Solar + PW Installed - question about breakers

[SoCal Jimmy]

So i had my solar and powerwalls installed yesterday (finally after 2 years of waiting on PW’s)

they took all the loads from the main panel and moved them into the load center and ran a 125amp breaker back to the main panel.

Doesn’t that seem a little under powered to take everything that was originally on a 200amp service and put it behind a 125amp breaker? I told them to leave our 50amp hot tub on the main panel but the idiots moved it over too, so now the spa draws power at night from the powerwalls too, which i didn’t want to be backed up. Now in an outage, i have to remember to go turn the breaker off so it doesn’t suck all the power during clean cycles.
i might just move that back to the main panel after their inspection next week.

Install photo attached of founder editions

 

[boaterva]

The 200 service was a theoretical max. The 125 is what you are using. I assume they left the main panel to use for any new loads that won’t be on the PW and will be on the old/main panel.

Yes the hot tub maybe should have been left on the main panel but the load calc should have had it originally on one or the other. Which was it? You should have a list of where the loads should be.

If it really is on the wrong panel I’d have them fix is as in a backup situation the PWs will be dead quickly if it’s a cold day and the pumps/heat are going. (Maybe not in SoCal, which is maybe the point?)

Nice looking install, BTW!

 

[bob_p]

We just completed installing and commissioning our new solar panels and PowerWalls - waiting for PTO (permission to operate) before we can run the system.

Our house has 3 150A breaker panels. One is for our two Tesla wall chargers and the other two are for the rest of the house (HVAC, pool, …).

After reviewing the actual power usage over the past 2 years, we concluded our max load (all HVAC, ovens, pool pumps running) was less than 20 KW of power for the two house breaker panels combined - so we connected both of the house breaker panels to the Backup Gateway, with 4 PowerWalls (which can provide up to 20 KW of power combined).

While the circuit breakers add up to more than 150A of potential power in each of our breaker panels - actual load was much, much less, so putting our two 150A panels onto a 200A Backup Gateway - with a max draw of 120A from the 4 PowerWalls should be OK.

Though I am planning to run some stress tests today to verify those estimates...

If you have a smart meter on your house and can get access to the historical data - that can provide a lot of insight as to actual energy usage - and what configuration you need to support your loads.

 

[Robotpedlr]

I am getting my two PW2s installed on Jan 9th and was going to post a question about how much I can (or should) connect to them. But I think I may see the answer based on the post above. But maybe I will post to see if someone can confirm my assumption.

I currently have a 200amp panel (connected to a 10.2KW solar set up). I was wondering if I need to have a critical load panel or if would be able to run a full house backup (my preference). In reading the Tesla PW specs I see that it can handle a 7kw peak draw and 5kw normal. I was just not sure if those are doubled if you have two PWs hooked up, like I will. I have an egauge energy monitor and my normal load is very low(1-2kw) and in worst case (hot tub + Heat Pump on, etc), I hit a peak of 8-10kw or so for a short period. I can easily turn my Hot Tub breaker off if power is expected to be out for some time, so I am not worried about the duration of backup. My real question is, will I be ok with those peaks (up to 9kw or 10kw) with 2 PW or do I need to separate some of the bigger loads (Hot Tub, Heat Pump) out?

Here is my usage over the last 3 weeks, which have been pretty cold her in Seattle, so Hot Tub is heating (black lines) and Heat Pump is working harder than normal (purple).

 

[jjrandorin]

I believe they install the critical loads panel either way, and simply move everything to that panel if they are doing whole home backup. At least thats what it seems like. My install is Jan 6th, and I am also getting 2 PWs installed. I have a 8.7kW solar system they are being connected to. I asked them for the install plans and they sent me over a 1 page document that shows the schematics with every circuit moved over to the critical loads panel. I have 2 AC units, but no pool pump, heat pump, etc etc.

 

[Robotpedlr]

I dont think you get a critical load panel unless you need one to separate out some circuits. Doesnt seem like it would make sense to just move everything to the critical load.

 

[wwhitney]

Depends on whether you have an "all-in-one" panel where your meter is in the same enclosure as your branch circuit breakers, as is common here in California. In which case you always get a new panel for all your backed-up branch circuit breakers, so that the Gateway can be installed between the meter and the backed up circuits.

