EG4 6500EX Off grid system - Is this DIAGRAM correct? You asked...

[energyhunter]

This photo diagram, DRAFT 2, covers my installation nearing completion. Yes, exposed wiring will be in conduits.

Question 1
Since the Critical Loads (CL) panel will eventually hold ALL of the circuits currently on my main, shouldn't I just leave the 200 amp entrance breaker that came with the CL panel? I am concerned the 60a breaker feeding the CL will not be adequate once all circuits are put on the CL

Question 2
Keeping in mind that this is not a grid-tied nor a mobile system, should the NG bonding screws be removed from BOTH inverters?
(Inverters were shipped on May 27, 2022)

Thanks to previous replies from PreppenWolf, Gavin Stone, dcg9381, Mattb4, Zwy, NEpowerandlight and others; I value highly your insights and advice.

​

 

[Zwy]

This photo diagram, DRAFT 2, covers my installation nearing completion. Yes, exposed wiring will be in conduits.

Question 1
Since the Critical Loads (CL) panel will eventually hold ALL of the circuits currently on my main, shouldn't I just leave the 200 amp entrance breaker that came with the CL panel? I am concerned the 60a breaker feeding the CL will not be adequate once all circuits are put on the CL

I put a small 70A breaker panel with a 60 breaker directly after the inverters, this gave me a place to tie in both inverter output neutrals. This runs to my 3 pole transfer switch. From transfer switch it goes to CL main breaker. The 70A panel is shown here bottom left.



This was done for a few reasons, the inverters are 15 feet away from panels and transfer switch. Second, if I decide to add 2 more inverters, the output from those will run in a separate conduit to the transfer switch and I would install another 70A panel for those 2 inverters. This also allows me to pair up inverters differently.

Question 2
Keeping in mind that this is not a grid-tied nor a mobile system, should the NG bonding screws be removed from BOTH inverters?
(Inverters were shipped on May 27, 2022)

Thanks to previous replies from PreppenWolf, Gavin Stone, dcg9381, Mattb4, Zwy, NEpowerandlight and others; I value highly your insights and advice.

​

Remove both bonding screws and update to latest firmware will work. I highly recommend a 3 pole transfer switch so you switch back to grid and completely bypass the inverters. With the pass thru neutral approach with the EG4 6500EX, you would have to shut down everything if you need to work on the system or have some type of way to jumper in neutral for the CL to bypass the inverter neutral.

 

[Mattb4]

1. You can leave the 200a breaker in place and chances are it has already a cutout in the cover plate which if you removed the breaker you would have to blank it out. Often the large entrance breaker is hard fastened directly to the panels bus bars and not easily removed anyway. Your 60a breaker becomes the service entrance breaker to the panel. Whether it is adequate for all your loads and appropriate for the EG4's AC out you would want to consult your manual. From your setup picture they are operating stacked to create 240vAC split phase.

2. Although it is not grid tied it is grid assist. You can look at this resource: https://diysolarforum.com/resources/grounding-and-bonding-for-eg4-6500-ex-inverters.322/ from FilterGuy.

 

[energyhunter]

I put a small 70A breaker panel with a 60 breaker directly after the inverters, this gave me a place to tie in both inverter output neutrals. This runs to my 3 pole transfer switch. From transfer switch it goes to CL main breaker. The 70A panel is shown here bottom left.

View attachment 138073

This was done for a few reasons, the inverters are 15 feet away from panels and transfer switch. Second, if I decide to add 2 more inverters, the output from those will run in a separate conduit to the transfer switch and I would install another 70A panel for those 2 inverters. This also allows me to pair up inverters differently.



Remove both bonding screws and update to latest firmware will work. I highly recommend a 3 pole transfer switch so you switch back to grid and completely bypass the inverters. With the pass thru neutral approach with the EG4 6500EX, you would have to shut down everything if you need to work on the system or have some type of way to jumper in neutral for the CL to bypass the inverter neutral.

