Navitron Renewable Energy and Sustainability Forum

SOLAR PHOTOVOLTAIC => Solar Photovoltaic Systems => Topic started by: Aunat on July 27, 2020, 11:45:00 AM



Title: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on July 27, 2020, 11:45:00 AM
Hi guys! Hope all is well....

I've been lurking for a while and posting very infrequently, but I figure that with the knowledge on here someone should be possibly able to help. I should first start off by saying that my solar installers have looked at this issue a few times and can't quite understand what's going on, so here goes.

My house is a new build with 3 phase installation. I have 55 x 365w LG (20.075kW total) panels and a 15kW SolarEdge 3-phase inverter. In addition to the panels I have 3 x Powerwall 2's and a backup gateway which is on the grey phase, which is phase 3.
Ok, so far so good. I also have a solar iBoost on phase 2, and the CT clamp is correctly connected to phase 2 within the meter cabinet on the outside of the house. The immersion is itself is connected to phase 2 as well.
However, when I put a load on to Phase 3, the iBoost comes on with approximately the correct amount of power. For example, one of my ovens is on phase 3 and when I turn it on, the iBoost kicks in to life sending 3kW to the immersion. If I put a 1kW load on phase 3, then the iBoost will send 1kW to the immersion. It literally mimmics whatever load I put on to phase 3. I also have an oven on phase 1, and it does not produce the same results.
I should also say that regardless of the level of charge of the batteries, the iBoost never comes to life unless there's a load on phase 3 - even if the batteries are 100% full, which can sometimes happen before 9am(!!), the iBoost won't kick in to life until some sort of load is put on to phase 3. - You can see the export to the grid in the Tesla app.
We have changed out the iBoost 3 times, upgraded the firmware, and we have also moved the CT clamp to phase 1 & 3 for testing purposes, but nothing happens which proves that the immersion is on phase 2.

Does anyone have any suggestions, because I've been banging my head against a brick wall with this issue now for nearly a year.  wackoold

Edit: I should also say that my meter imports between 1-2kWh a day (maybe this is something to do with the Powerwalls?) even though the batteries have been >50% continuously since early March.

TIA!


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: pj on July 27, 2020, 12:29:38 PM
It literally mimmics whatever load I put on to phase 3.
This says to me that you are putting the clamp on the wrong way round - it is seeing import as export. If you haven't already tried it, try putting the clamp on 180deg reversed - if it has an arrow on it, point it the other way.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: greentangerine on July 27, 2020, 12:45:46 PM
It literally mimmics whatever load I put on to phase 3.
This says to me that you are putting the clamp on the wrong way round - it is seeing import as export. If you haven't already tried it, try putting the clamp on 180deg reversed - if it has an arrow on it, point it the other way.

The clamp is somehow seeing the load on phase 3 as an export on phase 2, hence the conundrum and question. 

Would that happen if the CT was put on the neutral wire instead (as the neutral is shared)?  Maybe that's the issue.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on July 27, 2020, 01:33:25 PM
It literally mimmics whatever load I put on to phase 3.
This says to me that you are putting the clamp on the wrong way round - it is seeing import as export. If you haven't already tried it, try putting the clamp on 180deg reversed - if it has an arrow on it, point it the other way.


Thanks. I've just checked and there's two arrows on the CT clamp. One pointing towards meter & one towards consumer unit.

The meter iself (where I take the readings from) I assume is the meter! The arrow was pointing towards it, but I've now swapped it around, turned the oven on and the iboost doesn't kick in to life, which is a good sign, however batteries are currently at 72% charge and it's raining so, hopefully later today I'll come back with results. The theory is that once they reach 100% it should 'export' to the immersion, right?


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on July 27, 2020, 03:09:49 PM
Oooooook. So far the Powerwalls are up to 87%, and I've just noticed that the iBoost is whirring away at full chat - 2.99kW! So I checked my consumption and the house is using 7.1kW. After a bit of investigation it turns out the hot tub had come on just to warm up for 20 minutes, but the hot tub is on phase 1.  ??? ??? ???
Now I really am confused.

Attached is a photo of what my meter and iboost set up looks like.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Westie on July 27, 2020, 03:16:59 PM
It literally mimmics whatever load I put on to phase 3.
This says to me that you are putting the clamp on the wrong way round - it is seeing import as export. If you haven't already tried it, try putting the clamp on 180deg reversed - if it has an arrow on it, point it the other way.

The clamp is somehow seeing the load on phase 3 as an export on phase 2, hence the conundrum and question. 

