External limiting an GTIL2 SUN-1000G2 with raspberry

MDJGyurgeiz

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Feb 15, 2020
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Thank you very much. do you think you could think of amplifying the signal near the clamp and with a trimmer calibrate it to compensate for the longer cable length? but what board are you preparing that would work?
 

watts-on

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MDJGyurgeiz said:
Thank you very much. do you think you could think of amplifying the signal near the clamp and with a trimmer calibrate it to compensate for the longer cable length? but what board are you preparing that would work?

My board design doesn't have an input for an external CT clamp. It has an on-board one, but you can't feed your whole house supply through it. It is only meant for measuring the current to/from one inverter.

Basically it's the same as the official external limiter, but without the external CT clamp connection. The reason I didn't include it is because I already have a whole house energy monitor, so can get my import/export readings from that. This then also allows me to place the board adjacent to the inverter, which is too far from my meter tails for an external CT to have worked.

You could use it like that, however, you said you're not allowed to feed into the grid, but how strictly is that monitored? There will always be some latency between sensing the export power and reacting to it, meaning small amounts of power will be exported. In my case that is allowed.
 

aminet

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Doinit said:
Aminet why are u grounding your ct. also when using 2 cts one on each phase there is only 1 way to make the cable like I described above. Or am I wrong? When u get a second inverter u need to just parallel another 2 prong connector to second inverter. cable constructed like I said above. Its odd how the inverters switch back and forth between master and slave. Im trying to figure out how to dedicate one inverter as master all the time. Then install batteries on second inverter so that second inverter-batteries only get used when first inverter needs help with loads,Therefore prolonging batteries lifespan and keeping them charged more often.

I'm grounding the shielding around the CT..It's imperative to eliminate any chance of giving GTI a false reading of my power usage.

On another note. My single GTI with Limiter has been working well. I mentioned last year that I need to set up another GTI with another string of Solar Panelsfurther away to capture afternoon sun. So I have done that.Problem with it is I can't use a limiter because distance is too great and limiter accuracy is compromised and very inaccurate at 100+ feet.

So as a test, I have tried the following andI can not figure out why it isn't working.

I have the second GTI without limiter feeding into the same 240V lines as the GTI with limiter. The GTI withlimiter with 2 CTs in seriesare connected to L1 and L2 from grid before the panel and the GTIs as it should be. Problem is that on days where I get enough sun hittingthe 2separate banks of Solar arrays for GTI1 and GT2, the GTI with limiter doesn't throttle down and I register a back feed into Grid of -600W, -400W whatever. Can not do a slave master set-up either.

I have sat down drawn it out, thought about it, but can't understand why the GTI with limiter doesn't throttle back when it sees a feedback?
 

Doin it

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I am not grounding the CT or shielding at all and it always reads accurately...
also did u install the required resistor in your sensor cables wiring?
U are reading negative on both L1 and L2.. if u only read negative on one of the legs (once u correct the probelem) then this is normal.. the reason negative on one leg is normal (not backfeed) is due to the way your electric company meter reads your home usage..,, it reads both phases as a whole so negative on one leg gets subtracted from other leg to net zero..
 

Patalhetas

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Oct 24, 2019
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hi,
Im from portugal (european grid 230V, L1 and ground) I have two inverters GTIL 1000w with limiter, what i serching is the way to set this inverters, for one is the master until 900w and after that the second start too for give more power.
my setting is:
one is connect directly too the solar panels and the second too the batterys !!
and I need with the camp (or not) set the inverter is first ans the battery inverter the second, when the sun goes on, only the battery inverter working, until the sun comes again.

I think I can explain me !!?
 

Doin it

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You can have both inverters running off of the batteries and the inverters will use the available pv power before they use battery power.
If u insist on having one inverter powered by pv and other powered by battery, then you can try to put the limiting cables at different locations to try and get one inverter to be primary.
Are you using the newest version, the GTIL2?
Also you could go to the GTIL forum on Facebook to get more advice for these inverters
 

admintite

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Feb 5, 2020
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aquaman said:
I accessed the modbus a while back in this thread. Most of the registers seem to be nops. The only interesting data that I could access was the wattage being output.

