SPF Growatt 5000 ES System. Design review and suggestions

Jim Lee

New Member
Don't most people that want an off grid converter that is grid tied because they want PV first then battery then grid then generator. Doesn't that cover all the bases. Power no matter what. I'm in the planning process and ready to purchase 30 -395 watt panels. 2 x 6s2p and 1 x 3s2p. Each of the 3 string is wire to 1 of the 3 Growatt SPF 5000 ES inverter. 6 Li Fe EG4 Batteries connected to the inverters. The 3 inverters connected to a separate circuit box with a 50A breaker each. That breaker box set up with 1 or 2 (if safer) split phase Mid point transformers connected with 50A breakers. That breaker box is connected to my home main breaker box with a 60A or 100A breaker (not sure yet) connecting both circuit boxes. The Grid and my 19.5Kw Generac Generator pass through the 200A Transfer switch keeping the grid safe during grid outages is already installed. According to Signature Solar this is the system they want to sell me. Please explain to me why this won't work and what I need to do to make it work. I really don't want to burn my house down trying to improve it. Another question is when the grid goes down I think my generator will auto start even if I have PV or battery power. How could I control that. Any other suggestions would be appreciated, but please keep it simple if possible.
 
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iamrich

Solar Addict
Do you need three inverters? You should probably figure out how much inverter you need to power what you want to power in case of an outage and go from there.
 

Zwy

Solar Addict
Don't most people that want an off grid converter that is grid tied because they want PV first then battery then grid then generator. Doesn't that cover all the bases. Power no matter what. I'm in the planning process and ready to purchase 30 - 295 watt panels. 2 x 6s2p and 1 x 3s2p. Each of the 3 string is wire to 1 of the 3 Growatt SPF 5000 ES inverter. 6 Li Fe EG4 Batteries connected to the inverters. The 3 inverters connected to a separate circuit box with a 50A breaker each. That breaker box set up with 1 or 2 (if safer) split phase Mid point transformers connected with 50A breakers. That breaker box is connected to my home main breaker box with a 60A or 100A breaker (not sure yet) connecting both circuit boxes. The Grid and my 19.5Kw Generac Generator pass through the 200A Transfer switch keeping the grid safe during grid outages is already installed. According to Signature Solar this is the system they want to sell me. Please explain to me why this won't work and what I need to do to make it work. I really don't want to burn my house down trying to improve it. Another question is when the grid goes down I think my generator will auto start even if I have PV or battery power. How could I control that. Any other suggestions would be appreciated, but please keep it simple if possible.
The Growatt SPF 5000 ES is Euro 230V only. Signature Solar pushes these with with a transformer to get 120V. While it does allow 450VDC max from PV, I think you should explore other options and decide what might work best for what need.

What is your max load? Are you intending a critical loads panel separate?
 

Jim Lee

New Member
Do you need three inverters? You should probably figure out how much inverter you need to power what you want to power in case of an outage and go from there.
I plan to use my full house breaker box on my 3300 sq. ft. house. My heating and air conditioner is a 6 ton Geothermal unit and preheats my hot water before entering the on demand gas HW heater.. It's quite efficient at about 26 SEER and I installed a soft start. All lights are LED. I have 2 refrigerators and a double oven. A lot of this can be controlled to not use all at once. My Generator is 19.5Kw and and handles the whole house well. My intention is to use the PV when possible then the battery bank till gone then the grid for spikes and when needed and last, my generator when the grid is down and batteries depleted. I think I need 3 inverters to get 15Kw and 3 times $900.00 is only $2,700.00. That about as much as one 10 or 12 Kw cost. Still, any specific suggestions would be looked into.
 

Jim Lee

New Member
The Growatt SPF 5000 ES is Euro 230V only. Signature Solar pushes these with with a transformer to get 120V. While it does allow 450VDC max from PV, I think you should explore other options and decide what might work best for what need.

