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Growatt 24v - AC output reversed polarity?

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Hello,

I'm new to this so there's a large probability I probably screwed up, but anyway here's my question.

I have the Growatt 24v 3000w all in one, and I just hooked it up to 2 12v SOK batteries in series. I have the AC output going through a breaker, then feeding a GCFI outlet. The outlet works, but when I plugged in my outlet tester it is giving me the "hot/neutral" reversed code. I then tested the output terminals and the N terminal (which I have hooked up to the white wires) is the hot one, not the L terminal.

Any ideas as to what's going on? Are the terminals mis labeled?
 
Thanks for the quick reply... here's a few pics:
1. AC output Labels, and my wiring out of it.
2. Meter on ground and Neutral, showing 120v
3. Breaker box
4. Outlet tester.

Let me know if there's any other pics that might helpPXL_20210824_193431416.jpgPXL_20210824_193539392.jpgPXL_20210824_193436942.MP.jpgPXL_20210824_193546432.jpg
 
You haven't shown the outlet wiring. It is the simple things that trip us up. That inverter probably has the H and N floating. Where you bond ground to neutral is your responsibility. Ir really looks like you wired the outlet wrong.
 
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I don't see anything on the AC input. Do you have any other external grounds? If not, there is no ground reference, and the tester will show failed results.

Additionally, the Growatt unit does not bond neutral to ground when the inverter is generating AC. Even if the unit is grounded, you'll get a failed result on a 3-bulb tester, because neutral is "floating."

Is this a portable cart style build? That is a normal result for an non-grounded setup. Keep in mind, that GFCI outlet will NOT protect against a human touching hot. In some scenarios (Amp/PA system for microphones or musical instruments) this is a shock hazard.

Some other relevant discussions:
 
I don't see anything on the AC input. Do you have any other external grounds? If not, there is no ground reference, and the tester will show failed results.

Additionally, the Growatt unit does not bond neutral to ground when the inverter is generating AC. Even if the unit is grounded, you'll get a failed result on a 3-bulb tester, because neutral is "floating."

Is this a portable cart style build? That is a normal result for an non-grounded setup. Keep in mind, that GFCI outlet will NOT protect against a human touching hot. In some scenarios (Amp/PA system for microphones or musical instruments) this is a shock hazard.

Some other relevant discussions:
Thanks for the comments. No AC input hooked up yet... eventually will be hooked up to a generator, but I only plan on turning the generator on if the batteries are drained and there's there's no solar power. This is for an offgrid cabin... only needed to run LED lighting... fridge, stove, water heater, etc all run on propane and there's no air conditioning to worry about.

Yes, it's a portable cart style build. I have it on the dolly so that I can take it back with me when I leave the cabin. I'm not currently there, but will be so in a week or so, so I am testing everything out now.

I'll read up on those other threads.
 
This has me baffled. I am not sure why you would get any voltage reading from ground and Neutral. Is your PV hooked up correctly?
No PV hooked up at the moment. Just testing the AC output with batteries hooked up.
 
Thanks for the comments. No AC input hooked up yet... eventually will be hooked up to a generator, but I only plan on turning the generator on if the batteries are drained and there's there's no solar power. This is for an offgrid cabin... only needed to run LED lighting... fridge, stove, water heater, etc all run on propane and there's no air conditioning to worry about.

Yes, it's a portable cart style build. I have it on the dolly so that I can take it back with me when I leave the cabin. I'm not currently there, but will be so in a week or so, so I am testing everything out now.

I'll read up on those other threads.

You should look into grounding options for the cabin. Unless you have some existing copper water pipes running deep into the earth, you may need to install a grounding rod. Connect that to the inverter AC ground - input or output (they are connected together). Same for the generator - there should be a screw somewhere to ground the metal frame to that ground rod.
 
You should look into grounding options for the cabin. Unless you have some existing copper water pipes running deep into the earth, you may need to install a grounding rod. Connect that to the inverter AC ground - input or output (they are connected together). Same for the generator - there should be a screw somewhere to ground the metal frame to that ground rod.
This is on the top of my to do list when I get there. I believe that there is a grounding rod near/around the generator shed. My great grandfather who built it was an electrician (I clearly am not), so I suspect the old generator was grounded somewhere.
 
