MPP Solar LV6548 Inverter, Neutral+Ground Bonding, Completely Off-Grid
Vložit
- čas přidán 5. 07. 2024
- Featured Products: (affiliate links)
LV6548 Inverter... www.currentconnected.com/prod...
Reliance Transfer Switch... amzn.to/3quifk8
A discussion around the neutral ground bonding screw within the inverter and the reasons for removing it while using the inverter in an entirely off-grid application.
WARNING: Lithium batteries are dangerous and can result in fire! This video is NOT intended to be instructional or a "how-to" lesson. I am not a professional. Do not attempt anything you see here without first contacting a certified and/or licensed professional.
Chapters:
00:00 Introduction
00:30 MPP Solar's Response
02:07 Test System Wiring
03:32 Why Remove the Bond?
04:40 Reliance Transfer Switch
07:05 Conclusions
Recommended Stores: (Using these links helps support this channel)
Current Connected... store.currentconnected.com/?r...
Signature Solar... signaturesolar.com/?ref=lithi... ($50 Discount Code "LITHIUMSOLAR50")
Best LFP Source... www.18650batterystore.com/?rf...
SanTan Solar... www.santansolar.com/?ref=lsolar
Battery Hookup... batteryhookup.com/discount/BA...
Batrium BMS... www.batrium.com/
Contact Info:
My business email is lithiumsolardiy@gmail.com. You may contact me for sponsorships, product reviews, business-related questions, or any similar reason. I am not available for personal project questions or consultation. I will not respond to these emails.
NEW Twitter Page... / lithiumsolaryt
Disclaimers and Statements:
► I receive a small commission on purchases made using my affiliated links shared the video description and comments section. The views and opinions expressed here are my own, unbiased, and not influenced by this commission in any way.
► My videos are in no way intended to be instructional "how-to" lessons. I am simply documenting my project for informational purposes. Property damage, personal injury, or death may result, even when following manufacturer's instructions. I cannot be held liable for such damage or injury. It is YOUR OBLIGATION to ensure that you are complying with any local and federal laws as well as code and permit requirements. - Věda a technologie
LV6548 Inverter... watts247.com/product/lv6548-6-5kw-120v-solar-inverter-4kw-250v-mppt-bms-ul1741-built-in-wifi/?wpam_id=97 (affiliate link)
If there's anything you feel I missed or did incorrectly here, please let me know!
Hard to tell what size conductors you have chosen in your main panel. I think your main bonding jumper is sized incorrectly. The minimum size allowed is size 8 AWG copper and should be sized based on the size of the ungrounded conductor.
The THHN conductors from inverter to panel are #6. Are you saying the bond jumper should also be #6 to match? I used a piece of #10 in the video.
@@LithiumSolar If your ungrounded conductor is #6 then the main bonding jumper has to #8 minimum according to the NEC article number 250.102 (C) (1). Thanks for for the detailed reply. That's why we don't lose the bonding screw! haha
did you connect to an earth ground? did you remove the N-G bond screw
I talked to watts247 and Ian said that if wired as the manual says you shouldn't have any problems adding A/C input because the relay takes care of all of the N-G connections, I'm still confused on how it wouldn't cause a problem if wired into a panel that already has a N-G bond though, MPP told me that in order to meet UL it is required to have a N-G bond under battery mode
Andy Y at MPP Solar is very good for support. I've contacted their support twice in the last three years. They are always very helpful, and any spare parts are quickly dispatched, even for older model inverters. Cheers, from Australia.
Very good and correct information. I cannot think of a single circumstance where the bond should take place inside the inverter.
The bonding jumper has one single purpose: to complete a path from “neutral” to the equipment ground in case of a short circuit so that the breaker will trip. Having the jumper inside the inverter guarantees that a fault anywhere in the system will shunt some portion of the fault current across the circuit board, likely causing damage; even if the fault happens downstream of the inverter.
MPP should ship the inverter without the bonding screw installed.
The ship it this way so they are code compliant.
A lot of appliances come bonded neutrals from the factory, and I can’t understand why… Dryers, ranges.. etc. ??? This seems like the minute you plug in the appliance, you create a second bonded neutral in your system which is a giant no no. Why do they do this?
To Bond N-G or not to Bond N-G, that is the question. This subject sure has consumed a whole lot of "band width" lately on YT and on the DIY Solar Forum. I suppose its never redundant to discuss safety issues, especially one that seems to be so misunderstood. Thanks for the excellent tutorial, with so many new DIY'er entering this space we want everyone to be safe.