What is your max load? Are you intending a critical loads panel separate?
I realize the Growatt is 230V. That is the purpose of the mid point split phase inverter to split the 240 into 2- 120V phases. I think I want 2 in parallel to double the amps and to cover a possible problem mentioned on other sites of tripping one leg and not balancing the circuit panel. I've been studying the growatt quite a bit and it seem to do everything I want done. (unless I'm missing something) Please fill free to give me specific sites for other options. That is what I want to do is study other options before I make my purchase. I'm also confused a bit about the critical load panel. The separate circuit box I referred to , isn't that the critical load circuit panel. I just don't plan to put any house circuits in it. just 3 inverter and 2 transformer breakers and the breaker to connect to the house main breaker box. Thanks for any help in advance.
 

iamrich

Solar Addict
I guess I am just having a hard time wrapping my head around needing 15kw at once. My house is 2800sq ft and the biggest draw is the AC, but we rarely use more than 50kwh a day and that is in the heart of 100F summer here in Texas. My new house will be a little smaller, but all electric, so maybe I am in for a shock.
 

iamrich

Solar Addict
I'm also confused a bit about the critical load panel.
There are a few different ways you can power the house (probably more than a few).

Run the whole house off the inverters (Solar when available, Battery, grid, generator). This would turn the grid into just another source of power for your core system (the inverters).

Run just critical loads off the inverters. The grid powers most of the house, but the refrigerator/freezer and any other critical items are on the inverter and don't lose power if the grid goes away.

Grid powers the house, solar back feeds the grid, batteries are only used if the grid goes away

Sounds like you want the first case, which means you need to remove the grid from the main panel, feed your inverter(s) into the main panel, and then feed the grid (240v), Generator (also 240v?), and the solar all into the inverters which are also tied to the batteries. Basically your inverters are the core, and everything else feeds them.

I am no expert, so grain of salt and all that :)
 

Jim Lee

New Member
There are a few different ways you can power the house (probably more than a few).

Run the whole house off the inverters (Solar when available, Battery, grid, generator). This would turn the grid into just another source of power for your core system (the inverters).

Run just critical loads off the inverters. The grid powers most of the house, but the refrigerator/freezer and any other critical items are on the inverter and don't lose power if the grid goes away.

Grid powers the house, solar back feeds the grid, batteries are only used if the grid goes away

Sounds like you want the first case, which means you need to remove the grid from the main panel, feed your inverter(s) into the main panel, and then feed the grid (240v), Generator (also 240v?), and the solar all into the inverters which are also tied to the batteries. Basically your inverters are the core, and everything else feeds them.

I am no expert, so grain of salt and all that :)
Lets see if I've got what your saying. Nope, I don't. How can I connect the grid to the same panel the inverters and transformers are connected to, KaBoom! Do you mean I need a third panel. Now I'm lost. DO you know if anywhere on the Forum or internet someone has drawn a wiring diagram for the complete hookup of the Growatt, PV array, batteries, grid and generator to the house. Seems like that would solve a lot of problems for a lot of newbe installers. me for one.
 

iamrich

Solar Addict
Sorta like this (this is my off grid setup_). My stuff is all single phase 120v, but you can get the idea of the components.

1637705692308.png
 

Jim Lee

New Member
Sorta like this (this is my off grid setup_). My stuff is all single phase 120v, but you can get the idea of the components.

View attachment 73331
That makes it look almost to simple. Am I correct to say the Grid could connect between the Generator and the charge controller with a transfer switch. Also, your Charge controller could be the SPF Growatt 5000 ES with a Transformer.
 

iamrich

Solar Addict
I don't want to mislead you. I am a bit fuzzy on how to make the Euro model work with USA grid input. I would think it could be done, but not sure on the specifics. Same with the generator. My stuff is standard 120v/60hz, so there are no issues running. I am also a bit fuzzy on how many of those transformers you need as I think they are rated at 5kw, and you want to push 15kw through them.
 

