Microinverter into 120VAC single 'phase' ?

[Externet]

Hello.
Do 120VAC output microinverters exist, 'phase branch' and center-tap-neutral as for U.S. ?
I have several dormant spare 400W panels, wondering if can be additionally injected into the grid plugging the microinverter output to a plain 120VAC outlet (which is fed by a breaker in the main panel) Well, you can ignore the outlet part, going just to a single breaker.
Solar panels------------------->microinverter----------------->120VACoutlet------------------>1breaker-------------------->1phase branch of the utility
I prefer to keep separated from the main grid tied equipment.

 

[CNuthing]

NEP BDM-600-LV LINK

 

[Externet]

Thanks. So they exist. Good...
Found this one too ----> https://www.aliexpress.com/item/325...b16557764901512375e3453!12000026161302885!sea

 

[mizermizer]

NEP BDM-600-LV LINK

Would it be silly to consider using these for an RV installation? It looks like one of these could handle two of my 320Watt / 47V VOC / 8A ISC panels. Which is then AC coupled to a Victron Multiplus 3000W 24V inverter, in turn charging a 24V LFP pack. Seems like using microinverters handles DC fusing and arc-fault concerns. I was consider making a 2S DC configuration of those 320W panels, and if I have room grow that to a 2S2P arrangement, but then started thinking about fault protections, particularly arc-fault.

 

[fafrd]

Would it be silly to consider using these for an RV installation? It looks like one of these could handle two of my 320Watt / 47V VOC / 8A ISC panels. Which is then AC coupled to a Victron Multiplus 3000W 24V inverter, in turn charging a 24V LFP pack. Seems like using microinverters handles DC fusing and arc-fault concerns. I was consider making a 2S DC configuration of those 320W panels, and if I have room grow that to a 2S2P arrangement, but then started thinking about fault protections, particularly arc-fault.

Did you end up going the route of a 120VAC Microinverter coupled to a Multiplus?

Was it a Multiplus or a Multiplus II and are you happy with the result?

And did you end up getting a BDM600-LV or some other 120VAC Microinverter?

 

[mizermizer]

Did you end up going the route of a 120VAC Microinverter coupled to a Multiplus?

Was it a Multiplus or a Multiplus II and are you happy with the result?

And did you end up getting a BDM600-LV or some other 120VAC Microinverter?

No, I went traditional, keeping the panel array voltages down to less than 50 and not worrying about arc-fault. Two panels in parallel, and one by itself, feed into two different charge controllers. It's a full up Victron system with 3000/24/70 Multiplus, a 24V LFP battery made from 8x280AHr cells, a JK BMS, a Victron shunt, two of their charge controllers for the 3 x 320watt panels, a Victron 70-amp 24V-to-12V dc to dc converter, a Victron 12/24 dc-to-dc charge controller to charge the battery from my truck (if ever needed), and finally a Cerbo GX. Plus all the appropriate fuses and breakers (which require planning and space). I do not plan on carrying a generator at all, tired of those noisy things - especially when it's noise coming from a camping neighbor. So far the system runs everything I've thrown at it. Put a soft-start on the AC just for fun and to prove the point - so it runs the AC too. Of course I'd only get like 5 hours of AC before the battery would be dead, but maybe it'll be used someday. Now I have 120VAC and 12VDC twenty-four seven in the fifth wheel. It changes the possibilities, and opens some doors. I am adding things like a wi-fi router and external antenna.

Really loving it so far. And I think the extra cost of the Victron gear was worth it, knowing it's some of the best made, and quite refined. The device programming is right where you want it. And then viewing the system on the VRM Portal is nice when I'm away. Makes me comfy to see how it's doing. And then there is the reporting - which allows overnight tests. For example I tried to run the normally propane fridge on 120VAC just to see, and the report graphs show it cycling on and off all night long, at 300W on for an hour, then off for like 40 mins, and repeats.

 

[fafrd]

No, I went traditional, keeping the panel array voltages down to less than 50 and not worrying about arc-fault. Two panels in parallel, and one by itself, feed into two different charge controllers. It's a full up Victron system with 3000/24/70 Multiplus, a 24V LFP battery made from 8x280AHr cells, a JK BMS, a Victron shunt, two of their charge controllers for the 3 x 320watt panels, a Victron 70-amp 24V-to-12V dc to dc converter, a Victron 12/24 dc-to-dc charge controller to charge the battery from my truck (if ever needed), and finally a Cerbo GX. Plus all the appropriate fuses and breakers (which require planning and space). I do not plan on carrying a generator at all, tired of those noisy things - especially when it's noise coming from a camping neighbor. So far the system runs everything I've thrown at it. Put a soft-start on the AC just for fun and to prove the point - so it runs the AC too. Of course I'd only get like 5 hours of AC before the battery would be dead, but maybe it'll be used someday. Now I have 120VAC and 12VDC twenty-four seven in the fifth wheel. It changes the possibilities, and opens some doors. I am adding things like a wi-fi router and external antenna.

