Signature Solar EG4 6.5K Off-Grid Inverter | 6500EX-48

[ncsolarelectric]

What was acceptable in the past has NO relevance in a new install.

Grounding conductors have two and only two jobs in modern home wiring…

Static and surge dissipation, and overcurrent fault path…

Designing a system using the grounding conductor to carry current is a path to problems, and is against modern codes.

If that is your stance, then for you there is absolutely no way to parallel or split-phase configure ANY 120V inverters, except to void the warranty and the TUV UL1741 safety certification by removing the internal "customer inaccessible" N-G bond.

However, I will remind you and everyone here again, that when a unit is tested to a UL standard in a particular configuration and deemed "safe", it overrides the NEC. I have an Enphase system I just installed where the IQ Combiner 4, combiner box does not comply with the 120% rule that a service panel must comply with. Enphase specifically calls out in their manual that the 120% rule is not applicable, the IQ Combiner 4 is Code Compliant because it was UL Listed for this specific application. The same should also be true for the EG4 Inverters, given their cTUVus Certification to UL1741.

 

[ncsolarelectric]

i have a stupid question, unfortunately..whats the max amps the ac input can handle from utility? Is it the same as pv, 120a?

 

[HSN]

I am grateful for your responses and time.

I was less than clear about the situation. There will two separate systems at the same house. Currently, one is a standard residential 240 split phase service panel that feeds my house. The solar system is intended to be an off-grid source of power during grid outages that will feed a non-grid connected mini-split heat-pump and enable connection of 12 AWG extension cables to run a freezer, refrigerator, and a few lights in case the grid goes down.

An EG4 6548 EX inverter and EG4 5.1kV battery will be delivered 2022-06-01. I was going to connect my main service panel's AC into the EG4 6548 EX via a 125A sub-panel for AC into the inverter. From what I understand, to avoid more than one N-G bond in the house's electric system the inverter's N-G bond screw would have to be removed in order to enable grounding the inverter via the AC input fed from the main service panel.

Unfortunately, there appears to be no feasible code-compliant/permittable way to connect an off-grid inverter that is not UL Listed to a sub-panel connected to a main service panel. In order to have a legal installation in my area, a UL listed off-grid inverter must be installed by a licensed electrician and the installation must meet National Electric and International Construction Codes. Currently, the EG4 6548 EX inverter is not UL Listed. In my area, without UL listing, an inverter will not be permitted to be connected to the grid via a sub-panel.

Upon the realization that my original plan was not feasible, my thought was to run an Equipment Grounding Conductor (EGC) from the ground of the inverter's AC output panel back to the main service panel. To avoid multiple N-G bond points, the inverter's AC output panel would not bond neutral to ground but would instead be bonded back at the main service panel via the EGC run from the ground terminal in the sub-panel.

To make sure I have only one N-G in the system, I was going to remove the N-G bond screw in the inverter as if AC input power from the main service was supplied. I am still not sure if bonding the inverter's AC output panel to the service main ground is allowed by code.

Diagram 2 above is almost exactly what I was thinking with the exception that the diagram shows the N-G bond screw is still connected in the inverter.
Please advise on two questions:
1) if the inverter output AC panel is connected via EGC back to the main service panel's ground bar, should the N-G bond screw in the inverter be removed?
2) Does connecting the EGC to the main panel violate NEC code?

I apologize to the pros on the forum if my thoughts are naive, I am grateful for thoughts on the matter.

 

[wayne530]

I think people should stop relying on signature solar and others to figure out these products. I understand that they have a warranty and advertised use case, but if I had to ask them for help every two seconds, my channel would fail overnight. These systems are aimed at the diy market. When I am programming a microcontroller, I'm not asking the manufacturer every question I have. I'll find a way to make it work without asking for help.

And Richard works hard responding to questions. I feel bad for him. I appreciate what he contributes. It would be nice if some of you could say thanks Richard from time to time. And I'm not standing up for signature solar or any other solar equipment distributor. But man, they work a lot.

Totally agree, provided the manual has sufficient detail and information to answer installation questions. What I’ve found is that the manuals are missing information and in some egregious cases, contain plainly incorrect information. For example, and not at all to pick on Signature Solar, but there is no torque information for bolts on their EG4 battery or cabinet. When I emailed and called support, I got two completely different answers. Yes, these units target DIYers, but there are some things we should not need to guess at. Comprehensive and correct documentation would go a long way here IMO. The fact the LV6548 and 6500EX manuals have no discussion about how N-G bonding works in the unit is absolutely shocking (pun intended ).