Jim Lee

New Member
I don't want to mislead you. I am a bit fuzzy on how to make the Euro model work with USA grid input. I would think it could be done, but not sure on the specifics. Same with the generator. My stuff is standard 120v/60hz, so there are no issues running. I am also a bit fuzzy on how many of those transformers you need as I think they are rated at 5kw, and you want to push 15kw through them.
Just to help you understand, the 15Kw never goes through the transformer. The transformer only balances the load between the two phases. A 240v appliance pulls equal amps from each 120v leg, but if you are using 3-120v from the same phase the transformer needs to balance the two phases . The more equal you use the 120v phases the less goes through the transformer. I may not be explaining this exactly correct, but that is how it works. The reason for two transformers is if a problem trips a breaker to the transformer having a second one would prevent a major voltage problem.
 

iamrich

Solar Addict
Yeah, I watched a couple of videos and I think I have the concept. Pretty cool actually. I am still fuzzy on how to input the USA GRID AC and the generator as it appears the units are set for European wiring. There are a lot of videos on utube. David Poz has a few good ones and even signature solar has some. I would work with them to explain it to you. I figure you are dropping $15k or so with them, so they should be able to give you a explanation on how to make it work.
 

Zwy

Solar Addict
I don't want to mislead you. I am a bit fuzzy on how to make the Euro model work with USA grid input. I would think it could be done, but not sure on the specifics. Same with the generator. My stuff is standard 120v/60hz, so there are no issues running. I am also a bit fuzzy on how many of those transformers you need as I think they are rated at 5kw, and you want to push 15kw through them.
David Poz (Youtube) used a transformer with 2 GW 230V Euro models. If one uses the Euro models, there is no Neutral and that is where the transformer comes in.

As for needing 15Kw, if there is a well to run, then it just might take that to handle the surge. I struggled deciding between a low freq transformer inverters compared to high freq pure sine inverter. I decided in the end to go with high freq, hopefully the surge isn't too high. Pump is 2 years old, it was replaced under warranty after 4 years. If I knew 2 years ago I'd be installing solar, I would have sourced an inverter pump. I checked amp draw at locked rotor and I have 48 amps. My system may not run it, if so, there will be some changes coming.

Back to the transformer, there won't be 15kw thru it, only the inverters. The transformer is for 120V circuits.
 

Zwy

Solar Addict
I realize the Growatt is 230V. That is the purpose of the mid point split phase inverter to split the 240 into 2- 120V phases. I think I want 2 in parallel to double the amps and to cover a possible problem mentioned on other sites of tripping one leg and not balancing the circuit panel. I've been studying the growatt quite a bit and it seem to do everything I want done. (unless I'm missing something) Please fill free to give me specific sites for other options. That is what I want to do is study other options before I make my purchase. I'm also confused a bit about the critical load panel. The separate circuit box I referred to , isn't that the critical load circuit panel. I just don't plan to put any house circuits in it. just 3 inverter and 2 transformer breakers and the breaker to connect to the house main breaker box. Thanks for any help in advance.
You could use a GW Low Frequency inverter model, however is not parallel capable . https://watts247.com/product/new-gr...se-120v-240v-output-100a-at-120v-50a-at-240v/ This unit is limited to 7Kw and remember it is not parallel capable. It does have a place, high current starting loads.

This is what I finally decided upon times 2 for my system. https://watts247.com/product/lv6548...erter-4kw-250v-mppt-bms-ul1741-built-in-wifi/ These are max 4Kw PV input each input, so with 2 units I could have PV input of up to 16Kw.

If you desire 450V PV input, there is this one and it is parallel capable and can be grid feedback. https://watts247.com/product/lvx-6048-hybrid-solar-inverter-split-phase-120v-240v/ "Note this is a low frequency product, high surge capacity, with a built in auto transformer, No need to balance phases" PV input is max 20a so that would be around 9Kw.