Thank you Zwy. Your system looks well organized which I hope to achieve. I'm still fuzzy on the neutrals landed in the 70 amp breaker panel and the 3-pole switch setup, but I will study it some more; This reveals my lack of knowledge. I was thinking if I needed to do any work, say, on the inverters connections or adding conduits, I would first turn off the 60a breaker in the main that goes to the AC in on the inverters. I would make sure my pv isolator switches were both off and the nader breakers would be off, cutting off the batteries power in. I could power off the batteries as further precaution. Of course the inverters would be switched off and my current tester would be my best friend.

 

[energyhunter]

1. You can leave the 200a breaker in place and chances are it has already a cutout in the cover plate which if you removed the breaker you would have to blank it out. Often the large entrance breaker is hard fastened directly to the panels bus bars and not easily removed anyway. Your 60a breaker becomes the service entrance breaker to the panel. Whether it is adequate for all your loads and appropriate for the EG4's AC out you would want to consult your manual. From your setup picture they are operating stacked to create 240vAC split phase.

2. Although it is not grid tied it is grid assist. You can look at this resource: https://diysolarforum.com/resources/grounding-and-bonding-for-eg4-6500-ex-inverters.322/ from FilterGuy.

Yep, I will visit the manual for info on the breaker size to power CL panel after it has all the house circuits on it. Not sure the would address that specifically; When I finally put the balance of big loads on the CL panel, Part 2, then I could utilize the CL panel's 200a as power entrance to that panel. For now, Part 1, I could just use the 60a as power in and the 200a would just be dormant (making the CL essentially a lug panel) until I was ready for the 200a.

You know I was not familiar with the term "grid assist", thank you. I did see the video you link, a while back, but it still left me confused. Seems to me the electrical engineers that explain this stuff could dumb it down a little bit for the DIYers that comprise their primary market. With that said, I should be challenged to learn more.

 

[Zwy]

Thank you Zwy. Your system looks well organized which I hope to achieve. I'm still fuzzy on the neutrals landed in the 70 amp breaker panel and the 3-pole switch setup, but I will study it some more; This reveals my lack of knowledge. I was thinking if I needed to do any work, say, on the inverters connections or adding conduits, I would first turn off the 60a breaker in the main that goes to the AC in on the inverters. I would make sure my pv isolator switches were both off and the nader breakers would be off, cutting off the batteries power in. I could power off the batteries as further precaution. Of course the inverters would be switched off and my current tester would be my best friend.

The problem with using the pass thru neutral and you need to work on your system is neutral carries current. If the inverters are shut down and you wish to power the subpanel after the inverters using grid power, you need a method to jumper in a neutral if you need to work inside the inverters. With a 3 pole transfer switch, you completely bypass the inverter input hots and neutral, isolating the inverters and wiring from grid power.

When installing my system, I ran grid power thru the transfer switch to the subpanel. This allows me to do whatever work I wanted to do without having to deal with any live or neutral wires. If something goes wrong with my system and I want to switch to grid power bypassing the inverters, I can throw my transfer switch. It is very advantageous.

 

[EastTexCowboy]

Question 1
Since the Critical Loads (CL) panel will eventually hold ALL of the circuits currently on my main, shouldn't I just leave the 200 amp entrance breaker that came with the CL panel? I am concerned the 60a breaker feeding the CL will not be adequate once all circuits are put on the CL

My system is set up very similar to @Zwy 's system with a three pole double throw transfer switch, for the same reasons. On moving all your circuits from the main to the subpanel, my only concern would be to make sure you're not exceeding the output capacity of the inverters. Just because you have a 200a main breaker doesn't mean the inverters can deliver anything close to that. It's hard to tell from the photo but your main panel isn't full so maybe you're okay. That said, it depends on the load on all those circuits. You may want to make sure you do some load balancing between L1 and L2 as well. There are multiple threads here on that discussion, but essentially you have 60a of 120v available from each inverter. If you exceed that on one leg it's going to fall out with an overload, even if the other leg isn't loaded at all. Just one more thing to consider. I just recently learned from @timselectric that you can install an isolation transformer and address the balancing, but that's a whole other discussion.

 

[energyhunter]

The problem with using the pass thru neutral and you need to work on your system is neutral carries current. If the inverters are shut down and you wish to power the subpanel after the inverters using grid power, you need a method to jumper in a neutral if you need to work inside the inverters. With a 3 pole transfer switch, you completely bypass the inverter input hots and neutral, isolating the inverters and wiring from grid power.