Would that happen if the CT was put on the neutral wire instead (as the neutral is shared)?  Maybe that's the issue.

I wouldn't recommend monitoring the current in the neutral, it's an unbalanced 3 phase system so the neutral current will be the sum of the unbalanced loads.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Countrypaul on July 27, 2020, 03:45:43 PM
You said you have an oven on phase 1, if you trn that on now does the iBoost also see that as exporting and send the same amount of power to your immersion?


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on July 27, 2020, 03:56:11 PM
You said you have an oven on phase 1, if you trn that on now does the iBoost also see that as exporting and send the same amount of power to your immersion?

No.. it doesn't. The iboost doesn't do anything if I turn the oven on now ... Powerwalls currently @ 97% charge, and the iboost does not read 'HOT' meaning that the tank is full....


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Countrypaul on July 27, 2020, 04:16:42 PM
Just trying to work out what the results woud be if somehow pases 2 & 3 were the wrong way round in the CU end for example - but I'm having trouble getting my head round all the logic.

Could you move the CT clamp to phase 3 (keeping the direction as it is now) and see what happens?


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on July 27, 2020, 04:38:39 PM
Just trying to work out what the results woud be if somehow pases 2 & 3 were the wrong way round in the CU end for example - but I'm having trouble getting my head round all the logic.

Could you move the CT clamp to phase 3 (keeping the direction as it is now) and see what happens?


I had considered this and the answer is yes, I'll move it to 3 in a moment.

Batteries are now at 100%


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Fintray on July 27, 2020, 06:38:07 PM
I don't understand your statement:

"I should also say that regardless of the level of charge of the batteries, the iBoost never comes to life unless there's a load on phase 3 - even if the batteries are 100% full, which can sometimes happen before 9am(!!), the iBoost won't kick in to life until some sort of load is put on to phase 3. - You can see the export to the grid in the Tesla app."

You mention putting a load on phase 3 yet then mention that you see the export on the Tesla app?

Do you mean a load on phase 3 from the mains or from the Powerwalls?

I would expect that on a sunny day phases 1 & 2 would be exporting so the iBoost should be diverting from whichever phase it is connected to into the immersion.

It might be worth getting a clamp meter and positively identifying each phase to ensure there is no unintentional crossover.

Can you also take a picture from a bit further back so the whole consumer unit and fuses etc. can be seen?


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on July 27, 2020, 07:17:24 PM
Hi Fintray,

I'll try to explain what I mean..

Let's assume it's midday and the batteries are 100% STOC, and the array is producing 15kW;

Normally in this scenario the house would be using 0.8kW and exporting 14.2kW, even though the hot water tank is not hot. There's two ways to make the water hot - either put on the oven, or press the manual button several times to 120 minutes so it forces 3kW of power directly to it.

One would expect that any excess energy on phase 2 up to 3kW would be diverted to the solar iboost, but this just isn't the case.

Countrypaul;

I've moved it to Phase 3 and the same thing happens as previous. The hot tub is heating for a short period and the iboost has come on with 2.95kW of power even though the batteries are at 91% STOC.



Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Countrypaul on July 27, 2020, 07:26:06 PM
Just to be sure, the Hot tub is on Phase 1, the iBoost and immersion are on Phase 2 and the CT is one Phase 3. But when the Hot tub is turned on the iBoost starts diverting 2.95kW to the immersion?

Is the Hot tub a nominal 3kW?


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Countrypaul on July 27, 2020, 07:29:29 PM
Looking at you photo there are 3 neutrals joined together, presumably one for each phase, but no neutral linked to the supply - a I right or have I missed something?


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on July 27, 2020, 07:32:47 PM
Just for reference so I don't get confused either  ralph:



Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on July 27, 2020, 07:35:26 PM
Just to be sure, the Hot tub is on Phase 1, the iBoost and immersion are on Phase 2 and the CT is one Phase 3. But when the Hot tub is turned on the iBoost starts diverting 2.95kW to the immersion?

Is the Hot tub a nominal 3kW?

Hot tub phase 1 - correct
iBoost and Immersion on phase 2 - correct
CT is currently on phase 3 - correct (with the arrows pointing the wrong way)

But when hot tub is turned on the iboost diverts 2.95-3kW to the immersion. - correct.

The hot tub has a 3kW heater and a 3kW pump for the jets, so when both are on, it pulls 6kW. It's on a 16A breaker, single phase of course.

Edit:

Looking at you photo there are 3 neutrals joined together, presumably one for each phase, but no neutral linked to the supply - a I right or have I missed something?

I'm not 100% sure what you mean - would you like another picture?