The waterproof version capable of 600V PV is this one and it is waterproof version of the LVX-6048. There isn't too much information on it, it is limited to 7Kw PV input. https://watts247.com/product/lvx604...t-the-2k-range-add-yourself-to-the-watchlist/

With almost 12Kw of PV, you will most likely want something parallel capable with the ability to possibly have dual PV inputs per unit. The LVX6048 in parallel will work and the LV6548 in parallel will work easily with that size PV array.

I take it these are the panels you are considering? https://shop.signaturesolar.us/prod...-half-cell-bifacial-silver-solar-panel-by-ure
 

Jim Lee

New Member
You could use a GW Low Frequency inverter model, however is not parallel capable . https://watts247.com/product/new-gr...se-120v-240v-output-100a-at-120v-50a-at-240v/ This unit is limited to 7Kw and remember it is not parallel capable. It does have a place, high current starting loads.

This is what I finally decided upon times 2 for my system. https://watts247.com/product/lv6548...erter-4kw-250v-mppt-bms-ul1741-built-in-wifi/ These are max 4Kw PV input each input, so with 2 units I could have PV input of up to 16Kw.

If you desire 450V PV input, there is this one and it is parallel capable and can be grid feedback. https://watts247.com/product/lvx-6048-hybrid-solar-inverter-split-phase-120v-240v/ "Note this is a low frequency product, high surge capacity, with a built in auto transformer, No need to balance phases" PV input is max 20a so that would be around 9Kw.

The waterproof version capable of 600V PV is this one and it is waterproof version of the LVX-6048. There isn't too much information on it, it is limited to 7Kw PV input. https://watts247.com/product/lvx604...t-the-2k-range-add-yourself-to-the-watchlist/

With almost 12Kw of PV, you will most likely want something parallel capable with the ability to possibly have dual PV inputs per unit. The LVX6048 in parallel will work and the LV6548 in parallel will work easily with that size PV array.

I take it these are the panels you are considering? https://shop.signaturesolar.us/prod...-half-cell-bifacial-silver-solar-panel-by-ure
Yes, those are the panels. So far I'm really sold on the Growatt 5000 ES. 15Kw for $2700 and it seems to do exactly what I want is hard to beat. I still haven't Seen a diagram that shows all the hookups, meaning, PV to GW, Batteries to GW, Grid and Generator to Transfer switch then TS to ? (main Breaker box on House), GW to sub panel, Sub panel to Transformers. I need to see this on a diagram with assurance that it is correct. I would also Like to see where and what size fuses need to be placed throughout the system. I've seen how to connect most of these connections individually from David Poz and others, but haven't seen it all put together yet. example: I'm not sure what keeps the generator from starting if the grid goes down and PV and batteries are up and running. If that capability is in the converter I need to have it explained to me how. BTW, I absolutely AM NOT going to Netmeter. NO FeedBack to Grid. Where I live in OK Kiamichi Electric is Very Anti Solar unless they are doing it.
 

Zwy

Solar Addict
Rated max PV input for the GW SPF 5000ES is 5500w according to spec sheet. If you install all 30 panels, you will be over paneled. Some will tell you that isn't a problem, myself I don't like running things to the limit. But that max limit doesn't quite make sense if indeed PV OCV is rated at 450V and ISC is 100a. I'd be checking into that with Ian and do some more research.

At 30 of those panels, you will be installing as 6S5P? The reason for 6S is because 30 panels is easily divided by 6. With 6S5P, PV OCV would be 295v, ISC is 52a.

For that price per panel, you could buy something like these, you only need 22 of them for 12Kw, they are slightly longer however than a standard 72 cell module but for my MT Solar mount it still worked on a 16 cell mount after I contacted them. https://store.santansolar.com/product/new-ja-solar-530w-half-cell-mono-solar-panel/ If you went with these panels, you could go 24 panels, this allows different string configurations.