That helped me understand the dreaded ground loop scenario much better. Thanks for sharing the info.
This actually made a lot of sense 👍
@LithiumSolar So if you're only running one of these, have it connected to grid power at your main panel and your output is connected to a reliance transfer switch you should remove the bonding screw in the inverter correct? Thanks for all the great videos! Been following them to assist in assembling my own system!
Great video. I have two LV6548's that I am connecting for off grid. All I have left is the ground, as my data from my supplier shows each inverter grounded. But I don't see a grounding connection.
Others have mentioned to use the AC in ground lug. I to have the same 100a panel for my RV to connect to. It is bonding neutral to ground. I have the two 8' rods driven into the ground for my ground. I am going to remove the inverter bonding screw also.
If only one LV6548 is being used, it does not connect the ground to neutral when in pass-through mode, and you don't want to connect the ground-neutral at the LV6548 output panel either, as the bond is at the input grid main panel. When in battery/solar mode, the LV6548 uses a built-in relay to connect ground to neutral, providing a solution in the single LV6548 case. For multiple LV6548's all but one of the units need the bonding screws removed so that only one LV6548 provides the relay ground-neutral bond.
If MPP Solar shipped units without the bonding screws, then when running in battery mode, there would be no ground-neutral bond at all, unless the bond occurred at the output panel, in which case it would case a problem when the units run in grid pass-through mode. Also people may lose the bonding screws if not in the units.
If MPP Solar shipped units with bonding screws, then its OK for single unit operation, and for multiple units requires bonding screw removal for all except one.
If the designers had used the presence of the synchronization cable between units on all slaves, but enabled ground pass-through only for the master, then this entire mess could have been simplified.
It would seem something like that should be indicated in the user's manual; however, there's no mention of the ground screw whatsoever.
I’m a bit confused. I been using one lv6548 off grid with my 48v battery system and 4000 watts pv array and works great as I just hooked ac output to a 20 amp Home Depot surge protector temporarily. Works great however I use max 2500 watt loads. I recently bought the manual recommended 4awg for the ac output and wiring that to a simple sub panel so I have two breakers but then I noticed the green wire and this video issue. I’m planning to wire the sub panel grounds on a grounding bar that will also accept the larger green 4 awg ac input and run a ground wire to a grounding rod but is all this correct or even necessary? I don’t want to create a issue so I’m wondering how to do this easily. Any help will do. Thanks for great videos and content regarding lv6548 and solar in general! Top notch!
Great video, so if I understand correctly, this switch could be used to isolate a solar system from your main panel AND provide the solar subpanel with a neutral ground connection at the main panel AND allow backup main panel electricity to the switch? So once the switch was wired to the main panel, no additional ground neutral connection would need to be made corect?
Very relevant info. Thanks. Question - When adding inverters and maintaining 120/240, do you need to add them in two's?
I have the same transfer switch. It's served me well and great for solar and generator power.
My wife and I have a property where we wish to set up off grid solar/wind with generator back-up for our RV. Is this the type transfer switch best used for a 50 amp service to the RV?
So to use it with the N-G bond in the inverter you would wire it to a sub panel? If you wire it to an already existing panel I would remove the N-G bond from the inverter? If you use the Protran transfer switch I would remove the N-G bond in the inverter? If you use the AC input for pass through i would remove the N-G in the inverter for transfer switch, sub panel or existing panel?
Just commissioned two LV6548 inverters with grid connection wired as per MPP wiring diagram with one modification, I added ground lugs to the metal cabinets and ran a # 6 wire to a separate ground rod. I did not remove the bonding screw in the inverter. There was current flow on the white neutral wire but no current flow on the the green grounding wires. I’m not an electrician.
Yeah I am adding the ground rod and bar in panel box now but wondering if I need to take the screw out still if I just put my green ac output wire to ground as its a ground
Great video.. Curious what breaker panel you using?
I am using a Xantrex 2000/ 12V inverter which has an internal neutral ground bonded. I do not know how to defeat the internal ground connection at the inverter. (No info from Xantrex). So, to use this inverter, through a transfer switch, I had to not connect the ground from the inverter to the ground at the service panel. The question that I have is: Is it safe to not connect the ground from the inverter to the ground at the service panel? It seems as though you would still have fault protection through the circuit breaker in the service panel. Thank you for a great video.
