It turns out that this is a fairly common problem with the cheaper HF inverters. I've gotten quite a few responses from people using the same style inverter (whether SunGoldPower, MPP or EG4). In looking through the DIY Solar Forum, it seems like these cheaper inverters don't have proper isolation between the PV and AC H-Bridge. diysolarforum.com/threads/eg4-6500-voltage-on-pv-terminals.55201/#post-707937 If you're interested in learning more about earth grounding your panels, I found this resource on the diy solar forum to be extremely helpful! FilterGuy does a great job explaining things for even someone like me to understand! diysolarforum.com/resources/grounding-made-simpler-part-3-solar-panels.160/
@@JOHNDANIEL1 all I know is I got shocked like no tomorrow grabbing the handle to my shed and if running a ground lug to my house grounding rod stops that then I’m all about not getting shocked!
@@JOHNDANIEL1 it’s the poor isolation of PV from the AC of the all in one inverters it’s “AC power” that’s the shocker checked that with a meter not “ DC “it’s a known problem with many of the HF all in one inverters from what I understand. So the ground is to dissipate the AC back current off the frames.
No. Its nothing to do with cheap inverters its the design. The pv bus is switched twice per mains cycle to the neutral with alternative polarity. That basically means the panel potential moves up and down hundreds of volts as it switches with respect to earth because it is usually tied to neutral. That is not a problem because your pv voltage will kill you anyway. So why does the frame feel live? Its because it is capacitively coupling to the panel. Think of the pv cells as one plate and the frame as the other plate of a very small capacitor. Because the capacitance is tiny the AC current that flows is tiny. You can measure 50 to 150v with a suitable meter. If you ground the panels then you will no longer feel this. Does it matter? Not really. But the switching potential on the frames does emit radio interference and so grounding it reduces that a lot. But its nothing to do with cheap inverters its just an efficient way to do it and galvanic isolation will just introduce more loss.
Adam, as it was mentioned here already most likely what you see is High Frequency AC coupling from MPPT charger (built in 6500x). It's not 60Hz AC coupling/leakage from the inverter part of 6500x.... That explains why you see what you see... Most of the cheap meter won't show properly 100kHz frequencies. You better use a cheap oscilloscope for that. I won't be surprised if you also use a multimeter with LoZ setting and it will read almost nothing. I think I saw similar things with my 6500x when I was trying to put an EMI/RFI filter right at the PV input. That thing (it's internal MPPT in particular) emits quite a lot of interference on HF frequencies (Short waves) into the air :( It's all about internal circuit design. Grounding the frame is possibly the easiest thing to "deal" with this issues. It still will be coupling that 20-100kHz but you won't feel or see it :) Coupling is happening between PV cells and the frame... That structure forms sort of a capacitor.
This panel can put out close to 100 watts ru-vid.comUgkxOqI2yqX0XVrhR2BMJciTWrHJpG8FhJyg when positioned in the appropriate southernly direction, tilted to the optimal angle for your latitude/date, and connected to a higher capacity device than a 500. The built in kickstand angle is a fixed at 50 degrees. Up to 20% more power can be output by selecting the actual date and latitude optimal angle.The 500 will only input 3.5A maximum at 18 volts for 63 watts. Some of the excess power from the panel can be fed into a USB battery bank, charged directly from the panel while also charging a 500. This will allow you to harvest as much as 63 + 15 = 78 watts.If this panel is used to charge a larger device, such as the power station, then its full output potential can be realized.
Make sure the bare copper is not touching the aluminum frame. The copper and aluminum are dissimilar metals and with bare contact will cause corrosion. It’ll eventually eat into your aluminum.
Good point about the galvanic corrosion. That will happen to the clamps over time, assuming they aren't anodized. Or even with Aluminum and a stainless screw on the clamp.
Thanks for vid. Newest NEC codes say panels/mounting need to be grounded. I think in the past some people considered it optional and only as a means of lightning protection or something. NEC 690.41
The difference in your meters' voltage readings probably has to do with the meter input impedance. The source of the AC voltage you were detecting is capacitive coupling to the back-fed AC power. This normally is a very high impedance source so very little current in available. A high input impedance meter will register a higher voltage than a lower impedance (cheaper) meter because the lower impedance loads the source & pulls the voltage lower. It would be interesting to check the current drawn by each voltmeter to verify the actual power (volts x amps) involved. The charge you have detected is unlikely to be dangerous, but in the event of insulation failure (conductive voltage back-fed), it could become lethal. That's the whole reason for safety grounds in appliances: the internal voltage may energize the appliance chassis (outer case) in the event of internal insulation failure & should you touch a grounding source & the appliance case you become the conductor of lethal currents. Modern standards allow double insulation in place of a safety ground connection to the case. There is also value in grounding the panel frame if lighting frequently happens during storms in your area. The safety ground could prevent the lighting current from being routed into your home over the power leads by diverting it at the panels.
Thanks for the video. I am dealing with a lot of the same issues. I have two EG4-6500ex-48 and I am getting voltage on my racking and buzzing when I touch the panels frame. Also got low reading in the 40V ac with my cheap meter and 140v ac with my nicer fluke meter. 1 st world problems I know but it sure is frustrating. I have spent a good portion of my life listening to Signature Solar’s hold music.
Awesome video and purfect example of why grounding the frame is important. Cracks me up on other channels complaining about voltage and inverters are unsafe bla bla bla but they dont have the system complete🤷♂️ Great job Subscribed💥🤘
I just occurred to me I have a single ungrounded 435W panel setting on pavement against the house with an Enphase micro inverter on it, I've never noticed any potential on the frame, even when wet. I'll have to test it now that you reminded me!
Enphase inverters are grounded internally to the chassis through the green wire in the 240vac trunk line. The instructions for Enphase clearly state no external ground required. I have 36 of them and no external ground. I passed inspection.
