5k growatt question

[Deleted member 1888]

Ok so I saving to get this 5k growatt with transformer, I have seen vids on it and it seems to be a batter way to get 240 over a normal split phase. There is also the fact that a transformer can turn almost any inverter into a split phase. What I do no understand is can the growatt use a backup generator if the solar is not doing the job? I know the growatt has L1 L2 and ground but my generator have L1, L2, Neutral, and ground, how will that work?

GROWATT 5kW 5000ES (USA Model) OFF GRID INVERTER & Growatt Transformer Kit

5000W LVM- ES Off-Grid 240V GROWATT Inverter with Solar Charge Controller + integrated GROWATT Split Phase Transformer for true 120V/240V Split Phase Electricity! The GROWATT SPF 5000W LVM-ES is the all-in-one inverter/charger you need to take control of your energy bill. The 5000ES can work...

www.signaturesolar.com

 

[Struc]

The neutral is only for 120v loads. So, the Growatt only takes in 240v and outputs 240v.

 

[jMINTj]

The neutral is only for 120v loads. So, the Growatt only takes in 240v and outputs 240v.

You have to be careful with the Growatts, as they are labeled per what I believe are European specs. They have a ground, L, and N, both input and output. The voltage difference between what the Growatt inverter has labeled as L and N is 230v (default, can be set to either 220/240/208v). In NA language, this would be L1 and L2. Whatever the two hot legs of the generator are (with 240v differential) would need to go into the L and N 'AC input' terminals on the Growatt, despite what they are labeled for the generator. And you only get 230v (or whatever you select, as above) out unless you use some kind of transformer, normally an autotransformer or midpoint transformer. Just be careful of polarity. That's my understanding.

 

[MichaelK]

The neutral is only for 120v loads. So, the Growatt only takes in 240v and outputs 240v.

The neutral might be used for quality evaluation? I have a generator with a bad stator that produced lower voltage on L2. You could pull off the endbell and adjust the voltage to 240VAC, but it was imbalanced, with 140V + 100V =240V. A high quality inverter will detect this. Whether or not the Growatt will is a question. With my inverter (XW6848) it specifically mentions this.

 

[Tony Scott]

You have to be careful with the Growatts, as they are labeled per what I believe are European specs. They have a ground, L, and N, both input and output. The voltage difference between what the Growatt inverter has labeled as L and N is 230v (default, can be set to either 220/240/208v). In NA language, this would be L1 and L2. Whatever the two hot legs of the generator are (with 240v differential) would need to go into the L and N 'AC input' terminals on the Growatt, despite what they are labeled for the generator. And you only get 230v (or whatever you select, as above) out unless you use some kind of transformer, normally an autotransformer or midpoint transformer. Just be careful of polarity. That's my understanding.

If you buy the American model it is not a problem

 

[Tony Scott]

Ok so I saving to get this 5k growatt with transformer, I have seen vids on it and it seems to be a batter way to get 240 over a normal split phase. There is also the fact that a transformer can turn almost any inverter into a split phase. What I do no understand is can the growatt use a backup generator if the solar is not doing the job? I know the growatt has L1 L2 and ground but my generator have L1, L2, Neutral, and ground, how will that work?

GROWATT 5kW 5000ES (USA Model) OFF GRID INVERTER & Growatt Transformer Kit

5000W LVM- ES Off-Grid 240V GROWATT Inverter with Solar Charge Controller + integrated GROWATT Split Phase Transformer for true 120V/240V Split Phase Electricity! The GROWATT SPF 5000W LVM-ES is the all-in-one inverter/charger you need to take control of your energy bill. The 5000ES can work...

www.signaturesolar.com

Signature Solar explains connecting a generator in video.

 

[Cornwallav8r]

Ok so I saving to get this 5k growatt with transformer, I have seen vids on it and it seems to be a batter way to get 240 over a normal split phase. There is also the fact that a transformer can turn almost any inverter into a split phase. What I do no understand is can the growatt use a backup generator if the solar is not doing the job? I know the growatt has L1 L2 and ground but my generator have L1, L2, Neutral, and ground, how will that work?

GROWATT 5kW 5000ES (USA Model) OFF GRID INVERTER & Growatt Transformer Kit

5000W LVM- ES Off-Grid 240V GROWATT Inverter with Solar Charge Controller + integrated GROWATT Split Phase Transformer for true 120V/240V Split Phase Electricity! The GROWATT SPF 5000W LVM-ES is the all-in-one inverter/charger you need to take control of your energy bill. The 5000ES can work...

www.signaturesolar.com

To answer your specific question, you are correct. There are no generator inputs on this particular model. Just add a standard automatic transfer switch. I already had one in my system. So actually now there are 2 transfer switches, per the separate conversation below. If your generator is large and stable enough, when it transfers over to generator, starts up and outputs power, the Growatt will just think it's re-established utility power and keep rolling like nothing happened, assuming your batteries are carrying properly in between.

 

[Cornwallav8r]

The neutral might be used for quality evaluation? I have a generator with a bad stator that produced lower voltage on L2. You could pull off the endbell and adjust the voltage to 240VAC, but it was imbalanced, with 140V + 100V =240V. A high quality inverter will detect this. Whether or not the Growatt will is a question. With my inverter (XW6848) it specifically mentions this.

