is a process meter for 4-20ma accurate enough that way? 

(I am assuming the thing to do is clamp around line and neutral, the difference shows up to the clamp meter...)


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## brian john (Mar 11, 2007)

splatz said:


> Is a process meter for 4-20ma accurate enough that way?
> 
> (I am assuming the thing to do is clamp around line and neutral, the difference shows up to the clamp meter...)


Not sure, would have to read the specs under 4ma it may work but not be accurate.


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## telsa (May 22, 2015)

It would take insanely filthy Poco power// line side power to trip a GFCI circuit. 

In theory a super fast RC or RLC circuit could put enough distortion on the neutral to trip out its logic. ( I'd bet that the DVD machine is doing exactly this. )

The cheap solution would be to put inductors around the line-side inputs. These toroids can be found ten-a-penny inside your basic PC power supply. These ferrite puppies chop off high frequencies.

This is the ONLY line-side phenomenon that could fake-out the GFCI logic. You should collect some and use them to dope out just such issues. If they make the problem really go-away -- not too likely IMHO -- then you're a genius.

Far, far more likely is that you've got screwed-up gear that needs to go back to the factory. Period.


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## swimmer (Mar 19, 2011)

*Thanks*



brian john said:


> https://www.instrumart.com/products...L6bEE5Ue9enSUzGvglQt9tuoWV7gZmKIaApmZEALw_wcB
> 
> And to answer your question No.


Thanks. That's exactly what I needed to know. The vending machine company is now looking at it from their end.


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## swimmer (Mar 19, 2011)

*Update*

Thanks all for the suggestions. The equipment manufacturer is now looking at it from their side. This is the second such incident in my area, that I know of, and I'm sure there have been many others nation wide. I'd love to get the 5mA current clamp but can't justify the expense at this time. The ferrite toroids sound like something I should keep handy. 

Interesting note about about line side inductors, At one point I had the GFCI cord plugged into an adjustable auto transformer. I did this because the high voltage light on the UPS was lit. I measured 124V. The GFCI never tripped the entire time the transformer was connected which was about 30 minutes. Previously it tripped within 5 minutes. I disconnected the transformer and the trip time went back to 5 minutes or less. Reconnected the transformer and had a trip within 5 minutes. It might mean something or I may have been getting the old and familiar intermittent run-around.


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## telsa (May 22, 2015)

Transformers are inductors -- and will clip high frequencies.

So...

Think about it.


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## Naman Verma (Mar 22, 2018)

Hey There
According to me the fault can be the poor earthing of the equipment or it can the earth wire which is getting in contact with the live wire as the GFCI is very sensitive.....
All The Best


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## macmikeman (Jan 23, 2007)

Where in the hell is Chandigarh, and are the citizens short green people?


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## Naman Verma (Mar 22, 2018)

Well Go To Hell My Friend 
You Should Never ever underestimate Someone


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## CoolWill (Jan 5, 2019)

Naman Verma said:


> Well Go To Hell My Friend
> You Should Never ever underestimate Someone


That's no way to talk to a friend.


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## HackWork (Oct 2, 2009)

According to me Hax is the greatest electrician ever known.


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## MTW (Aug 28, 2013)

HackWork said:


> According to me Hax is the greatest electrician ever known.


:no::no:


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## HackWork (Oct 2, 2009)

MTW said:


> :no::no:


Damn you.


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## Southeast Power (Jan 18, 2009)

I have noticed some GFCIs will open when power is off and have to be manually reset. More so in the type mounted on a cord. Some hair dryers do that. 
Just a thought.


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## glen1971 (Oct 10, 2012)

macmikeman said:


> Where in the hell is Chandigarh, and are the citizens short green people?


Apparently Naman didn't want to take the time to elaborate on where they're from...

https://en.wikipedia.org/wiki/Chandigarh


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## Wardenclyffe (Jan 11, 2019)

HackWork said:


> According to me Hax is the greatest electrician ever known.


Open up Shop,...


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## Jarp Habib (May 18, 2014)

Southeast Power said:


> I have noticed some GFCIs will open when power is off and have to be manually reset. More so in the type mounted on a cord. Some hair dryers do that.
> Just a thought.


It's an intentional design characteristic of portable GFCI cords which are most likely to be used in construction. If the power blips out, it prevents the tool user from being caught unawares when the power returns, they have to put down their tool and go reset the cord.


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