I am glad MPP Solar responded to you. I have not been so fortunate. I am wanting to install four LV6548 inverters after so many positive reviews. However I am trying to select the best solar panels to use. The question I have asked MPP through their online form (twice) is about overpowering the inverter. Its rated for a max solar Voc of 250vdc and 8000 watts (2x4000) per inverter. Will the inverter limit the voltage and current or will this damage the inverter? From other end users comments it appears you can increase the amps and the inverter will limit it but increasing the voltage above 250vdc may be a problem. My goal is to have the inverters start producing power earlier in the day and produce later into the day even if I am not able to use 100% of the solar power during the peak sun hours. I am hoping MPP will respond before watts247 is out of stock again. Almost forgot to say thank you for your videos and information you share.
I think I found the information I needed, please respond if you see something wrong with my thought process. Page 7 of the LV6548 manual says, "Exceeding the maximum input voltage can destroy the unit!!". A well known US distributor said the wattage may be exceeded as I had hoped however the manual says, "maximum current load of each PV input connector is 18A". If my math is correct 250V at 18A that would be be 4500x2=9000watts so there does seem to be a bit of wiggle room. Looking at page 9 the recommended arrays seem to show the inverter being over powered if using Voc. Their calculations use Vmp and Imp for a total of ~7918watts. Using Voc and Imp the total is ~9307watts and using Voc and Isc the total is ~9887watts. In all scenarios the PV voltage is below 250Vdc. 6x33.7(Vmp)=202.2Vdc and 6x39.61(Voc)=237.66Vdc.
Max Amperage is exceeded in all scenarios. 2x9.79(Imp)=19.58Amps and 2x10.4(Isc)=20.8Amps. It appears the main thing is to keep the voltage(Voc) below 250. Sorry for the lengthy comments, and again, please correct me if I'm wrong. Thank you.
LV6548 Manual here > watts247.com/manuals/mpp/LV6548.pdf?x49702
I wrestled with this for two weeks. Saw a video you did about the internal ground screw.
I removed it, and all was well till Ian came along. A week before the storm, had lots of rain, and not much sun. Then the storm came by. My Bigbatteries died. Thought I had it figured out, as I ran A/C / Grid power (Generator) to try to charge the batteries. Ran generator, turned on connection, and the MPP's started flashing on and off. Could hear the relays kicking in.
didn't
don't
Great video, but I am still stuck.
Great video ! I’m doing a Battery Back up in case we lose electricity at night or during a storm , I have 4 100W solar panels which will be used to help charge my battery banks , I’m also messing around with alternative energy sources like a GM 10 SI 110A Big block low spin alternator & a Ford Mazda 150A eclipse alternator & a Gm 10 Si 120A High Amp Alternator which will be turned by 12V Dc motors , the only issues I see Are you are not supposed to leave constant current from the battery to the alternator or you can burn out a diode inside the alternator but I have testers and alternator 120 amp alternator with battery powered impact gun in my multimeter ground touching the case and the positive wire through the back grate of the alternator on the Gm you see 3 copper wires on the top under the case I was touching the wire on the left which is one of the exit points of the stater which is the copper winding underneath the case which AC current is flowing and then is translated into DC card for your automobile I tested 1,200 volts 1 Kw & 200W now I have to solder Romax wire to that each copper wire from what I’ve seen is a different phase the GM have three faces the Ford Mazda has five and also what I’ve learned because the magnets are so close to the copper winding it is very true sine wave because The closeness of the magnets to the Copper so literally you could run that electricity straight into your house and it won’t damage your computers or electrical items within your home but initial muscle having is trying to find an electrical modular to flow the battery voltage and the draw my home uses to Either stockyards in the spinning which will be controlled by the battery powered electrical Dc 12v , 3 generators the alternators & solar ! I figured out how to use it but trying to find the pieces that may not have been created yet to use ! I keep DC To Dc converter 60v to 48v step down 100A they do not make , or an Electrical Module to fallow the battery voltage and electrical use to send Dc 12v electricity to the Dc motors to start spinning to crest the electricity using “ but unable to find such an Animal on EBay , Amazon, AliExpress or Google ! If any knows where to get these items I have explained please leave a note where !
HOWdy L-S, ...
Thanks ...
That was a great EXPLANATION ...
COOP ...
the WiSeNhEiMeR from Richmond, INDIANA
...
