parallel inverters

It probably doesn't seem right, but I am unsure what some of these inverters are capable of, so is it possible to run 3 inverters on a 240v split phase system, 2 inverters in parallel on one leg then another single inverter split phase on the other leg? I am just wondering if I picked up 2 inverters up front then when I wanted to add on down the road if I could add 1 inverter at a time and purposely run unbalanced or if they had to be added in pairs?

Joes_Going_Solar said:

It probably doesn't seem right, but I am unsure what some of these inverters are capable of, so is it possible to run 3 inverters on a 240v split phase system, 2 inverters in parallel on one leg then another single inverter split phase on the other leg? I am just wondering if I picked up 2 inverters up front then when I wanted to add on down the road if I could add 1 inverter at a time and purposely run unbalanced or if they had to be added in pairs?

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Some can be used this way. Just have to check the specs.

Yes many can be setup this way, 1,2 or 3 per phase. The LV 6548 manual shows how to do this very well.

Well that's good news for adding to a system as needed. Thanks

Is there a reason you wouldn't use a split phase model like the EG6000 or LVX6048 and then just stack them?

BentleyJ said:

Is there a reason you wouldn't use a split phase model like the EG6000 or LVX6048 and then just stack them?

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Efficiency, future proofing, load balancing.

load balancing - putting 120v loads on a split phase inverter means you have to be cognizant of what load you have on which phase as they only support a fraction of load "out of phase". for the sake of discussion, a 6kw 240v may only support 2kw imbalance, and only 3kw per phase, which means you have to try and load balance your circuits which in practice can be difficult with transient loads. (think toasters on the kitchen vs hairdryers in the bathroom)

by moving to a 6kw 120v circuit there are no longer any issues with load balancing, or phase imbalance.

Efficiency - if you need 240v only for say shop tools or some such, then shutting down that inverter can save power due to standby power that is used.

future proof -if your starting with a small cabin and only need 120v at the start, and want to end with a shop that supports 240v 10 years from now, building as you go as you have budget.

Redundancy - 3 units allows you to fail 1 or 2 and still keep critical loads running in SHTF.

This is the reason I was asking. I was thinking about an aio 12kw growatt but if it fails then I have nothing. I can piece together a smaller system and build it as I go, and I like redundancy. I did look at the manual for the 6548 and seen where they show more inverters on 1 phase. I looked at victron and did not see that listed, as I am kinda thinking about spending the $ for victron gear. Anyone know if victron has that ability?

Joes_Going_Solar said:

This is the reason I was asking. I was thinking about an aio 12kw growatt but if it fails then I have nothing. I can piece together a smaller system and build it as I go, and I like redundancy. I did look at the manual for the 6548 and seen where they show more inverters on 1 phase. I looked at victron and did not see that listed, as I am kinda thinking about spending the $ for victron gear. Anyone know if victron has that ability?

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I have 1 but will have 3 of the new srne hyp 5000w series.

I have 3 phase power, going to put one on each leg. I am trying to decide if I should parallel 2 of them to get 240v or parrallel 3 of the to make 3 phase.

My question is what happens when 1 inverter fails or is shut down? I was thinking of putting my critical 120v loads on 1 inverter and possibly powering off the other 2 during a grid failure to save another 100w of standby. But what happens if the single inverter is powered on by itself when configured as part of a 2 phase or 3 phase group?

CableGuy said:

I have 1 but will have 3 of the new srne hyp 5000w series.

I have 3 phase power, going to put one on each leg. I am trying to decide if I should parallel 2 of them to get 240v or parrallel 3 of the to make 3 phase.

My question is what happens when 1 inverter fails or is shut down? I was thinking of putting my critical 120v loads on 1 inverter and possibly powering off the other 2 during a grid failure to save another 100w of standby. But what happens if the single inverter is powered on by itself when configured as part of a 2 phase or 3 phase group?

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I guess this applies to inverter failure also. Does a 3-phase setup with 3 inverter tripple the probablity of a single point of failure and actually undermine the idea of have 3 of these for redundancy?

Or imagine 3 units parrellel on a single phase. I would expect if 1 died, the other 2 in the group to keep going. Will they?

CableGuy said:

I guess this applies to inverter failure also. Does a 3-phase setup with 3 inverter tripple the probablity of a single point of failure and actually undermine the idea of have 3 of these for redundancy?

Or imagine 3 units parrellel on a single phase. I would expect if 1 died, the other 2 in the group to keep going. Will they?

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Yes, and yes.

If one inverter goes down I would not rely on the other two staying up and running, it depends on if the master or slave goes down, what the failure mechanism is and can the others carry on. None of the manuals have ever gone over this.

It would more than likely require manual intervention.
I wouldn't count on automatic isolation.

Someone must have simulated this. I said fail, but I am more asking what happens if I were to power off 2 of 3 inverters if the grid was down to save power. If the master (configured as 3 phase normally) would function standalone as 120v if the other 2 were simply taken offline, that would be easier to automate. 4G router and automation server will run off the 48v DC.

Most of the time, goal will be to use up battery at night for HVAC or power the shop if we work after sunset which happens a lot.

However, if we are expecting power outage weather I need (what i'm calling) a storm mode (externally automated) that will keep battery full after sunset, and ideally disable 2 of the inverters if the grid drops.

Now I am wondering if the inverters can be powered off/on via rs485, for conserving battery I might as well shut down all the inverters and enable 1 periodicallly when automation decides we need a NG heat cycle.