You haven't shown the outlet wiring. It is the simple things that trip us up. That inverter probably has the H and N floating. Where you bond ground to neutral is your responsibility. Ir really looks like you wired the outlet wrong.
Here's a few pics of the outlet wiring. The power is coming into the GCFI outlet from the right, then to the regular outlet, and then exits through the left going to up to another outlet in a separate PXL_20210824_210814270.jpg
PXL_20210824_210822490.jpgPXL_20210824_210804333.jpg
box.
 
I'm not sure about your inverter, but generally YOU must bond the neutral to ground. Depending on code that will be at the inverter or the distribution box. Some boxes have a screw that will bond to ground if installed. Your inverter should have both outputs floating till that is done. There will only be one bond in the system.

I understand your being unsure about all of this. Try this. Put an incandescent lamp between N and G. This should not light up and your tester will look fine. If that is the case, run a wire from N to G.
 
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I'm not sure about your inverter, but generally YOU must bond the neutral to ground. Depending on code that will be at the inverter or the distribution box. Some boxes have a screw that will bond to ground if installed. Your inverter should have both outputs floating till that is done. There will only be one bond in the system.

I understand your being unsure about all of this. Try this. Put an incandescent lamp between N and G. This should not light up and your tester will look fine. If that is the case, run a wire from N to G.
I put my meter on the following output terminals and got these results:
N to G = 123v
L to G = 0
N to L = 123v
 
I put my meter on the following output terminals and got these results:
N to G = 123v
L to G = 0
N to L = 123v
BTW, I'm in touch with Ian from Watts247 now, and he's helping me troubleshoot. Will post back after I have found the issue/solution and let you all know what I've found out.
 
This is on the top of my to do list when I get there. I believe that there is a grounding rod near/around the generator shed. My great grandfather who built it was an electrician (I clearly am not), so I suspect the old generator was grounded somewhere.

Yeah, that would be the way to go.

Here's a few pics of the outlet wiring. The power is coming into the GCFI outlet from the right, then to the regular outlet, and then exits through the left going to up to another outlet in a separate box.

Everything looks fine with your wiring.

BTW, I'm in touch with Ian from Watts247 now, and he's helping me troubleshoot. Will post back after I have found the issue/solution and let you all know what I've found out.

I would suggest 2 things to aid in troubleshooting:
1. If you are at location with on-grid power - temporarily run a ground between any grounded metal electrical box and the AC input ground terminal of the Growatt. Your voltage meter may mislead you otherwise.
2. Turn the circuit breaker off (that 25A SquareD you installed) to that GFCI outlet, which will remove any of its internal circuitry from potentially complicating your troubleshooting of the inverter output.

I'm not sure about your inverter, but generally YOU must bond the neutral to ground. Depending on code that will be at the inverter or the distribution box. Some boxes have a screw that will bond to ground if installed. Your inverter should have both outputs floating till that is done. There will only be one bond in the system.

I understand your being unsure about all of this. Try this. Put an incandescent lamp between N and G. This should not light up and your tester will look fine. If that is the case, run a wire from N to G.

I agree with you, however, OP should absolutely NOT bond neutral to ground on this setup until the inverter itself is properly grounded. The unbonded N output terminal will have 60V on it. If ground remains floating, bonding N to G might pop the inverter, or worse - electrify everything metal on this cart.
 
N to L = 123v with the red probe on L and the black prove on N?

I'm sure you saw that. You meter places no load on the inverter. I've seen situations like this a lot and they aren't real, just a minor stray load. That could just be a capacitor. Put a lamp on it. I will not believe those voltages till you do.

When the power is off have you ever done a resistance check between L and N?
 
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N to L = 123v with the red probe on L and the black prove on N?

I'm sure you saw that. You meter places no load on the inverter. I've seen situations like this a lot and they aren't real, just a minor stray load. That could just be a capacitor. Put a lamp on it. I will not believe those voltages till you do.

When the power is off have you ever done a resistance check between L and N?

I just did this and the lamp turned on.
 
I would suggest 2 things to aid in troubleshooting:
1. If you are at location with on-grid power - temporarily run a ground between any grounded metal electrical box and the AC input ground terminal of the Growatt. Your voltage meter may mislead you otherwise.
2. Turn the circuit breaker off (that 25A SquareD you installed) to that GFCI outlet, which will remove any of its internal circuitry from potentially complicating your troubleshooting of the inverter output.
Will do. I'm at home with a property grounded system, so I'll give that a shot. Thanks
 
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