 

[WilliamFR]

View attachment 96615

oh my god i don't know how i missed that, thanks

 

[HSN]

1) ....should the N-G bond screw in the inverter be removed? - Answered later in the thread - i.e., don't alter the certified configuration.
2) According to https://www.tuv.com/usa/en/ctuvus-certification.html
"...TÜV Rheinland of North America is accredited as a Nationally Recognized Testing Laboratory (NRTL), by OSHA (The Occupational Safety and Health Administration) in the United States, and as a Product Certification Body by SCC (Standards Council of Canada) in Canada. NRTL marks like those issued by TÜV Rheinland tell both consumers and business partners that your products have been thoroughly tested and specifically certified to comply with the electrical and fire safety regulations under the jurisdiction of the accreditation scheme.
...
With NRTL certification from TÜV Rheinland, you:

Demonstrate compliance with National Electric Code, OSHA, and SCC regulations and requirements"

That should mean that I can get permitted under the 2017 NEC.

 

[wayne530]

Looking for some assistance. I'd like to state the following.. this is my first solar project.... I may be an idiot. I purchased the 6500ex-48 from signature solar. I connected solar and ac in. I would like to use solar priority then grid to power the load. I can't seem to tell if I have this working. I do not have a battery connected as I plan to in the future. My goal was to simply reduce my kwh used from the grid during the day. When the inverter is powered on it shows a warning flash in the upper left of BP and the display shows bypass. I cannot seem to get this off of bypass, which I am under the impression is simply powering the load from the grid?

This may be a silly question, but did you update setting 01? The default is to run in utility/solar/battery priority. It must be set to solar/utility/battery by adjusting this setting. Please see page ~16 in the manual.

I’m not sure about the solar charge controllers in the EG4 inverter since they’re different than the ones in the LV6548, but there is also a minimum startup voltage. In my unit, it is 80V, which means below that threshold the inverter will not use PV. Have you measured the open circuit voltage of your string(s) to confirm you are above your minimum voltage threshold?

 

[wayne530]

If removing the bonding screw to make a safe and compliant parallel setup voids the warranty I can't purchase or recommend this product for those usage models.

I don’t know about EG4 (maybe @RichardfromEG4 can comment on this), but Ian at watts247 told me removing the bonding screw would not void the warranty on the unit.

 

[Zwy]

This has all be talked about at length in 2 other N G bonding threads.

That being said, the safety concerns have been addressed. A couple contributors here have opinions on what should be done, but being an all in one unit there are multiple use cases, and these units can fit many different types of installs. One of the installs that can safely be done, is a simple whole house main panel backfeed for OFF-GRID situation only. This Is for people that live in perhaps otherwise smaller residences with a single main distribution panel where the NG Bond will remain.

I understand that according to the manuals for these AIOs and the general "requirements" that these particular units all ship with the factory Bond Screws installed, are to operate by feeding a SUB panel only. In many places with sub 1600sqft homes and original 100amp max service to the residence, there is no economic or capacity based need to use a subpanel. The cost, time, and benefit associated with adding a "critical loads" panel to a residence such as this might b3 prohibitive enough for these use cases if that was the only way to install it. Many times the 100amp main load panel are all "critical loads" anyway.

The problem with just thinking one can use the existing main service panel and feed the inverters into it, is that you still need a main panel with N-G bond after the meter if one intends to have AC power on the inverter input. Either way you are adding another panel, either a main service panel (N-G bonded) or a subpanel after the inverters without N-G bond.

 

[ryantboldt]

This may be a silly question, but did you update setting 01? The default is to run in utility/solar/battery priority. It must be set to solar/utility/battery by adjusting this setting. Please see page ~16 in the manual.

I’m not sure about the solar charge controllers in the EG4 inverter since they’re different than the ones in the LV6548, but there is also a minimum startup voltage. In my unit, it is 80V, which means below that threshold the inverter will not use PV. Have you measured the open circuit voltage of your string(s) to confirm you are above your minimum voltage threshold?

I did change this setting to solar utility battery. Open string voltage was 200 volts.

 

[BuffaloTrace]

The problem with just thinking one can use the existing main service panel and feed the inverters into it, is that you still need a main panel with N-G bond after the meter if one intends to have AC power on the inverter input. Either way you are adding another panel, either a main service panel (N-G bonded) or a subpanel after the inverters without N-G bond.