Cheers, Wayne

 

[jjrandorin]

Im not sure what to tell you guys...

I am looking at the layout for my "to be installed" system. This is the document that shows what goes where.

I have a "regular" 200 amp square D panel. The meter is not attached to it, it is separate, and is a "smart" meter installed by the SCE. I have whole home backup install planned from Tesla.

I see:

200 amp main panel >>> Backup Gateway >>> "backup Loads" panel

I see "energy storage" boxes coming off the "backup loads panel
I see a list of circuits that are going in the backup loads panel, and its every single circuit I have currently, including my (2) AC units, and my 40 amp wall oven.

/shrug....

 

[bob_p]

Did a stress test to determine our peak power usage.

Our house had two 150A powers providing power to everything except for the Tesla chargers.

When the solar panels, 4 PowerWalls and Tesla Backup Gateway were installed, the two 150A panels were connected directly to the Backup Gateway with a single 200A breaker. The 4 PowerWalls should be able to support a peak load of 28 KW and a sustained load of 20 KW (90A @ 220V).

During the stress test, I ran all of the high power devices - 3 HVAC systems set to 65 degrees, all 3 pool pumps, plus both ovens set to 400 degrees. All of that generated a load of 22 KW - more than the PowerWalls would be able to sustain - and if I removed the ovens, we were around 12-14 KW of load.

So it's clear, at least based on what we have installed at our house, we were nowhere close to the 150A of draw per breaker panel.

Each of the ovens was drawing around 4 KW when heating (they draw less once the oven reaches the desired temperature). Since the odds of having both ovens heating and everything else running at the same time - I'm pretty confident we're fine.

The stress test confirmed the smart meter historical data for the past 2 years.

 

[gnumeric]

they took all the loads from the main panel and moved them into the load center and ran a 125amp breaker back to the main panel.

Doesn’t that seem a little under powered to take everything that was originally on a 200amp service and put it behind a 125amp breaker?

They did the exact same thing for my install. I got a whole home backup where they moved all the loads from my 200A main panel to the backup load center, and ran a 125A breaker back to the main panel.

I also thought the same thing, where it’s odd going from 200A to a 125A breaker, but I haven’t had any issues so far.

 

[jboy210]

So i had my solar and powerwalls installed yesterday (finally after 2 years of waiting on PW’s)

they took all the loads from the main panel and moved them into the load center and ran a 125amp breaker back to the main panel.

Doesn’t that seem a little under powered to take everything that was originally on a 200amp service and put it behind a 125amp breaker? I told them to leave our 50amp hot tub on the main panel but the idiots moved it over too, so now the spa draws power at night from the powerwalls too, which i didn’t want to be backed up. Now in an outage, i have to remember to go turn the breaker off so it doesn’t suck all the power during clean cycles.
i might just move that back to the main panel after their inspection next week.

Install photo attached of founder editions

Is that an ethernet connection on the wall. And is that how you connect the Gateway to the internet. If so, how has the connection worked?

 

[mspohr]

So i had my solar and powerwalls installed yesterday (finally after 2 years of waiting on PW’s)

they took all the loads from the main panel and moved them into the load center and ran a 125amp breaker back to the main panel.

Doesn’t that seem a little under powered to take everything that was originally on a 200amp service and put it behind a 125amp breaker? I told them to leave our 50amp hot tub on the main panel but the idiots moved it over too, so now the spa draws power at night from the powerwalls too, which i didn’t want to be backed up. Now in an outage, i have to remember to go turn the breaker off so it doesn’t suck all the power during clean cycles.
i might just move that back to the main panel after their inspection next week.

Install photo attached of founder editions

You really should have high power non-essential loads separate from backed up loads. You'll drain the power walls unnecessarily.
As for the 125 amp breaker, that can deliver 30,000 watts; more than enough. (I had the same thing done when we added a new garage and loft. No problems even with hot tub, heat pumps, etc.)

 

[jjrandorin]

You really should have high power non-essential loads separate from backed up loads. You'll drain the power walls unnecessarily.
As for the 125 amp breaker, that can deliver 30,000 watts; more than enough. (I had the same thing done when we added a new garage and loft. No problems even with hot tub, heat pumps, etc.)