When installing my system, I ran grid power thru the transfer switch to the subpanel. This allows me to do whatever work I wanted to do without having to deal with any live or neutral wires. If something goes wrong with my system and I want to switch to grid power bypassing the inverters, I can throw my transfer switch. It is very advantageous.

Thanks for patience Zwy as I was under the weather for a few days. It seems the next thing to do is get the inverters off the wall and remove the NG bonding screw in each. I also need to verify that the N and G are bonded at the main. (?) Now I show my ignorance.

Someone said, "I can explain it to you but I can't understand it for you." I think you break it down very well; I need to be learning more about the principles of neutral and ground and current flow. What kind of 3-pole transfer switch are you using? I checked at HD and they are very expensive. Any suggestions there?

 

[energyhunter]

My system is set up very similar to @Zwy 's system with a three pole double throw transfer switch, for the same reasons. On moving all your circuits from the main to the subpanel, my only concern would be to make sure you're not exceeding the output capacity of the inverters. Just because you have a 200a main breaker doesn't mean the inverters can deliver anything close to that. It's hard to tell from the photo but your main panel isn't full so maybe you're okay. That said, it depends on the load on all those circuits. You may want to make sure you do some load balancing between L1 and L2 as well. There are multiple threads here on that discussion, but essentially you have 60a of 120v available from each inverter. If you exceed that on one leg it's going to fall out with an overload, even if the other leg isn't loaded at all. Just one more thing to consider. I just recently learned from @timselectric that you can install an isolation transformer and address the balancing, but that's a whole other discussion.

You too, thanks for patience ETC, I'm doing much better. Here's my ignorance again: I was not even considering the output capacity of the inverters. For now I have placed newly bought 20 amp breakers in the CL/sub panel with no wiring yet. Referring to my Part 1 above, There are (15) 20 amp breakers on the CL plus a double pole 15 amp for the mini split I'm installing. That's it for the CL.

Here is what remains that I want to move to the CL at a future date: A total of (4) double pole breakers: (1) 100a 3 ton heat pump/AC, (1) 50a Range, (1) 30a water heater, (1) 30a dryer. Will the 2 EG4 6500 inverters be sufficient for that?

 

[EastTexCowboy]

Thanks for patience Zwy as I was under the weather for a few days. It seems the next thing to do is get the inverters off the wall and remove the NG bonding screw in each. I also need to verify that the N and G are bonded at the main. (?) Now I show my ignorance.

Someone said, "I can explain it to you but I can't understand it for you." I think you break it down very well; I need to be learning more about the principles of neutral and ground and current flow. What kind of 3-pole transfer switch are you using? I checked at HD and they are very expensive. Any suggestions there?

You shouldn't have to take them off the wall to remove the bonding screws. I can find some pictures for you but I think there are several here on the forum.

 

[EastTexCowboy]

You too, thanks for patience ETC, I'm doing much better. Here's my ignorance again: I was not even considering the output capacity of the inverters. For now I have placed newly bought 20 amp breakers in the CL/sub panel with no wiring yet. Referring to my Part 1 above, There are (15) 20 amp breakers on the CL plus a double pole 15 amp for the mini split I'm installing. That's it for the CL.

Here is what remains that I want to move to the CL at a future date: A total of (4) double pole breakers: (1) 100a 3 ton heat pump/AC, (1) 50a Range, (1) 30a water heater, (1) 30a dryer. Will the 2 EG4 6500 inverters be sufficient for that?

I suppose technically it depends on the actual amperage draw, but just off the breakers you won't be anywhere close. You have a total of 60 amp 240v to work with.

I'm curious about a 3 ton heat pump with a 100a breaker. Maybe that includes the heat strips but that's not typical. I think most 3 ton hear pumps are going to be a 30 amp breaker with a separate breaker for the heat strips and air handler. Those range from 40a to 60a that I've seen.

You're going to have to pick something.

 

[Adam De Lay]

You shouldn't have to take them off the wall to remove the bonding screws. I can find some pictures for you but I think there are several here on the forum.

Once you take the top cover off, here's the screw you want to remove. You'll want to remove the circuit board above the screw for easier access to the bonding screw.

