ElectricMotorcycleForum.com

Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: keeto on November 29, 2018, 08:52:20 AM

Title: Brand new 2019 Zero S, charging issue
Post by: keeto on November 29, 2018, 08:52:20 AM
Hi everyone.  I'm a new forum member (first post) and a new Zero owner.

Bought a Zero today.  It's a brand new 2019 Zero S, with the 14.4 battery.  Rode it home (47 miles) and plugged it in, but it tripped the GFCI a second or two after it started charging.  The outlet was old and probably only rated for 12 amps, so I ran out to the hardware store and picked up a new 20 amp GFCI outlet.  Installed it after double checking to make sure the wire polarity was correct.  Plugged in, and sure enough the GFCI tripped on the new outlet too.  BTW there is nothing else on this circuit at all... only the single dedicated GFCI outlet protected by a 20 amp circuit breaker.

For kicks I plugged my wet vac into the outlet, turned it on, and covered the suction hose end to put a little load on the motor.  No issues with the GFCI.

So I did a little searching on this forum and it seems this is a fairly common issue with the built in charger.  Recommendations seem to be to get a cheater plug, break off the ground prong from the charging plug, or charge from a non-gfci outlet.  I'll have to pick up a cheater plug I guess, but I'm not really happy to be forced to circumvent the GFCI protection.

So what do you all think... is it likely that the built in charger on my new Zero has an actual problem?  Or is this just par for the course and nothing to be worried about?  I don't quite understand why the charger would be tripping the GFCI unless there actually WAS a fault somewhere.  Maybe there's an induced current in the grounded charger case or something?

-k
 
Title: Re: Brand new 2019 Zero S, charging issue
Post by: jnef on November 29, 2018, 09:06:00 AM
While that is a common problem and solution, you should take it back to get it repaired.  Use that trick just as a temporary workaround and be careful.  Mine, and I believe most, will not trip a GFCI. By breaking off the ground pin, you are correct that the GFCI is partially bypassed. Hopefully it would trip if you touched the chassis and completed a ground path...

Or even better — upgrade the onboard charger with a SCv2.5.  :)
Title: Re: Brand new 2019 Zero S, charging issue
Post by: Richard230 on November 29, 2018, 08:46:25 PM
You should definitely have it checked out by your dealer and fixed under Zero's warranty.  For what it is worth, I don't have a GFCI on any of my electrical outlets and my 2018 Zero charges normally.  I have never tried to charge my Zero from a GFCI outlet as no one that I know has one on their garage electrical outlets, either. However, I would imagine that your dealer's electrical outlets are protected with a GFCI, especially in their service center.  So you could try charging there to see what happens.

Another thing you could do is to pick up a cheap unprotected outlet at your local hardware store and give that a try to see if the problem is the charger or the charger's response to a GFCI.
Title: Re: Brand new 2019 Zero S, charging issue
Post by: NEW2elec on November 29, 2018, 09:51:16 PM
I have GFCI outlet and it has worked fine for my 13 and 17 Zero's.
Maybe check your outlet voltage with a volt meter to make sure it isn't low.
Have you tried to charge it from an extension cord (12 AWG) and a regular outlet?
Title: Re: Brand new 2019 Zero S, charging issue
Post by: keeto on November 30, 2018, 01:57:22 AM
The voltage at the outlet is 120.1 vac.  I can charge the bike from a non-gfci outlet, and it charges fine when using a cheater plug in the gfci outlet to break the ground.  It can't charge from any of the 3 gfci outlets I've tried though.  Clearly it has an actual ground fault.  It's going back to the dealer today so it can be fixed.  Unfortunately, they don't have any gfci outlets at the dealer itself, so I'm curious how they're going to test it.   >:(

-k
Title: Re: Brand new 2019 Zero S, charging issue
Post by: DonTom on November 30, 2018, 02:57:59 AM
The voltage at the outlet is 120.1 vac.  I can charge the bike from a non-gfci outlet, and it charges fine when using a cheater plug in the gfci outlet to break the ground.  It can't charge from any of the 3 gfci outlets I've tried though.  Clearly it has an actual ground fault.  It's going back to the dealer today so it can be fixed.  Unfortunately, they don't have any gfci outlets at the dealer itself, so I'm curious how they're going to test it.   >:(

-k
There is a very simple fix for that issue.