Thats completely personal choice though. I look at it this way. If the load is not backed up, I cant use it during a power outage situation, even if I wanted to. If it IS backed up, I CAN use it, or not use it, by my choice, not a physical connection one. Thus, for me, I want every load that can be backed up, backed up, including my 2 AC units, and an outlet to charge my car... even though I never really "intend" to charge my 75 kW car battery with my 2 powerwalls. The thing is, I "could" give myself a little power from my solar to my car, in an outage situation.. enough to get to a supercharger or some other charger in the neighborhood.

Choice is good, at least for me it is. Not having the load on the backed up side removes choice in an outage situation.

 

[mspohr]

Thats completely personal choice though. I look at it this way. If the load is not backed up, I cant use it during a power outage situation, even if I wanted to. If it IS backed up, I CAN use it, or not use it, by my choice, not a physical connection one. Thus, for me, I want every load that can be backed up, backed up, including my 2 AC units, and an outlet to charge my car... even though I never really "intend" to charge my 75 kW car battery with my 2 powerwalls. The thing is, I "could" give myself a little power from my solar to my car, in an outage situation.. enough to get to a supercharger or some other charger in the neighborhood.

Choice is good, at least for me it is. Not having the load on the backed up side removes choice in an outage situation.

Except you'll have to manage it manually. And if you're gone, the battery will be depleted.
AC might be considered a necessity depending on the season and where you live.

 

[SoCal Jimmy]

Is that an ethernet connection on the wall. And is that how you connect the Gateway to the internet. If so, how has the connection worked?

yes, we built our house so i have Ethernet in every room of the house including one on each wall in the garage for things like this that may come up and need a dedicated hardwire.
i have the backup gateway and the Tesla solar gateway both hardwired and haven’t had any issues.

 

[Incredulocious]

Thats completely personal choice though. I look at it this way. If the load is not backed up, I cant use it during a power outage situation, even if I wanted to. If it IS backed up, I CAN use it, or not use it, by my choice, not a physical connection one. Thus, for me, I want every load that can be backed up, backed up, including my 2 AC units, and an outlet to charge my car... even though I never really "intend" to charge my 75 kW car battery with my 2 powerwalls. The thing is, I "could" give myself a little power from my solar to my car, in an outage situation.. enough to get to a supercharger or some other charger in the neighborhood.

Choice is good, at least for me it is. Not having the load on the backed up side removes choice in an outage situation.

The way I look at it, since I have my car set to charge overnight, if there were an unexpected power outage overnight I would not want the car (or any other unnecessary large usage) to take up all the stored backup energy before I even know there is an outage. And if I really need to charge the car off the Powerwalls for some reason, I could always plug into another circuit.

 

[gnumeric]

Elon tweeted that the integration between powerwalls and cars would be coming to prevent that sort of case from happening (charging your car when the grid is down and draining your powerwalls). I can’t find the tweet, but I remember it was a reply to DÆrik.

 

[bob_p]

Since we have two 150A breaker panels for the house circuits and we were planning to have 4 PowerWalls, since we were concerned the house could pull more power than the 4 PW could provide, the original plan for our system was to do a lot of circuit shifting between the two 150A breaker panels - putting the "essential" circuits in one breaker panel and the non-essential circuits (pool pumps, HVAC for the second floor, ovens, ...) into the second panel, which would be connected to the grid - not our PowerWalls.

But after the electrician reviewed our circuits and the actual smart meter history (for 2 years), we agreed to put both 150A breaker panels on the Tesla Backup Gateway, with a 200A breaker.

And after running stress testing, have confirmed that 4 PowerWalls should be able to handle load while we are away from home - and while we are at home, we should only be at risk if we are using both ovens and everything else is running (if we lose power in this situation, we'll just turn off the ovens!).

The only items that aren't on our PowerWalls are the two Tesla wall connectors - since they could draw 21 KW themselves if both charging at the same time at 48A...

 

[JayClark]

.
Choice is good, at least for me it is. Not having the load on the backed up side removes choice in an outage situation.

Agreed, I backed everything up, and use home automation and scheduling to force things off If needed. I too would rather have the choice at all times, in all situations.

 

[aesculus]

Agreed, I backed everything up, and use home automation and scheduling to force things off If needed. I too would rather have the choice at all times, in all situations.

The only thing I did not back up was the car charger. It's all downhill to the nearest SC for me.