Great video
great vid, MPP pic show to remove the screw mark in Red circle? all 12 of them? While I understand the N-G bonding should be only one place, what is the benefit of NG bonded at the panel, instead of inside the inverter?
The screw with the pink checkmark gets removed. This entire video was to explain why what you're proposing does not work when connecting the inverter to a main panel with a transfer switch.
In case of a fault, the ground wire can carry up to the maximum current which that inverter can output for a brief time until it's Over Current Protection engages. All that current will go through that PCB and screw! I would prefer it to go through a proper sized wire in the panel tbh...
I had a problem with my mpp lv 6548, the manufacture send me one of your video, ( and after long time I was able to fix the problem ), now if i can I will make you a question: how do I turn off not stand by but turn off my 2 6548 in line, that is connect on solar and battery only? Thank you!
Same issue with the growatt 3K inverter I have. I'm completely off grid, growatt still has bonded screw in place. If I don't bond N-G in my panel, my plug tester says I have an Open Ground. If I bond N-G in the panel, tester says my connection is good. How can get rid of the Open Ground without bonding in my panel?
Do you have your panel ground bar connected to a wire that goes to a grounding bar and if so can you refer the product to buy if needed? Thanks again
Are you referring to the 2nd ground bar I added in the breaker panel in order to keep the neutral and grounds separate?
Thank you.
Awesome video! That was very well explained and I have no doubt that an electrician would recommend this video! Also thanks for explaining the generator transfer switch, I havent seen how those are wired until now, they're pretty simple. One thought I have is that the neutral is very interesting, the generator transfer switch doesnt do anything with the neutrals because it just leaves both connected all the time. If it is running on generator supply then that current has to flow back to the transfer switch over the common neutral, so that wire should be the same gauge as your generator input. Hopefully people that may upgrade the generator connection and breaker upgrade that wire also.
I live in South Texas my house has a neutral to ground Bon in the main panel and it also has a neutral to Brown pawn in a meter
I have an LV6548 coming my way (soon, I hope). I know you went over this pretty thoroughly, but I am admittedly ignorant about the small details. What would be the downsides of leaving the screw in the LV6548 in and not bonding the neutral to ground? Is it because you want to use an actual ground rod for the breaker box? It does seem (again, speaking out of ignorance) that you would never really be grounded without the rod. I just don't want to take a chance of voiding my warranty for opening the unit. Any insights are appreciated, thanks.
In theory there is no downside in leaving the screw inside the inverter. You just need to make sure it is the only bond in your system, and best if you as well put a sticker on your inverter saying the N-G bond is inside there. You can still install a grounding rod to your panel connected to the grounding bar, and you will have to do this anyways if you want to use GFCIs and protect against ground leakage (humans touching L conductor in a grounded system and non-floating N). As Lithiumsolar said: there can be only one bond, and that's already all what is to say!
Now to the downside :) : In case of a fault, the ground wire can carry up to the maximum current which that inverter can output for a brief time until it's Over Current Protection engages. All that current will go through that PCB and screw! I would prefer it to go through a proper sized wire in the panel tbh...
@@RolandW_DIYEnergyandMore Thank you for that very informative reply!
@@SlimSh8E if you are connected to your main panel don't install your own ground electrode leave it to your main panel to ground. Email from MMP:
inverters now are with N-G short capability under inverter mode and when in line mode, N-G is OPEN. This is handled automatically and it's in line with requirement for application.
End of email.
Also leave your panel after the inverter unbounded. Don't mess with safety on your equipment it's UL listed for a reason
@@Roll2Videos I’m definitely far from an expert. But isn’t this inverter just “UL certified” not UL listed. How can we be sure that MPP Solar hasn’t made a mistake on this bonding issue?
@@RolandW_DIYEnergyandMore what if someone was running multiple inverters together wouldn’t you need to remove the bonding screws in each inverter because if you didn’t you would have more then one Ground Neutral bond? It seems that MPP really would need to have good documentation around this issue since they advertise these as able to be run in pairs up to 6 units?
thanks. don't forget the self heating basen batteries. We just got ours, but I'm not breaking them open. ;-)
I am connecting mine to my mobile homes breaker box and I am off grid. Should I remove the screw?
Would removing the neutral ground bond screw in the inverter change how using a generator as an ac input change?
At the very end when you describe the scenario where the inverter is connected to the grind panel where the N-G bond is already done, you did mention that the sub panel should not have the bond but didn't mention that the bond should also be removed from the inverter. But it should be removed everywhere, yes?