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on July 27, 2020, 07:44:58 PM
Some further pictures. The array is currently producing 1.9kW @ 7:59pm and the batteries are at 87% STOC. The iboost is bascially on full chat.



Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Countrypaul on July 27, 2020, 07:57:37 PM
Looking at you photo there are 3 neutrals joined together, presumably one for each phase, but no neutral linked to the supply - a I right or have I missed something?

I'm not 100% sure what you mean - would you like another picture?

Ok, my mistake, from your earlier picture I could see a JB with just 3 neutrals in but now I can see that each neutral is linked back to the supply and the JB I was looking at was just where you take two separate neutrals off to something else.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on July 27, 2020, 08:00:59 PM
No problem.

How do I troubleshoot this issue? any ideas? It's only been bothering me for a year lol.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Countrypaul on July 27, 2020, 08:04:28 PM
Does the isolator switch you have allow you to isolate each phase independantly, or only all 3 at the same time?

If you can isolate each phase separately, I was wondering if you isolate phases 1&3 and put the CT back on phase 2 whether the iBoost behaves properly?

My understanding of 3phase which is not great is that the total current in any 2 phases can be opposite to the current in the 3rd phase. That would mean if you have a 12Amp (3kW) load on one phase you would have -12Amp on the other phases. This might explain why turning a load on for a different phase to the one the iBoost is on triggers the iBoost even though there is no net export.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Fintray on July 27, 2020, 08:06:26 PM
"however batteries are currently at 72% charge and it's raining so, hopefully later today I'll come back with results. The theory is that once they reach 100% it should 'export' to the immersion, right?"

Just to clarify are your three Powerwalls linked together on the grey phase? If so I can't see how the Tesla app is showing it drawing a load when the iBoost is diverting power to the immersion.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on July 27, 2020, 08:45:55 PM
Does the isolator switch you have allow you to isolate each phase independantly, or only all 3 at the same time?

If you can isolate each phase separately, I was wondering if you isolate phases 1&3 and put the CT back on phase 2 whether the iBoost behaves properly?

My understanding of 3phase which is not great is that the total current in any 2 phases can be opposite to the current in the 3rd phase. That would mean if you have a 12Amp (3kW) load on one phase you would have -12Amp on the other phases. This might explain why turning a load on for a different phase to the one the iBoost is on triggers the iBoost even though there is no net export.

I don't think I can isolate one phase, or two. It's either all or none.

"however batteries are currently at 72% charge and it's raining so, hopefully later today I'll come back with results. The theory is that once they reach 100% it should 'export' to the immersion, right?"

Just to clarify are your three Powerwalls linked together on the grey phase? If so I can't see how the Tesla app is showing it drawing a load when the iBoost is diverting power to the immersion.

No - each phase has it's own Powerwall.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: brackwell on July 27, 2020, 09:18:21 PM
I am not sure you can even do what your attempting.  When 3Ph comes into the house you can pick off one of the Ph to give single Ph as you have done. This single Ph supply knows nothing about the rest, it does not even exist. What ever you do on the other single Ph supplies is irrelevant. Thats my understanding.

Why are you asking here and not the manufacturers of the equipment.

Assuming you inverter is exporting over all 3 Ph then if you fitted your CT clamp just after the inverter then your I boost would see an export at that point and switch on.

To get the 3 Ph to work as you have been trying then i think you need to pass all 3Ph wires through the clamp and then the clamp will register the net amount but will only come on as the last thing after house and batts.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Alan D on July 27, 2020, 09:43:23 PM
The Neutral goes from the incoming three phase supply to the meter.
From the meter to the three phase isolation switch.

Where does the neutral go from there. Double insulated grey cable with blue tape on it. ???


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on July 27, 2020, 09:49:28 PM
I am not sure you can even do what your attempting.  When 3Ph comes into the house you can pick off one of the Ph to give single Ph as you have done. This single Ph supply knows nothing about the rest, it does not even exist. What ever you do on the other single Ph supplies is irrelevant. Thats my understanding.

Why are you asking here and not the manufacturers of the equipment.

Assuming you inverter is exporting over all 3 Ph then if you fitted your CT clamp just after the inverter then your I boost would see an export at that point and switch on.

To get the 3 Ph to work as you have been trying then i think you need to pass all 3Ph wires through the clamp and then the clamp will register the net amount but will only come on as the last thing after house and batts.

Aahaa well that does make sense I guess...