If anybody else has better luck, please share :)

I have better luck sniffing the LCD display frames

aesanto said:
Hi to all

After reading carefully all posts, and with the knowledge adquired, i've managedto hack the LCD communication protocol and now I'm able to control the Inverter with an ESP8266 via WIFI.
But it not works perfectly. As at every power change it goes to zero before reach the target power.
I'm trying to understand why but so far no progress.

Also I need to decode the remaining protocol in order to get the values showed in LCD. For now i'm working without LCD.

As i understood, there is a frame of bits sent from LCD to the Inverter.
Over there there are some of them witch are the value of power limiting that we can set on LCD.
Changing this ones I can control the Inverter.

In the attached excel you can find the data and how i decoded the important bytes.

Lets see if can make this work smoothly.

Thanks

Hello,

just got two of these inverter's and very happy with them, i would be much happier if i could remotely monitor them. Do you mind sharing how you decoded the LCDdisplay? I have tried the RS485 but the registers are limited to DC volts and AC Volts and I can only read up to 125 registers, as someone mentioned before, must be a firmware protection.

Attached are the boards, which seem to be newer version than whats been posted here.


image_gwttgr.jpg

image_uxijbl.jpg


thank you
 

Patalhetas

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Doinit said:
You can have both inverters running off of the batteries and the inverters will use the available pv power before they use battery power.
If u insist on having one inverter powered by pv and other powered by battery, then you can try to put the limiting cables at different locations to try and get one inverter to be primary. --- I have a external limiter with two outputs (from 2 inverters)
Are you using the newest version, the GTIL2? --- yes
Also you could go to the GTIL forum on Facebook to get more advice for these inverters --- the facebook group use a mix language english and indian or something else :(
 

Doin it

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Can u use the internal limiter of the GTIL2 instead of the external limiter? The group does have mixed language but also has a see translation.
The only way I know to designate a primary with these inverters is to place current sensors before or after the other depending on what they are connected to.. separating loads etc.
 

Patalhetas

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Doinit said:
Can u use the internal limiter of the GTIL2 instead of the external limiter? The group does have mixed language but also has a see translation.
The only way I know to designate a primary with these inverters is to place current sensors before or after the other depending on what they are connected to.. separating loads etc.
what facebook group you say ?

yes, I have a external limiter!!

the external limiter have two output for the inverters !!

image_mkpxzd.jpg
 

Doin it

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You do not need to use the external limiter with the GTIL2.
Search Facebook using GTIL2 as keyword
 

Patalhetas

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Doinit said:
You do not need to use the external limiter with the GTIL2.
Search Facebook using GTIL2 as keyword

I only have GTIL group and the SunG Grid Tie Inverter with Limiter (Roger Naval)

I know I can use with a internal limiter (only the CT) but my inverters is a little far away from the fuse boxe. with only the internal limiter I need use 4 CT em parallel to give me "0"

U know another way ? I read many post with the famous ESP8266 but noting working yet !! I think
 

Doin it

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Yeah thats the group, Rogel... If your sensor wires have to be to long then you have to use external limiter. I dont know about how Portugal distributes its power to homes but in the USA on 2 CTs need to be used.
 

Joele

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Mar 30, 2020
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Hello guys, there is work in progress, where we have the madness to operate the internal sensor through an rs232 or 485 you will see then, I am attaching a hypothetical block diagram ...