So that there's only a single N-G bond in the entire system.
Off grid only with solar and backup generator. No grid feed. Should I earth ground at the all in one inverter case grounding screw seeing as that is my main service input to my sub breaker panel? Then how should i proceed if my generator becomes my main power source as a pass through and charger on my inverter? Do I keep the neutral and grounds together in my sub panel or separate? This is so confusing when you are not grid tied to the main panel earth ground. Any advice would be greatly appreciated.
I would suggest running this by a licensed electrician. I am not one and cannot give direct advice (sorry, I know that's probably not the answer you wanted).
I wonder if this is the same for the Growatt SPF-3000-LVM. Do you know?
I don't know anything about the Growatts to be able to comment. Some of theirs do look very similar to MPP Solar products...
I'm going to have to watch the video a few times. I thought will prowse is saying something different I just wired mine up today I just have one inverter and mY my neutral and ground are bonded in electrical panel. I think I did it like will prowse said. I better watch both videos again.
I know my power worked properly. I got 120 V I was running my compressor no problem.
Completely off-grid stand-alone
If you're not sure, best to be safe and ask an electrician. I am not one of those 🙂
I’ve read all the comments and still have one question: If I connect A/C power input from my main house and then create the exact same setup that is in this video, do I need to remove the N-G bond screw in the inverter and NOT add an N-G bond in sub panel b/c the N-G bond is coming from my main house panel?
If you keep the neutral bar and ground bar separate in the sub-panel then no - you should not need to remove the bond screw. The inverter disconnects the bond when it's operating in grid pass-through mode. That said, I am not an electrician and would encourage you to have one evaluate your plan ahead of time :)
sorry if i missed it , what size are your pv arrays panels wattage amperage , I'm finding it hard to stay below 18 amp inputs
I haven't actually connected any panels to this inverter setup yet. I'm kindof out of room to put panels at this point unfortunately...
Only bond the ground to the grounded conductor in a AC sub panel if you dont have a equipment ground from the main . Yours is more of A main panel so both can be used on the same bar. If you at least have a good ground electrode and 2 rods.
Do you have a clearer picture of the GN bonding screw? It is close to C59 ?
Yes, it's right next to C59 on my inverter. If you're not sure, MPP Solar's customer support can help.
I have asked others on this type of setup. With a 48v all in one inverter/solar charge controller and a very large rack battery. Can that breaker panel be wired to have a 30amp socket to plug in a RV plug. My simple mind thinking that I could build a system like this in the back of my 5th wheel under the sofa, with that receptacle wired out the side wall. Then the solar array wired down the back and into that setup. Then just plug the RV into itself like I was plugging into an RV park electrical pole. That would eliminate all the other wiring setups. And I would leave room to add additional rack batteries.
Short answer: Yes. My system is set up in [and on] a couple of shipping containers, and I ran 6 gauge wire from a 30a breaker to a outlet mounted on a post. Shore power!
As your circuits are set up there, you are working with a floating Neutral. Is that a concern for you? Or is that ground in the panel connected to a rod somewhere? Some modern appliances do need a true ground reference to work. I was always interested in how this looks like on these US split phase inverters when they have a floating N. Can you measure that N of that panel towards a G-pin of an outlet of your normal house installation? What does the Voltage say?
How does an appliance know if it has "a true ground reference" and for what purpose is it needed?
@@Sylvan_dB, those are mostly devices which burn some combustible substances like gas heaters, boilers, etc. They must make sure that the body of the device is on true Zero as it would be the last thing you want in your house to have sparks causing unintended explosions. As such appliances will also have metal pipes running to them, those pipes, etc. are also bonded to true ground by simply running through ground. Therefore, when an installation is connected to the grid, all these objects must also be electrically bonded to the equipment grounding system. But if you are using an off-grid inverter without a ground source, there wouldn't be such a bond and voltages would float around. Modern heaters do have circuits built in, which will monitor essential components for voltage build ups and not work if there is something suspicious going on.
@@RolandW_DIYEnergyandMore I understand all the why. I want to know how. I don't believe any such detection can be reliably done. If there is a way I've yet to see it, nor been able to devise it, and I've examined a lot of equipment.
