*update* Switching from old system to EG4, questions

[IAm_Not_Lost]

Hey all,

New member here, just had a couple of questions I was hoping for help with. I’ve used this forum a few times for info before and appreciate it. Off grid for about five years now, rural AZ, built our own barndominium, built our solar setup, solar vehicle setup and aux battery, etc.

Current setup, 55kw of FLA’s, two SMA 6048’s, two Midnite Solar classics, and 6,300 watts of solar. 48v system. My batteries have reached the end of their life, or soon will, and all the other equipment is in good shape, but - other than one of the Classics - older.

The panels are 265 watt panels, 24 of them, two strings of 12 panels with six in series. Midnite combiners.

I’d like to move to the EG4 lithium batteries, either the server rack or wall mount, haven’t decided, but I figure I’ll just grab two 6000XP’s for a few more thousand while I’m doing this so that everything meshes well.

My questions:

My solar array has two strings, and each set of PV inputs coming in is running about 18amps, more than what the 6000XP’s are rated for, but they have two MPPT’s each, so could I split the solar input wires (Y them) just before they hit the 6000XP to distribute the amperage? A few threads on here indicated you could parallel or pair the two MPPT’s in each inverter to allow for this. Trying to avoid buying another couple hundred feet of 10ga and spending a couple of days running more wire and re-doing the combiner boxes and surge protectors.

Second question, my current AC wiring that goes from the inverters to my AC panel is setup for the SMA’s, which were just 120 volt and you needed two to make 240 volts, so going to my AC panel there is just one hot from each inverter, combined neutral, and ground. Can I set up the 6000XP’s to just output 120v and synchronize their outputs so the wiring can stay the same? I don’t need each inverter to output 240.

Appreciate any help you can provide.

 

[Supervstech]

Sorry, no, you cannot split out a single string feed to different mpp's.

@SignatureSolarJess @HighTechLab

 

[IAm_Not_Lost]

Sorry, no, you cannot split out a single string feed to different mpp's.

@SignatureSolarJess @HighTechLab

Yeah, that’s what I would logically assume, but one of the threads on here had a reply or replies indicating you could, using a setting in the 6000XP that basically synchronized (paired?) the two MPPT’s that each inverter has. Figured I’d ask as I couldn’t find a definitive answer in the manual or get anyone from EG4 on the line.

Really unfortunate, as almost anyone with a reasonably sized existing system will have this issue. Seems like an odd limitation.

 

[SparkyJJO]

Why not just upgrade the batteries and stick with your SMAs?

 

[IAm_Not_Lost]

Why not just upgrade the batteries and stick with your SMAs?

Just a time/effort consideration. If I’m going to spend a bunch of time redoing half the system and spend a lot of effort getting the 4,000lbs of FLA batteries out of my utility room, I figure I’ll just streamline the system.

There should be plenty of folks who want a semi turn key setup with the SMA’s and Midnite Classics, probably could get a couple thousand for all of it. But, it may be a bad idea and I might regret it, or not do it, but as of right now I like the idea of having all EG4 equipment.

Edit: another consideration is just communication between all the components and modularity. The SMA’s are heavy, clunky, the interface is cludgy, and the aftermarket help from SMA has been horrible in my opinion (but, they are certainly workhorses). Anytime I had a question when I was setting everything up I just called Midnite solar instead of SMA. Also, having a system that uses easier to interpret apps on the phone and a more streamlined setup would be nice for my wife. It stresses her out knowing that if anything happened to me she wouldn’t be able to really comfortably work on the system.

 

[IAm_Not_Lost]

I guess a better way of asking about the AC wiring is: Can I just combine the respective hot legs from each inverter? Using a basic combiner box and two pole breakers? I wasn’t sure if that would cause any phase issue. I’m probably over thinking it.

 

[TM48]

I'm trying to get my head around your AC electrical system. You indicated you only have 120v circuits. What kind of load center do you have? I've never seen a 120v only LC. But to answer your question yes you can combine the two outputs in a load center. Typically two back fed breakers are used to combine the respective legs. Since the 6000xp has breakers you could combine them with Polaris connectors. If your going to spend 10 grand on batteries and inverters why not wire the AC with a new load center?
As for your PV you could use what you have but it would loose some power as the inverter would clip it to 17 amps. However depending on the VOC of your panels you may be better off re-configuring. What's the voltage on the two strings?

 

[Quattrohead]

There is a setting in the 6000 XP to combine the mppts but I don't know the details, I will try and find out from EG4 for you.
And each live leg from the 6000 XP will feed your existing lines from your SMA inverters, you just need to double check you know what you are doing there but I think it will be easy.
Basically your first SMA was L1 and your second SMA was L2.

