External limiting an GTIL2 SUN-1000G2 with raspberry

[EVtinkerer]

Some Info of - and a test programfor - the RS232 communication attached.

Wow, great info here.
Is it possible to adjust the undervoltage cut-off trough RS232?

When I order a unit now, wil I get the RS232 or RS485 version?

 

[uvfzero]

Letzte Aktualisierung:
Lesen der Wechselrichterdaten und Einstellen der Ausgangsleistung (ber RS232). Vielen Dank fr die guten Informationen in diesem Thread, die mir geholfen haben.

[diy] vyokgg [/ diy]
[diy] ywvzbo [/ diy]
[diy] ivycru [/ diy]

 

[chuckp]

Hi guys.

Did anyone ever manage to translate the communication protocol for the SUN-1000G2 into English.

Thanks

 

[RangerGress]

It's for sensing L1-N(120v) and L2-N(120v) of a split phase 240V system, and feeding back on the combined L1-L2(240v), right?
That wiring seems all wrong to me. Does it work well for you under all conditions?

I use 2 sensors wired in parallel (no resistor), feeding back just on L1-Neutral(120v). Obviously unbalanced, but no issue since the meter combines L1+L2 anyways.

When I used just 1 GTIL hooked to L1 and L2 that is the CT comboI used as it was on sale on ebay claiming to solve the Split phase problem.
Unfortunately as my panel was seriously unbalanced I was back feeding the grid even with those sensors like that.
Whetherthey are right wrong or just plain stupid I don't know :huh:I just know that they did not work properly for me.

Since then I got another GTIL and now feed L1 with one and L2 with one. No backfeed whatsoever but that is to be expected as I am no longer supplying an uneven panel with 1 GTIL

Here is the graph of one GTIL hooked to both L1 and L2 with the CTs as shown above.
You can see that the output of the GTIL LI and L2 are a mirror image of each other so whatever L1 was demanding was also supplied to L2. If L2 was not using anything it would backfeed it to the grid. If L2 was using something the difference was still backfeeding.
This was occuring till 4/12 when I installed the other GTIL and started to feed the legs separately.




This is what the chart looks like now absolutely no backfeed.




Neutral hookup I have no idea. I mean neutral has no potential (Voltage) as it is basically"earth"?.
Can you measure the current in a neutral wire? I suppose you can. As electron flow is electron flow no matter where in the circuit.
So we know that electron flow represents current which is measured in amps.
I have some spare CTs and will put one on the neutral on my panel and see if it correlates with the other legs. It will be an interesting experiment.

Wolf

Wolf,

First off thanks alot for the pictures! I will make my comments on the cable later.

I think your dual CT clamp set up didn't work because it seems to me you we're using a 120V GTI??? Ajw22 and myself use a 240v GTI. As ajw22 said your after the sum of the amperage draw. The CT clamps essentially take a sample of this back to the GTI to determine your power consumption.

I need to clarify a few things about the 240v split phase first before I continue with my understanding of CT clamp operation.

1. Neutral and Earth are NOT the same. The power company's neutral comes from the center tap. That's the 0v reference. You can essentially complete a 120v circuit using ground, from L1 and / or L2 but highly not recommended or safe.

2. If you turn on a hair dryer which draws 10 amps say from L1 and you put an ammeter on the neutral leg without anything drawing power from L2 You WILL get a 10A reading on the neutral leg. I'm sure of this. L1 will complete the 120v circuit through neutral. More on this in a second.

3. There should be no potential voltage difference between neutral and ground, unless you have something backfeeding voltage on the neutral but rest assured there will be a current shooting through the neutral wire to complete the 120v L2 or L1 circuit. After having said that that statement is not completely true because if you draw 10A off L1 and 10A of L2 then you'd actually not have any amperage through the neutral leg when L1 and L2 loads are balanced and this is where we run into problems with 1 CT clamp on the split phase electrical.service. Which is why a CT clamp on the neutral leg alone to report back an reading of your power usage can't be accurate but itself.

I am pretty sure that all these statements are true and accurate.

