Offgrid Cabin - Growatt 5000es and Generator connection options

solardad

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Getting ready to help setup a 2 X Growatt 5000es system with 2 transformers.
PV side will be sized to hopefully meet 100+% of needs but we still want a generator backup to power essential loads and charge the battery bank until solar can take over (500w-1kw loads and 3-4kw for charging).
And for reference planning on initially 15kw of batteries

My question is around wiring the connection from generator to one of the inverters. Looking to leverage the 2 wire start capabilities and auto start stop settings with the Growatt.

Have a Honda 7000w inverter generator that can do either 120v @ 30a or 120/240v 30a but can not do a straight 240v. Since the Growatt only has one hot leg on the AC in side could I still wire both legs from the generator to take full advantage of the output?

Generator - L1 to L1 of Growatt (120v)
Generator - L2 to N of Growatt (120v)
Generator - G to G of Growatt

I know the AC IN range per setting 3 is 90-280v but I don't know if the Growatt will freakout when it sees 120v on the N.

Also since the inverters are going to be in parallel would that cause an issue in only having one of the Growatts connected to the generator?

Does anyone have a similar setup already?

Thanks

<edit> see post 11 for finalized diagram
 
Last edited:

MichaelK

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Have a Honda 7000w inverter generator that can do either 120v @ 30a or 120/240v 30a but can not do a straight 240v. Since the Growatt only has one hot leg on the AC in side could I still wire both legs from the generator to take full advantage of the output?

Generator - L1 to L1 of Growatt (120v)
Generator - L2 to N of Growatt (120v)
Generator - G to G of Growatt

I know the AC IN range per setting 3 is 90-280v but I don't know if the Growatt will freakout when it sees 120v on the N.
Are you in the US? Seems so if you have a split-phase generator? I would question your statement as to the 90-280V AC IN range. Looking at the user manual for this model, it appears to be the European version designed for 230V, 50Hz AC. I don't know how the Europeans wire for ground, so yes, I would be very concerned about bonding ground to L2. Then there the added problem of 50Hz with a 60Hz generator?

Can you explain in more detail why you are not selecting Growatt's North American version, the 6000T, that is designed for split-phase operation? This sounds like a "can I make it work?" kind of project?
 

solardad

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Yes, US so split phase

Price per performance, high voltage MPPT range, low idle draw, etc. Inverter supports 240v at 60hz, no concerns on choice just looking for confirmation on connection
 

timselectric

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Generator - L1 to L1 of Growatt (120v)
Generator - L2 to N of Growatt (120v)
Generator - G to G of Growatt
Generator L1 + L2 = 240v
Growatt L1 + L2 (marked N) = 240v
There is no 120v
Until after your transformers.

Also since the inverters are going to be in parallel would that cause an issue in only having one of the Growatts connected to the generator?
When wired in parallel, they should be treated as one unit. Share the same AC input, AC output, and battery.
The only thing that can be separate, is the solar inputs.
 

solardad

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Generator L1 + L2 = 240v
Growatt L1 + L2 (marked N) = 240v
There is no 120v
Until after your transformers.


When wired in parallel, they should be treated as one unit. Share the same AC input, AC output, and battery.
The only thing that can be separate, is the solar inputs.
@timselectric Thanks for the info.
I think I should've been clearer in my question though.

My 120v reference was to the Generator output on its L1 and L2 legs since it is split phase.
Are you suggesting that is not an issue on the Growatt side when the generator is active and sending power to the inverter's L1 and N lines?

As for the parallel feedback how would you suggest one wire the output of the generator to the AC IN for two inverters...? Having a hard time wrapping my head around that.. diagram / picture?

thanks again
 

timselectric

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The manual provided with the inverter, has diagrams for wiring parallel. And yes, you would not be using the neutral from the generator. 240v only, from the generator to the inverters.
 

timselectric

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@timselectric Thanks for the info.
I think I should've been clearer in my question though.

My 120v reference was to the Generator output on its L1 and L2 legs since it is split phase.
Are you suggesting that is not an issue on the Growatt side when the generator is active and sending power to the inverter's L1 and N lines?

As for the parallel feedback how would you suggest one wire the output of the generator to the AC IN for two inverters...? Having a hard time wrapping my head around that.. diagram / picture?

thanks again
Is this the US version, sold by Signature Solar?
Or the European version, from somewhere else?
 

solardad

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Is this the US version, sold by Signature Solar?
Or the European version, from somewhere else?
Don't own one yet so open to suggestions which one to purchase. Thanks

<edit> and I guess a follow up question would be does it matter given the system will never see grid power?
 
Last edited:

740GLE

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My suggestion is to skip the 5000ES and source a proper split phase all in one and you’ll have no issues down the line.

But alas it seems like you’re focused on saving money and fixing the faults of the 5000ES.

