diy solar

diy solar

Generator to Growatt Inverter Neutral Bonding - Arg

@wgrippo

my bad, i should read the post twice to be sure, i gave you wrong information.......

1) run L1, L2, from generator to inverter/charger input, not to the main panel......my bad, didnt read it twice
run neutral to neutral buss and ground to ground buss in main panel
connect output of inverter/charger to main panel input, all 4 leads, L1 & L2 to appropriate breakers, Neutral to neutral buss and ground to ground buss

connect a 6 ga. wire from the neutral buss to the ground buss in your square D panel distribution panel
connect the ground rod to the ground buss
<EDIT> the one mistake in your original drawing is the omission of the neutral from the generator to the main panel. This will not matter when you are running on inverter from solar but when your batteries are dead and charging from generator you would not have a neutral supplied, many inverter / chargers are 240 volts only in and dont need a neutral to operate as a inverter or battery charger but to pass AC through from AC input to AC output then that neutral will be required

Again, i don't use off shore equipment so my experience is limited to what i know. I worked in American Electrical Industry for many years so that is what i know......electrical engineer at GE

It is very important that the neutral buss be connected to the ground buss at one point and one point only.
It is required in the NEC, and will prevent a problem with “circulating currents” running in loops between the neutral buss and ground buss. These “circulating currents” are created by noise supression devices which filter off EMI/RFI noise originating in electronics devices, which if not suppressed will cause nuisance tripping in GFCI devices which “see” the noise as leakage.

The NEC is seen by many as cumbersome and unnecessary but it was written to prevent tragedy, born from accidents that were not forseen.

The National Electrical Code is a product of the National Fire Prevention Association, not some government agency.
It was written for very good reason. If you value your family follow the NEC.....To the letter...
 
Last edited:
Thanks for the info. I will run the neutral from my generator input box to neutral bus in the panel, thanks for the suggestion.

I currently do not have the ground and neutral busses connected on my main panel. The neutral comes from the inverter and the ground goes to the grounding rods. All seems to work fine. If I leave them bonded at the generator (my generator doesn't have an easy way to unbond them), then I will have them connected at one point only, but only when the generator is connected to the house.
 
now I'm wondering if I really need a breaker between the generator and the inverter, mostly because I don't have on and town is 40 min away and it's Sunday so most likely the hardware stores are closed.

The generator has built in 25A circuit protection, so that should protect the inverter, right?

EDIT: skipping the breaker between the generator and inverter.
 
Last edited:
Hi everyone!… I am following this post closely as I have almost this exact configuration…

My problem is that if I common every neutral (main panel, sub panel and growatt inverter) it causes a trip in the growatt feed ac breaker. This ONLY happens when the growatt is bypassing the current from the grid (also neutral gets really hot).

If growatt inverter is generating its own current no problem with neutral at all and everything works well.

My main neutral comes from the transformer and it’s not grounded on the main panel. If I bond the neutral to ground at the main panel can I solve the problem?

My temporary solution was separating the neutral and made a independent neutral in the sub panel but now I have a +40v on this neutral. I presume it’s because it’s not grounded but at least it’s not causing a trip.

I am bringing a new electrician because I have the feeling I know more than the last one.
 
Hi everyone!… I am following this post closely as I have almost this exact configuration…

My problem is that if I common every neutral (main panel, sub panel and growatt inverter) it causes a trip in the growatt feed ac breaker. This ONLY happens when the growatt is bypassing the current from the grid (also neutral gets really hot).

You should have a neutral busbar in the main panel. This creates the common neutral. Are you certain you have neutral and ground in the GW hooked up correctly?

If growatt inverter is generating its own current no problem with neutral at all and everything works well.

I'd be seriously looking at the transfer switch connections, quite likely neutral and ground have been switched.

My main neutral comes from the transformer and it’s not grounded on the main panel. If I bond the neutral to ground at the main panel can I solve the problem?

Not necessarily. You have to determine if a ground exists at the meter socket, I've seen this already. Bonding is to be done at one point only to eliminate ground loops. If there is not any bonded ground anywhere in the system, then yes, you need to add one at the main panel.

My temporary solution was separating the neutral and made a independent neutral in the sub panel but now I have a +40v on this neutral. I presume it’s because it’s not grounded but at least it’s not causing a trip.

Very dangerous. And stray voltage can damage electrical components even the GW. That energy will want to go somewhere.

I am bringing a new electrician because I have the feeling I know more than the last one.
Yes, find a qualified electrician that knows what they are doing. The cost to hire someone that is qualified will be much cheaper in the long term than fried electrical components and personal injury or death.
 
Is there not a booklet or a white paper, or a bag of notes on napkins or something available that covers grounding and bonding for solar system installation? It seems like such an important subject with lots of bad information floating around. Anyone?
 
Back
Top