The manual states this:

How can I use a Solar iBoost+ on my three phase system?
There are 2 possible options:

1. Use one Solar iBoost+ on one phase with its own 3kW immersion or resistive load. In three phase
systems it is very rare that all phases are equally loaded so we recommend that the installer connects
the Solar iBoost+, the clamp and immersion to the phase with the lowest load.
2. Fit one Solar iBoost+ onto each phase, each with up to 3kW of load.

My understanding is that it was fitted to the lowest loaded phase which was 2, because we hardly use oven 2 you see. That's the only piece of equipment that would generate any decent load on that phase.

I could call them, but it's hard enough trying to explain to someone when I don't quite fully understand myself, so I was kinda hoping someone here could enlighten me.  :genuflect

The Neutral goes from the incoming three phase supply to the meter.
From the meter to the three phase isolation switch.

Where does the neutral go from there. Double insulated grey cable with blue tape on it. ???

I'm not sure... genuinely no idea.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: chris_n on July 28, 2020, 07:37:24 AM
Phase 2 and 3 swapped in th D.B?


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: ceisra on July 28, 2020, 09:39:18 AM
As an ex electrical engineer I can see a few issues which MAY be causing your problem.
From the large picture copied below.

Your current clamp and coiled white cable are resting against all 3 incoming live supplies and may also be against the neutral.

I would remove the 3 cable ties on the right hand side of the box and then separate out the 3 live cables  that leave the top of the isolator switch from the bunch of 6 cables. If possible then reattach your clamp  onto the required phase with 50mm spacing from any other cable, also uncoil the clamp cable and place the transmitter in the bottom of the box.

This may have no effect but its a first step

Roger
(https://i.postimg.cc/wRK7MGFs/photo-2020-07-27-19-56-38.jpg) (https://postimg.cc/wRK7MGFs)


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on July 28, 2020, 11:07:33 AM
Phase 2 and 3 swapped in th D.B?

Could be, but will need a qualified electrician to check..

As an ex electrical engineer I can see a few issues which MAY be causing your problem.
From the large picture copied below.

Your current clamp and coiled white cable are resting against all 3 incoming live supplies and may also be against the neutral.

I would remove the 3 cable ties on the right hand side of the box and then separate out the 3 live cables  that leave the top of the isolator switch from the bunch of 6 cables. If possible then reattach your clamp  onto the required phase with 50mm spacing from any other cable, also uncoil the clamp cable and place the transmitter in the bottom of the box.

This may have no effect but its a first step

Roger
(https://i.postimg.cc/wRK7MGFs/photo-2020-07-27-19-56-38.jpg) (https://postimg.cc/wRK7MGFs)


Done that, and confirmed it's back on phase 2 and pointing the correct way as per this guide: https://www.marlec.co.uk/wp-content/uploads/2018/08/SiB-Guide-1-Correct-Clamp.pdf?v=79cba1185463

Unfortunately I'm still getting the same issue - where I put the oven on (phase 3) and the iBoost kicks in to life..... I've logged a support call with Marlec, who are going to take two days to get back to me, so let's see.

Any other advice, or anything else I can try? Does anyone have any suggestions? TIA!





Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: chris_n on July 28, 2020, 11:30:31 AM
The hot tub has a 3kW heater and a 3kW pump for the jets, so when both are on, it pulls 6kW. It's on a 16A breaker, single phase of course.

6kW is 25A so shouldn't be on a 16A breaker!


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: ceisra on July 28, 2020, 11:51:04 AM
Sorry did not explain correctly
Add the clamp to the required  cable ( with spacing ) that goes  from the top of the isolator to bottom of box.
What is happening in my mind is the clamp is picking up current from a different phase due to the close proximity of the other cables.

Roger


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on July 28, 2020, 11:53:12 AM
The hot tub has a 3kW heater and a 3kW pump for the jets, so when both are on, it pulls 6kW. It's on a 16A breaker, single phase of course.

6kW is 25A so shouldn't be on a 16A breaker!

I doubled checked, and it's on a 32A breaker. That's my fault for not checking the breaker. Apologies.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: marcus on July 28, 2020, 01:00:00 PM
As a sparks it often surprises me how many of my fellow sparks are lazy about keeping track of phases - particularly in 'single phase consumption' DB's where 'it doesn't make any difference'.

So I'm with the others who suspect the phases are mixed up at the DB. You've tried moving the clamp onto Ph3 already; could you try it on PH1? Then if it still doesn't work either way on that cable then at least we've ruled it out.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: chris_n on July 28, 2020, 01:03:49 PM
Looking further back in the thread when you moved the CT on to phase 3 your loads on phase 1 started affecting it. This is again looking like the DB phase 123 do not correlate with the incoming 123. You could take the front off the DB yourself if you turn off the switch on the incoming supply at the bottom to at least see if the cable markings correlate.
Is it possible to see the loads on individual phases on the meter?


