So did Tesla Energy pull a permit for you and it wasn’t approved and that's when you found out? I’m guessing this was a decision handed down by your city’s building department. If they are contactable during covid by phone or email you can probably reach out to them with your permit number and ask if someone can explain the panel issue to you.
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Tesla called me and told me I needed to upgrad my brand new 200A panel. Does that sound right?
- Thread starter Cricket88
- Start date
I asked for it not to be backed up, because I did not want even the potential that my car would drain my powerwalls in the middle of the night if there was a power outage.
The ability for a model 3 to have a separate setting in the tesla app to not drain the batteries did not exist when my powerwalls were installed, and I dont trust that setting anyway. I asked for a 14-50 outlet on the backup side that I did not have before, and would only use it to provide a bit of power to my car in an outage if I needed to for "some reason".
TL ; DR, it was my choice that the wall connector was not backed up, at least I told them "I dont want that circuit backed up, everything else, I do"
SoundDaTrumpet
Member
The required back feed for 2 PW is 30A x 2 = 60A. Add in 8.4kW solar where I assume you have 40A inverter typical. In total 100A of back feed needs to be made available on the service panel.
@Cricket88 LP120-SR has 200A busbars (?) = 40A available back-feed.
1. Swap 200A LMB20 main breakers with 150A LMB15 = 90A available back-feed.
2. Swap 200A LMB20 main breakers with 125A LMB12 = 115A available back-feed.
3. 2500 square foot home. NEC load calculation: 128A (non-conservative)
You have too much load in your house to downsize the main breaker to 125A.
The new MPU installed with 225A busbars and 200A main breaker will be 225*120%-200A = 70A. Main breaker to 150A gives 120A back-feed. 150A breaker on the service panel can handle your NEC calculated home loads easily.
The above is the standard logic for MPUs.
@Cricket88 LP120-SR has 200A busbars (?) = 40A available back-feed.
1. Swap 200A LMB20 main breakers with 150A LMB15 = 90A available back-feed.
2. Swap 200A LMB20 main breakers with 125A LMB12 = 115A available back-feed.
3. 2500 square foot home. NEC load calculation: 128A (non-conservative)
You have too much load in your house to downsize the main breaker to 125A.
The new MPU installed with 225A busbars and 200A main breaker will be 225*120%-200A = 70A. Main breaker to 150A gives 120A back-feed. 150A breaker on the service panel can handle your NEC calculated home loads easily.
The above is the standard logic for MPUs.
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chrisbailey13
Member
So, in my install the breaker to the Gateway takes up 4 slots. Looking at your picture it looks like if you are only moving the 100a breaker you wouldn't have enough slots to support the breaker needed for the gateway. Assuming of course you would also need 4 slots available.
1 PowerWall is questionable for a house that size. The issues is a Powerwall can output only 5kW continuously, A/C would likely be not supported.
The other thing to remember is there a series of features that need to be installed to support even one Powerwall. Things like the Energy Gateway ( a smart, super fast switch that switch power sources to meet you needs in milliseconds), wiring to generation panel, etc. So the cost of the second (or 3rd or 4th) PowerWall is largely just the costs of Powerwall (I think that is $6,500).
Also, personally I would never use a NatGas generator. They are loud and switchover take tens of seconds versus milliseconds with powerwalls. The cut over is so fast with PW you might not even notice it. No clocks to reset, no light flicker, etc. We love ours.
Your main panel is definitely LP-120SR? That's a Solar Ready (225A bus) all-in-one: LP120-SR - 12 Space Outdoor All-in-One Solar-Ready Load Center with Main Breaker in Gray - Leviton So the picture in post #11 is upside down? The LP-120SR has the main breaker at the bottom of the distribution section as you can see in the 'Product Overview' pdf on the web page.
Since it's an all in one panel, the usual strategy of intercepting the feeder on the supply side for the Backup Gateway and making the panel into the non-backed up panel is not possible. As SoundDaTrumpet points out, downsizing the main breaker to 150A would allow 120A of power sources to be connected to the panel. The Backup Gateway could intercept the 100A feeder to your subpanel, and that would allow for (2) Poweralls (30A breakers) and one 7.6 kW solar inverter (40A breaker). Using more than 100A of power sources would require upgrading the 100A feeder, but the main panel itself could handle up to 120A of power sources (with the downsized main breaker).
