Having issue with GFCI tripping. Looking to see if Victron will comment or if there is a solution that doesn’t involve bypassing the ground/safety. I do understand that GFCI are set to 4-6ma in north America. There are past threads about this issue but have no real solution and I haven’t seen any comment from Victron on the issue.
This system is installed in a camper trailer with Multiplus II 12/3000/120 120v, 3x 330ah Smart Lithium, 440w Solar threw Smart solar MPPT 100/30. The rotary switch is used to supply the main trailer panel from shore 1(original) OR shore 2(new/Inverter).
Problem is that when the trailer is connected through MultiPlus to shore power which is provided from a 15amp GFCI on a house the GFCI trips. The receptacle trips and not the overcurrent Breaker in the house panel.
The GFCI doesn’t trip when using Shore 1. Trailer and all appliances work normally.
GFCI doesn’t trip until Multiplus is connected to the main trailer panel. Multiplus does work for charging the batteries without passing power on to the main panel, but this leaves the trailer without 120v while charging.
We have isolated every part of the system. Removed rotary switch and installed new line to main panel. GFCI trips immediately when MultiPlus connects to shore power and connected to trailer panel. If the line to trailer panel is connected to multiplus and removed from trailer panel GFCI holds.
Replaced inverter with new one and same results as above. This would indicate both multiplus are operating the same. Both correctly or both malfunctioning (very unlikely but not inconceivable)
Placed a short line and receptacle on the inverter output and was able to run 1500 watt heater without tripping GFCI
There is no connection between ground and neutral in the trailer. There are no shared neutral points between shore 2 and panel (ac in & ac out are isolated)
I had another electrician with 40+ years come out and confirm/check things with me and he also doesn’t know what is going on. There is talk on other threads that it might be EMI filter or capacitive leakage current, which my college also mentioned. Hopping for some sort of clarification on this issue, even if there isn’t a solution yet.
I did disable and still trips GFCI (2 second delay). The “non” connection I was referring to was to eliminate that from the potential cause of tripping GFCI. I have come across this both in residential and mobile installations.
Happy to answer any questions if you would like to discuss further. This is a reasonably common problem in the marine world and the solution is simple enough in concept. A plausible explanation is available for GFCI tripping in many cases.
In many cases intermittent tripping occurs with no fault. It is just plain old fashioned engineering that can be resolved if the problem is understood and once understood it will be crystal clear.
I did see your previous comments and found it very helpful. The more I dig into this issue the more I am finding that the culprit is a combination of the extremely low trip threshold of 7ma(recorded test) and the way the inverter transfers/switches between pass threw and inverting. I’m definitely curious about the b-stop device but being a Italian make i don’t know if it would work in north America (120/240v 60Hz vs 230v 50Hz) or would even be certified to be used here. The only other issue is cost 200euro = 300$ Canadian not including shipping and customs resulting in 400-600$+ device. As of right now client can charge lithium and run trailer, all though it does require switching where he plugs in the shore power cord to the trailer (inconvenience but not end of the world). Going to keep an eye on this issue and will update if any new info or solution comes in.
Unfortunately i don’t have a meter sensitive enough to measure 1mA increments. Did borrow a colleges ideal supply SureTest Circuit Analyzer, and found that GFCI will Trip at 7mA no mater where i test (direct on plug, in trailer, output of inverter). If the SureTest would trip lower at any point i would belive there is another leakage of current some where. The problem of GFCI tripping when multiplus is transferring is still not fully diagnosed. My current conclusion is that the combination of extremely low trip threshold of 7mA and the way the Multiplus transfers is causing the issue. No solution yet but still troubleshooting.
@LAD_Systems …Ok, firstly, a trip threshold of 7mA is very low for circuits that are aggregated together. It may be ok for one device but for a distribution point it is way too low. In some cases we have measured leakage of 4.5mA for one device.
You can also see the calculations for the typical leakage current for a single IEC socket with an EMI filter included. Ok, its not much current for one but if you have many of them it all adds up.
Ok, the multiplus switching can be explained as we have experienced exactly the same thing. When the multiplus is inverting, the neutral ground link is established (if that option is checked during commissioning). This is so any RCD downstream of the inverter will work even when the multiplus is disconnected from shore power and that ground neutral link snuffs out any downstream leakage. In other words any leakage on the output of the multiplus is never seen on the input when the multiplus is in inverter mode. When the multiplus is in passthrough the ground neutral link on the output of the multiplus is open, allowing the small leakage downstream of the multiplus to be seen by the RCD supplying the multiplus. This adds to the accumulation and trips the RCD.
The Italian company who makes the device is working on the lower voltage version for 120V countries. It already handles 60 or 50 hz. You are right about certification and that may be a problem. It is so simple however, and it is important to note that no power is supplied through the B-Stop and it merely sits across the active, neutral and ground. In fact you could simply plug it into the outlet to solve this problem. That’s what makes it look like snake oil, and that is why I wrote the paper describing it. It seems too good to be true. My only regret is I didnt invent it.
The frustration of nuisance tripping in the marine industry is rife with people going to all sorts of (sometimes dangerous) methods to prevent it. This device resolve the problem and very importantly, does not in ANY way reduce the effectiveness or sensitivity of the original RCD installed. That is very important as RCDs save lives.
Please read the paper and let me know if it doesn’t make sense. Always happy to hear any views on the contents. Nothing better than peer review.
It has been 12 days since I installed the B-Stop and a full week since the cement plant should have returned to normal operations. As stated in this thread, I was only encountering trips on week days at very specific times.
I’ve measured the mA leakage from my 3 inverters and they added up to very close to the tripping threshold. See this discussion for easy reference: RCD tripping on shore power