@@RolandW_DIYEnergyandMore btw, I had to bond my gas line to ground. Plastic pipe feeds the meter, and eddy currents were flowing between my hydronic air handler, boiler, and the csst gas pipe in my house and the clothes dryer. The dryer was 3 wire, ungrounded, and the hydronic plumbing was grounded only via the boiler and incidentally the air handler. The professionals who did the gas plumbing and the inspector missed that requirement.
@@Sylvan_dB yes. You know, I was saying that it can happen because I had a few comments on my channel from followers, who said that their heaters threw out error messages for grounding issues and didn't work until they followed my instructions how to ground and bond their off-grid system. Home installations should never be ungrounded/floating neutral anyways.
Why would you not keep the inverter bonded, and just keep the distribution service panel not bonded? That is the situation I’m in right now, and would like to know if it’s necessary to remove the bonding screw from my hybrid inverter.
See this video czcams.com/video/Fnmjvg-7H8w/video.html
My question is on my inverter is single phase 240 input and 240 output? In the manual says L1 L2 N input and output is L1 L2 output. It’s a 12kw split phase inverter. On the output from inverter does not show the neutral line to the panel . So does the ground is jumper to the neutral like your in the main panel?
This is NOT a split-phase inverter. If you require split-phase power, you will need two of these inverters.
Yes I understand that. My inverter is a off grid split phase . It can be wired 240 output or 120 output. My question is, the manual shows for 240 output L1 and L2 to the main panel. And the N not showing any connection from the inverter. So that means I have to jumper neutral and ground in the main panel just like your.
Can you use 1 leg of the lv6548 inverter to power the transfer switch...
Yes you can, but won't be able to use any 240V double-pole circuits obviously.
Get permission from the inverter manufacturer before removing the screw. It may void your warranty. I had to call Signature Solar to remove my screw because there was a warranty sticker over the cabinet screw. I kept the email permission in my folder just in case. It took a phone call and finally getting through to the electrical engineer to explain why I wanted to do it. He understood and gave me the email permission to open the case. My ground/neutral is bonded in my main panel and my transfer switch keep the neutral intact to the main panel.
My setup is very similar, but I chose to leave the screws in place, and run grounds from a rod to the AC inputs. ONLY a ground, no other input. However, my questions are;
-I assume since MPP is ok with the screw removal, it does not void the warranty?
- Running 2 6548's for 240v split phase, which option is better, remove both screws and bond at the panel, or leave them both in place...or, maybe remove one screw?
I think your option is closest to a standard configuration, and if you scale up you just remove the screws from any subsequent inverters.
My assumption is that since MPP Solar indicated it was ok to remove the screw, that it would not void the warranty - but that would be a question to ask them. Running two inverters in a split-phase configuration completely off-grid, I personally would run both inverters with the screw removed like shown in the video.
You should remove the bonding screws in any circumstance. If you need a EGC bonding jumper, use an actual solid copper jumper wire in the wire space at the bottom of the inverter. You do not want to use your very expensive inverter as a fault current jumper.
@@paulmccoy2908 So if I ground my panels, combiner box, and inverters to earth ground, doesn't that defeat the idea of a "floating" ground, which is essentially what this config is?
@@LithiumSolar What if you did not use the ac input but your ac output connects to your main panel that of course has bonded neutrals. I have a panel like your small one bonded like yours, coming from my two inverters and from there 4 wires go to my main 200A panel that has a xfer switch built in. Should I separate the grnd and neutrals in the small panelpanel?
The best possible result is full control over where the G/N bond occurs. If you look at the way the grid works, this bond happens in the service entrance panel, not at the service transformer. They shouldn't be bonding inverters. Bonds happen in the entrance panel for a reason. The mechanism to handle the fault resides in the panel, not the source. Hence why bonding is done there.
Is Romex allowed to be surfaced mounted? I always thought has to be protected from damage even though it's in a basement inspectors will not allow it.
Does this look like a permanent installation??
@@LithiumSolarI just assumed it was since you had conduit between the panel and the inverter.
Please describe the following situation. What if a generator is used to power the AC input of the inverter while using a transfer switch with a ground neutral bond in the main panel.
That would require analysis by an electrician for a proper explanation. I'm not familiar with generators and how they typically connect to off-grid systems.
Hi, please help me with one simple piece of information. I have an 8kW Solar Mpp and 10 solar panels of 590Wp each. The inverter, in the description, is 2x4000W. My question is: can I put all the panels -5900Wp on a single input to the inverter? VOC is 42V for each panel - the inverter supports Max. 500V. Or how is it better to proceed? Please I wait for your answer ASAP. Thanks,
No, that does not sound like the correct way to connect them. If you're not sure, I'd suggest contacting an electrician.
