New Tesla PW2 install on two phase house.

[paulp]

Sure.. hey can I ask another question to the brains trusts as we don't have powerwall3's yet...

If I was to install a PW3 with some panels on the other phase (currently without any Solar/batteries on it) - this would be connected not only on the other phase, but I could get some clamps directly around the main board.

I assume the PW3 (has it's own internal gateway).. has monitoring .. that correct?

How does this monitoring work? with clamps?

Is there anyone out there who has both a PW2 and PW3? Even set up on different phases..

Do they both then work ie "can be seen" as one in the app?

I then wouldn't need the separate wifi Neurio monitoring right?

thanks

JG

From the tesla website for its as yet not released PW3:

Can I add Powerwall 3 to my Powerwall 2? Can I add Powerwall 3 to my existing solar system?
No. Powerwall 3 can be added to other Powerwall 3 batteries and cannot be added to Powerwall 2 or Powerwall+ batteries. Powerwall 3 is not compatible with other solar inverters.

 

[Jay Gatsby]

From the tesla website for its as yet not released PW3:

Can I add Powerwall 3 to my Powerwall 2? Can I add Powerwall 3 to my existing solar system?
No. Powerwall 3 can be added to other Powerwall 3 batteries and cannot be added to Powerwall 2 or Powerwall+ batteries. Powerwall 3 is not compatible with other solar inverters.

You've misread my setup.
I have two phase.
The PW2 is on 1 phase (with a solar inverter) the PW3 would go onto the other phase
Why couldn't I do that?
The statement you've quoted refers to the different AC/DC nature of the powerwalls,....

 

[ausevdriver]

would a cheaper option than a whole new pw3 setup be to simply wire the charger only to the single phase with solar/pw2?

I feel like if you’re doing this for the payback of being able to charge cheaply from solar/battery then another $15k on batteries is just going to hurt your “savings” even more.

there are hundreds of thousands of dwellings here in Aus with 2 phase power

Is this a state specific or regional thing? Can’t say I’ve ever come across it in residential areas I’ve lived in.

 

[Jay Gatsby]

would a cheaper option than a whole new pw3 setup be to simply wire the charger only to the single phase with solar/pw2?

I feel like if you’re doing this for the payback of being able to charge cheaply from solar/battery then another $15k on batteries is just going to hurt your “savings” even more.


Is this a state specific or regional thing? Can’t say I’ve ever come across it in residential areas I’ve lived in.

Not sure what you mean by "wire the charger to the single phase with solar/pw2"? What "charger"?
I need to add more solar and powerwalls onto the other phase anyway. There is no other way to supply and backup those loads without doing that. Also I'd like to boost my solar collection anyway.
Finally no - it's not a regional thing. I'm 5km from the centre of Melb. It's just the way the house was rewired when they added a granny flat in a renovation that was done before moving here. Now its' done I'm stuck with it. Cheers

 

[ausevdriver]

What "charger"?

The car charger. If it was only connected on the power wall phase then it couldn’t cause the other phase to pull from the grid.

But probably best to ignore me because I’ve no idea obviously.

 

[Jay Gatsby]

The car charger. If it was only connected on the power wall phase then it couldn’t cause the other phase to pull from the grid.

But probably best to ignore me because I’ve no idea obviously.

Ah ok. sorry I didn't know what you meant... Sure.
Done that with charging already
The problem is with the net monitoring
I've done a deep dive on some other threads.
The app (and in fact the whole Tesla cloud/smart ecosystem) needs net metering at the main board to function properly.
In a two phase set up, if the PW isn't monitoring the main board, it operates as a separate entity, ie charges, discharges, backups just that one phase... It works fine doing that... sure.. but you lose some of the Tesla smarts overall.
For example right now?.. sun comes out, so PW starts to charge ...sucking all the solar. That means the other phase (without solar) pulls power from the grid (rather than being balanced at the meter as a net export)...
I've learnt that I could use a Neurino Wifi monitor at the main board...pull that info into the Tesla app to improve things but that's another $500- maybe more spend. And apparently they can be a bit flakey...
Alternatively I could only charge the battery when there is enough solar to cover the entire load (battery charge + the rest) on that phase..so wait till there is more solar power. Ok now in Summer (I collect 6-7KW 10am-3) but winter will be more of a problem
I've asked about some setting where I could set the PW charge rate, or limit it to charging at say 2KW or something, but there are no such setting. If I hardwire throttle it with resistors or something I will negate the warranty
It looks like it's going to be easier simply adding solar and a PW3 on the other phase (which I want to do anyway) and running the house as two separate systems
The app doesn't summate this as one, but I can do that anyway in Home assistant.
I'm lucky I just started out adding one PW and waiting to see how it all will work - build my final off grid (that's the aim..I'll eventually need 45KW storage anyway to cover winter)...so slowly as the tech settles
The main house needs more peak load anyway (thats where the stove, kitchen, heater etc is)
So PW3 will be ideal
I need more PWs as it is
(I'm in Melb afterall)
Thanks for your help.


