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To preface this, I work for a small start-up in the Agriculture field. We have a product which uses high voltage (30kv) corona wires to ionize exhaust air in animal facilities for odor and dust reduction. We have been having a very difficult time with GFCI outlets at one client's sites. It appears that our system trips the GFCI outlets (used because the outlets are mounted outside).

Note - I cannot replicate this in our warehouse yet. With 15A or 20A GFCI outlets (client uses 15A) I cannot get our system to trip the outlet.
I traveled to the client site the other day to see this for myself. The GFCI outlets trip at erratic intervals (once as quickly as 10min, another time it took 1.5hrs before it tripped). I checked the wiring on the outlet, it appears to be correct, nothing is downstream of that outlet. I plugged a hot air soldering station in to the outlet (draw of about 2A) and let it run for 1.5-2hrs and it did not trip the outlet. I systematically replaced all the parts on our power supply, and at each point the GFCI would eventually trip.

This occurs whether our power supply is connected to the high voltage wiring (which runs to about 200ft of exposed "corona wire").

The system itself essentially converts the AC to DC, steps it up to 30kv, then converts it back to AC before running it to the plate where it will connect with the HV wire (if the HV wire is connected).

We are really puzzled, and the worst part is the client has some sites (approximately 50%) which have the GFCI outlets and which are not experiencing this fault. They have even told me they have a site with one outlet which trips, and another which does not when plugged into our system.

The inconsistency, and the very erratic "lag" in the effect is making testing this difficult. I'd appreciate any thoughts people with more experience in this field may have.
 
TL;DR
GFCI appears to be tripped by our admittedly odd system. We are perplexed as to why, however.
To preface this, I work for a small start-up in the Agriculture field. We have a product which uses high voltage (30kv) corona wires to ionize exhaust air in animal facilities for odor and dust reduction. We have been having a very difficult time with GFCI outlets at one client's sites. It appears that our system trips the GFCI outlets (used because the outlets are mounted outside).

Note - I cannot replicate this in our warehouse yet. With 15A or 20A GFCI outlets (client uses 15A) I cannot get our system to trip the outlet.
I traveled to the client site the other day to see this for myself. The GFCI outlets trip at erratic intervals (once as quickly as 10min, another time it took 1.5hrs before it tripped). I checked the wiring on the outlet, it appears to be correct, nothing is downstream of that outlet. I plugged a hot air soldering station in to the outlet (draw of about 2A) and let it run for 1.5-2hrs and it did not trip the outlet. I systematically replaced all the parts on our power supply, and at each point the GFCI would eventually trip.

This occurs whether our power supply is connected to the high voltage wiring (which runs to about 200ft of exposed "corona wire").

The system itself essentially converts the AC to DC, steps it up to 30kv, then converts it back to AC before running it to the plate where it will connect with the HV wire (if the HV wire is connected).

We are really puzzled, and the worst part is the client has some sites (approximately 50%) which have the GFCI outlets and which are not experiencing this fault. They have even told me they have a site with one outlet which trips, and another which does not when plugged into our system.

The inconsistency, and the very erratic "lag" in the effect is making testing this difficult. I'd appreciate any thoughts people with more experience in this field may have.
Victor have you tried to change the GFCI which do go bad and should be tested every month? Everything else I have no idea
 
Have you measured the ground leakage current on the HV generator? If so, have you measured it over all relevant frequencies, e.g. the HV converter switching frequency? High frequency, high volltage circuits can pass significant current through small capacitances and there may be unwanted coupling from the converter into the AC line that the GFCI sees as leakage. Different GFCIs, with different characteristics, may be more or less sensitive to DC and high frequency components of leakage current, hence inconsistent results across different outlets.
 
We did not replace the GFCI as the breaker box is in an area requiring a shower-in. We did test the GFCI with a "tester" and also ran a 2A hot air gun off that outlet for close to 2hrs. The outlet doesn't seem to be faulty necessarily.
 
Have you measured the ground leakage current on the HV generator? If so, have you measured it over all relevant frequencies, e.g. the HV converter switching frequency? High frequency, high volltage circuits can pass significant current through small capacitances and there may be unwanted coupling from the converter into the AC line that the GFCI sees as leakage. Different GFCIs, with different characteristics, may be more or less sensitive to DC and high frequency components of leakage current, hence inconsistent results across different outlets.
I am not sure how I would measure ground leakage? This would be from the power supply itself, or from the ion emitting "corona line"? The power supply is fully potted, so I cannot open it up to measure any of the individual components. Additionally, we were able to swap the power block for the power supply with one we did not see an issue with at the warehouse, and still tripped the GFCI.

Our tech guy is trying to follow up a theory that we are getting some flow of electricity from the ion emitters, through the wet ground to the system's earth ground, which he is currently guessing might be connected to the neutral back at the breaker box. But we don't know how to measure if this is happening.
 