Also, what are the sizes of the A/C, oven, and EVSE breakers? If they add up to 125A or less, and you endeavor to get rid of the 15A breaker (should be possible), then you wouldn't need to downsize the main breaker. The 225A bus would be protected under a different rule than the 120% rule. That also means you could set a 125A non-backed up panel next to your main panel, feed it with a 125A breaker, and move all the branch circuit breakers to that new panel. The main panel would just have the two feeder breakers.
I don't see any 200A, 4 position branch breakers or feed thru lugs for Leviton, so the strategy of emptying out the main panel is not applicable to LP-120SR.
Cheers, Wayne
Since it's an all in one panel, the usual strategy of intercepting the feeder on the supply side for the Backup Gateway and making the panel into the non-backed up panel is not possible. As SoundDaTrumpet points out, downsizing the main breaker to 150A would allow 120A of power sources to be connected to the panel. The Backup Gateway could intercept the 100A feeder to your subpanel, and that would allow for (2) Poweralls (30A breakers) and one 7.6 kW solar inverter (40A breaker). Using more than 100A of power sources would require upgrading the 100A feeder, but the main panel itself could handle up to 120A of power sources (with the downsized main breaker).
Also, what are the sizes of the A/C, oven, and EVSE breakers? If they add up to 125A or less, and you endeavor to get rid of the 15A breaker (should be possible), then you wouldn't need to downsize the main breaker. The 225A bus would be protected under a different rule than the 120% rule. That also means you could set a 125A non-backed up panel next to your main panel, feed it with a 125A breaker, and move all the branch circuit breakers to that new panel. The main panel would just have the two feeder breakers.
I don't see any 200A, 4 position branch breakers or feed thru lugs for Leviton, so the strategy of emptying out the main panel is not applicable to LP-120SR.
Cheers, Wayne
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Thanks. My quote has my Tesla wall charger "not backed up" but it pulls 72amps. I haven't discussed with Tesla yet. I guess if we have a power outage now, I'm not charging my X, anyway.
Yeah you would need 3 powerwalls to even think about backing that up, and you likely wouldnt want it backed up anyway (even 3 powerwalls would be emptied by your car fairly quickly in a power outage). consider getting a power outlet on the backup side.. a 14-50 at 40 amps or 50 amps. That gives you choice to plug in if you wanted to in an outage for some reason. You likely wouldnt use the outlet otherwise but it gives you choice.
That's a great idea and what I'm thinking. That way I have control over "outage" charging. Would be nice for the powerwalls and car to talk even via the app. Some day.....
It does in a small way for the model 3, currently. I have an option in my app to set the powerwall charge level in an outage. Its supposed to be pushed to other Teslas at some point, but I dont know if I would want to "trust the software" in an outage for this.
here is what it looks like in my app, though:
Yeah good question. In our case the costs included the extra breakout panels, because we didnt' have enough room for all the extra circuits the powerwalls and Solar required; 5 additional "double" size 220 circuits, one for each powerwall, and one for each inverter. That adds up to 10 single circuit breaker slots needed, with them co-located in 5 pairs. The moment an electrician starts needing to rewire a panel, it's like automatically in the thousands it seems just for the labor.
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I'm totally new at all of this, just trying to learn. I have no EV's and no solar and no powerwalls. Tesla does not service my area, I'm attempting to find someone reliable to install some solar and a couple of PW's for emergency backup, since I lose power often. I'd like to get this done this year to take advantage of the 26% tax credit.
I've found this thread interesting and informative. From what I've learned, I would agree that there's no way that one or two PW's would suffice to charge an EV at any high rate and still leave enough power for the house. However, I would be very interested if a Tesla EV could possibly be used as a backup energy source to power the house. Wouldn't a Tesla EV be equivalent to several PW's? When it was depleted, make a trip to a Supercharger and you're ready to go again? Is this even possible, or practical? Does the hardware exists to do this?
Sorry if this is a sidetrack, but I saw the OP say that he didn't include a charging port to be supported by the PW and thought it related.