Cheers.

 

[paulp]

Not sure what you mean by "wire the charger to the single phase with solar/pw2"? What "charger"?
I need to add more solar and powerwalls onto the other phase anyway. There is no other way to supply and backup those loads without doing that. Also I'd like to boost my solar collection anyway.
Finally no - it's not a regional thing. I'm 5km from the centre of Melb. It's just the way the house was rewired when they added a granny flat in a renovation that was done before moving here. Now its' done I'm stuck with it. Cheers

I have 3 phase, 3 powerwall, and 1 gateway. I wanted all phases backed up and was prepared to by a gateway for each battery, so one complete setup for each phase with 10kw of solar on each. Tesla advised me at that time that three independant systems with one grid connecion was not possible. Assuming that advice was corret, it would be the same for two independant systems with one grid connection.

 

[paulp]

Ah ok. sorry I didn't know what you meant... Sure.
Done that with charging already
The problem is with the net monitoring
I've done a deep dive on some other threads.
The app (and in fact the whole Tesla cloud/smart ecosystem) needs net metering at the main board to function properly.
In a two phase set up, if the PW isn't monitoring the main board, it operates as a separate entity, ie charges, discharges, backups just that one phase... It works fine doing that... sure.. but you lose some of the Tesla smarts overall.
For example right now?.. sun comes out, so PW starts to charge ...sucking all the solar. That means the other phase (without solar) pulls power from the grid (rather than being balanced at the meter as a net export)...
I've learnt that I could use a Neurino Wifi monitor at the main board...pull that info into the Tesla app to improve things but that's another $500- maybe more spend. And apparently they can be a bit flakey...
Alternatively I could only charge the battery when there is enough solar to cover the entire load (battery charge + the rest) on that phase..so wait till there is more solar power. Ok now in Summer (I collect 6-7KW 10am-3) but winter will be more of a problem
I've asked about some setting where I could set the PW charge rate, or limit it to charging at say 2KW or something, but there are no such setting. If I hardwire throttle it with resistors or something I will negate the warranty
It looks like it's going to be easier simply adding solar and a PW3 on the other phase (which I want to do anyway) and running the house as two separate systems
The app doesn't summate this as one, but I can do that anyway in Home assistant.
I'm lucky I just started out adding one PW and waiting to see how it all will work - build my final off grid (that's the aim..I'll eventually need 45KW storage anyway to cover winter)...so slowly as the tech settles
The main house needs more peak load anyway (thats where the stove, kitchen, heater etc is)
So PW3 will be ideal
I need more PWs as it is
(I'm in Melb afterall)
Thanks for your help.


Cheers.

I reckon you are wired completely wrong. I cannot see how 2 phase is any different to 3 phase on the metering side. The gateway has two meters (including a nurio) that sort out the solar and mains metering and thereby determines when to call on the grid. My 7 solar breakers also go into the gateway spread across 3 phases.
The batteries charge when the system recognises excess solar, so that is after the house takes its needs.
The car charger is just another household appliance. The battery does not see it, but thats probably changed with the latest car charger.
The entire system is very set and forget

 

[Jay Gatsby]

I have 3 phase, 3 powerwall, and 1 gateway. I wanted all phases backed up and was prepared to by a gateway for each battery, so one complete setup for each phase with 10kw of solar on each. Tesla advised me at that time that three independant systems with one grid connecion was not possible. Assuming that advice was corret, it would be the same for two independant systems with one grid connection.

It depends how far the suboards (of each phase) are from the mainboard.
You can't say put one gateway near the mainboard then have a 75 meter run (like I've got) then connect a PW like 75m away...
At least that is what I was told..
The Gateway needs to be closer to whatever board (and loads) they are connected to...
I didn't plan my house wiring this way. I inherited it. Of course if I could change the wiring layout of the house I would. But its a 150 yr old house (shares wall to wall with neighbours) with a solid concrete paved yard (between the two dwellings - main house and the granny flat/garage) and that 75m run between the meter/main board and the sub-board (on the second phase)
If I have to I'll get the installer to call out a Tesla engineer from Head office here in Melb take a look before I plan for the Powerwall3's..
(if there is such a person)
Cheers

 

[paulp]

It depends how far the suboards (of each phase) are from the mainboard.
You can't say put one gateway near the mainboard then have a 75 meter run (like I've got) then connect a PW like 75m away...
At least that is what I was told..
The Gateway needs to be closer to whatever board (and loads) they are connected to...
I didn't plan my house wiring this way. I inherited it. Of course if I could change the wiring layout of the house I would. But its a 150 yr old house with a solid concrete paved yard and that 75m run between the meter/main board and the sub-board (on the second phase)
If I have to I'll get the installer to call out a Tesla engineer from Head offcie here in Melb take a look before I plan for the Powerwall3's..
(if there is such a person)
Cheers

My sub-board is adjacent my power wall installation. The house was designed for solar and batteries.
Tesla have some very clever powerwall people in Australia. The hard part is getting access to them, but be persistant and you will.