If they don't have a ground fault outlet, bring them one of these. (https://www.amazon.com/25-Foot-Circuit-Interrupter-Extension-Printed/dp/B008Y01NXQ) You may want to try it first on your bike to make sure it trips plugged into  a non-GFCI in your house. This extension cord is to go from a non-GFCI  to GFCI protection and should trip the same way.

GFCI simply works by detecting a difference in current going in the line from the current going out of the line.  Since they should always be EXACTLY the same, the slightest difference proves a short to ground and trips the GFCI. So GFCI can be added to any non-GFCI outlet.

Cheaper ways are to use one of with these without paying for the extension cord:

 Either two (https://www.amazon.com/Tower-Manufacturing-30340001-AMP-2-Prong-Single-Outlet/dp/B002KSKJFG/ref=sr_1_5?s=industrial&ie=UTF8&qid=1543529991&sr=1-5&keywords=two+prong+GFCI) or three prong. (https://www.amazon.com/Tower-Manufacturing-30439005-Auto-Reset-15-AMP-Grounded/dp/B00UOU6OVU/ref=pd_cp_60_1?pf_rd_m=ATVPDKIKX0DER&pf_rd_p=ef4dc990-a9ca-4945-ae0b-f8d549198ed6&pf_rd_r=GG5H87PG8QQTD7D0QMM2&pd_rd_wg=UtS7W&pf_rd_s=desktop-dp-sims&pf_rd_t=40701&pd_rd_w=CcSJU&pf_rd_i=desktop-dp-sims&pd_rd_r=3d0fe987-f41a-11e8-925d-3fca922f2bc9&pd_rd_i=B00UOU6OVU&psc=1&refRID=GG5H87PG8QQTD7D0QMM2l)

The extension cord is rated at 20 amps, but the other two cheaper ones are rated at 15 amps. But even these should still be okay for running the on board charger, which is around 13 amps max, IIRC.

-Don-  Auburn, CA

Title: Re: Brand new 2019 Zero S, charging issue
Post by: DonTom on November 30, 2018, 05:42:40 AM
So what do you all think... is it likely that the built in charger on my new Zero has an actual problem?  Or is this just par for the course and nothing to be worried about?  I don't quite understand why the charger would be tripping the GFCI unless there actually WAS a fault somewhere.  Maybe there's an induced current in the grounded charger case or something?k
My guess will be that the ground fault circuitry is overly sensitive to electrical noise. The bike itself probably picks up a lot of electrical noise. IMO, it's probably not a problem with the bike at all. My bike has also tripped GFI and I really didn't think much about it--just kinda inconvenient when we are trying to charge. But an easy fix to isolate the ground of the bike.

But to test for a serious problem, get an ohmmeter. Go direct to your bike's AC inlet. Put one lead on the ground and check the resistance to the other two prongs. It should be infinite (no readings). There could be a drop of capacitance in there that also can trip an over sensitive GF circuit. And IMO, many of them are a bit too sensitive.

IMO, the real problem with these GF tripping is the GFI are a bit too sensitive these days. They can trip on electrical noise and our bikes probably put out a lot of such noise  especially while they are charging.

-Don-  Auburn, CA
Title: Re: Brand new 2019 Zero S, charging issue
Post by: keeto on November 30, 2018, 07:02:49 AM
There is a very simple fix for that issue.


If they don't have a ground fault outlet, bring them one of these. (https://www.amazon.com/25-Foot-Circuit-Interrupter-Extension-Printed/dp/B008Y01NXQ) You may want to try it first on your bike to make sure it trips plugged into  a non-GFCI in your house. This extension cord is to go from a non-GFCI  to GFCI protection and should trip the same way.

GFCI simply works by detecting a difference in current going in the line from the current going out of the line.  Since they should always be EXACTLY the same, the slightest difference proves a short to ground and trips the GFCI. So GFCI can be added to any non-GFCI outlet.

Cheaper ways are to use one of with these without paying for the extension cord:

 Either two (https://www.amazon.com/Tower-Manufacturing-30340001-AMP-2-Prong-Single-Outlet/dp/B002KSKJFG/ref=sr_1_5?s=industrial&ie=UTF8&qid=1543529991&sr=1-5&keywords=two+prong+GFCI) or three prong. (https://www.amazon.com/Tower-Manufacturing-30439005-Auto-Reset-15-AMP-Grounded/dp/B00UOU6OVU/ref=pd_cp_60_1?pf_rd_m=ATVPDKIKX0DER&pf_rd_p=ef4dc990-a9ca-4945-ae0b-f8d549198ed6&pf_rd_r=GG5H87PG8QQTD7D0QMM2&pd_rd_wg=UtS7W&pf_rd_s=desktop-dp-sims&pf_rd_t=40701&pd_rd_w=CcSJU&pf_rd_i=desktop-dp-sims&pd_rd_r=3d0fe987-f41a-11e8-925d-3fca922f2bc9&pd_rd_i=B00UOU6OVU&psc=1&refRID=GG5H87PG8QQTD7D0QMM2l)

