Signature Solar refusing to give me support regarding the growatt es5000 and autotransformer.... Is this normal?

[JamesHird]

When there is so much confusion around the es5000 and the autotransformer. I wanted to confirm with Signature Solar that I was installing the setup correctly.

My simple question was, do I need to have leg 1 and leg 2 from the autotransformer going into a separate sub panel and do I need to ground the neutral from the autotransformer to a separate grounding rod.

Signature Solars response was, 'we can't give any advice on AC power. We can only advise on the DC side o things.'

This stinks like BS to me. Sounds like they're not standing behind a product they sold me. It doesn't fill me with much confidence anyway.

I'm new to solar, hence why I bought a all in one system. Maybe it was a mistake on my part to purchase a system that isn't as straight forward as I initially though.

Regardless, I'm feeling a little lost on this now. Is there anybody that can help me here?

My system is not grid tied.
I fully understand about balancing leg 1 and leg 2 from the autotransformer.

I've watched and read as much as I can on the matter and it's almost got me more confused than before.

Thanks in advance

 

[brandnewb]

I'm new to solar, hence why I bought a all in one system. Maybe it was a mistake on my part to purchase a system that isn't as straight forward as I initially though.

It's hardly a mistake on your part if you have made bad deciding based on bad intell.

I think it is only commendable that you tried to ease into the field with an all in one system. I for one am in the same boat as you are in terms of not knowing anything yet.

 

[NC_hydro]

I can understand why they wouldn’t want to give advice on the AC side of things. That’s something you’d research yourself or ask an electrician.

 

[Yurtdweller]

If they cannot give AC advise, it's probably because each state has different regulatory and licensing requirements for such things. Understandable, but I think they might indicate the issues in more detail. Is that the entirety of their response, or are we paraphrasing here? Regardless, I suspect it is a legal issue. Fwiw, I've built and scaled my system entirely from scratch, and I'm glad I did. I started with a single panel and a cheap pwm cc and a car battery. I'm now running 1kw pv, 14 kWh LiFePo4 self built batteries and 2000 kW inverter and couldn't be happier. I have no experience with the issue you are asking about, though. Good luck.

 

[RV10flyer]

Watch this…

 

[RV10flyer]

And this…

 

[RV10flyer]

And this one

 

[RV10flyer]

Here’s you another…

 

[RV10flyer]

And the last one…it should be clear…

 

[rhino]

I know in Minnesota it is a state law/regulation you can not give any advice for AC installations unless you are a licensed electrician in the state. You can however give advice on DC distribution. So they are not out of line.

 

[brandnewb]

I know in Minnesota it is a state law/regulation you can not give any advice for AC installations unless you are a licensed electrician in the state. You can however give advice on DC distribution. So they are not out of line.

Does this apply to on grid systems or also for an off gird system? I am wondering because even though I can imagine regulations to exist as to not mess up the greater grid I have a bit more reserve towards not being allowed to advice on off grid systems

 

[rhino]

Does this apply to on grid systems or also for an off gird system? I am wondering because even though I can imagine regulations to exist as to not mess up the greater grid I have a bit more reserve towards not being allowed to advice on off grid systems

I can't find the statute at the moment referencing it but I interpreted it as either since even off grid systems are supposed to be inspected.

 

[brandnewb]

@BenFromSignatureSolar I advise your company to be more verbose when telling clients some things can't be done.

This time around it seems reasonable for your comp. to have done so.

The time spent here by all could / schould have been avoided

 

[RCinFLA]

Both the videos are giving dangerous advice when they tell you can use multiple inverters with single autotransformer.

The Growatt autotransformer is just plain dangerous. It has no provisions to avoid overload. This autotransformer is actually a 2.5kVA rated transformer, not 5kVA implied. If you have an unbalanced 120vac load of 5kVA the transformer will get so hot in about 30 minutes it will just about melt solder.

At least the similar SolarEdge autotransformer (now discontinued product) has embedded thermocouple to measure transformer temperature. The mating SolarEdge inverter had input for autotransformer thermocouple to shut down inverter if autotransformer got too hot.

The Victron autotransformer is safe with a controller that monitors autotransformer and trips 240vac output from inverter by a solenoid activated dual pole 240vac breaker.

 

[zanydroid]

At least the similar SolarEdge autotransformer (now discontinued product) has embedded thermocouple to measure transformer temperature. The mating SolarEdge inverter had input for autotransformer thermocouple to shut down inverter if autotransformer got too hot.

The Victron autotransformer is safe with a controller that monitors autotransformer and trips 240vac output from inverter by a solenoid activated dual pole 240vac breaker.

Never been a fan of the Rube Goldberg home brew approaches to make an bare autotransformer safer. Not enough destructive testing etc…

Can you explain a little more what conditions the victron autotransformer protects against? Does it disconnect 120/240 output side on overheat and loss of neutral?

I assume the autotransformers that are designed to work with listed ESS and batteryless off grid backup are inherently safer to use in general. Would love to see someone break those down one day and write it up or do a video.

 

[rhino]

The data sheet has answers to some of your questions: https://www.victronenergy.com/upload/documents/Datasheet-Autotransformer-32A-and-100A-EN.pdf
It also has a built-in ground relay which is interesting since that is related to issue with original post.

 

[RCinFLA]

Does it disconnect 120/240 output side on overheat and loss of neutral?

No, has to shut off 240vac from inverter.

Victron may not check neutral current. Transformer temperature is minimum safety check. No circuit breaker will help unless it is 10 amp two pole 240vac breaker from inverter, and most people will not want to have their 5kVA inverter limited to 2400 watts output power.

Circuit breaker on neutral is the last thing you want as it will result in floating AC panel neutral putting all 120vac appliances fed from panel at risk of damage when their AC supply ranges from 0 to 240 vac depending on 120vac phase side load balance.

 

[Lexario]

As a technician working with solar for quite some time, I often quote what Article 690.4 of the NEC states:
(C) Qualified Personnel. The installation of equipment and all associated wiring and interconnections shall be performed only by qualified persons.
Note: See Article 100 for the definition of
qualified person.

That being said, if you don't know how to install a system, I recommend for you to seek out an individual who has the knowledge. Signature has to follow their guidelines, the manual the transformer comes with gives you an idea of what to do. Anything beyond that should be handled by an expert if you don't have a clear understanding of the matter. This is merely for your safety, as its been mentioned before, seeing as your dealing with dangerous equipment.

Now with THAT being said, wiring of the Growatt transformer will typically be: powered from an AC output panel with a breaker and the neutral in your load panel. Remember, the rule is ONE and ONLY ONE safety ground to neutral connection in the entire system. There is no connection between the inverter output neutral (because the 5kES doesn't have one) and the neutral that goes to the loads. This is because the autotransformer is creating a new neutral. Any load imbalance in the loads must be handled by the autotransformer, so its best practice to land that in the load panel.

 

[Quattrohead]

You have fallen into the trap of cheap but not usable in this country hack job.
SS used to push this setup hard but got raked over the coals here. It's just not safe to do.
Either a human or your 120v appliances could get hurt if something went wrong.
We educated them lol