I removed my bonding screws on my first set of units without taking them off the wall. Just make sure you have a screwdriver with a magnetic tip as you don't want to drop that screw further into the unit.

 

[Zwy]

Thanks for patience Zwy as I was under the weather for a few days. It seems the next thing to do is get the inverters off the wall and remove the NG bonding screw in each. I also need to verify that the N and G are bonded at the main. (?) Now I show my ignorance.

Someone said, "I can explain it to you but I can't understand it for you." I think you break it down very well; I need to be learning more about the principles of neutral and ground and current flow. What kind of 3-pole transfer switch are you using? I checked at HD and they are very expensive. Any suggestions there?

I currently have a 60A installed, the price back when I bought it new was $450, same one today is about $650. I ran across a 100A in this model from this seller. These are fusible, if you don't need it fused just install a copper bar across the terminals.

I had looked for a 100A initially but it was during covid supply issues and could not find anything under $1500 at the time, that is why I purchased the 60A. The reason for the 100A is if I decide to install 2 more inverters to run in parallel to the 2 installed. If I had to do it all over again, I'd looked for a 100A until I found what I wanted at the right price.

Be certain it is 3 pole so neutral can be switched. Some are 2 switched poles with a neutral lug. You see those pretty cheap.

 

[Adam De Lay]

I currently have a 60A installed, the price back when I bought it new was $450, same one today is about $650. I ran across a 100A in this model and paid way more for it from this seller. These are fusible, if you don't need it fused just install a copper bar across the terminals. https://www.ebay.com/itm/304829999575?hash=item46f948a9d7:g:-E8AAOSwvzxj3fMP&amdata=enc:AQAHAAABAJKVdw9UAC6DC9Htt8GBW5fQRd6XMv9ju7n8h4eMgQsGs8gmPQ4xhbRiRwGgmiDU6SYe5whJYDZUBDZ4dQZpspQfYjQDYdV0AT4I5GkIk8LEf8jFjBiZjw29Itpb9soVleG0jsHed71KEv+kgZhjW/wWJHRv2ij+7m7nbGTitO6TI8z4VdpKy1yHT3eKlV/UMtiqnKShS5wcrqauVKkCDtwRbDEO6Y/yf9Oy3FmZRLRb6WkYc4b4IONHRB2iuijhSPwo+IAbFu5QwHCrMOamb1NoJ8uKeCbF/WbzaHwpwwnc1Nfwf3cUH803iDizReuNMTlnCxlkPWExxjIFdkSu6Fc=|tkp:Bk9SR5LwjfTYYQ

I had looked for a 100A initially but it was during covid supply issues and could not find anything under $1500 at the time, that is why I purchased the 60A. The reason for the 100A is if I decide to install 2 more inverters to run in parallel to the 2 installed. If I had to do it all over again, I'd looked for a 100A until I found what I wanted at the right price.

Be certain it is 3 pole so neutral can be switched. Some are 2 switched poles with a neutral lug. You see those pretty cheap.

ebay is your friend when looking for transfer switches

 

[Zwy]

This is the 60A model I have installed now. Look around, you might find a deal. https://www.ebay.com/itm/1343311817...A+OE+cKzZH3k2rQhGa7dRJ7Q==|tkp:Bk9SR6KmgPXYYQ

 

[Zwy]

ebay is your friend when looking for transfer switches

I edited that after I posted when I realized the $150 item was only a safety switch and not a double throw.

 

[Adam De Lay]

I edited that after I posted when I realized the $150 item was only a safety switch and not a double throw.

Bummer.... I would have jumped on that right away!

 

[Zwy]

Always wondered if something like this mounted in a cabinet would work. But I don't want to burn my house down, I put too much work into it.

 

[Adam De Lay]

Always wondered if something like this mounted in a cabinet would work. But I don't want to burn my house down, I put too much work into it.

I would personally never trust anything like that. I've seen several types like that and they just look like cheap toys.

 

[Zwy]

Bummer.... I would have jumped on that right away!

The 100A one I linked is a good deal, even with the high priced shipping. The one I ordered came damaged by Fed Ex and the seller said Fed Ex denied the claim but offered me a refund of 15%. I took it, just a small dent on the side.