The CT = Current Transformer that came with my GTI is a 100A /50ma and interestingly enough the ohm reading is 125 ohms... 2 of these in series would be 250 ohms I would imagine. To be accurate we really aren't measuring resistance it's the impedance of the windings in the coil but I can't see why the resistor in your cable would be of any help. You are after the sum of the current readings. I do have one question which is unclear to me. If the GTI just takes the sample of the current reading and uses this alone to calculate the power usage you have from.the grid or if voltage is considered at all?

These CT clamps I do believe have a voltage range as well and this is something very important to consider. If anything to stay within design range. Especially in your case Wolf. If the voltage is considered ( which I doubt ) but not sure- then you would have perhaps provided a somewhat correct sum of the current to your GTI but your voltage since clamps are in series would be the sum of your voltages. I believe the voltage of my CT clamp which my GTI is expecting me to connexct to 240v would be 3.3v , your 120v GTI would be seeing the SUM of the voltages. If your clamps where in parallel then you would NOT add the voltages. Your voltage from CT clamp to GTI is always constant- what changes with power consumption is the sample of the current draw.

Can you tell me what your CT clamps have stamped on them or take a picture? I think we are gonna get to the bottom of this soon.

---

This is what I use at the moment, and it's working 100% as intended. Senses the currents on L1 and L2, and feeds the sum back on L1. No resistors used, except for the one inside the GTI (I assume there is one).
I actually have 2 GTILs (with 4 sensors)set up in the same way. They don't share the work equally, but L1 feedback is always equal to or less than L2 consumption.





I'm thinking of rewiring myGTIL1000s to L1/L2 (240V) to hopefully increase efficiency, but then I will need to halve the sensed current. I think this could be achived by adding another burden resistor (same value as the GTIL internal one) into the sensor cable.

---

__________________________________________________________________________________________________________
Here's RangerGress's post.
I apologize for making such a large post. I should not have quoted so much content.

I have residential 3 phase, 240V on each, relative to the other 2 phases. The 70yr old house got a wiring panel during the 1970s when apparently 3phase was popular <shrugs shoulders> These last couple posts about 240V single phase have been interesting, but I'm having problems applying the info to 3phase. I have a 2KW Sun GTIL that, per the instructions, plugs into a nearby 240V outlet, but in my case it's 2 of my 3 legs, and they are 120deg apart, not 180deg apart.

I'm trying to figure out how to help the GTIL sense how much power to produce, with reasonable accuracy, and not having much luck. I've a second sensor inbound, and I'm not even sure if the 2nd sensor ideas in this thread and elsewhere even apply to 3 phase. Specific questions:

1. Will the second sensor help my GTIL accurately sense how much power to produce?
2. Is there any solution better than simply buying 3x 1KW GTILs that operate plug into 110V? Or maybe that won't work either because I don't have a 110VAC feed line to put the sensor on?
3. I ordered a 2KW GTIL for a 110/120V system. I was quite surprised that I needed to cut the plug and connect it to 220/240V. Does that indicate that the seller goofed and accidentally sent me a 220V system?

 

[Korishan]

RangerGress: Put your replies "outside" the quote tags/blocks. Otherwise it's almost impossible to know where "your" replies are at. I fixed this one, assuming your only reply was at the bottom.

 

[Wolf]

3. I ordered a 2KW GTIL for a 110/120V system. I was quite surprised that I needed to cut the plug and connect it to 220/240V. Does that indicate that the seller goofed and accidentally sent me a 220V system?

You did not goof The GTIL 1000 is both 120V and 240V capable.
The GTIL 2000 is only 240V capable it will not work on 110V.
Wolf

 

[RangerGress]

RangerGress: Put your replies "outside" the quote tags/blocks. Otherwise it's almost impossible to know where "your" replies are at. I fixed this one, assuming your only reply was at the bottom.

Thanks for the assistman. I'm still puzzling out how this forum software handles quoting.

3. I ordered a 2KW GTIL for a 110/120V system. I was quite surprised that I needed to cut the plug and connect it to 220/240V. Does that indicate that the seller goofed and accidentally sent me a 220V system?