I read somewhere guy had an EG-4 6500 his utility called him said he was back feeding turned out the inverter was back feeding through the input side on a off-grid inverter. The panel not the only place it back feeds voltage. One reason I went with a Sol-Ark If your off grid don't want to spend the extra money have to work around their issues like you pointed out you can save the money.
@@AdamDeLay07 I'll look around might have been on DIY forum can't find it now I'll keep looking or could have been a YT comment on a video review of the 6500.
Most installers appear to just ground the aluminum racks, not each panel. When I worked at Edwards AFB, CA, you soon learn to touch a water fountain with your knuckles. A spark would jump 1/4" thru the air. Ditto when I lived near Chicago in winter, in a building with no humidifier. That little buzz is nothing. Likely from current leakage thru the inverter. But, smart to ground the frame in case the inverter shorts grid-power to the frame via the solar cells.
When I was installing a ground washer was placed between the panel and the frame that digs into the metal of both panel and rack which was per code but I still put a ground lug on each panel anyway. The ground was hooked to the rack then each panel down the line. Haven't noticed much if any corrosion between stainless set screw lead alloy ground lug and copper ground wire but I live in the desert so not so much moisture
you get the same effect with a bench PC . if your disconnect the earth wire so the PV power supply is floating, you will get some shocks, like static electric cos of the way the switch mode power supply (ATX) works, its a capacitive coupling - annoying getting zapped.
If I wasn't worried about things being thrown from the mower at the panels, I might actually do that! The wooden frames get the panels up high enough to keep them from being hit.
Regarding the craftsman meter. It depends on the input resistance of the meter. I have a high end fluke that is very sensitive. It reads 200 volts AC o the PV lines but my cheaper Chinese meter reads about half that.
It’s surprising how many people I’ve heard have felt the voltage on their frames. Apparently on cheaper HF inverters, there’s no isolation between PV and AC. You would think there would be on all inverters.
@@AdamDeLay07 we all love high end Inverters but they come at a premium price, My Growatt works great two issues I have with it high idle consumption and what we just spoke about otherwise I got Power
Cheap multimeter has a lower resistance in voltage mode Since your pannels should have a restance of a minimum of a few K ohm And your meter resistance is low it drops the voltage A volt meter with a higher resistance means less voltage drop in the pannels insulation
Thank you for the video I just had this discussion after wood frame installation - and my installer was not sure why earthing was needed. Now I can share your video w him :). Keep up the good work going energy positive!
HOWdy A-D-L, ... Thanks - this is one of the 1st things that I did on each of my SIX (6) Arrays ... Grounding LUGS + 6-AWG Bare Copper Wire ... into my ECO-WORTHY Six String Combiner-Box ... 36 PV Panels = run in a 6S / 6P configuration ... COOP ... the WiSeNhEiMeR from Richmond, INDIANA ... ...
Good Video much to consider... On a side note: I don't know if this will someday go national, but Insurance companies in "our" area are starting to cancel home policies that have more than 10k of solar panels attached to their roofs. The risk of fire is very high if not installed correctly. It's a catch 22 for people who don't have a lot of property to put the panels on the ground...
Did you try measuring it with a Low Impedance Meter.? Most meters are High Impedance. If you stuff up, a High Impedance meter will conduct less short circuit current making them a little bit safer than a Low Impedance Meter. However, a High Impedance meter will give you inaccurate readings of 'Ghost' or 'Phantom' Voltages from Capacitive Coupling and sometimes from Inductance. Switch Mode Power Supplies and Inverters, which both have high frequency switching creating some coupling, and some the cheaper versions have a capacitor coupling the (relative) low voltage and extra low voltage sides of the switching units. Some can also contain Noise Filters between the LV and ELV circuits also.
Impressive. Between the isolation in the inverter and floating the output. Yeah they're supposed to be grounded for a reason. They're metal objects and they can become live so you want them grounded to Earth potential in case there's anything wrong with the equipment or if a wire accidentally comes in contact.
I figured it would get absorbed by the battery and by the capacitors in the charge controllers. But I guess not. Wow. New information.... that's why I like your channel! I would posit that the power factor of your AC loads would also have a significant effect on the ripple you are seeing on the frames, since poorer power factor directly feeds-back through the inverter to the DC side.
Appreciate that! Hard to say. I’ve found most things with a poor PF cause my lights to go nuts in the house. I’ve only found 3 things in the house with poor enough PF to flash the lights.
@@eddietee6305 The issue being talked about here is a more indirect path where some of the AC couples back into the DC wires. There are three ways this can happen. * The first is direct coupling backwards through the AC inverter... it ends up looking like ripple on the DC side. * The second is direct coupling backwards through the AC inverter due to reverse current due to a poor power factor. Basically, when there is a poor power factor on the AC side, some of the energy will actually couple back through to the DC side. In large inverters this energy is mostly captured by capacitors and re-fed back into the inverter. In cheap inverters this energy just couples back to the DC side and ends up as stronger ripple on the DC side. * The third way is through EM radiation. Any AC waveform radiates energy. The energy will couple into any wires in proximity to that EM radiation (regardless of insulation). That is how AC winds up on the frame. We see similar issues crop up with AC breakers, for example. If you turn off an AC breaker and there is no load on its output grounding it, i.e. the output is open, you will measure significant AC on the output even though the breaker is open. Usually somewhere around 50-80VAC. Very little current can couple through, but it is certainly enough to give you a shock. The effect is even more pronounced with a contactor or relay... sometimes enough energy couples through that LED lights will continue to flicker or light dimly even though the switch / relay / contactor / breaker is "off". So that is how we wind up with AC on the solar panel's frame... and it is indeed often enough voltage to give someone a significant buzz. Grounding the frame fixes the problem. But determining the best place that the frame should be grounded to is actually a really difficult problem for a multitude of reasons. i.e. should it be to a nearby house ground wire from a plug? Do you have to run a ground wire all the way to the house grounding rod or main service breaker box? Do you need to sink another grounding rod into the ground near the house? There is no right answer.