As for diagrams, there are plenty in the archives here plus Ian has some on his site https://watts247.com/ that show some general information. Each member here has their own type of setup dependent upon batteries, BMS, SCC and inverters. There is no one size fits all. Signature Solar should provide you one if you are looking to buy one of their kits.
 

iamrich

Solar Addict
Since this is off grid, do you need new panels (not sure what permits/rules you have)? If you have the real estate, for $3k you could get x60 250w used panels. Run them 10S2P (5000w) per inverter and you would have 15kw at peak sun.
 

Jim Lee

New Member
You could use a GW Low Frequency inverter model, however is not parallel capable . https://watts247.com/product/new-gr...se-120v-240v-output-100a-at-120v-50a-at-240v/ This unit is limited to 7Kw and remember it is not parallel capable. It does have a place, high current starting loads.

This is what I finally decided upon times 2 for my system. https://watts247.com/product/lv6548...erter-4kw-250v-mppt-bms-ul1741-built-in-wifi/ These are max 4Kw PV input each input, so with 2 units I could have PV input of up to 16Kw.

If you desire 450V PV input, there is this one and it is parallel capable and can be grid feedback. https://watts247.com/product/lvx-6048-hybrid-solar-inverter-split-phase-120v-240v/ "Note this is a low frequency product, high surge capacity, with a built in auto transformer, No need to balance phases" PV input is max 20a so that would be around 9Kw.

The waterproof version capable of 600V PV is this one and it is waterproof version of the LVX-6048. There isn't too much information on it, it is limited to 7Kw PV input. https://watts247.com/product/lvx604...t-the-2k-range-add-yourself-to-the-watchlist/

With almost 12Kw of PV, you will most likely want something parallel capable with the ability to possibly have dual PV inputs per unit. The LVX6048 in parallel will work and the LV6548 in parallel will work easily with that size PV array.

I take it these are the panels you are considering? https://shop.signaturesolar.us/prod...-half-cell-bifacial-silver-solar-panel-by-ure

Rated max PV input for the GW SPF 5000ES is 5500w according to spec sheet. If you install all 30 panels, you will be over paneled. Some will tell you that isn't a problem, myself I don't like running things to the limit. But that max limit doesn't quite make sense if indeed PV OCV is rated at 450V and ISC is 100a. I'd be checking into that with Ian and do some more research.

At 30 of those panels, you will be installing as 6S5P? The reason for 6S is because 30 panels is easily divided by 6. With 6S5P, PV OCV would be 295v, ISC is 52a.

For that price per panel, you could buy something like these, you only need 22 of them for 12Kw, they are slightly longer however than a standard 72 cell module but for my MT Solar mount it still worked on a 16 cell mount after I contacted them. https://store.santansolar.com/product/new-ja-solar-530w-half-cell-mono-solar-panel/ If you went with these panels, you could go 24 panels, this allows different string configurations.

As for diagrams, there are plenty in the archives here plus Ian has some on his site https://watts247.com/ that show some general information. Each member here has their own type of setup dependent upon batteries, BMS, SCC and inverters. There is no one size fits all. Signature Solar should provide you one if you are looking to buy one of their kits.
The $2700 I mentioned is for 3 Growatt Inverters capable of 6000W each, so I would not be over paneled. Earlier in this string I mention I would be running 2 string @ 6s2p and 1 string @ 3s2p. 3 paralleled Growatts for 3 strings of panels. The 6s2p would be about 295 VOC and about19.2A. (only miner clipping at very maximum production) 52A would not work at all with Growatt inverter with 18A max production. As far as the 530w panels, 23 panels would produce the same as the 30 I've priced at the same cost. the only draw back for me on that is your larger panels at 62 lbs. each would be pretty difficult for me to handle. The smaller ones at 49 lbs. will be a challenge for me. (I'm 69 years old)
 
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