You did not goof The GTIL 1000 is both 120V and 240V capable.
The GTIL 2000 is only 240V capable it will not work on 110V.
Wolf

Eco-Worthy's site is kinda deceptive. Really makes it look like 110 is an option for the 2KW device. See pic.Is irksome.

 

[pflicht]

What brand does both 110 and 220 for a 1000w inverter?

 

[Cheap 4-life]

What brand does both 110 and 220 for a 1000w inverter?

They do not supply 110v and 220v at the same time. The 1kw supplies 110v or 220v. When used to supply 220v it can supply all of a 220v load and all of the 110v loads.

---

It's for sensing L1-N(120v) and L2-N(120v) of a split phase 240V system, and feeding back on the combined L1-L2(240v), right?
That wiring seems all wrong to me. Does it work well for you under all conditions?

I use 2 sensors wired in parallel (no resistor), feeding back just on L1-Neutral(120v). Obviously unbalanced, but no issue since the meter combines L1+L2 anyways.

When I used just 1 GTIL hooked to L1 and L2 that is the CT comboI used as it was on sale on ebay claiming to solve the Split phase problem.
Unfortunately as my panel was seriously unbalanced I was back feeding the grid even with those sensors like that.
Whetherthey are right wrong or just plain stupid I don't know :huh:I just know that they did not work properly for me.

Since then I got another GTIL and now feed L1 with one and L2 with one. No backfeed whatsoever but that is to be expected as I am no longer supplying an uneven panel with 1 GTIL

Here is the graph of one GTIL hooked to both L1 and L2 with the CTs as shown above.
You can see that the output of the GTIL LI and L2 are a mirror image of each other so whatever L1 was demanding was also supplied to L2. If L2 was not using anything it would backfeed it to the grid. If L2 was using something the difference was still backfeeding.
This was occuring till 4/12 when I installed the other GTIL and started to feed the legs separately.




This is what the chart looks like now absolutely no backfeed.




Neutral hookup I have no idea. I mean neutral has no potential (Voltage) as it is basically"earth"?.
Can you measure the current in a neutral wire? I suppose you can. As electron flow is electron flow no matter where in the circuit.
So we know that electron flow represents current which is measured in amps.
I have some spare CTs and will put one on the neutral on my panel and see if it correlates with the other legs. It will be an interesting experiment.

Wolf

Wolf,

First off thanks alot for the pictures! I will make my comments on the cable later.

I think your dual CT clamp set up didn't work because it seems to me you we're using a 120V GTI??? Ajw22 and myself use a 240v GTI. As ajw22 said your after the sum of the amperage draw. The CT clamps essentially take a sample of this back to the GTI to determine your power consumption.

I need to clarify a few things about the 240v split phase first before I continue with my understanding of CT clamp operation.

1. Neutral and Earth are NOT the same. The power company's neutral comes from the center tap. That's the 0v reference. You can essentially complete a 120v circuit using ground, from L1 and / or L2 but highly not recommended or safe.

2. If you turn on a hair dryer which draws 10 amps say from L1 and you put an ammeter on the neutral leg without anything drawing power from L2 You WILL get a 10A reading on the neutral leg. I'm sure of this. L1 will complete the 120v circuit through neutral. More on this in a second.

3. There should be no potential voltage difference between neutral and ground, unless you have something backfeeding voltage on the neutral but rest assured there will be a current shooting through the neutral wire to complete the 120v L2 or L1 circuit. After having said that that statement is not completely true because if you draw 10A off L1 and 10A of L2 then you'd actually not have any amperage through the neutral leg when L1 and L2 loads are balanced and this is where we run into problems with 1 CT clamp on the split phase electrical.service. Which is why a CT clamp on the neutral leg alone to report back an reading of your power usage can't be accurate but itself.

I am pretty sure that all these statements are true and accurate.

The CT = Current Transformer that came with my GTI is a 100A /50ma and interestingly enough the ohm reading is 125 ohms... 2 of these in series would be 250 ohms I would imagine. To be accurate we really aren't measuring resistance it's the impedance of the windings in the coil but I can't see why the resistor in your cable would be of any help. You are after the sum of the current readings. I do have one question which is unclear to me. If the GTI just takes the sample of the current reading and uses this alone to calculate the power usage you have from.the grid or if voltage is considered at all?