Good morning Adam With my system I think I’d be fine because I’m using sign post which are metal and they are into the ground at the bottum Update on my new growatt 3 5KW System. Such a great setup. Don’t get me wrong I’ve had a few codes but nothing like the pile of garbage I had with the 2 EG4 6kw inverters And the flickering is pretty much gone And I’m running my whole house. Air compressor jacuzzi tub washer dryer and all the normal stuff Super happy with my change in the system. Have fun Adam and keep up the great solar videos coming 👍🏼
Glad to hear after so long of you having issues, your finally able to just use a system and almost forget about it because it just works! Thanks for sharing!
Interesting. I also have wooden frame ground mounts. I grounded mine during installation as required by the NEC. I drove an auxiliary ground rod at the panels and also bonded them back to my service panel. I haven't noticed anything when I've touched the panels, probably because of earth grounding and bonding. I'm using the EG4 6500 inverters as well. I'll have to check for voltage from panels to ground. I'm surprised there is any voltage at all with a grounded panel system.
Yeah apparently the cheaper HF inverters don’t have any isolation between the PV and AC. At least that’s what I’ve heard from people who know a whole lot more about this stuff that I do.
@@AdamDeLay07 Yes, that's correct. Or more specifically, they don't have high quality energy recovery from the AC that couples back through the transformer, or any shielding from the EM.
I'm not sure whether you are allowed to ground to both location at the same time when the grounding rods are really far apart. At a minimum, see if there is a significant DC voltage differential at the house between the ground wire coming in from the array (while disconnected from house ground), and the house ground. Having a really long ground wire going across the field could increase the damage that nearby lightning causes by giving it a low impedance path into the house, which might not otherwise occur.
@@junkerzn7312 This is a great topic for conversation. First NEC 690.47B does allow for and additional ground rod at the panels, in fact in that same section, "the support structure for a ground mounted PV array shall be considered a grounding electrode", ground mount system grounds are addressed. To me a steel ground mount racking system really can't be isolated from acting as a grounding electrode. A wooden one probably can, so long as it's not damp or wet. I've watched Mike Holt's videos who would agree with your scenario. I would also agree if either one of the DC power carrying electrodes was grounded, or there were no grounding conductors between the array and building service panel. Something to consider too, would be a direct lightning strike to the array. I understand that no system would protect sufficiently for a direct strike, I do believe that a greater part of that energy would go directly to the earth ground at the panel and may in fact reduce damages to the system in the building. On my system, I used #4 solid copper to ground my array to the auxiliary ground rod, and #8 stranded to bond to the building service. As I started out saying, this is a wonderful topic for discussion.
@@backtothepast1850 Yes, total agreement. There is very little real-world data supporting one scheme verses another. The distance is going to matter a lot, too. I have a main system on the garage roof which is right next to the service ingress. The grounding for that is obvious. But I also have a bunch of panels hanging off the back deck on the entire other side of the property, 200+ feet away. At the moment I have that tied into a simple house circuit's ground but I just don't know if that is the best solution. For a remote array in a field, I'm more partial to grounding at the array since it is already partially grounded there anyway, but not feeding a ground wire all the way back to the house. Instead, I'd have surge protection at the house for PV- and PV+ tied to house ground. The idea being to protect the house systems as much as possible from damage. In that case I think sinking a second ground rod AT the house and tying it into the house ground (if the main rod is on the wrong side of the house for example) might be reasonable. But I just don't know. Really just my ruminations as an EE. But an EE is not usually a certified electrician.
Had to go back trough to find those comments. Looks like he was testing at the PV inputs of the inverters. Not exactly sure how he tested because it wasn’t mentioned, but he said his tests revealed “20VDC and 0VAC”.
Because it's not necessarily an inverter problem, it's an end user design problem. These should have been earth grounded from the beginning. This is a common problem in the DIY community. People think they can cut corners and save money, this is the result. There should be no AC voltage at your racks. I would bet he has AC/DC grounds mixed at some point. There should be no way AC voltage is present on your panel racks.
@@AdamDeLay07 I'm glad you've brought this to our attention. I'm going to hook up the 48V 3000TL LVM by rich solar in my trailer this season. I will have to test my array. I used the MidNite Solar MNDC-GFP63 in my diy combiner box.
@@Scotty2Balls Code in Canada 64-222 Photovoltaic module bonding (see Appendix B) 1) Exposed, non-current-carrying metal parts of photovoltaic modules shall be bonded to ground. 2) Module bonding connections shall be as specified in the module installation manual. Δ 3) Notwithstanding Subrule 2), bonding connectors intended for bonding photovoltaic modules and installed in accordance with the manufacturer’s instructions shall be permitted to be used. 4) The connections to a photovoltaic module shall be arranged so that removal of a photovoltaic module from a photovoltaic source circuit does not interrupt a bonding conductor to other photovoltaic source equipment. S
I suppose that the producers of invertors assume the Regulator/Inventor unit as well as panels are always grounded. The AC voltage is just a residual voltage with very low current, which is harmless (and cheap multimeter with lower internal resistance therefore indicates lower voltage than real). Anyway grounding is good practice in case the Invertor gets broken to avoid risk of real and dangerous AC current (or in the case of voltage surges during storms).
A great video …. Had the same issue my limited understanding is due to transformer less inverters get capacitance leakage on the dc lines from the ac. I was getting about 30v to earth on mine from a Growatt 5000es. There are specific washers and plates that cut into the anodising to further help get that stray current ground. I got ac and dc current on the panels also
Very interesting discussion. I have two LV6548 and... 6:05 He's not the only one that got popped, don't ask haha 12:19 I'm seeing around 90V on mine with a Fluke 14:21 I'm no engineer but I suspect that, while there is voltage, it's just leakage current (very, very small amount). Perhaps the Craftsman has lesser resistance between the probes? Don't know, just a guess.