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on July 28, 2020, 01:05:49 PM
Sorry did not explain correctly
Add the clamp to the required  cable ( with spacing ) that goes  from the top of the isolator to bottom of box.
What is happening in my mind is the clamp is picking up current from a different phase due to the close proximity of the other cables.

Roger

I assume you mean like this Roger, and it seems to work. I'll only definitively know the answer when the batteries STOC is <100% and I can put the oven on. At the minute it's being cleaned so out of action  :genuflect



Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: chris_n on July 28, 2020, 01:09:41 PM
As a sparks it often surprises me how many of my fellow sparks are lazy about keeping track of phases - particularly in 'single phase consumption' DB's where 'it doesn't make any difference'.

So I'm with the others who suspect the phases are mixed up at the DB. You've tried moving the clamp onto Ph3 already; could you try it on PH1? Then if it still doesn't work either way on that cable then at least we've ruled it out.
Crossed posts, I remember getting a call from one of my techs (electrician) at about 4 in the morning, as their shift started we were just getting running after a digger had damaged our incoming cable. All machinery on the shop floor was single phase but during the night they couldn't get roller shutters and dock levelers to work. After he explained what was going on he was told to "change the f'ing phases". I could hear his sigh as I put the phone down!


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on July 28, 2020, 01:10:38 PM
As a sparks it often surprises me how many of my fellow sparks are lazy about keeping track of phases - particularly in 'single phase consumption' DB's where 'it doesn't make any difference'.

So I'm with the others who suspect the phases are mixed up at the DB. You've tried moving the clamp onto Ph3 already; could you try it on PH1? Then if it still doesn't work either way on that cable then at least we've ruled it out.

I'm 99.99% sure I've moved the clamp to phase 1 in the past with similar useless results...

In regards to checking the phases at the distribution board, someone is coming later this week who is qualified. But yes this had been my main thought process, thinking that it could be incorrectly labelled on the distribution board.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Mostie on July 28, 2020, 01:47:35 PM
ok so here's my thoughts on this, I reckon its the meter  tomato:  you can have 3 phase with 3 single meters, when my parents place was changed to a single 3 phase meter we got the sum of all the phases through the meter, so .... it has 10kw of PV and 3 inverters, the PV diverter is DIY from here   https://mk2pvrouter.co.uk/3-phase-version.html
it monitors all 3 phase currents and all 3 phase voltages, it diverts to 2, single phase immersions.

I wonder if it would make a difference if you moved your CT to the other side of the meter....


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: brackwell on July 28, 2020, 04:27:09 PM
Thoughts for today. Not an electrician.

I believe you can use the CT clamp on both + or _  .   3Ph only has one negative which must be a net value for the whole 3Ph so put the clamp on that ??

Is it technically possible to fit lightweight single cables along side the 3 positive cables to act as proxy and all 3 could be fed through clamp and end up giving a net value of the 3 Ph ??

Not like true electricians to be so quiet, perhaps they dont bother with us anymore, not geeky enough.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Countrypaul on July 28, 2020, 05:03:39 PM
Thoughts for today. Not an electrician.

I believe you can use the CT clamp on both + or _  .   3Ph only has one negative which must be a net value for the whole 3Ph so put the clamp on that ??

Is it technically possible to fit lightweight single cables along side the 3 positive cables to act as proxy and all 3 could be fed through clamp and end up giving a net value of the 3 Ph ??

Not like true electricians to be so quiet, perhaps they dont bother with us anymore, not geeky enough.

Not an electrician either but:

If the 3 phases are 120 degrees from each other which I believe they are, then a 1 kW load on each will surely result in a 0kW load on the neutral (assuming PF =1).


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on July 28, 2020, 05:29:12 PM
I think ceisra was correct. The iBoost seems to be working as it should.

I'll report back tomorrow with a definitive answer - thanks for all your help and suggestions in the meantime.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: brackwell on July 29, 2020, 06:44:35 AM


Not an electrician either but:

If the 3 phases are 120 degrees from each other which I believe they are, then a 1 kW load on each will surely result in a 0kW load on the neutral (assuming PF =1).

Yes i can see that but what happens when the Ph become widely imbalanced and the net is export but not on the Ph that carries the I Boost, as the case in question?