The problem with just thinking one can use the existing main service panel and feed the inverters into it, is that you still need a main panel with N-G bond after the meter if one intends to have AC power on the inverter input. Either way you are adding another panel, either a main service panel (N-G bonded) or a subpanel after the inverters without N-G bond.

Note "OFF GRID".
I've read through the other threads with you guys on the different use cases. It depends on what you want to do and what you need require.

You're talking about adding a main service panel as if there is some new construction taking place. This is not the case for most people. Everyone has a main service disconnect usually containing the NG Bond. The use case I was referring too would be particular to many commonly used and standard approved and existing electrical installations.

In my case I won't be adding any electrical panels or load centers. I'll be utilizing a perfectly functioning 60 year old load center that contains an NG bond and generator inlet to a lockout breaker to be utilized for OFF GRID only. Otherwise one can always setup a secondary OFF GRID sub panel later if one wanted to add onto the offgrid setup later.

I have a unique situation wherein my plans would actually work best if these inverters could create NG bond in ac input / bypass and no bond in invert mode. But that's neither here nor there as my intention is entirely offgrid utilizing a lot of roofspace.

 

[FilterGuy]

Diagram 2 above is almost exactly what I was thinking with the exception that the diagram shows the N-G bond screw is still connected in the inverter.
Please advise on two questions:

Sorry.... there are so many conversations I am unsure what 'Diagram 2' you are referring to. Are you talking about the 2nd document in my resource? If not could you copy and paste the diagram you are talking about.

1) if the inverter output AC panel is connected via EGC back to the main service panel's ground bar, should the N-G bond screw in the inverter be removed?

I would like to see a diagram, but in general, I think the answer is no. By itself, connecting the EGC back to the main panel does not necessitate removing the ground screw. Whether or not the ground screw needs to be removed will be dependent on the N-G bonds and Neutral routing of the system.

Where things get complicated is the path of the neutrals and how Many N-G bonds might be in the system.

2) Does connecting the EGC to the main panel violate NEC code?

No. In fact, it is best to have a single EGC system within a building.

 

[FilterGuy]

I the dual example with AC connection you provided in your redline series I still see one bonding screw removed. I thought it was determined to leave all bonding screws intact?>

@bones1, I don't know if you were addressing that to me, but here is a response.

Edited for preciseness.
I have not determined that leaving all the bonding screws in place is correct for all cases. In fact, I believe there are some situations where the inverter bonding screw should be removed. (There is a significant disagreement about this on the thread).

I did not do the red-line document. The redlines all seem to be about routing the EGC with the current-carrying conductors. (Not about the NG-Bonds) There is a valid concern about the EGC routing and I am thinking about how to best address that.

 

[FilterGuy]

OK, I think I understand the issue now, however as I indicated, in my setup, there's is no AC input whatsoever. It's a manual transfer switch so whenever I wish to use mains power I just flip the switch. Now if I was going to use AC inputs on the inverter, it would make more sense to use the internal transfer switch and eliminate the reliance. And this is where I'm seeing the major disagreements as to whether it's safe with or without the screw. Who is right? I don't know, but I don't want to make an expensive mistake.

Is this what you have?


The problem with this is that there are two NG bonds. (Others on this thread do not see the dual NG bond as a problem, but I do.)

However, if you remove the NG bond screw the system will always only have one bond. (The inverter acts like a portable generator that does not have an NG bond)

 

[FilterGuy]

The NEC articles I think are applicable are 250.24 (Dual-Fed Services), para. (5)(C). Also, 250.30(6) Multiple Separately Derived Systems.

NFPA 70, NEC 2020:

250.24(5)(C)

Yes there is a need to run EGC with the ungrounded conductor. I will be updating the document with suggestions on how to do this.

The other part of this just says that the will be a Main Bonding Jumper at the service entrance. It does not address multiple bonding jumpers or multiple independently derived sources.

250.30(6)


This simply states that two different separately derived systems can share a grounding electrode. (I personally think that within a single building, they really should share the grounding electrode and not have separate ones. I am not sure why they did not make it a requirement)

This does not address the bonding question.

 

[HSN]

Sorry.... there are so many conversations I am unsure what 'Diagram 2' you are referring to. Are you talking about the 2nd document in my resource? If not could you copy and paste the diagram you are talking about.

I would like to see a diagram, but in general, I think the answer is no. By itself, connecting the EGC back to the main panel does not necessitate removing the ground screw. Whether or not the ground screw needs to be removed will be dependent on the N-G bonds and Neutral routing of the system.

Where things get complicated is the path of the neutrals and how Many N-G bonds might be in the system.