Good luck!
 

timselectric

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Don't own one yet so open to suggestions which one to purchase. Thanks

<edit> and I guess a follow up question would be does it matter given the system will never see grid power?
The non US version, internally bonds the L2 (marked as N ) to ground. You will have to open it up (voiding the warranty) and remove the bonding screw.
Or just purchase the US model , sold by Signature Solar.
This inverter, in combination with a transformer. Is perfect for an off grid situation. A lot of bang, for the bucks.
I love mine, and will be expanding with more in parallel.
 

solardad

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The non US version, internally bonds the L2 (marked as N ) to ground. You will have to open it up (voiding the warranty) and remove the bonding screw.
Or just purchase the US model , sold by Signature Solar.
This inverter, in combination with a transformer. Is perfect for an off grid situation. A lot of bang, for the bucks.
I love mine, and will be expanding with more in parallel.
@timselectric Thanks for the info. I have read similar comments on the US vs EU version and I was planning on the US.

I came up with a line diagram for the GEN input and worked in a bypass switch in case the system is down for maintenance etc..
When building the diagram the question of how do I protect the 120v loads if the transformer craps out came up - so I diagramed that out also. Based on a Poz's video I incorporated a 3p breaker that powers a 120v dedicated panel for just those loads. So if the breaker trips based on L1 / L2 / N the whole panel is down.

Goals
  • Redundancy. If inverter or transformer has issue then they system stays up
  • Expansion. Easily add another Inv. or Trans. if needed via breaker slot
  • Protect 120v loads. 3p breaker protects the N
  • GEN auto start based on Inv. dry contact switch & menu settings

I'd be interested in your thoughts. Am I over complicating the setup with the 3p breaker? Not sure if I am planning on a "hell freezes over" scenario with a transformer dying but I figure it would be the same if not lower risk than a transformer going in a split-phase inverter.. maybe? Thanks!

<edit> diagram edited to reflect removal of 3p breaker and replacement with 120v coil relay, relay momentary switch and proper grounding. Thanks @timselectric for assistance.

J-J_2.png
 
Last edited:

timselectric

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@timselectric Thanks for the info. I have read similar comments on the US vs EU version and I was planning on the US.

I came up with a line diagram for the GEN input and worked in a bypass switch in case the system is down for maintenance etc..
When building the diagram the question of how do I protect the 120v loads if the transformer craps out came up - so I diagramed that out also. Based on a Poz's video I incorporated a 3p breaker that powers a 120v dedicated panel for just those loads. So if the breaker trips based on L1 / L2 / N the whole panel is down.

Goals
  • Redundancy. If inverter or transformer has issue then they system stays up
  • Expansion. Easily add another Inv. or Trans. if needed via breaker slot
  • Protect 120v loads. 3p breaker protects the N
  • GEN auto start based on Inv. dry contact switch & menu settings

I'd be interested in your thoughts. Am I over complicating the setup with the 3p breaker? Not sure if I am planning on a "hell freezes over" scenario with a transformer dying but I figure it would be the same if not lower risk than a transformer going in a split-phase inverter.. maybe? Thanks!

View attachment 93022
I don't see any need for the 3 pole breaker. The 30a transformer breakers cover the input, and therefore the output.
The 120v loads panel can be feed at the main lugs.
(Instead of the 50a breaker) it's already protected by the 50a breaker in the 240v loads panel.
I don't see a N/G bond. This should be located in the panel that the transformers are connected to.
If you want to protect against neutral loss. Add a 2 pole relay (120v coil) ahead of the 120V loads panel.
Controlling the two hots.
Feed the relay coil from a single pole breaker in the 120V loads panel.

TWTADE/JQX-62F-2Z Coil Voltage AC 110V 80A DPDT Electronmagnetic Relay,High Power Relay AC 110V https://www.amazon.com/dp/B07FCJFGL9/ref=cm_sw_r_cp_apan_i_G746QJTZZS20M06WNP7F?psc=1
 
Last edited:

solardad

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I don't see any need for the 3 pole breaker. The 30a transformer breakers cover the input, and therefore the output.
The 120v loads panel can be feed at the main lugs.
(Instead of the 50a breaker) it's already protected by the 50a breaker in the 240v loads panel.
I don't see a N/G bond. This should be located in the panel that the transformers are connected to.
If you want to protect against neutral loss. Add a 2 pole relay (120v coil) ahead of the 120V loads panel.
Controlling the two hots.
Feed the relay coil from a single pole breaker in the 120V loads panel.

TWTADE/JQX-62F-2Z Coil Voltage AC 110V 80A DPDT Electronmagnetic Relay,High Power Relay AC 110V https://www.amazon.com/dp/B07FCJFGL9/ref=cm_sw_r_cp_apan_i_G746QJTZZS20M06WNP7F?psc=1
Ahhh... I think I get it. Would look something like this correct? The relay monitors the 120v from the 120v panel and if that breaks (H or N dies) it kills the 50a that feeds into the 120v panel?

<Edit> just updated the diagram correctly reflect ground + N bond location


1651237061524.png
 
Last edited:

timselectric

If I can do it, you can do it.
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Ahhh... I think I get it. Would look something like this correct? The relay monitors the 120v from the 120v panel and if that breaks (H or N dies) it kills the 50a that feeds into the 120v panel?

