Export Limit with Growatt inverters?

[fafrd]

My unit is the SPH3000, not the 6000. In July, when the system was installed, the peak production was about 2000w - with 2275w panels I produced a bit over 15kWh daily. The unit is fairly cool when working, as it is in a well vented area with no direct sunlight.
The communication with the Easton is by RS485 - I read recent that there is supposedly a similar wireless solution, but lately it's not working with hybrid inverters.
Most of the configuration can be made in the inverter, but it's easier through Growatt's server. I believe the dongle needs to be connected to the internet and the configuration must be made through Growatt's server, but as the system was installed by the company that I bought it from, I didn't really pay attention.
The build quality looks good - but it's Chinese... When they installed, the LCD screen and buttons weren't working - the ribbon connecting then to the main board wasn't properly attached. The installer made a joke that they included a hex key in the package so the installer could fix it right away...

Appreciate all the info. If these inverters support zero-export through a CT-based sensor communicating to the inverter via RS485 and they are quiet even under load, I’m going to put the Growatt SPH on my shortlist…

 

[fafrd]

It’s showing 2 CTs wired together if you look at E. That’s what I do with the GTIL2s to allow their 240v to limit correctly.

But the other pic is showing a meter. The inverter in the pic doesn’t look like the sph model from your first link.

The inverter in the USA link is shown installed with a transformer to get splitphase

I’ve been looking at that wiring diagram and may have found an issue.

There is a separate Automatic Transfer Switch so that, when the grid goes down, EPS load is switched from grid to EPS and Autotransformer serves split-phase 120V power to EPS loads (within max balancing capability of Autotransformer).

That’s all fine, but the Autotransformer is also in parallel with grid when the grid is present, which means imbalance of both EPS loads as well as non-EPS loads will flow through Autotransformer (which may be too much for it’s capacity).

Using this EPS-Series inverter to offset 240V consumption (using double-CT clamp) but not to provide EPS (and so no transformer needed) should work fine, but Growatt may have devided that the market self-consumption-without-EPS here on the US was too small…

 

[Jim Lee]

Does anybody know what Signature Solar in Texas has to say about this. I just got a quote for a 48v SPF 5000 ES off grid Inverter for $899.00 plus $399.00 for the Transformer Kit and it's my understanding that the load will pull first from PV and charge the battery with extra or pull from the battery if needed then the load will pull from PV the battery and Grid if needed with zero export. Only problem is I can't find out from anybody how it does it, or how it is connected to my home service panel without back feeding. By the way I also have a 22Kw generator with Auto transfer already on my house and I'd like to know what electrical changes I will have to make. I ready to make a major purchase, but can't until I understand how it's going to work. any comments would be greatly appreciated.

 

[fafrd]

Does anybody know what Signature Solar in Texas has to say about this. I just got a quote for a 48v SPF 5000 ES off grid Inverter for $899.00 plus $399.00 for the Transformer Kit and

it's my understanding that the load will pull first from PV and charge the battery with extra or pull from the battery if needed then the load will pull from PV the battery and Grid if needed with zero export.

You need to be precise about which ‘load’ you are talking about.

The ‘Critical Loads’ or EPS served by the AC output will not export by definition (which is what it sounds like you are talking about).

It’s my understanding that the Growatt SPF inverters only draw power through the AC input and only generate power out of their AC output (to Critical Loads).

The purpose of this thread is Growatt inverters that also generate output power out into the AC input to serve house loads that are not critical loads while the grid is up (offsetting consumption).

So the inverter needs to export power, but only up to the limit that zeroes out consumption measured by the CT sensor (hence ‘zero-export-to-CT-sensor’ capability).

The SPH-series Growatt inverters appear to support exporting power out the AC input to offset consumption, but your SPF-series inverter does not.

Only problem is I can't find out from anybody how it does it, or how it is connected to my home service panel without back feeding. By the way I also have a 22Kw generator with Auto transfer already on my house and I'd like to know what electrical changes I will have to make. I ready to make a major purchase, but can't until I understand how it's going to work. any comments would be greatly appreciated.

Suggest you spend some time searching for ‘SPF’ and ‘Growatt’ in case there is already a Growatt SPF owner’s thread appropriate for your questions and start a new thread if no such Growatt owner’s thread already exists..,

 

[Cheap 4-life]

I’ve been looking at that wiring diagram and may have found an issue.

There is a separate Automatic Transfer Switch so that, when the grid goes down, EPS load is switched from grid to EPS and Autotransformer serves split-phase 120V power to EPS loads (within max balancing capability of Autotransformer).

That’s all fine, but the Autotransformer is also in parallel with grid when the grid is present, which means imbalance of both EPS loads as well as non-EPS loads will flow through Autotransformer (which may be too much for it’s capacity).

