Question about Growatt AC IN

sunshine_eggo

Happy Breffast!
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Okay, I'm questioning everything now.

@automatikdonn has your setup and a diagram.

What's killing me is that it looks like his mains ground is connected to AC-in ground, and I've seen that cause problems, so I'm withdrawing from this because I'm going to mess you up.

Ignore everything I've said.
 
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uzernaam

New Member
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Nov 6, 2021
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sunshine_eggo,

It looks like what you're saying is feed one hot leg of my utility mains into the AC input of the Growatt L terminal, and the other hot utility leg to the N terminal.

I hope that N terminal is floating and not grounded.

Remember, although this is not a "grid tie" inverter, it can pull AC power from the grid to assist in powering loads if other sources are insufficient. I like this feature and want to use it if possible.
 
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sunshine_eggo

Happy Breffast!
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sunshine_eggo,

It looks like what you're saying is feed one hot leg of my utility mains into the AC input of the Growatt L terminal, and the other hot utility leg to the N terminal.

I hope that N terminal is floating and not grounded.

Remember, this "inverter" can pull AC power from the grid to supplement power generated from solar if the load is too great. I like this feature and want to use it if possible.

See above post. don't listen to me.
 

Bud Martin

Photon Sorcerer
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Aug 27, 2020
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Does this Growatt model has a relay that connect the Neutral to safety Ground when it is in inverter mode?
Does it say anything like that in the user manual?
Updated:
I just download and look at the manual. https://watts247.com/manuals/gw/SPF 5000 ES User Manual.pdf?x52188
Setup program #24 see page 19
24 Allow neutral and grounding of AC output is connected together: When enabled, inverter can deliver signal to trigger grounding box to short neutral and grounding(for expansion) Disable: Neutral and grounding of AC output is disconnected. (Default) Enable: Neutral and grounding of AC output is connected. This function is only available when the inverter is working with external grounding box. Only when the inverter is working in battery mode, it will trigger grounding box to connect neutral and grounding of AC output.
Allow neutral and grounding of AC output is connected together: When enabled, inverter can deliver signal to trigger grounding box to short neutral and grounding(for expansion)
 
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uzernaam

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Does this Growatt model has a relay that connect the Neutral to safety Ground when it is in inverter mode?
Does it say anything like that in the user manual?

This is NOT a grid-tie inverter. It only pulls grid power when the loads are greater than the solar can provide alone. (At least that's how it can work provided you've changed the settings for it to do so.)

I created a neutral (which is bonded to a ground rod) on the 240v output of the inverter with a midpoint transformer.

Now my concern is on the input side of things. It's running on solar DC just fine, and if I pull more AC OUT than the solar can supply, it gets the rest from the batteries. But I don't want it to do this. I want to keep the batteries topped off at all times (they are lead-acid for now) and grab power from utility mains to assist the solar if insufficient for the load. Some have called this "grid assist" which is a term and feature I like and want to use.
 

uzernaam

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Bud Martin

Option 24 is in regards to AC output.

My question is regarding AC input: What happens if 120VAC is fed into the "N" terminal (and 120VAC of opposite polarity on the "L" terminal) ?
 

uzernaam

New Member
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Nov 6, 2021
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So I got off the phone with some tech guys at Signature Solar, and they say I can run 240V split phase into the N and L1 AC input terminals without a problem.

I'll post an update if I die or explode.
 

uzernaam

New Member
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Nov 6, 2021
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I'm speaking to you from beyond the grave.

I was electrocuted, and then I exploded.
 

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hipringles

Solar Enthusiast
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I use this setup, but only to charge the batteries *not* as an A/C bypass. I have it as you mention in comment 20 and it charged batteries without issue.

I am sure an EE will loose their mind at this: but it doesn't "see" -120/+120, as the "120" is only refrence to neutral, which in this case is exactly out of phase, thus its "seeing" 240V
 

Bleedingblue

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The Growatt 5000 inverter can use the AC input to supplement the solar power to assist in charging the battery or supplying AC loads.

The AC INPUT is labeled in the attached picture

Ground | L | N

...and it expects 230 volt input.

I could run red and black phase outputs from a double-pole breaker in my USA service panel to the L and N terminals of the inverter, but would this work if the neutral terminal is expecting 0V and the L terminal expecting 230V AC? Can the neutral terminal of the AC in actually swing between + and - 120V so long as the line terminal sees the same voltage but at opposite polarity?

Would the Growatt neutral terminal on the "AC INPUT" possibly short to ground if fed this way? Or do the L and N terminals simply pull current so long as there is a voltage difference between them, even such that it's OK if the N terminal is actually seeing 120V AC?

Also, the manual is not clear to me, but it seems you can change a programming setting for the AC input to work with as little as 90V AC, but it doesn't say why you would need this, or specifically if you need to do this when using on a split-phase utility such as in the USA.

Thanks!


I use these type of units here in the U.S. just fine. Just have to wire it up right and get a minitransformer that is $350. Use L1 to Hot, L2 to neutral and ground to ground.
 

jsmalone1

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Aug 30, 2021
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The Growatt 5000 inverter can use the AC input to supplement the solar power to assist in charging the battery or supplying AC loads.

The AC INPUT is labeled in the attached picture

Ground | L | N

...and it expects 230 volt input.

I could run red and black phase outputs from a double-pole breaker in my USA service panel to the L and N terminals of the inverter, but would this work if the neutral terminal is expecting 0V and the L terminal expecting 230V AC? Can the neutral terminal of the AC in actually swing between + and - 120V so long as the line terminal sees the same voltage but at opposite polarity?

Would the Growatt neutral terminal on the "AC INPUT" possibly short to ground if fed this way? Or do the L and N terminals simply pull current so long as there is a voltage difference between them, even such that it's OK if the N terminal is actually seeing 120V AC?

Also, the manual is not clear to me, but it seems you can change a programming setting for the AC input to work with as little as 90V AC, but it doesn't say why you would need this, or specifically if you need to do this when using on a split-phase utility such as in the USA.

Thanks!
I have 2 of these inverters. The L & N on the AC input and AC output is single phase 240 volt. To use 120 volt you simply use an auto transformer to generate a neutral from the output.
 

Signature Solar

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Jun 26, 2020
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the standard practice is L1 on the L terminal in and L2 on the N terminal in
120v in will not work
 

Bleedingblue

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May 12, 2020
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These units do not put out 120v they are 240v. From the AC in L1 goes to hot and L2 goes to neutral. Ground is ground. Be sure if using multiple units all of em have L1 to hot and L2 neutral. Not mixed up
 

Sky-HHI

On Hilton Head Island in South Carolina
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Sep 24, 2019
Messages
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I don't understand why you would want to add complexity to your system by getting a European unit and an auto transformer. Each component has loss thru it and just makes it more complex. Yes, I understand you get the max output from the unit on both legs but why not just spend the money to get a unit that is built for our system in North America. I don't see the rest of the world buying North American units and converting them into European units.
 
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