Paralleled EG-4 6500EX on a 120V single phase system?

[timselectric]

creating two 120 V lines that are electrically 180 degrees apart,

Incorrect
Split-phase is single phase. There is one one phase, one sine wave, all current moves together in the same direction.

 

[zanydroid]

FWIW the market appears to be heading towards 120/240 in favor of 120 inverters so might consider ripping the bandaid off now for converting to split phase panel

 

[zanydroid]

Incorrect
Split-phase is single phase. There is one one phase, one sine wave, all current moves together in the same direction.

From the perspective of the second internal inverter the world is indeed upside down though

It is itself connected output upside down so the double negative brings the two back in the same direction.

 

[timselectric]

Not sure if there is, but certainly not hard to do. Take 2-3K inverters, like my Growatts, configure for 120/240 (out of phase 180 to neutral) and put them in one enclosure and in essence you have a 2 phase inverter. I suspect the 6000XP does the same unless it has a auto transformer, but then it would not be truly transformer less.

Your understanding of current flow is flawed.
It's not your fault. There's a lot of misinformation on the internet.
I'm not sure why so many people have trouble understanding split-phase.
Most members here, seem to grasp the concept of connecting power sources in series. (Batteries & solar panels) But they don't seem to realize that split-phase is the same thing.
When sources are connected in series, the voltage is additive and the amperage stays constant.
Split-phase is two 120v sources in series. It's just that simple.

 

[timselectric]

From the perspective of the second internal inverter the world is indeed upside down though

It is itself connected output upside down so the double negative brings the two back in the same direction.

There is no "double negative" , whatever that means.
It's just two 120v inverters connected in series.
Each one provides 120v. And together, they provide 240v.

 

[zanydroid]

There is no "double negative" , whatever that means.
It's just two 120v inverters connected in series.
Each one provides 120v. And together, they provide 240v.

The 120V inverter have a common neutral. Let’s label these the top inverter and bottom inverter, corresponding to L1 and L2.

If you configured both inverters to output with no phase difference with each other, the L1 to L2 voltage is 0, this is the config that OP wants

You need to set a 180 degree phase difference to get split phase

BUT. The way the double negative comes into play is that the top and bottom inverters are not in series in the same direction. If they were in the same direction then the bottom inverter would be set to 0 degrees.

What would you configure the degree difference between inverters for two parallel 120v based on your notation?

In a Wye setup would you program the inverters to be 120 degrees apart or 30 degrees?

 

[apctjb]

SRNE makes some 5kW 120V units that can be stacked in parallel for 120V only or 120V / 240V

Had not heard of this brand but took a look and you are correct. Does EG4 make there own stuff or are they private labeling/repacking the electronics?

 

[zanydroid]

Had not heard of this brand but took a look and you are correct. Does EG4 make there own stuff or are they private labeling/repacking the electronics?

Private label + extra layer of support / local regulation handling.

EG, if there is a regulatory problem, EG4 has a slightly higher chance (they've filed paperwork/updated their processes in response to issues) to solve it than LuxPower (zero based on what I've seen on this forum, beyond getting the original listing certs).

 

[apctjb]

Your understanding of current flow is flawed.

No doubt, its flawed on most things these days. That said this is my understanding...

 

[zanydroid]

Notice how the bottom one goes - + and the top one goes + -

That was what I was trying to explain earlier.

Tim’s assumed measurement axis for his writeups (consistent across his post history on this forum) has + - on the bottom one.

No doubt, its flawed on most things these days. That said this is my understanding... View attachment 210728

 

[apctjb]

Private label + extra layer of support / local regulation handling.

Thanks, that is what I thought but not 100% sure.

 

[timselectric]

You need to set a 180 degree phase difference to get split phase.

Incorrect
If they were out of phase, any amount of degrees. They wouldn't be able to produce 240v , combined.

In a Wye setup would you program the inverters to be 120 degrees apart or 30 degrees?

A WYE system is 3-phase. (3 separate phases) the 3 phases are placed equally around a 360° axis of time. Which is why they are 120° of separation.

But that has nothing to do with this conversation.
We are only talking about a single phase.
A WYE system is 3 individual split-phase systems, with a common connection between the 3 neutrals.

 

[timselectric]

What would you configure the degree difference between inverters for two parallel 120v based on your notation?

There is noo degree difference.
They are connected in parallel.

 

[42OhmsPA]

Had not heard of this brand but took a look and you are correct. Does EG4 make there own stuff or are they private labeling/repacking the electronics?

Private label, lately Lux Power (which was a great move imo) prior Voltronic, Megarevo, maybe some others.
You do get US based support, it's seems to be getting much much better based on feedback here.

 

[zanydroid]

In a Wye setup would you program the inverters to be 120 degrees apart or 30 degrees?

For 120 degrees I believe all the inverter - will be connected to the neutral. For wye the other choices are confusing.

For split I believe either polarity is plausible to use

 

[zanydroid]

There is noo degree difference.
They are connected in parallel.

But if you say the two inverters are configured to 0 degrees, why does connecting the L1/L2 in 120/240V mode cause magic smoke?

 

[zanydroid]

Incorrect
If they were out of phase, any amount of degrees. They wouldn't be able to produce 240v , combined.

If you look at OP’s picture where both inverters have - output connected to neutral, does this still apply?

Anyway I think we both understand this and haven’t agreed before in other threads on the notation difference explaining why some people insist on 180 degrees so we can agree to disagree again

 

[timselectric]

No doubt, its flawed on most things these days. That said this is my understanding... View attachment 210728

That drawing is also incorrect.
The positive and negative markings are shown opposite of how they actually are.

 

[timselectric]

But if you say the two inverters are configured to 0 degrees, why does connecting the L1/L2 in 120/240V mode cause magic smoke?

That would be a dead short. (Which could cause "magic smoke")
But they are not at zero degrees (except for once every second)
They move through the full 360 degrees.

 

[zanydroid]

The positive and negative markings are shown opposite of how they actually are.

IMO this depends on how the inverters are connected and programmed. I don’t understand how your point of view on configuring phase angles generalizes to handle both split phase and wye configurations in the same 120V inverter