I've found this thread interesting and informative. From what I've learned, I would agree that there's no way that one or two PW's would suffice to charge an EV at any high rate and still leave enough power for the house. However, I would be very interested if a Tesla EV could possibly be used as a backup energy source to power the house. Wouldn't a Tesla EV be equivalent to several PW's? When it was depleted, make a trip to a Supercharger and you're ready to go again? Is this even possible, or practical? Does the hardware exists to do this?
Sorry if this is a sidetrack, but I saw the OP say that he didn't include a charging port to be supported by the PW and thought it related.
Using the car requires Vehicle to Grid (V2G) support. This has been talked about, but there is no support at this time for this in Tesla cars. There are a number of issues to worked out including impacts on battery life, connectivity, hardware upgrade required to vehicle and home, and control of charging/discharging.
charlesj
Active Member
I just recently learned my son in Chandler, AZ is talking to Tesla about a full system, abt a 10k PV and 4 PW.
While they want a new main panel as it has no room for any expansion, it will still be 200A so
the number of PW is not the reason for upgrade but some other reason as stated, recalled, no expansion, or no real document of brand and size?
While they want a new main panel as it has no room for any expansion, it will still be 200A so
the number of PW is not the reason for upgrade but some other reason as stated, recalled, no expansion, or no real document of brand and size?
SoundDaTrumpet
Member
charlesj
Active Member
SoundDaTrumpet
Member
I would recommend walking to both adjoining neighbors’s houses to take a photo of their label (with their permission of course!), and provide that to Tesla. High chance that the 1980s built home was a tract home.
Also, there are BR type circuit breakers which are compatible with Bryant and Eaton (these are the types that Tesla uses in their back up load center or TEG2 (mentioned by someone on TMC)). I see there is a Bryant circuit breaker already installed. There are Eaton BR quad breakers that can be used to free more space for branch circuits.
The other issue which I ran into with my 2003 panel was that some parts may not be available anymore. I suspect that it might be the main breaker. I could not locate a main breaker to convert my 6 throw Main Lug Only to accept more circuit breakers. <—for example.
andy.connor.e
Member
I have a solar roof on order, 9.36kW. I put in a 200A panel a few months ago to prepare for it, and called Tesla to make sure it was going to be compatible. I have a regular Square D 200A MCB panel from Home Depot. It looks like the panel you have is a load bank specifically for solar. Tesla might use a different outdoor load bank panel than what you have, and it looks like others have said something about a 150A main breaker instead of the 200A. If thats all that Tesla requires, then you should be able to swap out the main breaker and not put in a brand new panel. Personally, i would call to clarify this and provide the panel model that you have and have them explain what specifically they require out of it that warrants the new panel.
caltrader
Member
Well, I might not have read all the responses, but the reason for new panels is determined by local electrical codes. In a conversation with a 3rd party installer, most main panel configurations in the Southwest US use an integrated Meter design, utility meter and breakers in the same cabinet. I looked at the Leviton power panel, and it's of this integrated design.
The Powerwall installation MUST intersect or go BETWEEN the utility meter, and the circuits feeding your home. That's nearly impossible with an integrated meter panel. In most cases there's no room to run (4) 2/0 wires out the side of the panel. These wires are almost 1/2" in diameter each and don't bend much at all, not to mention, the modification to the panel would violate NEC wiring codes.
A whole house backup installation requires ALL the circuits to be spliced and extended to a new main panel. All that remains in the original panel is the original main breaker and a new breaker of the same Amperage that feeds the Gateway.
An essential circuit backup is similar with less splices and all the essential circuits routed to a new power panel.
I recently had Tesla install 3 PW's for whole house backup, and that's how it was done.
The Powerwall installation MUST intersect or go BETWEEN the utility meter, and the circuits feeding your home. That's nearly impossible with an integrated meter panel. In most cases there's no room to run (4) 2/0 wires out the side of the panel. These wires are almost 1/2" in diameter each and don't bend much at all, not to mention, the modification to the panel would violate NEC wiring codes.
A whole house backup installation requires ALL the circuits to be spliced and extended to a new main panel. All that remains in the original panel is the original main breaker and a new breaker of the same Amperage that feeds the Gateway.
An essential circuit backup is similar with less splices and all the essential circuits routed to a new power panel.
I recently had Tesla install 3 PW's for whole house backup, and that's how it was done.
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