Actually, no, it probably wouldn't if wired as some say to do. That is, to not use the generator's neutral at all. And the Growatt never sees the neutral in the system ever, in the first place. The loads however... if you are using an autotransformer, the generator's neutral is redundant, no?

 

[SignatureSolarJames]

Actually, no, it probably wouldn't if wired as some say to do. That is, to not use the generator's neutral at all. And the Growatt never sees the neutral in the system ever, in the first place. The loads however... if you are using an autotransformer, the generator's neutral is redundant, no?

you are correct, the neutral from the generator is unneeded

 

[Ozark Tinkering]

I would direct anyone who's using or hoping to use the auto transformer configuration to hop over to this discussion on system neutral conductors and the effects of harmonics. https://diysolarforum.com/threads/safe-grid-use-of-the-5000es-and-transformer.34121/page-21

 

[chadjones99]

what if you are using a single phase 120 volt output generator? Can I run the 120-volt output of my generator into the transformer ( growatt ) and get 240 output ? ( like on the outback auto former 240-x )

 

[timselectric]

Yes
But, the output would be half of the generator output.

 

[chadjones99]

Yes
But, the output would be half of the generator output.

I figured that much, makes sense that your splitting your output over 2 legs. My concern was, after watching videos of this transformer, people using it to split a single 240 down to 120. I wanted to make sure that when I connect it to single-phase 120 it did not split it into 2 legs of 60 volts.... I cant find anything online including the manual ( online ) that shows different wiring configurations

 

[timselectric]

I figured that much, makes sense that your splitting your output over 2 legs. My concern was, after watching videos of this transformer, people using it to split a single 240 down to 120. I wanted to make sure that when I connect it to single-phase 120 it did not split it into 2 legs of 60 volts.... I cant find anything online including the manual ( online ) that shows different wiring configurations

Just land one hot and neutral from the generator.
And both hots for the output.

 

[timselectric]

I figured that much, makes sense that your splitting your output over 2 legs. My concern was, after watching videos of this transformer, people using it to split a single 240 down to 120. I wanted to make sure that when I connect it to single-phase 120 it did not split it into 2 legs of 60 volts.... I cant find anything online including the manual ( online ) that shows different wiring configurations

Also, in case it needs to be said.
Do not connect the generator to the auto transformer.
If the auto transformer is connected to the Load side of the inverter.

 

[Solar Guy Richard]

In my humble opinion, do not hook a generator up to an inverter at all - the size of the generator typically needs to be far oversized to stay within inverter specs for incoming 'clean' energy - especially under loads. It's far easier to plug in a battery charger and charge your batteries with a generator and you typically don't see any real measurable loss from doing this.
James (our owner) did a pretty informative video:

It's an older video but the principles remain. Let me know if you have questions.

 

[timselectric]

In my humble opinion, do not hook a generator up to an inverter at all - the size of the generator typically needs to be far oversized to stay within inverter specs for incoming 'clean' energy - especially under loads. It's far easier to plug in a battery charger and charge your batteries with a generator and you typically don't see any real measurable loss from doing this.
James (our owner) did a pretty informative video:

It's an older video but the principles remain. Let me know if you have questions.

I definitely agree.

 

[chadjones99]

Thanks for the reply, here is my thought process 1) a 48-volt high amp battery charge is very expensive. the one in the inverter is cheap. 2) the generator will not be rated higher than inverter but that's ok, because its a passthrough inverter, and the inverter will only kick in when the generator is off. And 3) When running the generator I won't be power heavy loads just enough to power my RV ( lights, tv etc ) while charging the battery pack.
Does that not sound ok ?? This is why I want to use a transformer to split the single-phase output of the generator, just so I have both legs on pass though while charging. I thought about just bridging the L1 & L2 on the input side of the inverter to have 2 legs hot in the RV but I'm not sure how the inverter I bought would react I know some are ok with that ( like the Victron muli plus ) But I bought a 8kw growatt split phase inverter

 

[timselectric]

Thanks for the reply, here is my thought process 1) a 48-volt high amp battery charge is very expensive. the one in the inverter is cheap. 2) the generator will not be rated higher than inverter but that's ok, because its a passthrough inverter, and the inverter will only kick in when the generator is off. And 3) When running the generator I won't be power heavy loads just enough to power my RV ( lights, tv etc ) while charging the battery pack.
Does that not sound ok ?? This is why I want to use a transformer to split the single-phase output of the generator, just so I have both legs on pass though while charging. I thought about just bridging the L1 & L2 on the input side of the inverter to have 2 legs hot in the RV but I'm not sure how the inverter I bought would react I know some are ok with that ( like the Victron muli plus ) But I bought a 8kw growatt split phase inverter

It will have to be feed with 240v.
But, you could buy a charger. For the cost of the transformer. Unless, you plan to unhook the transformer from between the inverter and loads, and rewire it in front of the inverter. Every time you want to charge batteries.

 

[timselectric]

Or, add in a couple of transfer switches.
But, that's even more costly. And, more complex.