Really loving it so far. And I think the extra cost of the Victron gear was worth it, knowing it's some of the best made, and quite refined. The device programming is right where you want it. And then viewing the system on the VRM Portal is nice when I'm away. Makes me comfy to see how it's doing. And then there is the reporting - which allows overnight tests. For example I tried to run the normally propane fridge on 120VAC just to see, and the report graphs show it cycling on and off all night long, at 300W on for an hour, then off for like 40 mins, and repeats.

I’m not installing in a vehicle but looking to base a small 120VAC backup power system in my home, so I’m very interested in your experience with Victron products.

I’ve currently got 1kW of DC-coupled PV charging a 560Ah 24V LiFePO4 battery through a 60A Epever SCC (and my battery is also using a JK BMS).

I’ve considering getting a Multiplus II 120x2 or 120x1 as the heart of this new system and was thinking about switching the PV from DC-coupled to 120VAC-coupled which is what led me to this thread.

I’m planning to use the external CT to have the MPII offset load on both AC output and AC input but what I’m trying to understand is how best to set up the MPII so that any excess power not being used to offset loads can be used to charge the battery rather than being throttled or exported.

With 120VAC-coupled to the AC output, I’m pretty sure the MPII supports a mode where it will offset load as priority 1 then charge the battery with any remaining power as priority 2 and then either export y through AC output of throttle AC-coupled power through frequency shift as the last priority.

What I’m not as clear on is whether those same options can as easily be supported through DC coupling or not an if yea, which other pieces of Victron gear that requires.

Will a Victron Battery Shunt alone allow the MPII to ‘know’ the amount of available DC-coupled PV power available or must I also have a Victron SCC to get that capability?

I don’t need to worry about and voltage conversion as you do, but I’d appreciate your advice on the minimum MPII-based set-up to self-consume as much DC-coupled power as possible.

 

[fafrd]

I’m not installing in a vehicle but looking to base a small 120VAC backup power system in my home, so I’m very interested in your experience with Victron products.

I’ve currently got 1kW of DC-coupled PV charging a 560Ah 24V LiFePO4 battery through a 60A Epever SCC (and my battery is also using a JK BMS).

I’ve considering getting a Multiplus II 120x2 or 120x1 as the heart of this new system and was thinking about switching the PV from DC-coupled to 120VAC-coupled which is what led me to this thread.

I’m planning to use the external CT to have the MPII offset load on both AC output and AC input but what I’m trying to understand is how best to set up the MPII so that any excess power not being used to offset loads can be used to charge the battery rather than being throttled or exported.

With 120VAC-coupled to the AC output, I’m pretty sure the MPII supports a mode where it will offset load as priority 1 then charge the battery with any remaining power as priority 2 and then either export y through AC output of throttle AC-coupled power through frequency shift as the last priority.

What I’m not as clear on is whether those same options can as easily be supported through DC coupling or not an if yea, which other pieces of Victron gear that requires.

Will a Victron Battery Shunt alone allow the MPII to ‘know’ the amount of available DC-coupled PV power available or must I also have a Victron SCC to get that capability?

I don’t need to worry about and voltage conversion as you do, but I’d appreciate your advice on the minimum MPII-based set-up to self-consume as much DC-coupled power as possible.

Being more specific, I just looked at the cost of a Victron SCC and it’s out of my budget for this project, while the Victron smartshunt is not.

So my specific question is whether you believe a 3rd-party SCC to charge the 24V battery through a Victron Smartshunt will be sufficient to deliver the kind of self-consumption control I am looking for it will that whole rig only work correctly with a Victron SCC?

If I need a Victron SCC, just switching to AC-coupling looks like an easier and cheaper way to get there..

 

[mizermizer]

I can't add much detail for you since I haven't been through an exercise like your talking about. But I can say some things (that you probably already know).

Pretty sure the Multiplus always prioritizes charging the battery first (unless you specifically defeat that). So it won't export or throttle back until battery has reached float. It will ramp up it's charging until the programmed current limits have been reached (both charge current and AC input current have programmable limits). Also note the ability to export power out the AC input is defaulted to off.

With AC coupled microinverters on the Multiplus output, the Multiplus has no longer knows what the actual AC output loads are, unless you add a CT. And then use that CT data to manage things at some level, which I'm not sure how tricky that becomes. This is because with AC coupled you have multiple sources of AC power feeding the load, one of them (the microinverters) not visible to the Multiplus. But maybe not being visible doesn't matter in the big picture, it just looks like a smaller load, or even as a negative load (power the can be used to charge the battery).

