11.8Kw Ground mount and 3-SPF Growatt 5000 ES, Grid pairing and backup Generator. But will it work?

SignatureSolarJames

Make DIY Solar Great Again
Joined
Jun 26, 2020
Messages
122
the drawings here are really good. 2 things would be a good improvement:
-make the output panels a "main breaker" type so that you can shut off all inverters at once
-combine all the AC inputs on a similar main breaker panel before landing on a 125A breaker at the main load panel

If you use the "AC combiner" strategy on you system you will be able to manage it more effectively.

you might consider a 100-125A Bypass switch https://www.homedepot.com/p/GE-100-...ency-Power-Transfer-Switch-TC10323R/100171587 for the AC in and AC out panels, connecting your load panel to the load side, the AC out of the inverters to the Generator side and the AC in to MDLP at your house.

This will allow for easy transfer from inverter back to grid in case of maintenance, upgrade or repair in the future.

We do not do drawings but we sure do comment on them.
 

PLCdude

New Member
Joined
Jan 27, 2021
Messages
1
the drawings here are really good. 2 things would be a good improvement:
-make the output panels a "main breaker" type so that you can shut off all inverters at once
-combine all the AC inputs on a similar main breaker panel before landing on a 125A breaker at the main load panel

If you use the "AC combiner" strategy on you system you will be able to manage it more effectively.

you might consider a 100-125A Bypass switch https://www.homedepot.com/p/GE-100-...ency-Power-Transfer-Switch-TC10323R/100171587 for the AC in and AC out panels, connecting your load panel to the load side, the AC out of the inverters to the Generator side and the AC in to MDLP at your house.

This will allow for easy transfer from inverter back to grid in case of maintenance, upgrade or repair in the future.

We do not do drawings but we sure do comment on them.
Hence I added an extra charge controller.
Your 3x inverter diagram is quite complicated and uses transformers that whilst reliable, protecting them with a breaker AS YOU SHOULD means that IF the breaker were ever to trip, you will stress and fry various 120v devises in your home. Its a bodge to make non USA equipment to work here.
Get the proper stuff and do it right.
With little modification you do need to worry about burning anything. I’m electrical engineer and intend to deploy similar system with 3 ea 5k es inverters in parallel. My design for 120v side will be different since I will be using 10KVA transformer with 240VAC primary and 120/240 secondary feeding 120vac panel Instead using auto transformer.
 

Hedges

I See Electromagnetic Fields!
Joined
Mar 28, 2020
Messages
10,609
Couple of things, some others have commented on first one.

If you have 240V inverter output and rely on auto-transformers to establish 120/240V split phase, if those auto-transformers go offline you fry some 120V electronics.
I've thought about this issue before, and one solution is to gang the breaker for autotransformer to a breaker feeding the panel. That way, if the 30A breaker on auto-transformer trips it also shuts off 50A breaker feeding panel.
Difficulties with that include you have 2x autotransformers and multiple inverters, may exceed ability to gang. And, spacing between breaker levers may make ganging difficult.

Another possible was to address:
1) Feed inverters to a panel with only 240V loads. No issue with lost neutral.
2) With 30A breaker from 240V panel, feed a sub panel with hardwired autotransformer (no breaker) and multiple 120V loads. If 30A breaker trips disconnecting transformer, loads are shut off and protected. (better to use one 10kW transformer and larger breaker.)

I would like to have a thermal protector on the transformer. Ideally that would work by tripping the 30A breaker remotely. Also fan cool.

All these fancy breaker configurations may be easier to accomplish with DIN rail hardware.

Other possible issue:
240V from grid, L1 and L2, go to Growatt input.
Output of Growatt goes to autotransformer, establishing grounded neutral as midpoint.
If grid goes down, Growatt disconnects from its AC input. Does that only disconnect what it considers Line (your L1)? Or does it disconnect what it considers Neutral as well (your L2).
If It's Neutral remains connected to its output L2, 120V away from grounded Neutral on your sub-panel, it backfeeds 120V into your AC grid connection L2. Trouble is, grid is down so you're now backfeeding grid.

You need to determine if Growatt has a 2-pole disconnect, isolating both AC input wires Line and Neutral.
If you have one on hand, should be able to measure with meter for continuity.
 

EchoPapa

New Member
Joined
Dec 19, 2021
Messages
19
Watch this on grounding the 5000es. SS is modifying or having GW modify the internal ground to neutral inside the 5000es

 

Struc

Collecting Parts!
Joined
Sep 20, 2021
Messages
176
Location
Oconomowoc / Land o Lakes WI
Post the thread. Posting just that video is very misleading. Lots of additional information has been posted about that video.

 
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