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

JamesHird

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Jan 10, 2022
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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
 
I kind of understand because if they advise you, And you get it wrong and burn your house down, or electrocute someone, then they can be at blame.

Kind of a gray area in my book. Im kind of surprised they didn't suggest you hire a professional electrician if you don't know what you're doing.
 
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
Our techs aren't licensed electricians and there is a great deal of liability involved if they advise someone on wiring and things go wrong on the AC side of things. If they were to misspeak and you fry your unit we can send another one, if they tell someone how to wire a system on the AC side and they burn their house down... different scenario. We do sell these as DIY systems so there is a bit of expectation on the end user to be able to hook it up. When it doubt, call an electrician.

Things I can tell you, tie your ground into your existing house ground. Do not drive a second grounding rod under any circumstances. You should run the legs from the transformer into a subpanel and bond neutral and ground at the first point of disconnect.
 
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Don't have any personal knowledge but might suggest looking at @DavidPoz vids on this. He has done several that discuss correct auto transformer hookup/use and he strives to give good/correct info - which may benefit you're own setup. You can search "Transformer" or "Auto Transformer" at his site for vids.
Here are some examples:
 
Don't have any personal knowledge but might suggest looking at @DavidPoz vids on this. He has done several that discuss correct auto transformer hookup/use and he strives to give good/correct info - which may benefit you're own setup. You can search "Transformer" or "Auto Transformer" at his site for vids.
Here are some examples:
David Poz is always a good choice. He definitely knows his stuff
 
My system is not grid tied.
You need to explain this statement in much greater detail for anyone to help you.

When I see this statement, I think a cabin in the woods that is not connected to any external power source. If that is the case, you absolutely need a grounding rod of some kind, but you only want one and it should be bonded to neutral in only one place. If you have a ground cable imbedded in your slab for instance, you will use that.
 
You need to explain this statement in much greater detail for anyone to help you.

When I see this statement, I think a cabin in the woods that is not connected to any external power source. If that is the case, you absolutely need a grounding rod of some kind, but you only want one and it should be bonded to neutral in only one place. If you have a ground cable imbedded in your slab for instance, you will use that.
This is true. In my case, I see "not grid tied" and I think you have Utility supplying you with power, but you are not selling back/backfeeding.

It means different things to different people.
 
Thank you all for the responses. I do understand the liability side of giving advice.
I am going to get a licenced electrician to check over my work before it goes live. I just want to fully understand what i am doing and build a safe, correct system first time
What I mean by 'not grid tied' is a cabin in the middle of the woods, not connected to any external power. Apart from there isn't a cabin yet. I haven't built that yet. Haha.
 
OK--- before I type anything............I AM NOT GIVING ADVICE, I am sharing MY ideas IF I was in the OP position.........THAT MEANS i AM NOT RESPONSIBLE FOR ANYTHING OTHER THAN SOMETIMES A SPELLING OR TYPING ERROR.

I (me) would NOT tie an auto transformer's middle tap to ground without a clear understanding of the circuit powering the autotransformer. An autotransformer is not an isolation transformer. Sure an auto job provides the opportunity to be able to get 120/120 from a 240 source.

A safer approach is to use an isolation transformer available from many places such as Ebay. Final comment, if I did not know what I was doing, I would do nothing.
 
 
I am going to get a licenced electrician to check over my work before it goes live. I just want to fully understand what i am doing and build a safe, correct system first time
What I mean by 'not grid tied' is a cabin in the middle of the woods, not connected to any external power. Apart from there isn't a cabin yet. I haven't built that yet. Haha.

Likely a licensed electrician doesn't understand how auto-transformers work, and knows even less about inverters.
He should be able to do standard wiring to code, and follow some electrical wiring plans.

SS sells an auto-transformer which received UL listing. Used according to the way it was tested by NRTL, it should be safe regarding some risks.
How it could/should be used with an inverter depends on the rest of the system. Not having grid connection removes some risks.
The model I saw instructions for has breakers which disconnect at some degree of overload, and the circuit should then disconnect your 120V loads as well so they don't see incorrect voltage.


Does it have a 3-pole breaker, interrupting Neutral as well as Line1 and Line2?
That addresses one of my concerns.
 

Some transformers are not advertised to be isolation. For example, a few years ago I purchased (Ebay) a 5kw transformer that had multiple secondary windings with taps. I have forgotten all the details but remember I was able to select a primary to secondary ratio that provide isolation between an inexpensive Ebay 4KW inverter and the circuitry on my boat.

Inexpensive inverters seem to work OK and are advertised for ''vehicle use'' only. They do not have expensive, heavy internal power transformers. Their internal circuitry uses what is known as an H bridge with the load connected in essence to the bar in the letter H. Recommend that you seek more info on this type of circuit if interested....to complicated for me to explain here exactly how it works other than to alert you that the so called ''grounded conductor'' one finds in home wiring does not exist in these circuits. Both the so called + and - output connections have voltage reaching peaks of about 170V alternating at the line frequencey ....usually 60Hz.
 
That's a pretty standard response. It's on you to make sure everything is hooked up right.
 
... Final comment, if I did not know what I was doing, I would do nothing.
Good sound advice. Not one I followed during my life.

I followed the advice, "If I knew what I was doing I might not do it.", school of thought. :)

I do think that I would leave transformer selection and wiring (other than following a schematic drawing) to the experts.
 
Sometimes I've purchased something (like a Growatt 240v only) and it wasn't what I really wanted - e.g. 240v/120v. Instead of backing up and buying something to meet my needs directly (like an MPP Solar or other unit that has 240v/120v) I start going down 'rabbit holes' to 'make it work' and this (usually) takes more work / is more trouble than it should be. I agree 100% that one shouldn't deploy something you don't understand.

Perhaps consider backing up and buying something with 240v/120v to start with and avoid the whole issue.
 
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