The extension cord is rated at 20 amps, but the other two cheaper ones are rated at 15 amps. But even these should still be okay for running the on board charger, which is around 13 amps max, IIRC.

-Don-  Auburn, CA

The bike charges from a GFCI outlet as long as I break the ground wire connection (I used a cheater plug rather than breaking off the ground prong).  So I don't think the two prong you've got listed above would help, though the 3 prongs would as long as the ground prong on the source outlet was actually grounded.  It makes total sense... the bike is fairly well isolated from the physical pavement underneath it by the rubber tires.  The kickstand could theoretically be a path for current I guess, but again, it's sitting on pavement so there's practically no way for the bike to leak current into the actual earth.  The current leakage has to be through the ground wire of the charging cord.

I spoke with Zero technical support, and they said it's not supposed to trip a GFCI.  They said to take it back to the dealer for a diagnosis and repair, so that's what I did.  Now I've gotta twiddle my thumbs until I get the bike back.  No loaner possible, unfortunately.  It's a bit frustrating to pay for it and then not be able to ride it... but these things happen and I'll do my best to be patient.   ::)

-k
Title: Re: Brand new 2019 Zero S, charging issue
Post by: heroto on November 30, 2018, 08:52:20 AM
Post edited. Sorry I failed to understand the complexity of the problem, my original post was dumb.

Still, checking current flow with a kill a watt current meter might provide some useful info, and it's cheap. How much current is the moto really drawing?  Bad charge cable arcing?


https://www.amazon.com/P3-P4400-Electricity-Usage-Monitor/dp/B00009MDBU/ref=asc_df_B00009MDBU/?tag=hyprod-20&linkCode=df0&hvadid=167125429392&hvpos=1o1&hvnetw=g&hvrand=3218669496347224830&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9008422&hvtargid=pla-306572288073&psc=1

Edit:
Title: Re: Brand new 2019 Zero S, charging issue
Post by: DonTom on November 30, 2018, 09:49:43 AM
kill a watt current meter on amazon. All questions will be answered, and it's cheap.
How is that going to show a ground fault?

-Don-  Auburn, CA
Title: Re: Brand new 2019 Zero S, charging issue
Post by: keeto on November 30, 2018, 10:09:36 AM
How is that going to show a ground fault?

-Don-  Auburn, CA

My question as well.   :D

I probably should have gotten an amp reading from the ground wire before dropping the bike off at the dealer.

-k
Title: Re: Brand new 2019 Zero S, charging issue
Post by: DonTom on November 30, 2018, 10:13:29 AM
The bike charges from a GFCI outlet as long as I break the ground wire connection (I used a cheater plug rather than breaking off the ground prong).  So I don't think the two prong you've got listed above would help,
It would help if you wanted to still have GF protection without tripping the GFI in the outlet that you plug this into. A cheap way to get your GF protection without tripping the other one.
though the 3 prongs would as long as the ground prong on the source outlet was actually grounded.  It makes total sense... the bike is fairly well isolated from the physical pavement underneath it by the rubber tires.  The kickstand could theoretically be a path for current I guess, but again, it's sitting on pavement so there's practically no way for the bike to leak current into the actual earth.  The current leakage has to be through the ground wire of the charging cord.
Yep! If there really is a current leakage, but I have my doubts on that.

I spoke with Zero technical support, and they said it's not supposed to trip a GFCI.  They said to take it back to the dealer for a diagnosis and repair, so that's what I did.  Now I've gotta twiddle my thumbs until I get the bike back.  No loaner possible, unfortunately.  It's a bit frustrating to pay for it and then not be able to ride it... but these things happen and I'll do my best to be patient.   ::)
I bet they find nothing wrong and it still trips. I expect you will have a long wait to get your bike back.

I assume it has more to do with the design of our bikes and the electrical noise our on-board chargers put out than an actual fault to ground. But I hope to be proven wrong on this issue so there will be a fix that actually works that won't require a redesign of our on-board chargers.

