Newer models of EG4 6500ex are built without the bonding screw

[FilterGuy]

It is too early to say for sure, but it looks like the ODM builds them in batches.

There is no way a seller is going to post a "This is the way to wire it" answer because that answer is subject to a huge variety of laws globally.

They said they will post a video of how the NG bonding works in the unit. It's then going to be up to the electrician to make it code compliant to the use case.

I don't see how this response is the negative you are painting it out to be. They said they are going to give the info. Is that not what you wanted?

I agree there are many ways to wire it, but I am not asking them how to wire it. I am asking whether the product supports a common neutral arrangement. There is an important distinction between the two. I am asking what the product specifications are, not how to wire it.


In order for an electrition (Or anyone else) to safely set the system up, they must know what the unit specs are.

 

[FilterGuy]

There is a relay inside the unit that will form a bond if no bond is present from an outside source, like an AC service panel. If AC gets disconnected, the relay kicks in and automatically forms a bond in the unit.

This describes the unit if the bonding screw is in place. Without the bonding screw, it does not work this way. Without the bonding screw, the relay is disconnected and the inverter never makes an internal bond. Therefore, when in pass-through mode, the output circuit has the grid bond but in battery mode, there is NO bond. If the user adds a bond to the output, then in battery mode there is a bond, but in passthrough mode there are two bonds. (Two bonds does not meet NEC rules) Consequently, without the bonding screw, the only way to set the system up is with a common neutral.

 

[FilterGuy]

You would have to add it. Which would be the responsibility of the installer.

How would the installer add it?

 

[Bud Martin]

We are shooting a video today to clear this matter up completely. There is a relay inside the unit that will form a bond if no bond is present from an outside source, like an AC service panel. If AC gets disconnected, the relay kicks in and automatically forms a bond in the unit. I invite anyone currently using these units to test this with an Ohm's meter. Or you can wait until the end of the week and watch our video. I will post the link in this thread.

So is the screw removed after you get the safety compliance certificate from TuV?
The certificate is date 4-26-2022, according to buyers here the date on the unit with screw removed is in 10-2022, so did EC4 resubmit the change to TuV? If they did then you should have new date of certificate.
Post #49:
I just received my replacement units a few days ago and I can confirm both units had the bonding screws removed. I had earlier units with the manufactured sticker showing 07/22 and those had the bonding screws. The newer units I have show 10/22 and those have them removed.

 

[vladkgb]

We are shooting a video today to clear this matter up completely. There is a relay inside the unit that will form a bond if no bond is present from an outside source, like an AC service panel. If AC gets disconnected, the relay kicks in and automatically forms a bond in the unit. I invite anyone currently using these units to test this with an Ohm's meter. Or you can wait until the end of the week and watch our video. I will post the link in this thread.

I just tested my units sent without the bonding screw (10/2022 build date), they are setup in off grid mode, no AC input for bypass. There is no bond between neutral and ground while they are inverting. So this statement is false:

There is a relay inside the unit that will form a bond if no bond is present from an outside source

 

[FilterGuy]

I'd like you to show the NEC rules for it.

The primary article for grounding and bonding in the 2020 code is 250.

The place that requires an NG bond in the 2020 NEC code is 250.24. (When you read it, keep in mind that in NEC parlance neutral is "Grounded Conductor"

Then go read 250.6 (Objectionable current). Since multiple N-G bonds create objectionable current, this section pretty much prohibits multiple N-G bonds.

 

[Bud Martin]

I just tested my units sent without the bonding screw (10/2022 build date), they are setup in off grid mode, no AC input for bypass. There is no bond between neutral and ground while they are inverting. So this statement is false:

Can you take the pictures of the AC Volt meter reading between L and Ground, Neutral and Ground during inverting?

 

[PreppenWolf]

How would the installer add it?

That's their job to figure out. The installer is responsible for code. If you buy a microwave, the microwave doesn't come with a schematic on how to wire your electrical panel. If you buy a solar panel, it doesn't come with instructions on how to build a solar system.

The AIO is one part of a system and the system installer is responsible for figuring it out. This is not a new concept in electrical or any other discipline where integration is required.

I get you want more info. Hey I'd like more info too. But the seller is not required to tell you how to build your system.

 

[FilterGuy]

That's their job to figure out. The installer is responsible for code. If you buy a microwave, the microwave doesn't come with a schematic on how to wire your electrical panel. If you buy a solar panel, it doesn't come with instructions on how to build a solar system.

The AIO is one part of a system and the system installer is responsible for figuring it out. This is not a new concept in electrical or any other discipline where integration is required.

I get you want more info. Hey I'd like more info too. But the seller is not required to tell you how to build your system.

If I understand that statement correctly, it is saying the seller and manufacturer have no responsibility to provide specs for the system.
(As I said in an earlier post, saying whether the unit handles common neutral is part of specifying the system so we CAN figure it out)

I guess we will have to agree to disagree.

 

[FilterGuy]

I put together a chart showing what configurations 6500 will work without the bonding screws.