Thanks! I’ve heard from several people who’ve been…”surprised”. 😁 I imagine that might be the reason the craftsman didn’t show the same info. Especially since it showed proper voltage from the grid power.
@@AdamDeLay07 Here's a fun one to add - if you have 2 inverters connected to form standard 120/240 power and you have a solar array connected to each inverter, you have nearly 200VAC between the frames of both arrays!
@@LithiumSolar it’s funny you mentioned that. I was talking to someone else that had multiple strings from multiple inverters on a single array. The strings in the array ended up being bonded together due to the mounting hardware. Got a really good zap. Said he’d never felt anything like it before!
@@AdamDeLay07 I was just wondering what putting a Ferrite filter on the PV lines would do. I'm just getting into solar and don't have the equipment yet to try myself.
I live to use the charge controllers that are just charge controllers instead of using the all-in-ones. By seperating out the charge controller from the inverter and having the battery in between, you get zero issues like this.
25 volts would not have been enough to create that buzzing. Your meter isn't reading it accurately. Edit: as you saw by using the other meters. I also question their accuracy... you really need peak voltage, and the best those meters might give you is true-RMS - an average. In any case tho, the current is minimal, nothing to worry about other than a possible surprise.
Buzzing is from static charge possibly thousands of volts, very little amperage, that’s why it’s not zapping you. Caused Most likely from the wind passing over your panels. This is not from a/c. You seem to have some a/c voltage,most likely from your inverter but likely is fantom voltage with no real amperage. A small wire from your panels to ground will dissipate this type of voltage. Earth grounding will not dissipate and zero out a/c voltage. If you have true a/c voltage with small or large amperage it will continue to flow on the wire even if earth grounded. Electricity does not only follow the path of least resistance, it follows ALL paths. This is why we use grounding not earthing. Very confusing but it is very important to know the difference.
Another possible reason for the difference in meter readings is that the inexpensive meter might not take RMS measurements. So, if the AC being measured is not a sine wave then the measurement may be different. Why might it not be a sine wave? Ask the inverter :)
The trouble is grounding may not work. Ground is not always zero potential. I have installed many systems including wooden frames and have never seen this potential . Of course you earth,grounding the metal frame may help with indirect strikes. As others have said this potentail you are getting is induced AC comming from a switched mode charge controller.
I have an eg6500ex split phase system and I can measure 200 VAC on either of the PV connectors and I can feel some electrical charge on the frame although I did not measure. it. I also have a wood racking.
Great video, and I like your discovery process. I do have a question: aside from static charge and induced current from nearby lightning strikes (or other nearby high frequency EM fields) there shouldn't be any voltage buildup between the panels and ground, and once you've discharged it, there shouldn't be any substantial voltage potential left. So why is it that your system shows a persisting voltage difference? I'm not an expert, but logically there has to be a continuous source of energy "charging" your panels' frames. I can think of two options: 1) Internal: there's some kind of "leak" in your system. 2) External: there's some kind of external source of energy, e.g.- a persisting EM field, strong enough and close enough to induce current in the metal parts of your panels. The first reason seems a lot more likely. If you find the reason for this, (and the solution:) please share it with the rest of us. Thanks
Thanks! Your exactly right, there shouldn’t be anything there. After more research, it actually looks to be a fairly common problem with cheaper AIO inverters (I always say there has to be some compromise getting all the components in the AIO inverters to play nice together). So it seems there’s limited to no isolation between the PV and AC H-bus, which then allows AC Ripple back to the panels. I still don’t understand how voltage shows up on the frames when they’re not connected to the pv lines at all, but I know it’s happening. I trust people a lot smarter than me for the explanations. diysolarforum.com/threads/eg4-6500-voltage-on-pv-terminals.55201/#post-707937
FYI: I used a 4" Grinding Wheel to remove a "patch" of ANODIZATION to BARE Aluminum where my Grounding-LUGS attached with Stainless-Steel 1/4" SAE Bolts COOP ...
If you are not feeling a shock now since your panels have been grounded still doesn't make it safe because electricity is still running through your body. No 100 plus voltage should be on those panels, there is a fault somewhere and is causing that problem at the panels. Grounding the panels so that you can touch safely doesn't solve the problem it is only masking it.
Voltage tests need to be done with a load connected. Most meters don't have enough internal impedance to create a load. A Knopp type voltage tester provides a load so it would provide a more accurate voltage measurement. Even in your vehicle... if you place your meter across the battery you'll read approximately 12.7 vdc. Now turn on your headlights and you will get a more accurate measurement of the state of the battery. Yes the voltage will drop some. Now crank the starter and you really check the capacity of the battery!
I was going to suggest a drill stop. I had to drill out the holes on all the panels of the last array I installed and that's how I did it. But the step drill would work too.
a small note about your measurement on 8:17 - the black wire should have been plugged in on the com terminal for VAC measurements! Concerning the measurement difference on 13:20 - this might have to do with the AC waveform - as the KLEIN Tool Multimeter is a TrueRMS and the cheap one is probably not -> the "true RMS" has most probably have the more correct value - it would be interesting to check the voltage with an oscilloscope as this would show the waveform causing this AC ... maybe this could give a hind about the source of this AC voltage.
Thanks! You know your the first person to catch that I had the probe in the wrong port. I didn’t even catch that. Guess I’ll have to try and retest again. Yeah, your not the first person to tell me I need to get a scope. Might just have to bite the bullet and get one for testing.
@@AdamDeLay07 as the cheap and the true RMS show different values, this is an indication, that the waveform is not a sinus. This is the reason why the cheap one measures correctly at the mains which is a sinus waveform
I have never seen that with my two 12K home system. Started up my two shop 6500EX’s….same bs before grounding. A little scary at first. I guess we get what we pay for. I didn’t even have both pos and neg leads hooked up to the panel.