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on July 29, 2020, 12:16:29 PM
Ok, so this morning I got up at 6:25am to blazing sunshine through the window. Having checked my batteries STOC on the app, 67%... technically there should be 0.00kW saved on the iBoost. To my total dissapointment there was 4.64kW saved since midnight.

However, I did put Oven 1 on and the iBoost doesn't now kick in, so I may turn the CT clamp around later today when I'm back home to see what results I get from that.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Countrypaul on July 29, 2020, 12:56:51 PM


Not an electrician either but:

If the 3 phases are 120 degrees from each other which I believe they are, then a 1 kW load on each will surely result in a 0kW load on the neutral (assuming PF =1).

Yes i can see that but what happens when the Ph become widely imbalanced and the net is export but not on the Ph that carries the I Boost, as the case in question?

From my understanding (as remember I'm not an electrician, and I know you aren't either so this may be the blind leading the blind) the neutral will only carry the current that is different across the 3 phases, so if one phase has 2kW and 2 phases have 1kW the neutral will have 1kW. The same would apply if exporting and the loads on different phases were different (and less than export on each phase). If the phases had loads of say 1, 3, and 4 kW, presumably the neutral would carry 5kW (or would it be 3, 4 or 6?  ??? arghh... definitely need some help on this one) and which way would it appear import or export?

I suppose one question that follows from this is what does a 3 phase inverter do? Does it put the same power out to each phase, or does it check the individual phase voltages and attept to balance them and therefore the whole 3 phase load? 3 separate single phase  inverters seems trivial if they have independant feeds.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: greentangerine on July 29, 2020, 02:22:43 PM
Just thinking out aloud as I'm not sparks either but what happens if a live and neutral are reversed somewhere in the installation so that a load is essentially seen on the shared neutral?

The issue has to be a wiring fault otherwise I'm sure this would have come up before.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Countrypaul on July 29, 2020, 04:30:29 PM
Just thinking out aloud as I'm not sparks either but what happens if a live and neutral are reversed somewhere in the installation so that a load is essentially seen on the shared neutral?

The issue has to be a wiring fault otherwise I'm sure this would have come up before.

If you reverse the live an neutral will you get a load on the neutral or will it show as a load on the live anyway? If it was a simple resistance heater for example it would not matter which way round the L&N are it will still put a load on the live.

As for it being a wiring fault, could be, but we can't work out what - so I'm sure any ideas would be welcome.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: TT on July 29, 2020, 05:05:39 PM
His CPD are  remember


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Countrypaul on July 31, 2020, 08:00:27 PM
Did you get the phases checked out and if so what is the result?


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on August 01, 2020, 06:42:17 PM
No not yet. He didn't turn up... typical electricians...  ::)


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: cg617 on August 02, 2020, 05:21:18 PM
I'm confused.
I like drawings, as they tend to graphically show what's going on and if there is an 'error' in the system usually shows it up.
A three phase system, I'm assuming this isn't the UK, don't recognise the equipment in the cabinet.

I would imagine that the solar and batteries are on the same phase, and there can't be any cross connect of power between phases as they are 120deg out of phase.  So this would result in anything on the two phases not having the solar/batteries not benefitting from any of the home grown generation or storage.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Countrypaul on August 02, 2020, 05:27:13 PM
I'm confused.
I like drawings, as they tend to graphically show what's going on and if there is an 'error' in the system usually shows it up.
A three phase system, I'm assuming this isn't the UK, don't recognise the equipment in the cabinet.

I would imagine that the solar and batteries are on the same phase, and there can't be any cross connect of power between phases as they are 120deg out of phase.  So this would result in anything on the two phases not having the solar/batteries not benefitting from any of the home grown generation or storage.

If you read the thread he says that there is a powerwall on each phase, and a Solaredge 3 phase inverter.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Fintray on August 02, 2020, 05:30:02 PM
I'm confused.
I like drawings, as they tend to graphically show what's going on and if there is an 'error' in the system usually shows it up.
A three phase system, I'm assuming this isn't the UK, don't recognise the equipment in the cabinet.

I would imagine that the solar and batteries are on the same phase, and there can't be any cross connect of power between phases as they are 120deg out of phase.  So this would result in anything on the two phases not having the solar/batteries not benefitting from any of the home grown generation or storage.

Label on the incomer says Western Power Distribution, so definitely in UK.
Western Power Distribution is the electricity distribution network operator for the Midlands, South Wales and the South West.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: cg617 on August 02, 2020, 09:43:01 PM
Countrypaul, my bad, forgot the 3-phase inverter bit and assumed the 3x powerwalls were on one phase.