No. In fact, it is best to have a single EGC system within a building.

Sorry about the ambiguous diagram reference, I meant the bottom diagram in your reply to my earlier question that showed the EGC returning from the critical loads panel back to the main service panel. I think I am starting to understand both why there's confusion about this topic and questions regarding whether or not to remove the N-G bond screw in the LV6548 style inverters.

In my case, it may be safest to have an electrician install a sub-panel connected to my house main service panel to be the inverter AC input source which should then provide a single path to the grounding coductor at the main service panel. It appears that using a service panel supplied single LV6548 to serve as a battery/solar assisted UPS device actually makes the grounding of a single LV6548 relatively straight-forward: don't remove the N-G bond screw inside the panel; connect the Inverter AC out with EGC to critical load panel ground; do not create a neutral-ground bond in the critical load panel. Is that correct?

 

[FilterGuy]

Sorry about the ambiguous diagram reference, I meant the bottom diagram in your reply to my earlier question that showed the EGC returning from the critical loads panel back to the main service panel. I think I am starting to understand both why there's confusion about this topic and questions regarding whether or not to remove the N-G bond screw in the LV6548 style inverters.

In my case, it may be safest to have an electrician install a sub-panel connected to my house main service panel to be the inverter AC input source which should then provide a single path to the grounding coductor at the main service panel. It appears that using a service panel supplied single LV6548 to serve as a battery/solar assisted UPS device actually makes the grounding of a single LV6548 relatively straight-forward: don't remove the N-G bond screw inside the panel; connect the Inverter AC out with EGC to critical load panel ground; do not create a neutral-ground bond in the critical load panel. Is that correct?

Diagram 2 above is almost exactly what I was thinking with the exception that the diagram shows the N-G bond screw is still connected in the inverter.

Is this it?

In this diagram, the inverter is the only source of power for the critical load panel. As such, it needs to establish the NG bond. Consequently, leaving the inverter bonding screw in is the correct answer.

1) if the inverter output AC panel is connected via EGC back to the main service panel's ground bar, should the N-G bond screw in the inverter be removed?

No, it should not be removed.

2) Does connecting the EGC to the main panel violate NEC code?

No. It does not violate the code. In fact, the code specifically says two independently derived sources can share the grounding electrode. (See post #365)

 

[HSN]

Is this it?
View attachment 96670
In this diagram, the inverter is the only source of power for the critical load panel. As such, it needs to establish the NG bond. Consequently, leaving the inverter bonding screw in is the correct answer.


No, it should not be removed.


No. It does not violate the code. In fact, the code specifically says two independently derived sources can share the grounding electrode. (See post #365)

Yes, that is the diagram I would use for the inverter if I did not connect it to the main panel and used it only with solar and battery. The cognitive link I was able to make came from your excellent diagram that enabled me to see the flow paths clearly. I had some confusion regarding whether the EG4 6548 EX is 'UL Listed' but resolved that by going to the TUV site that verified it's certification was accepted as a synonym for UL Listing. Once I verified that both the battery and the inverter NEC compliant from a certification perspective, my original goal of connecting the inverter to a sub-panel fed from the main AC service panel became theoretically feasible if I can get the system design permitted by my city and the build to pass inspection. I an very grateful for the help you have given to me, what was obscure is now much clearer.

 

[wayne530]

I did change this setting to solar utility battery. Open string voltage was 200 volts.

Since troubleshooting this issue is not really related to this thread, you might get more help posting a new thread, or feel free to DM me and I'm happy to try to help. The LCD display probably has all the information you need to understand how the inverter is operating. Without a battery, it should show as:

or

where the former indicates that PV power is insufficient to power all loads, thus it is supplemented by the grid, and the latter shows PV power is powering all loads without grid support. See page ~38 in the manual.

You can also cycle through the LCD display (see page ~31 in the manual) to get some more detailed information on each PV controller. 200V is well below the 500V supported by the 6500EX.

 

[WattAboutThat]

I agree 100%. I'm going to stick with sol ark for grid tie recommendation. The UL certificates are still nice for Offgrid use, and some are saying they can pass inspection, but not everywhere. Especially in places like California. They have an approved inverters list and not many are on there.

I will always be objective. Ever since I was a little kid I was always arguing and trying to solve problems. If you think I'm doing something wrong, let me know. Signature solar sounds very confident that their system can pass inspections, but I would stick to using them Offgrid. I think the sol ark would be a better option.