How on earth can that happen? The frame should be completely isolated from the cells and internal buss connectors. The glass and silicone layers should insulate all electronics. Is there something that Renogy is not telling us about their panels or did this happen with all of your panel brands? Something I am missing?
It turns out that the cheaper all in one inverters (like the eg4 6500 and the MPP lv6548) have some issue with their H-bus and isolation. It allows AC to somehow bleed on to the PV frames. I don’t understand much of it myself but I’ve had much smarter people than me try to explain it. It’s over my head. diysolarforum.com/threads/eg4-6500-voltage-on-pv-terminals.55201/#post-707937 It’s not specific to the Renogy panels, because it happens on my SolarEdge panels as well. It all goes back to the AIO inverters. Ultimately it reinforces the need to make sure you earth ground your panel frames.
@@AdamDeLay07 Wow! Crazy. I have not checked my new array but the old one is on that big metal frame from Powers Solar Frames. I may check just out of curiosity.
@@CountryLivingExperience yeah just pick one panel that’s connected to your 6500s and disconnect the ground. Then measure the AC voltage between the panel frame and the ground wire. It’s been a while, so I can’t remember if I found out that you had to have AC In connected to the inverter for the voltage to show up. I know I’ve heard of others with this issue on both EG4 6500s as well as the LV6548s. I’ll be interested to hear what you find out.
@@natesdiysolar So after talking with someone who had 2 lv6548s that got bit with the voltage on his panel frames, we came to the conclusion that he might have had strings from 2 different inverters on the same array, and they were being electrically connected by the washers holding the panels down. That would increase the voltage on the frames. Just FYI.
bare foot in moist grass... might get a better feel for it... my low buget all in one had poor mppt anyway,... new set up has low frequency victron. with outboard smart mppt.. seems like much more production and micro adjust parameters bluetooth.. nice upgrade
Yeah my son and nephew figured that one out when they were walking past the panels after coming out of the pool... Glad to hear you've got a nice upgrade! Victrons are in a completely different ballpark than most systems!
I can't say for sure, but I think the problem would lie in the grounding of your inverters. Electricity will take the shortest path and that should be through your inverter back to your panel ground. I recently watched a video from a guy explaining that grounding your solar panel frames is not only unnecessary but dangerous since it becomes a lightning magnet.
It turns out that this is a fairly common problem with the cheaper HF inverters. I've gotten quite a few responses from people using the same style inverter (whether SunGoldPower, MPP or EG4). In looking through the DIY Solar Forum, it seems like these cheaper inverters don't have proper isolation between the PV and AC H-Bridge. diysolarforum.com/threads/eg4-6500-voltage-on-pv-terminals.55201/#post-707937 If you're interested in learning more about earth grounding your panels, I found this resource on the diy solar forum to be extremely helpful! FilterGuy does a great job explaining things for even someone like me to understand! diysolarforum.com/resources/grounding-made-simpler-part-3-solar-panels.160/
The Kline is likely an RMS meter. And get those MC4 connectors off of the ground. Check out my wooden rack that I just built. It goes to a DC assist heat pump.
What about checking if there’s a ground and neutral bond in the inverter or your main panel. It might be ghost voltage and may be the reason for cheaper meters not getting a correct reading. Testing a light bulb between the panel and ground if it comes on it’s real electricity. If it does come on then it’s ghost voltage. My guess by the way. And thanks for the great vids.
Thanks for the comment! So the main panel did have a ground neutral bond but the inverter didn't. It turns out that this is a fairly common problem with the cheaper HF inverters. I've gotten quite a few responses from people using the same style inverter (whether SunGoldPower, MPP or EG4). In looking through the DIY Solar Forum, it seems like these cheaper inverters don't have proper isolation between the PV and AC H-Bridge. diysolarforum.com/threads/eg4-6500-voltage-on-pv-terminals.55201/#post-707937
If you look at your buss bars inside your panels you will see they do not connect in any way with the metal frames not sure where your static voltage is coming from. My panels are also mounted on wood frames and
Thanks, yes I'm aware that there's no direct connection. It turns out that this is a fairly common problem with the cheaper HF inverters. I've gotten quite a few responses from people using the same style inverter (whether SunGoldPower, MPP or EG4). In looking through the DIY Solar Forum, it seems like these cheaper inverters don't have proper isolation between the PV and AC H-Bridge. diysolarforum.com/threads/eg4-6500-voltage-on-pv-terminals.55201/#post-707937
Use the Klein and check the Hz of the ungrounded panel. Obviously you have AC current, but at what hertz? A reduced hertz might explain why the craftsman fails to pickup the full voltage.
I would be more concerned as to why the system is back feeding AC into the PV array.. I have a similar setup where my panels are literally on the ground or blocks, and I move them around as well and have not noticed this. Iv been thinking of grounding my panels as well. How many watts is your pv array..
@Adam De Lay I'll do some research once I get my lv6548s running. Wonder if it has to do wth ground neutral bond. Im thinking of off loading the charging to a Victron mppt and just using the inverters as inverters only.
@@natesdiysolar that’s an interesting thought. Wonder how the inverter consumption would change if you never use the mppt? In my case, the only time the fans work really hard is when I have a lot of Solar coming in. Even with larger loads, it doesn’t seem like the fans run that hard.
check the same when turning off the inverter output but with solar still charging the battery's. probable same thing i experienced with voltronic inverters (same inverter builds, different color and branding). they seem to put ac back trough the solar input only when the inverter is making AC power. also got shocked by them when was installing metal sheet finishing around a metal roof with panels installed on the metal roof.