These CT clamps I do believe have a voltage range as well and this is something very important to consider. If anything to stay within design range. Especially in your case Wolf. If the voltage is considered ( which I doubt ) but not sure- then you would have perhaps provided a somewhat correct sum of the current to your GTI but your voltage since clamps are in series would be the sum of your voltages. I believe the voltage of my CT clamp which my GTI is expecting me to connexct to 240v would be 3.3v , your 120v GTI would be seeing the SUM of the voltages. If your clamps where in parallel then you would NOT add the voltages. Your voltage from CT clamp to GTI is always constant- what changes with power consumption is the sample of the current draw.

Can you tell me what your CT clamps have stamped on them or take a picture? I think we are gonna get to the bottom of this soon.

---

This is what I use at the moment, and it's working 100% as intended. Senses the currents on L1 and L2, and feeds the sum back on L1. No resistors used, except for the one inside the GTI (I assume there is one).
I actually have 2 GTILs (with 4 sensors)set up in the same way. They don't share the work equally, but L1 feedback is always equal to or less than L2 consumption.





I'm thinking of rewiring myGTIL1000s to L1/L2 (240V) to hopefully increase efficiency, but then I will need to halve the sensed current. I think this could be achived by adding another burden resistor (same value as the GTIL internal one) into the sensor cable.

---

__________________________________________________________________________________________________________
Here's RangerGress's post.
I apologize for making such a large post. I should not have quoted so much content.

I have residential 3 phase, 240V on each, relative to the other 2 phases. The 70yr old house got a wiring panel during the 1970s when apparently 3phase was popular <shrugs shoulders> These last couple posts about 240V single phase have been interesting, but I'm having problems applying the info to 3phase. I have a 2KW Sun GTIL that, per the instructions, plugs into a nearby 240V outlet, but in my case it's 2 of my 3 legs, and they are 120deg apart, not 180deg apart.

I'm trying to figure out how to help the GTIL sense how much power to produce, with reasonable accuracy, and not having much luck. I've a second sensor inbound, and I'm not even sure if the 2nd sensor ideas in this thread and elsewhere even apply to 3 phase. Specific questions:

1. Will the second sensor help my GTIL accurately sense how much power to produce?
2. Is there any solution better than simply buying 3x 1KW GTILs that operate plug into 110V? Or maybe that won't work either because I don't have a 110VAC feed line to put the sensor on?
3. I ordered a 2KW GTIL for a 110/120V system. I was quite surprised that I needed to cut the plug and connect it to 220/240V. Does that indicate that the seller goofed and accidentally sent me a 220V system?

---

The 240v supply from the 1kw or 2kw inverter is the same. It does not backfeed when connected to a splitphase main panel. Most electric company meters read the homes power usage at 240v. It doesnt care about neutral. The dual ct clamps are wired in series to allow the 220v inverter to supply the total amps the home is using. The meter is brought to zero or to the amount the grid is still supplying.
Grid tie inverters do not need to be split phase, they are not offgrid inverters. GTIL2 only needs to bring down the 240v consumption that the electric company meter sees.
Heres the proof. Electric bill perfectly matches what the iotawatt says I use monthly. Ebill says 176, iotawatt says 174, close enough

---

I use 2 of the 240v 2kw inverters. I have explained in detail in the link.. https://www.facebook.com/groups/1455824754596738/

---

Using the graph below, It would appear since the Iotawatt is using 120v references for each mains, that the 240v inverter supply is backfeeding. Its not. The meter only uses 240v reference.

Wolf was seeing backfeed using the 240v supply from these inverters (that actually wasnt happening) on one of his mains that were using a 120v reference. That backfeed amount he is seeing is netted with the underfed amount on the other leg. This equals zero, or the amount of power the grid is still using.