Normally you would measure the leakage at the AC line input of the unit, bearing in mind that many leakage test instruments will display the leakage at line frequency, not necessarily including any leakage taking place at high frequency due to coupling back from the HV step-up converter.

some flow of electricity from the ion emitters, through the wet ground to the system's earth ground, which he is currently guessing might be connected to the neutral back at the breaker box

This explanation is a bit back-to-front but it does relate to what I'm talking about. There should be a complete return path for your ionisation current, from corona wire, through the real ground, up the ground wire of the power cord, to the grounded end of the HV generator, or via any other ground connection that the user is supposed to make to your unit. The fact that neutral and ground are connected should be immaterial, as the return current passes through the ground connection not the neutral and hence the GFCI will not detect it. But if there is AC coupling for high frequencies from your HV circuit into the secondary of the 120V power supply in the unit, then the official ground return path may be partially shunted for HF by the hot and neutral of the line cord, and hence passing through the GFCI.
 
Normally you would measure the leakage at the AC line input of the unit, bearing in mind that many leakage test instruments will display the leakage at line frequency, not necessarily including any leakage taking place at high frequency due to coupling back from the HV step-up converter.



This explanation is a bit back-to-front but it does relate to what I'm talking about. There should be a complete return path for your ionisation current, from corona wire, through the real ground, up the ground wire of the power cord, to the grounded end of the HV generator, or via any other ground connection that the user is supposed to make to your unit. The fact that neutral and ground are connected should be immaterial, as the return current passes through the ground connection not the neutral and hence the GFCI will not detect it. But if there is AC coupling for high frequencies from your HV circuit into the secondary of the 120V power supply in the unit, then the official ground return path may be partially shunted for HF by the hot and neutral of the line cord, and hence passing through the GFCI.

Thank you Lucien. The problem we keep facing is we cannot replicate this in the warehouse. Even putting our corona wires just 4' from the GFCI outlet we are not getting any results in the warehouse, only at the client site. We are considering adding ferric clamps to both the power supply power cord, and possibly to the upstream wiring for the GFCI outlet just to see if that can resolve the issue.

Something that has started coming up in our troubleshooting is the possibility that this is something specific to the client site. I'm waiting on answers from them, but these are very long buildings (500' or so) so if the breaker box is at one end, there could be an extensive run of branch line to the GFCI outlet. I don't know if that is too long, and could cause any random tripping of the GFCI.
 
I would personally avoid guessing and start by eliminating simple things first with reliable measurements, e.g. by measuring the leakage current of the device as I mentioned earlier. It sounds like you need the services of an experienced electronic engineer who can take measurements and set up simulations with knowledge of the parameters that are most likely to be worth investigating.
 
I would personally avoid guessing and start by eliminating simple things first with reliable measurements, e.g. by measuring the leakage current of the device as I mentioned earlier. It sounds like you need the services of an experienced electronic engineer who can take measurements and set up simulations with knowledge of the parameters that are most likely to be worth investigating.
You're right, I suspect I do need the services of an experienced electrical engineer. The system simply is not adding up properly.

This is what I did at the client site (keep in mind, I had been at this site a number of weeks ago, both systems were tripping the GFCI at that time):
The site had two of our systems running at 2 separate barns. Systems are outside, and approximately 150ft away from each other.
Because of the distance from the breaker, the first thing I did at Barn A was disconnect the ground wire from the back of the GFCI. We had a theory that the GFCI may be picking up stray electricity from a long ground wire. After I did this, the system at Barn A remained on for multiple hours.
At Barn B, instead of just removing the ground wire, I tied another ground from the ground going into the back of the GFCI to a grounded rebar post installed below the outlet. Following the same theory as Barn A, we thought this rebar post would be a suitable way to dump any excess energy. Barn B tripped the GFCI within 10 minutes.
Since the added ground wire seemed to be a problem, I disconnected the ground completely at Barn B, to make it similar to Barn A. Barn B again tripped within about 10 minutes. I figured maybe the outlet was bad, so I did a hot-swap on the GFCI outlet... still tripped within 10 minutes. I put a clamp around the incoming (building) hot and the neutral to see if there was any current leakage, got 0 Amps. I tried putting some ferrite cores around the power cord, as well as one on our high voltage wire. It still tripped within 10 minutes. I even unplugged the High Voltage wire, so the system was just running as the power supply... still tripped in 10 minutes.

During all this, the other system (Barn A) was running. So I swapped the two systems. I took the Power Supply for Barn B over to Barn A and vice-versa. Intriguingly, the GFCI tripping followed the Power supply. I thought I had the problem. Barn B was now stable (with the PS from Barn A) and I just packed up the other Power Supply to take back to the shop to diagnose.

Well, by the next morning, Barn B had tripped as well. It just doesn't react in a scale of 10 minutes, but apparently a scale of multiple hours.

And what's most confusing, this Power Supply, which tripped within 10 minutes at the client site, at each barn.... has been running in our shop for hours now without any failure.

I'm completely baffled. It makes zero sense.
 

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