Initially with your Craftsman meter you had the red lead on the right and the black lead on the left. The black lead would normally be in the center common terminal for all measurements if I'm not mistaken. Later on you had the black lead in the center and the red lead on the right. I don't know what model meter that is, but I would think that how you had it in the second half of the video was correct.
The left hand terminal is strictly for amperage using the red lead in that position. The black common lead should be in the center terminal. If I'm correct, that meter is worth $250 on Amazon which is not an inexpensive meter relatively. It would be worth you checking the fuses inside the tool, as I suspect you may have at least one blown fuse. Of course the meter may also be defective. Not reading the correct voltage. May also be due to what is called input impedance. If the impedance is too low, it may be pulling the voltage down. When you measure it. I kind of doubt it.
It might be interesting to test the current to ground from the panels to see how much power is going through. Also something that is confusing me, if the inverters are in fact injecting AC power to the solar panels how is it showing up on the frames? Every panel I have tested there is no continuity from either the positive or negative wires to the frame. ???
When I looked, the current barely even registered on the meter, so that's why I barely feel anything when I touch the panels. Unfortunately I don't understand how it's all happening either. Someone much smarter than me told me (and I'm gonna try and remember exactly what he said) that "in cheaper HF inverters, there's no isolation between the AC and PV." Because there's no isolation, you really wana make sure to earth ground the panels to dissipate any leakage. This might help a little bit: diysolarforum.com/threads/eg4-6500-voltage-on-pv-terminals.55201/#post-707937
Hmm. Mike Holt has a channel about grounding. Very important. Anything earth grounded should be bonded.... All ground rods should be bonded, is what I'm trying to say. Could get deadly if you become part of that bind naturally.
Adam, one note, you mentioned grounding the panels on the shed roof for protection in case it gets hit by lightning but earth grounding is not for protection against direct lightning strikes. I recommend watching Mike Holts video on grounding and bonding where he does a wonderful job explaining the difference and purpose of the two. You are correct that earth grounding allows for dissipation of any static buildup or electrical surges due to "nearby" lightning strikes.
I'm gonna trim that comment out of the video to avoid any confusion, because it obviously isn't the reason to ground the panels. I really appreciate you pointing that out!
@@AdamDeLay07 haha dude I had the same issue and I spent countless hours searching and watching youtube videos trying to understand the purpose of grounding and bonding. Mike Holts videos are the best reference that I found for understanding the purpose of both and to understand the best code compliant techniques for wiring
I followed Mike Holtz explaining earth grounding of solar panels and bonding the ground of the system. I have 12 panels on an adjustable wooden ground mount. I have none of your issues with AC voltage back feeding the panels. In his series he definitely suggests not earth grounding solar panel arrays or generators. He does however suggest earth grounding the inverters and bonding all components including the transfer switch if used. This is a separate grounding rod specifically for the solar system and all components. I also installed EMP SHEILD units on my main grid 200 amp panel. The 2 inverters and my batteries. My system has worked flawlessly for about one year now and my panels are not earth grounded. Perhaps you have not grounded your system properly causing the back feeding to your panels. Please check out Mike Holtz and his series on grounding and and bonding. His expertise is used in court cases and has been documented many times. Personally I don't think your problem is with earth grounding your panels. I think it's with the way you earth grounded your system. Good luck and I hope this helps.
Sorry but I have to disagree with your statement. A separate roof mounted lightning rod ,or rods hooked to a earth grounding rod will dissipate a lightning strike. A grounding rod for an electrical system can actually attract a lightning strike. As will a metal light pole, flagpole, basketball goal, etcetera. Including your roof mounted and ground mounted solar panels or backup generator. Check out Mike Holtz!
@@djblingazworld yeah it all depends on the space you have as well as the voltage specs of your solar charge controller. In this video, the problem was solely due to the EG4 6500. It doesn’t matter what panels you have, you would still have the same problem.
The voltage on the panels is caused by parasitic capacitance between the cells and the conductive frame. Its not a fault its inherent in the inverter design and no indication of quality. Because the capacitive coupling is extremely weak you don't need to earth the frames but its better to do so for radio interference reasons. The multimeters read differently for two reasons. The switching of the panels to neutral is a square wave that inverts on each half of the AC waveform. Multimeters try to measure true RMS ac voltage and depending how they do it will disagree on the value. Secondly, because the parasitic capacitance is very small any load will quickly reduce voltage nothing low cost meters are much lower impedance and so load up the thing they are measuring much more and so you see a low voltage. A good meter will be very high impedance meaning you'll see much higher voltage, neither will be correct, you need a scope for that and I done it for you and measure 400V peak to peak on mine. If I stick my fingers on it my body loads it up reducing it to about 25V. Its neither dangerous nor anything to worry about.
If you are measuring AC voltage on the solar panels, this is a feedback from inverter. You better test your inverter, most of them high freq are floating.
Thanks for the comment. It actually turns out that this is a fairly common problem with the cheaper HF inverters. I've gotten quite a few responses from people using the same style inverter (whether SunGoldPower, MPP or EG4). In looking through the DIY Solar Forum, it seems like these cheaper inverters don't have proper isolation between the PV and AC H-Bridge. diysolarforum.com/threads/eg4-6500-voltage-on-pv-terminals.55201/#post-707937
I'm using my 6500 for home backup, but plan to add some PV. I did some measurements from the black and red PV1 input cables to gnd, and to each other using my Fluke meter. I don't think this is high frequency AC. I measured 230V from red to gnd, 190V from black to gnd and 40V between red and black. This is with the Fluke set to EITHER AC or DC. It appears that the path is very low impedance, so I can't just ground the black PV input lead, and I can't connect the ground lead from my Tektronix scope to either lead to look at the signal. I ordered a handheld battery operated scope so that I can investigate further.