<Edit> just updated the diagram correctly reflect ground + N bond location


View attachment 93032
Yes, that's it.
Looks good.
 

RichardfromEG4

The "Do-What's-Needed" Solar Guy
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Generator sizing with an inverter is not fun. Let me start there - most generators output a sine wave that deviates by more than 5% unless at less than a 50% load. This can lead to long term damage of your inverter. James (SS owner) does a great video explaining this here. Essentially you need to buy an inverter that is 2x as large as your inverting capability PLUS YOUR LOAD to maintain this balance. Not worth the money.

That being said, I'd recommend just buying a battery charger, and plugging that into the generator to charge batteries, and just have those be inverted by the inverter for power to your electricity. For a few hundred dollars, it saves a number of headaches.

Additionally the 5000ES has no neutral lines. The N is an international designation and is actually L2. So, you have L1, L2, and ground from the inverter. You would need to use an auto transformer or isolation transformer to get a neutral for 120v loads.

Finally - depending on where you buy the inverter there may be a N/G bond inside the machine. We don't sell units with that but others do.
 

timselectric

If I can do it, you can do it.
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Ahhh... I think I get it. Would look something like this correct? The relay monitors the 120v from the 120v panel and if that breaks (H or N dies) it kills the 50a that feeds into the 120v panel?

<Edit> just updated the diagram correctly reflect ground + N bond location


View attachment 93032
Forgot to mention one thing. You need to bypass the relay, to get it running in the beginning. This can be done with a momentarily push button, feed by a single pole breaker in the 240v loads panel. (Making sure that it's on the same phase as the feed in the 120V loads panel)
 

solardad

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Messages
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Generator sizing with an inverter is not fun. Let me start there - most generators output a sine wave that deviates by more than 5% unless at less than a 50% load. This can lead to long term damage of your inverter. James (SS owner) does a great video explaining this here. Essentially you need to buy an inverter that is 2x as large as your inverting capability PLUS YOUR LOAD to maintain this balance. Not worth the money.

That being said, I'd recommend just buying a battery charger, and plugging that into the generator to charge batteries, and just have those be inverted by the inverter for power to your electricity. For a few hundred dollars, it saves a number of headaches.

Additionally the 5000ES has no neutral lines. The N is an international designation and is actually L2. So, you have L1, L2, and ground from the inverter. You would need to use an auto transformer or isolation transformer to get a neutral for 120v loads.

Finally - depending on where you buy the inverter there may be a N/G bond inside the machine. We don't sell units with that but others do.
@RichardfromSignatureSolar

Thanks for the comment, I did happen to see the video earlier.

This scenario is different than the one that was outlined.
  • Cabin static load is expected to be 200-300w/hr. and not 8kw.
  • Use of generator would be temporary and not long term, until the sun is shining again to charge battery and or generator charges the battery to cutoff voltage.
  • Cabin today is using a similarly sized generator for loads that can not be met by temp. solar system with no issue.
Aware of the lack of neutral and have planned for a '120v' or split phased panel, see diagram

Thanks
 

RichardfromEG4

The "Do-What's-Needed" Solar Guy
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@RichardfromSignatureSolar

Thanks for the comment, I did happen to see the video earlier.

This scenario is different than the one that was outlined.
  • Cabin static load is expected to be 200-300w/hr. and not 8kw.
  • Use of generator would be temporary and not long term, until the sun is shining again to charge battery and or generator charges the battery to cutoff voltage.
  • Cabin today is using a similarly sized generator for loads that can not be met by temp. solar system with no issue.
Aware of the lack of neutral and have planned for a '120v' or split phased panel, see diagram

Thanks
Thanks for the update. I try to read as fast as I can be definitely miss details on stuff when I try to help! I hope you get a good working system and it lasts you a long time!
 

eddieriv95

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Ahhh... I think I get it. Would look something like this correct? The relay monitors the 120v from the 120v panel and if that breaks (H or N dies) it kills the 50a that feeds into the 120v panel?

<Edit> just updated the diagram correctly reflect ground + N bond location


View attachment 93032
Hi, I’m in the same boat. 5000 US growatt (from signature solar). I’m looking for a clean off grid only diagram. The grid tied diagram they provided is not really what I need. I’m working through the AC connection side. Could I run the inverter AC out to a 60A fusible Square D H222n type insulated switch as my primary AC cut off and then feed into a 120/240V load panel. I’ve seen people note a 50A 2 pole breaker for the inverter and 30A 2 pole breaker for the solaredge transformer. Is that what most people are using? My loads include a shed with lights and plugs and a 30A 120V RV outlet. Im adding a 25A breaker for 230v water pump, and eventually a sub panel to service a small cabin heated by wood and a mini split, with some appliances (fridge, microwave, coffee maker, toaster etc. but using propane for cooking and water heating. Today I just want to get the shed and RV taken care off. Any advise appreciated
 
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