Number of inverters	# of Bonding screws in place	Upstream N-G bond on Input	Downstream N-G bond on output	Common Neutral	Code Compliant	Comment
1 or more	0	None	No	No	NO	No N-G bond in battery mode
1 or more	0	None	Yes	No	Yes	The Downstream bond covers battery mode and any unbonded passthrough
1 or more	0	Yes	No	No	NO	No N-G bond in battery mode
1 or more	0	Yes	Yes	No	NO	Multiple NG bonds in Passthrough mode
1 or more	0	Shore power	No	No	NO	No N-G bond in battery mode
1 or more	0	Shore power	Yes	No	NO	Multiple NG bonds in Passthrough mode
1 or more	0	None	No	Yes	NO	No N-G bond in battery mode
1 or more	0	None	Yes	Yes	Yes	The Downstream bond covers battery mode and any unbonded passthrough
1 or more	0	Yes	NO	Yes	Yes	The upstream bond covers all modes
1 or more	0	Yes	Yes	Yes	NO	Double NG bond in battery mode
1 or more	0	Shore power	NO	Yes	NO	Shore Power Bond may not be present in battery mode
1 or more	0	Shore power	Yes	Yes	NO	Double NG bond in battery mode

Notice that without common-neutral, the only configuration that works is one without the grid on the input and a bond added to the output.

In order to support a system that has the grid on the input but without the bonding screws, a common neutral is needed.
In fact, if common neutral is supported, there are reasonable configurations for all stationary installs. (Including using the Reliance transfer switches)

Also note that without the bonding screws, there are no configurations that work with shore power (The bonding screws are needed for a mobile installation).

 

[Zwy]

The primary article for grounding and bonding in the 2020 code is 250.

The place that requires an NG bond in the 2020 NEC code is 250.24. (When you read it, keep in mind that in NEC parlance neutral is "Grounded Conductor"

Then go read 250.6 (Objectionable current). Since multiple N-G bonds create objectionable current, this section pretty much prohibits multiple N-G bonds.

Not what I'm referring to. Below is what I'm referring to.

If someone get shocked by a 6500EX that is not installed to code, the person getting sued is going to be the installer. Not the manufacturer. And since this is a DIY forum, not a professional electricians forum, the person getting shocked is likely the person who installed it so.... ?‍

I'm referring to this post, where he stated it wouldn't be installed to code. Does the code differentiate between changes made to an inverter N-G bond mid stream without noting it changed the N-G bond?

How could an electrician install this unit if they don't have any idea how N-G are to be bonded. If the unit had bonded N-G dynamically in the past and the wholesaler (Sig Solar) told them it does, (much like the post above in post #59) then the electrician would not bond a critical loads or panel with the inverter as source.

Then the wholesaler doesn't tell anyone they have been removing the bonding screw, the electrician is unaware and installs it the same as they always have.

Who violated the code? Does the code address this scenario? Nope, it simply states there needs to be one N-G.

 

[timselectric]

All that we really need from Signature Solar is to say whether or not they have a problem with common neutral. They don't have to recommend it. Just say that it doesn't create a problem for their equipment. Or if it does. And if so, the reason why would be appreciated.

 

[mudman455]

If it is a single unit and not wired with a common neutral, the internal bonding of the inverter must be left in place.


Depending on the setup, the internal bonding could easily make EMI worse because of the loops in can create.


You are touching on the major concern I have with these Value-Priced inverters. If the system requires stacked units or a common neutral, the user must make a Sophi's choice between multiple untenable options.

I received my 6500 s that same time frame and my bonding screws were in.

 

[FilterGuy]

I updated the chart to include using the bonding screws.


Note: If a cell is blank, the associated parameter does not matter for that row.

 

[FilterGuy]

We are shooting a video today to clear this matter up completely. There is a relay inside the unit that will form a bond if no bond is present from an outside source, like an AC service panel. If AC gets disconnected, the relay kicks in and automatically forms a bond in the unit. I invite anyone currently using these units to test this with an Ohm's meter. Or you can wait until the end of the week and watch our video. I will post the link in this thread.

Where should we look for the video? Will a link be posted here?

 

[timselectric]

That's what the last sentence says.

 

[FilterGuy]

We are shooting a video today to clear this matter up completely. There is a relay inside the unit that will form a bond if no bond is present from an outside source, like an AC service panel. If AC gets disconnected, the relay kicks in and automatically forms a bond in the unit. I invite anyone currently using these units to test this with an Ohm's meter. Or you can wait until the end of the week and watch our video. I will post the link in this thread.

Is there an ETA on the video?

 

[BenFromSignatureSolar]

Our videographer has been shooting several this week. I would assume he'll be editing tomorrow and we should see them being released tomorrow afternoon or Monday.

 

[FilterGuy]

@BenFromSignatureSolar

Two questions:
1) If someone has a 6500 that did not ship with the bonding screws, do they have a supported way of getting and installing the screw? Will the process require documentation from the installer?
2) From reports on the forum, it appears that the 6500 units that ship without the bonding screws started with the units that have a manufacturing date of 10/2022. Can you please confirm or correct this?

 

[BenFromSignatureSolar]

1. Will have an answer for this question tomorrow. I need to look into that further.
2. That is correct