 

[meloccom]

My sub-board is adjacent my power wall installation. The house was designed for solar and batteries.
Tesla have some very clever powerwall people in Australia. The hard part is getting access to them, but be persistant and you will.

I have a PowerWall (1), the OG Tesla home battery.
I made the mistake of not asking for the battery to be capable of power outage backup. I can’t get Tesla to provide anything to my chosen electrician to allow me to retrofit that feature, they have steadfastly refused to support the product beyond its existing functionality. I’m also an early Model S owner and have even tried through TOCA to get Tesla to talk about my request But no dice.
So if you’re buying any Tesla PowerWall, make sure you specify the full functionality at first instance as there’s no guarantee that it might be changed or upgraded at a later time.

 

[Quickst]

When set to charge from solar, loads on the phase without solar, pull power from the grid. When the battery is physically off, (and the sun is out) this does not happen

Also when the sun is out and I plug in the car to charge off the powerwall, same thing happens – this is particularly bad after 3pm as the phase without solar pulls hi tariff power – defeating the whole purpose of maximising the solar charging of the car – rather than waiting until after 9pm to charge off low tariff.

Sorry one more time for the dummies please. I dont understand what you are saying


You have 2 phases
Phase A has the PW battery + solar and the current clamps are connected to that phase
Phase B is not connected to a battery + solar

When the sun is shining can you confirm:
Phase B draws power from the Grid
Phase A , loads will draw also power from solar and excess goes to charging the battery

When sun is not shining can you confirm:
Phase B continues to draw power from Grid
Phase A draws power from battery until it is depleted and then draws power from the grid

When the battery is "physically off" - what does this mean?
When the sun is shining and you plug the car in what actually happens? And what do you prefer to happen?

 

[Jay Gatsby]

Will confirm all... when the sun is actually out!

 

[Gareth Oakes]

It sounds like the PW2 knows nothing of the second phase, I believe PW2 can be setup to monitor up to three phases to support the net metering that you are after. If your installer can't fix this then not sure what else you can do except find an installer who is knowledgeable enough to resolve it for you.

 

[Jay Gatsby]

Sorry one more time for the dummies please. I dont understand what you are saying


You have 2 phases
Phase A has the PW battery + solar and the current clamps are connected to that phase

Correct

Phase B is not connected to a battery + solar

Correct

When the sun is shining can you confirm:
Phase B draws power from the Grid

Correct

Phase A , loads will draw also power from solar and excess goes to charging the battery

Correct

When sun is not shining can you confirm:
Phase B continues to draw power from Grid

Correct

Phase A draws power from battery until it is depleted and then draws power from the grid

Correct

When the battery is "physically off" - what does this mean?

I have turned off the battery inverter isolator

When the sun is shining and you plug the car in what actually happens? And what do you prefer to happen?

The battery is charging and also the car is charging. They both act as a "load" on Phase B
I've gone back to only charging at night on off peak power.

@Gareth Oakes nailed it. The PW2 and "gateway smarts" knows nothing about the second phase. (And I know nothing about the Tesla smarts). I assume it needs to know what is going on at the meter in order to for these smarts to "know what to do" - ie when to charge discharge etc to get maximum effect (savings) from the battery. Given I can't tell the battery when to charge, discharge, and at what rate, how else can I resolve this? It's all locked into the smarts of the software ... I think it needs sensors at the main meter (to sense whats goin in out at the grid) to operate properly. The question is what the best way to do this? Cheers

 

[Gareth Oakes]

The question is what the best way to do this? Cheers

We had a similar issue with our battery system (not Powerwall) and in the end the installer came back and moved our energy monitor device out of the switchboard in our house to the actual meter box at the perimeter of our property. Once they were effectively monitoring all net power flows in/out of the meter box we had accurate energy data and our battery worked as expected.

 

[Jay Gatsby]

@Gareth Oakes this is very frustrating - clearly I need a Neurio meter installed. Seems like a no brainer.. Like you I can't be the only one in the country who has installed the battery and gateway out the back of the property a long way from the main meter. Not everyone has a brand new house with wiring all to go and a garage in the front of the property near the phase inlets from the grid. YEs I get it - that's the new architectural design - but that has not been the case prior to this century. Nor is the PW and gateway a brand new product to this market..It's been over 4 years... 4 bloody years... The Neurio has been around 5 ..you'd think every "certified installer" was all over this...but it's not to be.. Why is it always the blind leading the blind in this part of the world? So one has popped up on ebay - I can import from the US for $135 - and almost DIY with the help of a local electrician - why should I pay the $500 plus for the equipment alone via a "certified" Tesla installer, when they have had no idea what to do in the first place? What woudl you do? Just import it and get on with it, or wait yet another month for them to argy bargy fart arse around via Tesla - deciding what to do?