Will the same method apply to the MPP LVX 6048?
I have not used the LVX 6048 so I can't answer with certainty.
Beginner here - Do you have the panel box grounded to a copper pole outside in the ground?
In this setup, the panel is not earthed. I am not an electrician and highly suggest contacting one regarding this topic if you're unsure. This setup is just for testing batteries, it's not powering a home or anything.
Good question he cant say that panel is his main panel without rod ground wire coming in from outside to earth bar
If the inverter was considered as your main panel with the G+N bond and you set up your panel as a sub would everything still work the same. Then with the automatic G+N bond when in inverter mode and when in grid tie the G+N is open (done by the unit) wouldn't the give you more flexibility?
This is what MPP said to me in a email
Hi,
Yes, all our inverters now are with N-G short capability under inverter mode and when in line mode, N-G is OPEN. This is handled automatically and it's in line with requirement for application in most countries.
Also note
In the event when inverter output is disconnected from grid, N-G needs to short to ensure there's no leakage voltage that could trigger RCD to trip. This is needed to ensure GFCI will work.
Would the GFCI in the unit still work if you move the bond
One more quick question does code state it needs to be bonded at the power source?
Yes, GFCI will still work fine in the example system I have here. Yes, if the panel was considered a sub-panel, you would want to leave the bond screw installed. This video is not about use with a sub-panel.
@@LithiumSolar I really like your videos but I don't think you are right about the GFCI how will it measure an amperage difference between ground and neutral if it is bonded after the GFCI? Also I'm not sure if I explained the main panel versus sub panel analogy properly. Thx
Unfortunately for those who want to use the Protran style switches MPP has also stated that any shared neutral solution is unsupported. We have had quite this Erie’s of go rounds on the forums on these topics.
When you say shared neutral, you're referring to the input/output issue where they cannot be connected, correct? If so, that would also not apply to the purely off-grid user; however, is still problematic for a product. I've been casually reading through some.of the threads here and there.
@@LithiumSolar point, and to your credit you did specify that you were not feeding AC in, but I still wanted to call that out. I loved my protran and used it for years as a pure emergency backup with a bonded portable genset knowing the risks associated with current on the EGC. These units don’t function well as pure standby backups when coupled with LIFEPO4 batteries that want to be cycled. These units are designed to be integral to daily ops. In a pure off grid situation then why open the inverter to remove a bond you will recreate elsewhere, and why use a protran at all. If you’ve no other source, the 6548 is your bonded source
@@edwardbyrd7667 inverters now are with N-G short capability under inverter mode and when in line mode, N-G is OPEN. This is handled automatically and it's in line with requirement for application
@@Roll2Videos huh?
I have a protran and I was told that the input and output neutral is bridged which makes it not work with the inverter
Could you please post the image MPP sent you for disconnecting the ground/neutral bond? I'd like to have that for reference.
The picture was shown in the video.
@@LithiumSolar Uh yes I saw the video, but a screen capture of that part is not even close to having the resolution that would make it any good for future reference.
@@vananderson2895 It's pretty much the resolution they provided to me (if you set it to 4K). You can obtain the same file from them by dropping them an email and asking.
@@LithiumSolar I'm sure it's absolutely beautiful in 4k. But not everyone has a 4k monitor. A screen capture records the resolution of the pixels on your screen, not the resolution of the underlying video stream, no matter how magnificent. And since CZcams doesn't have a "zoom" function, you can't screencap the individual parts of the image and piece together a nice, high res version of the picture your want.
So, as an alternative, the LV6048 comes with Gnd Neutral L1 L2 allready, would this solve the issue?
Isn't that one of the ones that actually has two inverters assembled inside the case? I don't have one myself to verify.
@@LithiumSolar That is an interesting question, I never had them apart !
So now you have me wondering, humm...
I see David Poz did a build Jan 11 2020 with the very similar 5048, he says in that vid that the 5048 is two side by side 2.5kw inverters set 180 degrees out of phase with each other. assuming this is correct, then, does this solve the potential problem?
So i couldn't resist, yeah I opened up the 6048, and yup it is two 3kw units side by side.
Using an ohm meter the Gnd-N are not connected.
Good points on confusing issue. However, not having the romax in conduit going to the outlets is concerning to me and makes it difficult to trust a course on grounding safety.