 

[Madcodger]

FWIW, we're totally off grid and I combine the output of three 6000xps using three breakers and a dedicated main lug load center (does not have a breaker that shuts the whole panel down). These combine to feed a standard load center (has a main breaker that isn't used, but if someone ever wants to connect to the grid, they can do so easily by adding an interlock switch). As an aside, that then has a subpanel because I really like to separate things out on individual circuits, but you likely don't need that. Check out the video that @Will Prowse made on the 6000xp and you'll see how to combine multiple devices easily using a main lug load center.

It does sound like you need to split up your strings, as others have noted.

Here's another idea... Pick up the phone and call either Current Connected (my choice) or Signature Solar (I haven't used them personally), both of which are active here. Speak with Technical Sales. They'll guide you to what you need and in my experience (with Current Connected) will not try to oversell you.

 

[NC_hydro]

I would think before replacing such quality inverters (SMA) with Beta Boxes like EG4, especially since you are off the grid and want things to work reliably. If you are really wanting to change inverters...Victron, or Midnight Solar The One or a pair of Rosies. Maybe you can afford to be cheap but I can't afford to go cheap EG4 inverters..... I'd also look into the MNS Batteries, the PowerFlo16 or the smaller one if you're unable to handle near 300lb batteries.

 

[Quattrohead]

From the manual -

PV Input Mode 3: Two MPPT connects to same string.
MPPT #can utilize up to 17 amps, do not exceed the inverter’s MPPT circuit rating of 25A
Each MPPT can take 4kw of panels.

The current and wattage ratings are soft limits, they can take a little more without breaking them, but the max voltage of 480v is a HARD limit.

 

[Quattrohead]

I would think before replacing such quality inverters (SMA) with Beta Boxes like EG4, especially since you are off the grid and want things to work reliably. If you are really wanting to change inverters...Victron, or Midnight Solar The One or a pair of Rosies. Maybe you can afford to be cheap but I can't afford to go cheap EG4 inverters..... I'd also look into the MNS Batteries, the PowerFlo16 or the smaller one if you're unable to handle near 300lb batteries.

Look, if you are going to keep banging this drum, at least don't include the new Midnite inverters as they are the same age and they are still working on firmware and software improvements too.
You sound like James stole your girlfriend

 

[SparkyJJO]

I would think before replacing such quality inverters (SMA) with Beta Boxes like EG4, especially since you are off the grid and want things to work reliably. If you are really wanting to change inverters...Victron, or Midnight Solar The One or a pair of Rosies. Maybe you can afford to be cheap but I can't afford to go cheap EG4 inverters..... I'd also look into the MNS Batteries, the PowerFlo16 or the smaller one if you're unable to handle near 300lb batteries.

Um, to call EG4 beta boxes and then suggest Midnight The One which is very much a beta box at this point is kind of... well... Your bias is showing

I still think keeping the SMA inverters online is probably the best. Replacing just the batteries is not redoing that much, I think @IAm_Not_Lost is best served upgrading batteries and leaving the rest be if it handles everything he wants. I don't see much benefit in attempting to streamline the system as it is going to be a lot more work for little (any?) gain. Having to redo the solar strings, rewire the AC, all that stuff... Why? Just change the batteries, adjust the charging parameters, done.

 

[Quattrohead]

Yes I have bias too, I am using the EG4 equipment to run my house 100% and don't have any Midnite gear.
I can also agree that I would keep the SMA inverters unless their is a very good reason to change them out.

Actually, I do have 3 Midnite SPD's

 

[SparkyJJO]

Everyone has biases. Some are just more biased than others.
I'll take LF over HF inverters all day every day. Not due to experience. Just bias. The only HF inverter I have is a 300W in the van lol.

 

[TM48]

Everyone has biases. Some are just more biased than others.
I'll take LF over HF inverters all day every day. Not due to experience. Just bias. The only HF inverter I have is a 300W in the van lol.

Better stock up cause most companies are switching to hi frequency.

 

[Brucey]

I would think before replacing such quality inverters (SMA) with Beta Boxes like EG4, especially since you are off the grid and want things to work reliably. If you are really wanting to change inverters...Victron, or Midnight Solar The One or a pair of Rosies. Maybe you can afford to be cheap but I can't afford to go cheap EG4 inverters..... I'd also look into the MNS Batteries, the PowerFlo16 or the smaller one if you're unable to handle near 300lb batteries.

The powerflo 16kWh has a 2A active balancer, would def suggest that over the eg4 powerpro.

 

[NC_hydro]

Um, to call EG4 beta boxes and then suggest Midnight The One which is very much a beta box at this point is kind of... well... Your bias is showing

I still think keeping the SMA inverters online is probably the best. Replacing just the batteries is not redoing that much, I think @IAm_Not_Lost is best served upgrading batteries and leaving the rest be if it handles everything he wants. I don't see much benefit in attempting to streamline the system as it is going to be a lot more work for little (any?) gain. Having to redo the solar strings, rewire the AC, all that stuff... Why? Just change the batteries, adjust the charging parameters, done.