And yes, even at the component level there are differences. I understand. And it costs a ridiculous amount of money to get full approval. I changed the title and thumbnail if the video, and also added a disclaimer. I'll add a section soon telling people to buy a sol ark, UL listed batteries, and get an electrician to install it. That way it can pass inspection anywhere on the planet.

Will, while I agree that Sol-Ark is the standard barer for inverters, and they are claimed to have great customer service, they make it extremely hard to become a dealer for their products, such that a small business installer can NOT afford to meet their massive barrier to entry, of nearly $600,000 per year minimum purchase requirements! This seems to be designed to keep the small business installer away from using their products. So if you are not a million dollar enterprise from the get go, your company is not welcome to purchase, resell, and install sol-ark inverters! I for one find this outrageous!
Please clarify if the company claims different requirements than i have indicated. I got this info from one of their reps, which I thought was rude, disrepectful, and un-business like!

I would love to purchase, resell, and install
sol-ark products, but they apparently do not want any resellers that are not big corporations.

I am hoping maybe I just talked to a bad rep from the company, but so far I have not been able to get any different info from anyone else at sol-ark.

It is sad to see a great company put such unprofessional representatives into positions of power, that then make the company look bad.

But the bosses will likely never know how their sales representatives belittle potential clients, because the representatives have little business acumen.

I hope someone can show that what I am saying is incorrect, because I really do want to buy, sell, and install their products, but so far it is not looking like a possibility.

Please research and advise.

thx

 

[WattAboutThat]

If you have multiple 6500s, producing 120V at 180 degrees out of phase, each phase providing 120V to Leg 1 and the other to Leg 2, does this affect which Leg you should use to power the inverters, from the grid as a backup source of power?

In other words, does the AC from the grid, used to connect to each inverter, need to be on alternate power legs from the grid?

 

[WattAboutThat]

Can anyone determine if the 6500 inverters have an internal relay, that connects the Neutral to the Ground under defined conditions?

If such a relay exists, can we get a clear indication of which conditions cause the G-N to be bonded by closing the relay, and which conditions will cause the G N to NOT BE BONDED by opening the relay?

And can this open or close of the relay be programmed or modified in the settings or parameters?

thx

 

[ncsolarelectric]

The problem with just thinking one can use the existing main service panel and feed the inverters into it, is that you still need a main panel with N-G bond after the meter if one intends to have AC power on the inverter input. Either way you are adding another panel, either a main service panel (N-G bonded) or a subpanel after the inverters without N-G bond.

All you need is a fused AC disconnect, UL Listed with a ground and neutral bar. Then you make a line-side tap at the meter. Feed that directly into your inverter and then into the backed-up panel.

 

[ncsolarelectric]

If you have multiple 6500s, producing 120V at 180 degrees out of phase, each phase providing 120V to Leg 1 and the other to Leg 2, does this affect which Leg you should use to power the inverters, from the grid as a backup source of power?

In other words, does the AC from the grid, used to connect to each inverter, need to be on alternate power legs from the grid?

It's a good practice to keep things consistent, you don't want to cross phases between inverters. That could get confusing.

 

[Will Prowse]

Will, while I agree that Sol-Ark is the standard barer for inverters, and they are claimed to have great customer service, they make it extremely hard to become a dealer for their products, such that a small business installer can NOT afford to meet their massive barrier to entry, of nearly $600,000 per year minimum purchase requirements! This seems to be designed to keep the small business installer away from using their products. So if you are not a million dollar enterprise from the get go, your company is not welcome to purchase, resell, and install sol-ark inverters! I for one find this outrageous!
Please clarify if the company claims different requirements than i have indicated. I got this info from one of their reps, which I thought was rude, disrepectful, and un-business like!

I would love to purchase, resell, and install
sol-ark products, but they apparently do not want any resellers that are not big corporations.

I am hoping maybe I just talked to a bad rep from the company, but so far I have not been able to get any different info from anyone else at sol-ark.

It is sad to see a great company put such unprofessional representatives into positions of power, that then make the company look bad.

But the bosses will likely never know how their sales representatives belittle potential clients, because the representatives have little business acumen.

I hope someone can show that what I am saying is incorrect, because I really do want to buy, sell, and install their products, but so far it is not looking like a possibility.

Please research and advise.

thx

Oh sure but you can still distribute them for cheap as a small business from another larger distributor. Same with victron. Sol ark is not special in this regard. Same with large volume solar panels. Typically small businesses and installers simply buy them from larger distributors for wholesale prices. This is actually common across most products. Doesn't sound like you understand the industry that well. What type of distribution or installation business do you run? What are you currently selling?