Romex is not typically run in conduit. The wiring should not be exposed at this height, however this is a test set up as I mentioned. Assuming you reside in the US, you should be following the NEC for wiring requirements.
@@LithiumSolar I have never seen Romex pass code outside of conduit below 8’. Per National Electrical Code: 334.15 Exposed Work. In exposed work, except as provided in 300.11(A), cable shall be installed as specified in 334.15(A) through (C).
(B) Protection from Physical Damage. Cable shall be protected from physical damage where necessary by rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC conduit, Type RTRC marked with the suffix -XW, or other approved means.
@@jcschwarb As I literally just said...
1) The wiring should not be exposed at this height (indicating that you are correct)
2) This is a test setup (it's been taken down long ago)
3) Follow the NEC
This system is not grounded untill you have ground rod with wire from outside to your earth bar , and double pole circuit breaker as your main breaker with ( L1&N) so L1 is your hot(Life wire and N goes to neautral bar .
You say your panel is main right? And you have L1 and N and E . That panel or your box should have ground rod to earth bar
Solar Grounding Issue
I watched this video
czcams.com/video/Fnmjvg-7H8w/video.html
And he discusses the issue of grounding, but still a bit confusing on if the bonding screw should not be in the inverter so ground is not energized.
Here is my thinking and please tell me if I am wrong:
All of the inverters should not have a grounding screw in them, and the sub panels off of inverters should also keep neutral separate from ground.
To get ground, either the inverters are all plugged into grid as backup power, so they connect to ground thru that plug,
if you decide to unplug ALL inverters (must be all so no crossing of grounds), then ALL Inverters’ plugs that would have bern plugged into the grid for backup power - should be plugged into a NON POWERED OUTLET that only has a ground connection no hot or neutral in this outlet, so that the inverters are all connected to a ground.
My thinking is to have an outlet strip or connected outlets, with a switch that in one direction connects ALL Inverters to the Grid power and grid ground (this is as backup power not for backfeed into grid). So in this scenario, all inverters have backup power and common ground.
When switch is in other direction, ALL Inverters are not connected to grid power for backup, those lines hot and neutral are not connected, only the ground is connected to a separate ground rod to provide ground for entire system when not using grid as backup.
Could achieve this with a separate breaker panel with two breakers that have metal piece to make so only one breaker can be on at a time.
And the ground wire to the inverters are switched from grid ground with power to
independent ground without power wires.
One breaker feeds from grid w ground
other breaker only feeds from separate ground
But you do not ground the box to the grid ground, it would have to be grounded to whichever active ground is being used at the time by the inverters.
Does that make any sense?
Please be critical I prefer to find the correct answer, my opinions are of no relevance if they are wrong.
Thank you.
excellent discussion for a non electrition LOL!
I can't tell if compliment or sarcasm lol, but either way - thanks :) Hopefully I didn't say something silly.
@@LithiumSolar Sorry for being ambiguous. I think this is a very good discussion about what could be an easily made mistake for non-electrician. I'm an EE but not an electrician so I will have to give your discussion a lot of thought when I'm installing a transfer switch with the LV6548.
Guess I have to change plans. The bonding screw you showed must be under the cover. If I remove cover, warranty sticker will be damaged. Plan B I guess.
I'm not sure what country you're in; however, courts in the US have ruled that removal of those stickers cannot void a warranty. Additionally, MPP Solar themselves stated that it was ok to remove the screw, so...
@@LithiumSolar Sent them an email, and haven't heard response yet.
Thanks for the update. Sure would make my life easier.
230 v system? grounding no grid mid jungle here
2:54 that wire is WAY too small for the capacity - should be 50A+
4:12 that also makes the breaker panel part of that potential voltage on ground / loop circuit.
I think you are misunderstanding a few things here...
Use 8 ga as others said.
Thanks. I will be replacing the ground/bond with #8.
Another point is where your reference to earth is.
In this example, the system is floating - no tie to an earth reference.
😎👌👍🖖✌🤓
Yes👍🔋⚡ 💡
🇺🇦✌☀
MPP putting MC4s shows how little they know about the US market.
Yep, needs a strain relief...
Around 4 minutes into your video you answered your own question... if you have one ground neutral bond in the machine itself ... then don't do it in the panel ... keep them separated in panel.... it's that simple. Not getting it.
I think you're missing the point of this video. There is no "separate panel". It runs through a standard transfer switch without a switched neutral.
first