Sorry for the bad english, google translator...
Stay tuned...
image_gqpxxf.jpg
 

watts-on

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kmsj13 said:
Mine is GTIL v1.2, does the DB9 Port labeled with REMOTE is RS232 or RS485?
I don't know if any of the units are fitted with RS485, but the best way to sure is to check the interface board and google the chip. I'm sure you will find it is an RS232.
 

kmsj13

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watts-on said:
kmsj13 said:
Mine is GTIL v1.2, does the DB9 Port labeled with REMOTE is RS232 or RS485?
I don't know if any of the units are fitted with RS485, but the best way to sure is to check the interface board and google the chip. I'm sure you will find it is an RS232.

Thanks for your suggestion but the WIFI Plug being advertised by our local seller is like this "https://www.aliexpress.com/item/32785505345.html" and it seems it is using RS485. I will try to check the IC being used later this night.
 

kmsj13

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I opened my GTIL2 and saw this Wifi Plug Ver 1.2 which is different from PCB of Sir Watt.
The IC doesn't have any label so i wonder if its MAX3232 IC.

image_weokpd.jpg



I tried to use lights to see the connection:
DB9:
PIN 5 -GND
PIN 2 - Might be TX
PIN 3 - Might be RX
PIN 12 - 12v


image_cibaoz.jpg

image_pwefrm.jpg

image_nyyurn.jpg
 

jkammler

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Apr 11, 2020
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Hallo,

I also use this unit - and was looking into controlling the output. From what I learned so far :

- My box has a RS232 output, same board as shown in the last post from kmsj13 (the chip is a MAX3232).

- Could confirm the 4 pins being used (pins 2,3,5,9).

- On pin 9 some 12.x volts against pin 5 (ground).

- I can control the power output (Watts) by using a 5kohm poti when connected to the normally not used, open 2 pin socket, in the row of sockets where the externel sensor cable also goes to (see the 2nd picture from 12-31-2017, 12:10 AM, from rolands post, the black and red cable). Did not need to connect anything else to ground so.

- This control is possible only when the "Limit Mode" checkbox is NOT checked.


That is what I could confirm on my box.


Next step:

- Use a MCP4132 as Digi_Pot controlled by a Raspberry PI (I think I get this to work).

- For current meassuring I will use ACS758LCB-050B modules, where the analog (out2) signal is converted by a ADS1115 to I2C on the Raspberry.


Question: Did I overlook a translated version of the "Eybond Modbus RTU Protocol V100" document ? Since I did not yet get the RS232 interface to talk to me yet, so I assume I do something wrong. Does anyone know of a quick test (some confirmed string to send) for this interface?


Your help is greatly appreciated.
 

kmsj13

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Apr 10, 2020
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jkammler said:
Hallo,

I also use this unit - and was looking into controlling the output. From what I learned so far :

- My box has a RS232 output, same board as shown in the last post from kmsj13 (the chip is a MAX3232).

- Could confirm the 4 pins being used (pins 2,3,5,9).

- On pin 9 some 12.x volts against pin 5 (ground).

- I can control the power output (Watts) by using a 5kohm poti when connected to the normally not used, open 2 pin socket, in the row of sockets where the externel sensor cable also goes to (see the 2nd picture from 12-31-2017, 12:10 AM, from rolands post, the black and red cable). Did not need to connect anything else to ground so.

- This control is possible only when the "Limit Mode" checkbox is NOT checked.


That is what I could confirm on my box.


Next step:

- Use a MCP4132 as Digi_Pot controlled by a Raspberry PI (I think I get this to work).

- For current meassuring I will use ACS758LCB-050B modules, where the analog (out2) signal is converted by a ADS1115 to I2C on the Raspberry.


Question: Did I overlook a translated version of the "Eybond Modbus RTU Protocol V100" document ? Since I did not yet get the RS232 interface to talk to me yet, so I assume I do something wrong. Does anyone know of a quick test (some confirmed string to send) for this interface?


Your help is greatly appreciated.

Hi,
does the pcb looks the same as yours v1.2?
I tried using usb-rs232 serial but cant get data, i tried usb-rs485 serial but i was getting some data corruption and cant decode strings...
 
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