Output 240v from split phase inverter

[delion19]

Hi all,

This is my first post, hoping to get some advice on how to move forward. First, a description of my problem.

My parents house is currently set up for solar power, along with a connection from the power company. The goal is to have solar be the primary source (with gel cell battery storage), and power company secondary. The house is in the Caribbean, and is wired for both 110v and 240v. The line in from the power company provides 240v. Recently, the old inverter was damaged beyond repair. A new one (EGC 6000XP 8000w) was installed. The issue is that the inverter is a split phase L1, L2, N, but the caribbean uses L & N (single phase) how can I turn split phase to single phase with one Live wire and a neutral.

What I've considered so far
1. Use a simple step up transformer and feed 110v in with 240v out. The drawback is in the efficiency, will only support 1/2 the inverters potential.

2. Use a split phase transformer like here that can provide the needed conversion. The problem, this takes a single 240v and outputs two 110v. Thinking because it's automatic, the reverse should be true, input two 110v from inverter and output one 240v. Another problem I encountered, according to the tech person I spoke with, the two devices are not compatible.

Any advice or direction would be appreciated. I can also attach an image if it would help understanding.

 

[CRenner]

What Brand/Model was the old inverter?
Did it do 230 or 240?

 

[delion19]

What Brand/Model was the old inverter?
Did it do 230 or 240?

Hi, the last one was an 10kw mpp Solar inverter 48v 230vac 80A MPPT

 

[BentleyJ]

The post is a little confusing, how is the house wired for both 120V and 240V if the power company only supplies 240V? Where is the 120V coming from and do they have any 120V appliances?

To answer you question specifically: The new inverter will supply 240V between L1 & L2. As far I know it should work if the neutral is left unconnected.

 

[Quattrohead]

I know the 6000 XP will not work with only 110 input but I don't know if it will work with 240 only input without the neutral.
And yes you need to investigate a little more how your parents place is getting the 110, I suspect it's set up the same way as all USA homes unless it's one of the x British or French colonies perhaps.

 

[CRenner]

I would guess that you have the wrong inverter, you need an international one that delivers 230v 50h.

 

[zanydroid]

+1 to figuring out how the 120 was created previously and how that was referenced to grounding system and utility power.

You probably have to pick between 120 OR 240, not both, from a 6000XP. EXCEPT in the case where the house was hooked to grid via an isolation transformer so that the 240 are split phase and not L-N.

This is not a config that is commonly discussed on this forum so I will highly recommend you to temper advice you get here. If anything you have to understand very precisely what you have now, and get principles here rather than recipe.

It is probably not uncommon in some expat communities with lots of custom homes in 230V power countries, however those people are not posting here.

 

[delion19]

The post is a little confusing, how is the house wired for both 120V and 240V if the power company only supplies 240V? Where is the 120V coming from and do they have any 120V appliances?

To answer you question specifically: The new inverter will supply 240V between L1 & L2. As far I know it should work if the neutral is left unconnected.

Oh, for the 120v, they had a simple stepdown transformer from 240 to 120 which powered all 120 outlets in the house.

 

[delion19]

I know the 6000 XP will not work with only 110 input but I don't know if it will work with 240 only input without the neutral.
And yes you need to investigate a little more how your parents place is getting the 110, I suspect it's set up the same way as all USA homes unless it's one of the x British or French colonies perhaps.

Yes, it's in a former British colony

 

[delion19]

+1 to figuring out how the 120 was created previously and how that was referenced to grounding system and utility power.

You probably have to pick between 120 OR 240, not both, from a 6000XP. EXCEPT in the case where the house was hooked to grid via an isolation transformer so that the 240 are split phase and not L-N.

This is not a config that is commonly discussed on this forum so I will highly recommend you to temper advice you get here. If anything you have to understand very precisely what you have now, and get principles here rather than recipe.

It is probably not uncommon in some expat communities with lots of custom homes in 230V power countries, however those people are not posting here.

120 was done using a step-down transformer which powers all 120 outlets in the house. 240 inlet from power company powers everything else.

 

[zanydroid]

120 was done using a step-down transformer which powers all 120 outlets in the house. 240 inlet from power company powers everything else.

Got it. So there are no imported 120/240 appliances. Just 120.

You aren’t going to be able to get both voltages without a step down (which you do have). You also are going to have to think hard about how to manage N-G bonding. Any internal dynamic bond (I’m not familiar with this inverter) will for sure not work. You are also going to have to think hard about whether this inverter’s transfer behavior (switch both legs) is the right thing.

What is the N-G bonding scheme in your country? (I don’t know the notation, what I’m asking about is whether the bond is done at the utility or in the house). Are inverters supposed to disconnect both legs when off grid?

Why use the US version of this inverter? LuxPro has a native 230V version. The native version (if responsibly designed and imported) for your country will ideally have sorted out the bonding and leg switching details.

 

[Vigo]

The simplest way through this is to pretend your inverter cannot supply 120 and simply hook 240 to the existing transformer and all will be as it was.

To rewire the home "properly" to use the 120 from the inverter would require us to know exactly how it was wired now.. Does it have a split phase distribution panel or does it have all the 120 outlets wired 'separately' from all the 240 outlets?