From the photos and some comments I've drawn up this simplified diagram of the system, probably loads missing though.  But what immediately struck me was where the power flows are in relation to the position of the iBoost CT clamp.
As an aside, the picture from the app showing the power flows doesn't indicate which phase it's showing.  I'm hoping it's not showing the net results of all three phases combined, as this would n't help with troubleshooting.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: cg617 on August 02, 2020, 09:46:49 PM
With the diagram

(https://i.postimg.cc/ThJHk68H/Powerwall.jpg) (https://postimg.cc/ThJHk68H)


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Countrypaul on August 03, 2020, 12:16:56 AM
I think you have misinterpreted the solar iBoost - the Boost is connected to phase 2 and to the immersion heater, it also has a wireless CT oround the phase2 cable in the meter cabinet.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: cg617 on August 03, 2020, 06:54:27 AM
Haha.  Right again, I was rushing, never a good thing.  I did have it on phase 2, but on the diagram had it connected between the inverters and the load.  Then realised it's actual location may be pertinent so drew the 'box' for the cabinet and moved the connection of the CT clamp...  to the wrong phase. 
The annoying thing is the software I used for drawing it is on a computer that doesn't allow loading pictures to this site, so I have to email it across computers...   :(


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on August 03, 2020, 02:52:51 PM
Yes I'm UK - Midlands.

I'm currently at this stage (after talking direct to the Solar iBoost manufacturer)...

The CT clamp is currently on the middle cable coming out of the L2 henley block, and when batteries reach 100% STOC then it does import correctly to the iBoost - there is a however - the iBoost is still 'saving' some energy (ranges from 2-4kwh) before the batteries reach 100% STOC, but at least it's not mimicking any loads on phase 1 anymore. I can't remember which way the clamp is, but it's definitely working 'better' than it was.

I think what I'm going to do is get the immersion moved to P3 and the clamp moved to P3. I've got a feeling it may be something to do with the backup gateway on P3 somehow.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Countrypaul on August 03, 2020, 04:49:59 PM
Are the 3 powerwalls connected together at all? I am wondering if they behave as a true 3phase system or just 3 completely independant single phase systems. If they are completely independant then once the one on phase 2 is fully charged I would expect that whatever is exporting from the PV inverter is available to the iBoost (and consequently the immersion), if the powerwall is 3 phase could it be attempting to balance things and therefore causing phase2 to show less PV export than we expect?

Similarly does teh 3 phase inverter export the same power on all phases, or does it try and balance the voltage (and current?) between phases so they all appear the same?

Completely out of my sphere of expertise, I can see the questions, but have no idea of the answers.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Aunat on August 03, 2020, 11:54:51 PM
Are the 3 powerwalls connected together at all? I am wondering if they behave as a true 3phase system or just 3 completely independant single phase systems. If they are completely independant then once the one on phase 2 is fully charged I would expect that whatever is exporting from the PV inverter is available to the iBoost (and consequently the immersion), if the powerwall is 3 phase could it be attempting to balance things and therefore causing phase2 to show less PV export than we expect?

Similarly does teh 3 phase inverter export the same power on all phases, or does it try and balance the voltage (and current?) between phases so they all appear the same?

Completely out of my sphere of expertise, I can see the questions, but have no idea of the answers.

Hi Countrypaul,

I'll attempt to answer the questions as best as I can. I come from an IT background, not electrical so here goes.

The Powerwalls are set to 5kW each (not 3.68kW as they are out of the box), which means I have 15kW of power (assuming it's dark, no solar). If I set my Tesla to charge at say 18A, the car will pull 13.5kW from the Powerwalls (my incoming voltage is ~250V) so that now leaves 0.5kW per phase of spare power you would assume - however if I turn say the hot tub on, which pulls 3kW, it will pull 0.5kW from each battery and the rest from the grid, resulting in a maximum power draw of 15kW even though the batteries are on different phases and the hot tub is single phase. This has been confirmed by Tesla to be correct as my app only shows one picture of a Powerwall but with a x3 in the middle of it - so all batteries move up and down with the same state of charge regardless of what phase pulls the electricity...

So theoretically if I had an 10.8kW power shower on a single phase, the batteries would provide 3.6kW each as they all discharge and charge at the same rate.... somehow  ??? ???


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: ceisra on August 04, 2020, 09:33:20 AM
Aunat
Nothing wrong with a background in IT
My last 25years were spent working on large computer networks with multiple firewalls/internet connections.
Started out as time served electrical engineer then industrial electronics then process control.

My initial comment about moving the clamp was based on the amount of flux that was created around the tightly packed cables.