The graph-iotawatt below shows the backfeed and underfed on main1 and main 2 with individual 120v references. Similar to the graphs Wolf shared. Wolf you needed to add main1 and main2 together then you will actually read your homes power usage like the electric company reads it. You can also see total power used on the graph I shared. Which is main1 and main2 added together. There isnt a backfeed. The total power used sum matches my electric bill every month.




I didnt want to put this info here because this thread is for external limiting the gtil2 with raspberry, but seen questions I could answer

 

[Cheap 4-life]

Sorry link was wrong. Replaced with correct link

 

[Cheap 4-life]

Ranger the 2kw GTIL2 will only supply 240v. Theres a few sellers that advertise the 2kw as 120v. This is incorrect

 

[Cheap 4-life]

ajw22. I am using 2 GTIL2. I am using 2 CTs and paralleling an additional aero connector for the second inverter. Works wonderfully

 

[Wolf]

ajw22. I am using 2 GTIL2. I am using 2 CTs and paralleling an additional aero connector for the second inverter. Works wonderfully

My answer to your PM message as you do not accept PM messages.
If you are going to use the PM system please turn on "Receive private messages from other users" as it is very frustrating to answer an PM and get this popup.



when you attempt to returnthe message!
To enable your PM account to be able to receive PM's please check the following.




Thanks

Wolf

Thanks for your input. I appreciate it. One of the reasons I switched back to 1 unit per Mains was I needed more wattage anyway.
So I now have 2 GTIL2 supplying ~850W each on L1 and L2. Whether the first installation of the GTIL2 1000 was back feeding or not you are more than likely right as my understanding of split phase 240 has increased. So nevertheless the process has tought me a lot and at this point I am satisfied with the results I am getting now. BTW I have always had and still do have negative values turned on on my IoTaWatt and I see an occasional 2 maybe 3 Watts back feeding on one or the other line but that is so negligible I am certainly not worried about it.
Wolf

 

[Cheap 4-life]

Sorry bought that. Didnt know I had to change settings to receive pms. I changed it thank you

---

What do you mean by you needed more wattage? That shouldnt affect which voltage the inverters should supply. For instance I have 2 240v GTIL2 going.
Glad your happy with it. Ive also learned a lot since installing these inverters. Btw Art Lowery suggests that if a user wants to say undetected by the grid then they should not use a 120v supply from these inverters. I dont know exactly why. I think it has something to do with the inverters trying to supply 120v power when the loads are 240v, and the meter reads 240v and inverters supplying 120v unbalances the 240v or something. Hes the creator- main seller of the dual sensing cables for 240v.

 

[Wolf]

Sorry bought that. Didnt know I had to change settings to receive pms. I changed it thank you

---

What do you mean by you needed more wattage? That shouldnt affect which voltage the inverters should supply.
Glad your happy with it. Ive learned a lot aswell since installing these inverters. Btw Art Lowery suggests that if a user wants to say undetected by the grid then they should not use a 120v supply from these inverters. I dont know exactly why. Hes the creator- main seller of the dual sensing cables for 240v.

---

My initial GTIL2 was a 1000. A 1000 was not enough Wattage to power all my house at times so I got another 1000 and now I have 2000W.
1000W on L1 and 1000W on L2 =2000W orin reality max abt 1800W.

Wolf

 

[Cheap 4-life]

you could have connected the second inverter to 240v the same way the first was connected to 240v. Switching back to one unit per mains (120v) would not enable you to have more wattage than connecting the second inverter at 240v same as the first

 

[Wolf]

you could have connected the second inverter to 240v the same way the first was connected to 240v. Switching back to one unit per mains (120v) would not enable you to have more wattage than connecting the second inverter at 240v same as the first

Could have but didn't
All in all watts are watts 120 or 240.
Wolf

 

[aleks2a]

Hi All, 2 CT sensors should be connected in series or in parallel? for 240V split phase?

 

[Cheap 4-life]

Series. It is also recommended to use a resistor to make the resistance of the dual cable similar to the resistance of a cable that uses one ct. a trim pot helps fine tune

 

[ajw22]

I've done mine in parallel, to add the currents produced by the CTs. No additional resistor.