Brand new Kia vs Brand new Toyota Sure both are new but one is a Kia (EG4) and the other is a Toyota (MNS). You know exactly what I mean. They're not beta boxes because they are new it's because they are EG4 and we know the history of them and SS. Sure, if the only thing you can afford at the time is an EG4 they have their place, but in the course of 10-20yrs they're most likely going to cost you more than if you bought something quality. You also conveniently skipped over the point that my first recommendation was Victron. The fact that you suggest keeping the SMA's tells me know you know the riskiness of going EG4

 

[TM48]

Brand new Kia vs Brand new Toyota Sure both are new but one is a Kia (EG4) and the other is a Toyota (MNS). You know exactly what I mean. They're not beta boxes because they are new it's because they are EG4 and we know the history of them and SS. Sure, if the only thing you can afford at the time is an EG4 they have their place, but in the course of 10-20yrs they're most likely going to cost you more than if you bought something quality. You also conveniently skipped over the point that my first recommendation was Victron. The fact that you suggest keeping the SMA's tells me know you know the riskiness of going EG4

Hate to tell you this but Toyota has turned to shit.

 

[SparkyJJO]

Brand new Kia vs Brand new Toyota Sure both are new but one is a Kia (EG4) and the other is a Toyota (MNS). You know exactly what I mean. They're not beta boxes because they are new it's because they are EG4 and we know the history of them and SS. Sure, if the only thing you can afford at the time is an EG4 they have their place, but in the course of 10-20yrs they're most likely going to cost you more than if you bought something quality. You also conveniently skipped over the point that my first recommendation was Victron. The fact that you suggest keeping the SMA's tells me know you know the riskiness of going EG4

Well I wouldn't buy a Kia or a Toyota so whatever there lol.
In my mind, if something is released and is very buggy it is a beta box, I don't care who makes it. Some minor quirks are one thing, but anything more than that gets me annoyed very quickly.
The real reason I suggested keeping the SMAs is because of cost, effort, and benefit. The SMAs work, and do their job, why spend the money to replace them? It is going to be more complicated too, so more time involved. And what really is the benefit, they have similar power outputs, so why do it?
My answer would be the same if the brands were reversed. If what he has works, and he is happy with how it performs up til now, why spend the time and money to change it?
I have had neither SMA nor EG4 equipment, so no first hand experience. I do know the 6000xp is not a voltronics box, which in of itself makes it superior than its predecessors.

 

[IAm_Not_Lost]

I'm trying to get my head around your AC electrical system. You indicated you only have 120v circuits. What kind of load center do you have? I've never seen a 120v only LC. But to answer your question yes you can combine the two outputs in a load center. Typically two back fed breakers are used to combine the respective legs. Since the 6000xp has breakers you could combine them with Polaris connectors. If your going to spend 10 grand on batteries and inverters why not wire the AC with a new load center?
As for your PV you could use what you have but it would loose some power as the inverter would clip it to 17 amps. However depending on the VOC of your panels you may be better off re-configuring. What's the voltage on the two strings?

I have a normal AC load center that has two 120v legs coming in to make 240. My question was with regard to the EG4 inverters each having 120 and 240 capability and each having two hots, a neutral and ground, whereas my SMA’s only have a hot, neutral, and ground.

So I wanted to make sure I could combine the legs of the two EG4 inverters. Which it appears isn’t an issue.

 

[IAm_Not_Lost]

Um, to call EG4 beta boxes and then suggest Midnight The One which is very much a beta box at this point is kind of... well... Your bias is showing

I still think keeping the SMA inverters online is probably the best. Replacing just the batteries is not redoing that much, I think @IAm_Not_Lost is best served upgrading batteries and leaving the rest be if it handles everything he wants. I don't see much benefit in attempting to streamline the system as it is going to be a lot more work for little (any?) gain. Having to redo the solar strings, rewire the AC, all that stuff... Why? Just change the batteries, adjust the charging parameters, done.

And yes, I may still keep the other stuff and just upgrade battery, we’ll see.

 

[NC_hydro]

Hate to tell you this but Toyota has turned to shit.

Oh I agree, some of their new stuff they screwed the pooch. I'd still get a Toyota over a KIA. IT WAS A METAPHOR.

 

[IAm_Not_Lost]

You guys have an opinion on their server racked batteries versus the wall mount ones? Other than the server racked being individual easier to assemble and more modular, any other major design benefit?

For me, three of their 14kw wall units would fit nicely and be a perfect extra amount compared to what we currently have.

 

[SparkyJJO]

I see benefits to both. Go with what fits your space best, IMO.