Using this EPS-Series inverter to offset 240V consumption (using double-CT clamp) but not to provide EPS (and so no transformer needed) should work fine, but Growatt may have devided that the market self-consumption-without-EPS here on the US was too small…

Critical loads (powered by inverter AC output not inverter AC input) are only powered from the AC output when the grid is down. When the grid is up I’d assume the critical loads panel is powered by the main panel not the inverters AC output. When the grids up the main panel gets power from the inverters AC input not the inverters AC output. So the loads in the main panel and the loads in the critical panel are both using the grids transformer (and possibly the auto transformer) to handle the unbalanced legs when the grid is present so I’d assume the grids transformer alone can handle that.

 

[fafrd]

Critical loads (powered by inverter AC output not inverter AC input) are only powered from the AC output when the grid is down. When the grid is up I’d assume the critical loads panel is powered by the main panel not the inverters AC output. When the grids up the main panel gets power from the inverters AC input not the inverters AC output. So the loads in the main panel and the loads in the critical panel are both using the grids transformer (and possibly the auto transformer) to handle the unbalanced legs when the grid is present so I’d assume the grids transformer alone can handle that.

Oh, it’s not a question of the grid’s transformer not being able to ‘handle’ any imbalance or going out of whack in any way.

The point is that the Autotransformer and the grid transformer are in parallel and any imbalance in house load will be seen by the Autotransformer before it is seen by the grid transformer )which is at the other end of much longer wires).

So whatever maximum capacity can be handled by the Autotransformer (presumably protected by a breaker), the whole-house imbalance may be enough to trip the breaker (at which point all of the imbalance will go on to the grid transformer, no biggie).

I’m guessing that ‘zero export’ solutions that can result in export on one leg balanced by import on the other leg will never be endorsed / approved by the Powers That Be.

Do that may explain why Growatt has seemingly pulled back on the SPH-Series inverters got the US market.

 

[Jim Lee]

"The Growatt SPF 5000W ES is the all-in-one inverter/charger you need to take control of your energy bill. The 5000ES can work without batteries and even pair with the Utility if solar is not enough to power a load. Can Stack 6 Units! (30kW of Capacity)
This backup power, self consumption, export blocking inverter is great for any off grid application. With a max PV Input of 450Vdc and 6000W, this 25lb inverter packs a MASSIVE punch." This is a Quote from their advertised page. To be precise the load I'm talking about is the only load panel on my house right now. Not one that is created in the future. What do they (signature Solar) mean when they say you can pair with the utility if solar is not enough to power a load. It seems to me that if I'm powering my house (The Load) with PV and I need more amps than the inverter will pull from the battery until it can't get enough from the battery then it will "PAIR" with the utility to power my house. The system I'm about to buy is 30-395 watt panels, 3 SPF 5000 ES Growatt off grid converters with a 5kw midpoint transformer and 6- 48v 100 AH LiFe batteries. My question is how do I connect the PV power to the house and still PAIR with the grid if the PV or batteries cant handle a serge or the batteries are low or down. If I'm paired with the grid what keeps the PV or battery from back feeding the grid. I understand how my ATS keeps my generator separate from the grid, but they NEVER pair. ?????

 

[Cheap 4-life]

Oh, it’s not a question of the grid’s transformer not being able to ‘handle’ any imbalance or going out of whack in any way.

The point is that the Autotransformer and the grid transformer are in parallel and any imbalance in house load will be seen by the Autotransformer before it is seen by the grid transformer )which is at the other end of much longer wires).

So whatever maximum capacity can be handled by the Autotransformer (presumably protected by a breaker), the whole-house imbalance may be enough to trip the breaker (at which point all of the imbalance will go on to the grid transformer, no biggie).

I’m guessing that ‘zero export’ solutions that can result in export on one leg balanced by import on the other leg will never be endorsed / approved by the Powers That Be.

Do that may explain why Growatt has seemingly pulled back on the SPH-Series inverters got the US market.

I’m thinking the auto transformer should be wired into only the critical loads panel. When the grids down, the inverters AC output should go thru the auto transformer.

 

[fafrd]

I’m thinking the auto transformer should be wired into only the critical loads panel. When the grids down, the inverters AC output should go thru the auto transformer.

Look at the wiring diagram - the Autotransformer is in parallel with the EPS Critical Loads.