 I hope they do find something as this is a common problem with our Zeros tripping GFs.  Some are a lot more sensitive than others where they trip. And I think the new GF outlets are the most sensitive to electrical noise and such than are the older ones.


-Don-  Auburn, CA
Title: Re: Brand new 2019 Zero S, charging issue
Post by: DonTom on November 30, 2018, 10:24:13 AM
My question as well.   :D

I probably should have gotten an amp reading from the ground wire before dropping the bike off at the dealer.

-k
Yep, but I expect all you will find is a little ripple. Ever look at the on board supply wattage? It jumps all over the place, unlike the Zero quick chargers that don't do that at all.

I can almost bet the jumpy readings we get on our onboard chargers have something to do with the ground faults tripping-- and not from leakage to ground.  IOW, I think it's more of a design problem. But I hope I am wrong and if they find a fix, please let me know.

FWIW, I do not have a lot of faith in most Zero dealers.  Like I said, my bikes have also tripped ground faults. I wouldn't be surprised to find out all of our Zeros will trip SOME GFIs but not others. The GFI outlets  do not all have the same sensitivity and I mean to electrical noise more than an actual ground fault.

-Don-  Auburn, CA
Title: Re: Brand new 2019 Zero S, charging issue
Post by: keeto on November 30, 2018, 07:41:31 PM
Don- my 5.5 hp (which clearly isn't drawing that much power otherwise it'd trip the 20 amp breaker) wet vac doesn't trip this GFCI outlet.  Neither does a big blender, nor a coffee grinder.  I don't have anything else that I can think of that would be electrically "noisy" to throw at it, but I'm satisfied that the outlet isn't to blame.  This outlet only trips when there's a ground fault.  Personally, I think the acceptable level of current flowing down the ground wire is 0.000 amps.  It's tripping from the Zero due to some current flowing down the ground wire, and it happens every single time I plug the bike in and almost always within the first 5 seconds once the actual charging starts.  Whether it's just a weak induced current, or something more dangerous, I dunno.  I could have and should have taken a few more readings before dropping it off.  In any event, it's at the dealer and since I bought the bike literally 2 days ago it had best not be too long of a wait to get it back... neither Zero nor the dealer will like the result if that happens.

-k
Title: Re: Brand new 2019 Zero S, charging issue
Post by: JaimeC on November 30, 2018, 11:34:39 PM
Until I saw these posts, I was completely oblivious to the fact that the dedicated line I had run from the house to my garage back in 2016 SPECIFICALLY for my Zero was, indeed, a GFCI outlet.  I've been using it successfully with both my 2016 S, and now with my new 2018 S without any issues.

Of course, now I've PROBABLY jinxed myself...
Title: Re: Brand new 2019 Zero S, charging issue
Post by: DonTom on December 01, 2018, 12:13:53 AM
Don- my 5.5 hp (which clearly isn't drawing that much power otherwise it'd trip the 20 amp breaker) wet vac doesn't trip this GFCI outlet.  Neither does a big blender, nor a coffee grinder.  I don't have anything else that I can think of that would be electrically "noisy" to throw at it, but I'm satisfied that the outlet isn't to blame.  This outlet only trips when there's a ground fault.  Personally, I think the acceptable level of current flowing down the ground wire is 0.000 amps.  It's tripping from the Zero due to some current flowing down the ground wire, and it happens every single time I plug the bike in and almost always within the first 5 seconds once the actual charging starts.  Whether it's just a weak induced current, or something more dangerous, I dunno.  I could have and should have taken a few more readings before dropping it off.  In any event, it's at the dealer and since I bought the bike literally 2 days ago it had best not be too long of a wait to get it back... neither Zero nor the dealer will like the result if that happens.-k
All those other items you're trying might not have the same characteristics (frequency of the noise, etc) as your Zero.

So many of our Zeros have tripped GFI (It's even mentioned here (https://zeromanual.com/wiki/Common_Problems#GFCI_Faults) in the Unofficial Service Manual) that I doubt they all have an AC leakage  problem to ground. It's most likely something in the basic design of our bikes that causes some of our GFI's to trip.

FWIW, my GFI  does NOT trip at this house  when on my SR. But it trips EVERY time (within a few minutes) when I use the 120 VAC GFI outlet at the Colfax train station.  Same bike, same extension cord, dry weather, etc.