Are you testing this with the panel connected to your inverter? Here's what I've found by someone a whole lot smarter than me on the topic: diysolarforum.com/threads/eg4-6500-voltage-on-pv-terminals.55201/#post-707937
I scoped the PV input leads to ground and found that I have a 430Vp-p square wave at 60 Hz on the black lead, and 470Vp-p square wave on the red lead. These are clean, well defined square waves. Is this normal?
@@AdamDeLay07 Thanks for the link. I will definitely weigh in on this. I also contacted Signature Solar about this and will contact EG4. There should be a warning in the manual. I think a lot of people probably assume that the PV input, being an input and not an output, would be safe to touch. I got shocked while wiring my PV disconnect breaker. It could easily be lethal. You can draw a LOT of current between either PV input lead and ground.
Personally, I don't get it either but it turns out that this is a fairly common problem with the cheaper HF inverters. I've gotten quite a few responses from people using the same style inverter (whether SunGoldPower, MPP or EG4). In looking through the DIY Solar Forum, it seems like these cheaper inverters don't have proper isolation between the PV and AC H-Bridge. diysolarforum.com/threads/eg4-6500-voltage-on-pv-terminals.55201/#post-707937
@@AdamDeLay07 yes but all of my solar panels do not have an electrical connection to either the positive or negative leads. The panel is suspended by glass.
@@RICHIE26636 correct, all panels should have an air gap between the panel and the frame. Like I said, I still can’t explain exactly how it’s happening at the panel, but it is coming from the inverters. Not being an electrical/electronic expert, I really can’t explain other than what’s been told to me by people much smarter than me.
Depending on the inverter used is the grounding of it,, EG4 will send charge back to panels,, dnt like it so it may be the issue ,, try measuring the voltage on the receptacle of the mppt side without panels...
If I recall, I did check that when I was upgrading my PV connections and I thought I was getting 35v directly from the terminals without any PV connection.
i was getting 70VAC @ 144 MHZ on my 8 x 340 watts array until i grounded it, your getting maybe 20 milliamps but it still give you a zap, doubt its dangerous but uncomfortable to the touch !
My question is this... even if the invertor is sending a signal out to the panels. How is it that the frame of the panel is connected to either the positive or negative wire of the panel. Do you show concuctivity between either of those wires and the panel frame? I'd hope not! In short.. how does ac on the wires translate into ac on the panel frame? My guess would be some kind of incuction from the panel traces closest to the frame.
I didn't see any conductivity between the panels and the frames. I've tried to understand how it's actually happening and haven't been able to figure it out myself, but I'm not the only one experiencing this issue. It turns out that this is a fairly common problem with the cheaper HF inverters. I've gotten quite a few responses from people using the same style inverter (whether SunGoldPower, MPP or EG4). In looking through the DIY Solar Forum, it seems like these cheaper inverters don't have proper isolation between the PV and AC H-Bridge. diysolarforum.com/threads/eg4-6500-voltage-on-pv-terminals.55201/#post-707937
I got shocked pretty good today by my shed and I know understand why “earth grounding” the all in one are necessary! My question is did you run your wire back to your service panel grounding or directly to the house grounding rod outside? Would love to see that part! Thanks so much for the videos!!!!
I believe I saw your thread on the forum. It's not pleasant at all... From everything I've seen, it should be run back to the main grounding conductor of the structure. When I set it up though, I had it on it's own ground rod. Can't say I fully understand it, but I can tell you I don't get shocked after earth grounding the frames. From what I've read though, the cheaper HF inverters tend to have little to no isolation between the PV and AC H-Bus.
If you put another rod in, it will create a ground loop between the two rod locations. These also won't connect the two locations (home/building/inverters) to panels thus they'll have different charge levels and can still shock you. The other issue is the "loop" issue which if lightning hits it'll pass through your equipment and loop back through the rod. This doesn't happen if you have 1 centralized location to go to into the actual earth-ground Which is why it should just be ran back to the house and then attached to the breaker box ground or somewhere there
I found the shocking aspect when the panels were wet. I was curious as well and after testing I thought the ac voltage on the panels was due to the solar cells producing power. I disconnected the panels from the eg46500 inverter as you did and found a small voltage still exists but then I added a small resistance load to the panels +- to get the panels producing current and the frame voltage when up so I assumed the frame voltage was a by product of the panels producing power. I would like your feedback on your thoughts.
Yeah once I discovered the “voltage leak” for lack of a better term, I avoided the panels when it was wet outside. Unfortunate I’m not super familiar with the underlying workings of solar panels. In your isolation test though, I’m assuming any voltage you saw on the frame would have been DC, correct? I guess either way it really emphasizes the need for grounding!
Thanks for the video, grounding is one of the hardest things to learn in solar! Can I ask what size gauge wire you’re using for grounding? I would imagine it’s eight gauge? 🖖
Grounding is essentially for safety of person. Nothing else. The theory behind grounding is that if a metal part becomes "hot" and you accidentally touched it, then it is expected that most of the current will not flow thru your body to ground but would flow via the ground wire/earthing conductor to earth. Taking the path of least resistance.
I don’t understand how the inverter is allowing voltage to leak onto the panel frames. Aren’t the positive and negative cables of the panels tied ONLY to the solar cells? They shouldn’t have any contact at all with the frame, unless there’s a problem, correct? At any rate, that’s precisely why we earth ground chassis and frames, to give a zero-resistance path for any misplaced current. It’s better than making a human resistor out of some poor soul.
So interesting that many of us have the same inverter clones but varying issues. This made me curious. I have an SP6548 that has been giving me issues with flickering from day one. It too had ac voltage on the frames of my ground array before I grounded them. I borrowed aMPP LV6548 that I hooked up yesterday and 0 flickering lights. This video made me want to check the panels. Just pulled my grounding rod and checked... 0 ac voltage on my frames. Is this voltage leakage from the units another defect? Brought up a great point, always ground your panels. Thanks for the video Adam.