There are many things that surprise me about your installation but lets not go there.

As a microgen system you should have been provided with full documentation including wiring diagrams, do they exist.

When and if your electrician turns up do you have/is there a plan as to what is tested

Could you also point me in the direction of documentation on the powerwalls please.

Roger






Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Fintray on August 04, 2020, 09:56:59 AM
The CT clamp is currently on the middle cable coming out of the L2 henley block, and when batteries reach 100% STOC then it does import correctly to the iBoost - there is a however - the iBoost is still 'saving' some energy (ranges from 2-4kwh) before the batteries reach 100% STOC, but at least it's not mimicking any loads on phase 1 anymore.

I wouldn't worry too much about the iBoost saving some energy before the batteries reach 100%, in my system the PV diverter for the immersion will come on when there is an excess above what the PW2 can take and there is a bit of toing and froing between the PW2 and the PV diverter.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: Countrypaul on August 04, 2020, 10:20:55 AM
As I said earlier, I'm not an electrician, my background is chemistry and IT for the Pharmaceutical and fine chemical industries.

I am not clear on the details of how your Powerwall works, but the fact it draws from all 3 batteries when there is a load on one phase (if I have understood correctly) suggests to me it could be interfering with what the iBoost expects. I don't know if you can turn the Powerwall off for a short period in order to test things, but if you can that might provide some clarity.

If the PV is generating say 10KW and the Powerwall is charging using all 10KW then the iBoost (P2) sees nothing.
If an oven 3KW (P3) is turned on, then that phase will not be able to charge at the same rate as other phases, so if the PW eases back its charging so all three phases are equal could that result in a 3KW export on phases 1 & 2?


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: cg617 on August 04, 2020, 03:55:57 PM
Hi Aunat,

Again, the information you're providing is open to misunderstanding (I appreciate you don't have an electrical background), so a previous comment made about wiring diagrams or additional photos (diagrams preferred) would help although photo's might show the physical connectivity to be different to the diagram.  But it would baseline the starting point for investigation.

The Powerwalls are set to 5kW each (not 3.68kW as they are out of the box), which means I have 15kW of power (assuming it's dark, no solar).

Although 5kWh each does give 15kWh in total, you can't use power from one phase on another (phase shift).
So if all three powerwalls are on a single phase, then either your hot tub OR your immersion would benefit, not both (or neither if they are on the third phase).  If you have a powerwall on each phase (three powerwalls and three phases sounds much more sensible but 'design' might alter that connectivity), then all home devices can benefit, but the batteries won't be used evenly.  Unless the three powerwalls are sitting behind some monitoring control and can release energy to whichever phase needs it, not even sure that is an option.

As you can see, lots of questions, but until we understand the system, it's difficult to help.


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: marcus on August 04, 2020, 04:23:30 PM
I was thinking that Rogers advice had sorted the issue, and if what you say about the 3 powerwalls all charging/discharging as a balanced system is true, then that would certainly explain the iboost's behaviour, as it would see exports on ph2 overnight if the other two phases were seeing greater demand from the battery and divert those ph2 exports to the immersion.

If the 3 the powerwalls really are set up for balanced charge/discharge  wackoold (which might make sense if they were all on one phase, or in an industrial 3ph system where the bulk of the loads were balanced 3ph), then i'd look into getting them re-configured as 3 independent systems - If possible (ought to be - though you may need 3 gateways).


Title: Re: Tesla Powerwall 2's + Solar iBoost = Problem?
Post by: cg617 on August 04, 2020, 05:14:45 PM
Just checked the spec of the powerwall 2 and noticed that the charge/discharge rate is 3.68kW charge and 5kW discharge.  I thought your figures were storage capacity. 
So basically you have 3x 'powerwall 2', total storage 39kWh.

The photo's you provided earlier show:-
Grid supply (bottom left)
going to (the grid meter), so far so good
then going to (a 3-phase breaker), still good
then going to (somewhere outside of the cabinet)  now we are into the realmes of vagueness and where we could use some clarity.

Tyhe three individual connectors at the top of the photo show connectivity from outside of the cabinet,
I'm guessing the leads coming in at the top are the solar generation (so from the 3-phase invertor and generation meter?)
and the 6 leads coming from the bottom are in vaguely the consumer cabinet and the power walls, but if anything else is going on, we don't see sight of it from the photos.

I seem to remember that the powerwall 2 is able to work in isolation of the grid and charge from the grid, so there may be some automatic isolators that cut the grid from everything else, that just makes it all the more 'interesting?'