Whatever powers the critical loads is also feeding the Autotransformer…

 

[Capt Bill]

Also found this installation manual which lists the full set of Growatt inverters supporting this zero-export capability: https://midsummerwholesale.co.uk/pdfs/growatt-2500-6000tl-xe-export-limitation.pdf

I would love to hear from someone in this forum who has sucessfully hooked up the Growatt MIN 2.5-6k TL-X grid tie inverter to usa 240vac split phase standards . I originally lost interest in those GroWatt Grid Ties when I read the spec sheet saying; 230vac (180-280v) 50/60Hz "single phase" ... for AC Output. At that time, that killed my interest ... until I saw signaturesolar on youtube explaining how that can work on usa split phase set up: Growatt 5kW ES + Mid-Point Transformer Explained! 120V/240V - HD

... & the Power Limiter Option has perked up my interest. I will come back and study this thread for discussions about grounding etc.

 

[fafrd]

I would love to hear from someone in this forum who has sucessfully hooked up the Growatt MIN 2.5-6k TL-X grid tie inverter to usa 240vac split phase standards . I originally lost interest in those GroWatt Grid Ties when I read the spec sheet saying; 230vac (180-280v) 50/60Hz "single phase" ... for AC Output. At that time, that killed my interest ... until I saw signaturesolar on youtube explaining how that can work on usa split phase set up: Growatt 5kW ES + Mid-Point Transformer Explained! 120V/240V - HD

... & the Power Limiter Option has perked up my interest. I will come back and study this thread for discussions about grounding etc.

If you only care about powering loads without export while the sun is shining, that set-up will work.

But since the Growatt MIN-series inverters can only be powered by solar energy and not powered by a battery, they are not going to suitable for offsetting consumption from battery power after the sun has gone down..

 

[fafrd]

Just ran into this: https://www.simplesolarix.com/product/sr-series-hybrid-off-grid-and-on-grid-inverter-with-ct-sensor/

It claims to support ‘zero export to CT sensor’ functionality, so the most important feature of Solark as far supporting self-consumption through the AC input.

Need to find cost as well as who manufactures it…

 

[fafrd]

Just ran into this: https://www.simplesolarix.com/product/sr-series-hybrid-off-grid-and-on-grid-inverter-with-ct-sensor/

It claims to support ‘zero export to CT sensor’ functionality, so the most important feature of Solark as far supporting self-consumption through the AC input.

Need to find cost as well as who manufactures it…

They also have this ‘low voltage’ hybrid that also appears to support zero-export-to-CT-sensor’: https://www.simplesolarix.com/produ...n-off-grid-solar-inverter-with-long-warranty/

This is another Chinese ‘company’ that appears to have just materialized.

At least this low-voltage hybrid inverter appears to be a rebadged versions of the new Pro lineup of hybrid inverters being manufactured by Huayu: https://www.huayu-energy.com/cpxq?product_id=504

These ‘low-voltage’ inverters from Huayu and Simple Solarix are single-phase 230/240VAC (so they will need an Autotransformer to supply split-phase backup power), while this higher-power ‘NA’ Hyayu hybrid model supports split-phase output: https://www.huayu-energy.com/cpxq?product_id=54

 

[fafrd]

One of the only things up and running on Huayu’s website is their catalog: https://hkw1f1f74-pic47.websiteonline.cn/upload/HuayuHybridInverterCatalogue.pdf

 

[cfreitas]

I have a Growatt SPH 3000 and I'm having trouble to configure the zero export functionality, since I can not run a cable from the meter to the inverter. Does anyone know a way of doing it using wireless?

 

[nelsonjrgomes]

There is supposedly a wireless solution but I believe that there is currently some kind of problem with SPH firmware that doesn't allow it - I've read it from the installer of my inverter that it used to work, but recently has stopped. Growatt is supposedly trying to solve that problem, but I have no details.

 

[fafrd]

I have a Growatt SPH 3000 and I'm having trouble to configure the zero export functionality, since I can not run a cable from the meter to the inverter. Does anyone know a way of doing it using wireless?

Can I ask where you purchased your SPH 3000 and how much you paid?

Will be interested to see if you find a solution - how far is the inverter from where you want to position the CT sensor?

 

[cfreitas]

The inverter cost was about 1270€ + 23% (VAT-sales tax).

I don't think the distance is the main problem, in my case. I've the main electric board on the ground floor and the inverter on the 2nd floor, but no decent way to run cables between them.

 

[fafrd]

The inverter cost was about 1270€ + 23% (VAT-sales tax).

I don't think the distance is the main problem, in my case. I've the main electric board on the ground floor and the inverter on the 2nd floor, but no decent way to run cables between them.

And the unit comes with a direct-connect (analog) CT sensor or is the CT sensor wired to a small communication box which is wired to the inverter?

 

[nelsonjrgomes]

And the unit comes with a direct-connect (analog) CT sensor or is the CT sensor wired to a small communication box which is wired to the inverter?

This is the CT sensor that comes with SPH inverter.