In the DC coupled world I like to think of the charging via SCC's (of any brand) as separate from what the Multiplus is doing as for as it's needs to run any AC loads present. What I mean is the SCC's feed the battery what they can. And the Multiplus takes from the battery what it needs to run AC loads. And those two activities add together through the current shunt. So in theory they might exactly cancel each other and effectively the SCC are directly feeding the Multiplus, and the current shunt reports zero battery current. Or a portion of the SCC current is being used to run an AC load (via the Multiplus inverter) and the rest flows into the battery. And that behavior does not rely on Victron in any way.

I think all you lose not going with Victron SCC's is reporting capability about what the panels generated over time, and a 'complete' real-time picture of what currents are going where.

And I'm far far far from a Victron guru, but there may be options on how to measure current. Maybe the Multiplus itself internally has the means to measure it's DC current. In my system I told it the external Victron shunt is king.

There are some pretty good online manuals for the Multiplus. If think if you get into the 'wizards' (I think there called wizards, can't remember for sure though) you can see how to use external CT's to control some behavior.

 

[fafrd]

I can't add much detail for you since I haven't been through an exercise like your talking about. But I can say some things (that you probably already know).

Pretty sure the Multiplus always prioritizes charging the battery first (unless you specifically defeat that). So it won't export or throttle back until battery has reached float. It will ramp up it's charging until the programmed current limits have been reached (both charge current and AC input current have programmable limits). Also note the ability to export power out the AC input is defaulted to off.

With AC coupled microinverters on the Multiplus output, the Multiplus has no longer knows what the actual AC output loads are, unless you add a CT. And then use that CT data to manage things at some level, which I'm not sure how tricky that becomes. This is because with AC coupled you have multiple sources of AC power feeding the load, one of them (the microinverters) not visible to the Multiplus. But maybe not being visible doesn't matter in the big picture, it just looks like a smaller load, or even as a negative load (power the can be used to charge the battery).

In the DC coupled world I like to think of the charging via SCC's (of any brand) as separate from what the Multiplus is doing as for as it's needs to run any AC loads present. What I mean is the SCC's feed the battery what they can. And the Multiplus takes from the battery what it needs to run AC loads. And those two activities add together through the current shunt. So in theory they might exactly cancel each other and effectively the SCC are directly feeding the Multiplus, and the current shunt reports zero battery current. Or a portion of the SCC current is being used to run an AC load (via the Multiplus inverter) and the rest flows into the battery. And that behavior does not rely on Victron in any way.

I think all you lose not going with Victron SCC's is reporting capability about what the panels generated over time, and a 'complete' real-time picture of what currents are going where.

And I'm far far far from a Victron guru, but there may be options on how to measure current. Maybe the Multiplus itself internally has the means to measure it's DC current. In my system I told it the external Victron shunt is king.

There are some pretty good online manuals for the Multiplus. If think if you get into the 'wizards' (I think there called wizards, can't remember for sure though) you can see how to use external CT's to control some behavior.

This was helpful, especially about the DC coupling.

PV generation reporting is not a priority for me and neither is a ‘real time picture’.

So if I’ve understood what you wrote correctly, a 3rd-party SCC can take care of charging the battery and throttling back DC-coupled charge current once the battery is full independently of the MPII.

And the MPII can be configured to offset loads from DC-power (either SCC and/or battery) with a programmable cut off based on battery state (SOC if there is a shunt, possibly battery voltage if there is not).

I did start reading some Victron guides and see that they have some sophisticated capability to make decisions based on battery SOC, and for any of those features, you clearly need a shunt

 

[mizermizer]

So if I’ve understood what you wrote correctly, a 3rd-party SCC can take care of charging the battery and throttling back DC-coupled charge current once the battery is full independently of the MPII.

yes

And the MPII can be configured to offset loads from DC-power (either SCC and/or battery) with a programmable cut off based on battery state (SOC if there is a shunt, possibly battery voltage if there is not).

Yes. And you should test that your MP cutoff 'beats' the JK low voltage shutdown. The tricky part comes in when you have one cell in the pack that runs down first, your JK shuts off (as it should) even though total pack voltage hasn't reached your MP shutoff. Then the real fun starts when the JK turns back on into the MP with empty input capacitors. The JK likely reports a short and turns off. Then repeats. How do I know this ... seen it in action. Looking for a good way to avoid that scenario. I have just raised my MP cutoff to 22.5VDC to avoid. Which ain't too bad, but problem can still occur.

 

[cs1234]

@mizermizer

You could try using this battleborn csl500 precharge device. Discussed in this thread on the forums.