Thanks! That’s interesting that you showed 0v when testing the LV6548. I’ve heard those can have a nasty zap. There has to be another common denominator. I’m wondering if it’s using AC In. Have to test to find out.
@@AdamDeLay07 Watts247 has the LV6548's on sale right now. After all the headaches and what I spent on filters, rma shipping, new bulbs, dimmers etc .. for 1k... just cutting my losses at this point. Something deff not right with these units.
air friction creates static. you can take a bare copper wire and set it vertically in the air and it will produce voltage. the higher the wire the more the voltage. main reason they run lines in the air, that static helps boost the grid
Hahah. That's funny, but not true. Transmission lines are in the air because air is a great insulator. If one were to try to bury the lines instead, the cost of doing so becomes enormous because massive amounts of extra insulation would be required. Transmission lines are HIGH up in the air because they are energized from tens to hundreds to even a million volts, and that energy can easily couple into anything nearby. Since ground is basically ground, such coupling can be catastrophic. So the lines are high up in the air... and even so you can still feel the electricity in the air when you walk under a high tension line. There is a voltage differential in the air that goes up with height, and the voltage itself can be quite significant. But the amount of current you can draw from it is miniscule because you more or less instantly deplete the electrons in the air next to the wire (wind or not). i.e. the voltage differential will disappear when you try to suck energy out of the wire. Static electricity from air friction is an equal opportunity employer. It isn't generally all that much energy in the first place, and it applies equally to all the wires in the transmission line so it does not create any sort of voltage differential that could be harnessed.
@@junkerzn7312 you are just repeating what you were told by another that has no clue. all you have to do if go read about other things and put it together but you wont , it requires reading lot of it and ohh yeah, the ability to comprehend
In my case there was no buzz, but i was feelinig it. Definitely not pleasant. Makes me wonder though why in my case it was stronger, but I do have a 240v mpp solar, so the voltage is probably higher.
That’s provably it. I know a friend of mine had one array that had a mix of panels between the two inverters. They were all bonded together using the mounting hardware but not grounded. He got a really good jolt when he touched his. Said he never felt anything like it. Had to be due to the fact that a part of the array was going to one inverter and the other part was going to the other inverter. Double whammy.
Run an equipment grounding conductor with from the frames of the panels with the dc conductors to the ground terminal in the inverter. The ground terminal in the inverter should also be connected to the associated ac distribution panel and the grounding electrode system. This isn’t a mystery and it is mandated in NEC 690.45 and 690.47. Not much of a mystery.
Real test is take your shoes off and lick the solar panel. If you stick to it then something is wrong. That coating on the frame of the panels is to prevent grounding it's there to isolate them.
That was static electricity, not "back feeding of the inverter". The only thing that can backfeed from your system is the "niose" or harmonics from the inverter.
Apparently this is a common problem with cheaper HF inverters. There’s no isolation between the PV and AC. diysolarforum.com/threads/eg4-6500-voltage-on-pv-terminals.55201/
This subject is confusing to me. An expert told me if you ground the pv wire before charge controller, their should not ba a problem with inverter feeding back AC current to panels. DC power doesn't need grounding because its a 2 cable system unlike AC power which is designed with 3 cables to be grounded.
Most systems I’ve seen, you should not be grounding the pv wire at all. Your correct, DC power doesn’t need a ground, it’s all about safety though. It turns out that this is a fairly common problem with the cheaper HF inverters. I've gotten quite a few responses from people using the same style inverter (whether SunGoldPower, MPP or EG4). In looking through the DIY Solar Forum, it seems like these cheaper inverters don't have proper isolation between the PV and AC H-Bridge. diysolarforum.com/threads/eg4-6500-voltage-on-pv-terminals.55201/#post-707937 If you're interested in learning more about earth grounding your panels, I found this resource on the diy solar forum to be extremely helpful! FilterGuy does a great job explaining things for even someone like me to understand! diysolarforum.com/resources/grounding-made-simpler-part-3-solar-panels.160/
Electricity always wants to return to source, it doesn't favour going to ground like people think, the ground has a high resistance. If there is a power leak that should be stopped, not just connected to ground in the hope it just goes away
It turns out that this is a fairly common problem with the cheaper HF inverters. I've gotten quite a few responses from people using the same style inverter (whether SunGoldPower, MPP or EG4). In looking through the DIY Solar Forum, it seems like these cheaper inverters don't have proper isolation between the PV and AC H-Bridge. diysolarforum.com/threads/eg4-6500-voltage-on-pv-terminals.55201/#post-707937
@@AdamDeLay07 I guess part of what I'm meaning is, it takes both voltage and amperage to electrocute someone, only about 50v and 0.1 amp depending, especially across the heart. You were over the 50v but the amps are unknown, at this point, clearly it was very low and or your shoes were good insulators on dry ground etc. Older auto ignition systems ran at 40kv+ but amps were so low you would only get a non deadly shock etc. I'm wondering if the inverter manufactures are allowing some residual a/c voltage backflow, but just being very limited on the max allowed amperage, so they think it is safe. And this is also why the SEARS multi-meter didn't work accurately in that situation. Still concerning that they would make them that way, thanks again!
It sounds like you have a floating earth bonding issue??..might be a good idea to also check your house earth bonding as well??.. could be a issue with the big inverter earthing (by yours mains fuse board).. sounds like it's floating??
Thanks for the comment. My main ground is intact and not floating. Apparently this is a known problem with cheaper HF inverters. There’s no internal isolation between PV and AC.
Now I wonder what these inverter/MPPT units backfeed when panels are mounted in a mobile application (RV, cargo trailer, etc). No chance to regularly earth the panels in that scenario.
@AdamDeLay07 you do, but it's not "earthed". Would that make a difference? The DC circuit is grounded to the chassis, which is considered the 'zero potential' or 'reference ground', but that isn't the AC bus. So I'm not sure really...