-Don-  Auburn, CA

Title: Re: Brand new 2019 Zero S, charging issue
Post by: Electric Cowboy on December 01, 2018, 08:43:43 AM
Tripping a GFCI is a problem. If you do anything other than fix or replace your charger, you are asking for trouble.

Saftey 3rd is a joke for the race track, not the home. I just want to make this clear. Fix or replace the charger, don't work around safety, working around safety translates to danger.

Now you know. The decision is yours.
Title: Re: Brand new 2019 Zero S, charging issue
Post by: DonTom on December 01, 2018, 10:50:58 AM
Tripping a GFCI is a problem. If you do anything other than fix or replace your charger, you are asking for trouble.

Saftey 3rd is a joke for the race track, not the home. I just want to make this clear. Fix or replace the charger, don't work around safety, working around safety translates to danger.

Now you know. The decision is yours.
I really see no realistic safety issue. One would have to try very hard to get shocked from  a charging Zero, even  without GFCI.  The frame is grounded to the AC plug (when not bypassed) so that makes the frame safe to any other ground when the stock 3 prong plug is used.

Now with GFCI and bike's ground bypassed, what happens?   . . .

If one comes in contact between  the hot terminal of the AC plug and any ground,  the GFCI will trip. If the bike is involved here or NOT. The GFCI is in the OUTLET, not in the bike.

IOW,  the GFCI will STILL WORK NORMALLY. The GFCI is in the OUTLET, not the bike, and the GFCI in the outlet  is NOT bypassed in ANY way. Even if the bike is not grounded. GFCI does NOT even require a ground to work normally. Unless  when we are the ground path to the hot wire, which causes it to trip, as it should.

Get between hot and ground of a working GFCI outlet and it  will trip no matter what you do at your bike, frame of bike grounded or not.

So where is the real safety issue here, since bypassing the frame of the bike has NO effect on the outlet's ground fault protection?

The GFCI  nuisance tripping is simply that, a nuisance.  Since ungrounding the bike has no effect on the GFCI at the outlet, the GFCI will still work normally, even if you somehow try your very best  to get zapped at the bike. For us to try to  get the shock, with the bike involved or not,  it will cause the differential voltage to trip the GFCI at the outlet.

The bike has no GFCI. It's all done in the outlet. And as long as we do not modify the outlet itself, the GFCI will still work as it should, no matter what we do to our bikes.

I think the very best argument one can make on the opposite side is that having both, the bike grounded via the outlet and the GFCI outlet is a type of double protection. IOW, if the GFCI is broken and will not trip (which can and does sometimes happen) the bike frame is at least still grounded. 

-Don-  Auburn, CA
Title: Re: Brand new 2019 Zero S, charging issue
Post by: Electric Cowboy on December 02, 2018, 03:37:26 AM
@Don I respectfully disagree with your saftey reccomendations to the OP Keeto whos skillset we do not know.

If he is having trouble with the calex he should replace it. It is the #1 replaced part on a Zero and the only part that I think is not very good on a Zero.

If your #1 part being replaced by the manufacturer is truipping GFCI you need to replace it as that charger is going to fail on you at the most inopportune time.

Brian T Rice did a post mortum on his own DEAD calex while I was bolting up one of the very original Super Charger v2.5 onto his bike. Brian is a no nonsense guy and bases what he says on facts and datum more than most people. You know what his result was? The calex caught on fire inside its potting and went out before exiting the charger case...

If the charger is having an issue, take it to the dealer and get it replaced ASAP. Don't risk it.
Title: Re: Brand new 2019 Zero S, charging issue
Post by: DonTom on December 02, 2018, 04:05:49 AM
@Don I respectfully disagree with your saftey reccomendations to the OP Keeto whos skillset we do not know.

If he is having trouble with the calex he should replace it. It is the #1 replaced part on a Zero and the only part that I think is not very good on a Zero.

If your #1 part being replaced by the manufacturer is truipping GFCI you need to replace it as that charger is going to fail on you at the most inopportune time.

Brian T Rice did a post mortum on his own DEAD calex while I was bolting up one of the very original Super Charger v2.5 onto his bike. Brian is a no nonsense guy and bases what he says on facts and datum more than most people. You know what his result was? The calex caught on fire inside its potting and went out before exiting the charger case...

If the charger is having an issue, take it to the dealer and get it replaced ASAP. Don't risk it.
If his is the only bikes that is tripping the same GF that other Zero's do not trip, then I agree with what you're saying. We do not yet have all the facts. It will be interesting to see what the dealer finds.

-Don-  Auburn, CA
Title: Re: Brand new 2019 Zero S, charging issue
Post by: DonTom on February 21, 2019, 11:44:35 AM
I spoke with Zero technical support, and they said it's not supposed to trip a GFCI.  They said to take it back to the dealer for a diagnosis and repair, so that's what I did.  Now I've gotta twiddle my thumbs until I get the bike back.  No loaner possible, unfortunately.  It's a bit frustrating to pay for it and then not be able to ride it... but these things happen and I'll do my best to be patient.   ::)

-k
If you're still around this forum, I would like to know what the final outcome was. Does your bike no longer trip GFCI outlets?  If so, what did they do?

-Don-  Reno, NV

Title: Re: Brand new 2019 Zero S, charging issue
Post by: Electric Cowboy on February 22, 2019, 06:10:02 AM
I second the desire to know the end result as this is good data for forum members.
Title: Re: Brand new 2019 Zero S, charging issue
Post by: keeto on June 13, 2019, 09:13:42 AM
Sorry for the zombie thread, but I haven't been around the forum at all since I initially posted about this issue.

The dealer where I bought the bike (Fort Walton Beach FL) didn't know how to diagnose the issue.  As a matter of fact, they didn't even understand the definition of "ground fault".  Heh.

I discussed this issue with Zero, but they were also less than helpful.  I like the bike a lot.  It's got some major warts, but riding it is a blast and it fills the need I have for an electric motorcycle.  That all said... I won't be buying another motorcycle from Zero due to the way they refused to help me out with this issue.  And I steer people away from Zero because of my experience with their crappy customer service.

Charging the bike still trips some (but not all) GFI outlets.  I carry around a cheater plug for outlets that are problematic.  Not an ideal solution, but it's cheap and easy and works for now.  At some point I plan to replace the charger.

-keeto
Title: Re: Brand new 2019 Zero S, charging issue
Post by: DonTom on June 13, 2019, 10:58:05 AM
Sorry for the zombie thread, but I haven't been around the forum at all since I initially posted about this issue.

The dealer where I bought the bike (Fort Walton Beach FL) didn't know how to diagnose the issue.  As a matter of fact, they didn't even understand the definition of "ground fault".  Heh.

I discussed this issue with Zero, but they were also less than helpful.  I like the bike a lot.  It's got some major warts, but riding it is a blast and it fills the need I have for an electric motorcycle.  That all said... I won't be buying another motorcycle from Zero due to the way they refused to help me out with this issue.  And I steer people away from Zero because of my experience with their crappy customer service.

Charging the bike still trips some (but not all) GFI outlets.  I carry around a cheater plug for outlets that are problematic.  Not an ideal solution, but it's cheap and easy and works for now.  At some point I plan to replace the charger.

-keeto
Thanks for the update. Unfortunately, I am not a bit surprised by any of that. But IMO, a slight unbalance to ground just isn't a big deal. My bike  had tripped ground faults as well, and I simply assume it some very minor issue in the design of the onboard charger. It simply means one side of the AC line has a little more high resistance (or capacitive reactance) to ground on it than the other.  IOW, the current on the return is slightly less than going in on the hot, proving a path to ground.

I would only be concerned if it instantly tripped every GFI outlet tried, which then could be showing a close to a dead short to the frame.

-Don-  Reno, NV

Title: Re: Brand new 2019 Zero S, charging issue
Post by: MrBlc on June 13, 2019, 01:09:22 PM
As an electrician i would agree with Brandon here.. Never joke with security.. Shit will burn if ignored.
Having said that, we've also seen over time that the tolerance levels of GFCI devices vary wildly..
They can trip on anything between 12 and 28 mA. All of which are within requirements..
AC/DC units all have a certain degree of noise sent to the ground wire.. This again depends on the quality of the circuit and therefore can in some cases make a very sensitive GFCI device trip while others dont..

If fault tripping is experienced a few places it could be a sign of deterioration within the electrical circuit, but it could also be oversensitive GFCI..
If the frequency of places increase it's worth investing time in testing more closely.

Speaking of GFCI devices and AC/DC setups.. in EVSE setups there's a requirement (in .eu at least) that these circuits must have proper DC filtering or GFCI type B protection installed. This because we KNOW that large DC circuits will feedback very high frequency noise up the feed and create a problem with type A devices.
So.. Unprotected circuits are no joke either.. This is systems you really should not cheap out on the protection of..