Complicated install, lack of clear info from Tesla

[roofsolartexas]

Hello everyone, I've been calling Tesla back and forth speaking to my rep to get information. A little back ground, I'm getting a new Tesla Solar roof and potentially two power walls, on a small 2/1/1 in Fort Worth.

I'm having an electrician relocate my service entrance, install a new meter, and a new 200 AMP panel. I asked Tesla already, if these would be compatible before he ordered them and provided the model numbers, I was told YES. I asked, because I saw solar ready load centers and wanted to verify. My set up will be power from the pole, to the meter, to a disconnect(yes, a separate disconnect), from the disconnect inside to a 200 AMP panel.

My next question that I'm having trouble getting answered, is if I do two Power Wall's and do an entire home back up, is this wired directly to my 200 amp load center?

The second question I needed clarity on, does the Gateway have lugs in there that have back up power to the load center, and separate lugs for a panel that is not backed up?

I ask this question, because originally Tesla was discussing installing a second load center for dedicated circuits. Then, they said I don't need one I can just wire it directly to my 200 AMP panel for full back up if I do two Power Walls. If I do one power wall, I would need a separate load center.

Question Three. If the Gateway has provisions to back up one load center, and provisions for NON back up load center, I would rather wire my 200 AMP main as the back up. THEN, have the sub panel as the NON back up.

Why would I want a second panel as a non back up?

The main panel would house all of my electrical outlets, lights, central A/C, etc. In the future, I may install a mini-split A/C that runs off 208 Volts in the garage, or an extra room. I may get a jacuzzi that has a pump, a large air compressor, etc. I don't want this stuff on back up. It is much easier to put this on an auxiliary panel that is not backed up, then it is to manually go in and tie in to essential loads.

If I do the whole house back up and I'm not home to shut off loads during a power failure, I'm concerned the Gateway will shut the power off due to an over load. I will basically have to large loads, a 1.5-2 toon Goodman central A/C that has yet to be installed, and a 208 volt hot water heater. I will have a dryer and some other large loads that do not need to be backed up.

If anyone could post pictures of the inner workings of their gateway or share experiences, this would be great. I'm reading conflicting stories. For example, one guy posted on the Tesla forum they wanted him to pay $4,200.00 to upgrade his 200 AMP load center to a new load center. Why, I don't know. I'm also hearing about dishonesty, either intentionally or through mis-information, I do not know.

I really would like to clarify this. I did ask the Tesla specialist if I would need a solar ready load center, and the answer was no.

All I was able to find online was a picture of a Gateway from a UK customer. How ever, it was just a glimpse of it. Their electrical systems are different than ours over here. I didn't see any plug ins for the Power Wall, except for communications. Thanks.

 

[roofsolartexas]

My load center and meter are not solar ready, FYI. The load center I picked is a GE load center TM2020CCU and the Meter U7040-XL-TG. thanks.

 

[roofsolartexas]

I apologize, I'm not allowed to edit my post or I would, so I'll add to this. The electrical install has not began yet, so this is the critical time to plan and do it right.

Another question, if my electrician installs a sub panel with the circuits that I don't want backed up, will Tesla be okay with this? I wasn't sure if they would say I would have to use their sub panel, or if they had a special sub panel.

Finally, I do NOT want wires tapped with wire nuts from the main panel to the sub panel. I want a clean install. I'm not an electrician, I just happened to see a video on youtube of a guy wiring a transfer switch, to back up one single circuit for the furnace. I don't know if this is customary or what. Thank you.

 

[power.saver]

Look at the diagrams on Page 2 of this document. It shows the placement of the various components. It sounds like you want the Partial Home Backup. I'd recommend that configuration since you have some loads you don't want backed up.

 

[roofsolartexas]

Thank you for the response. I don't think you understood my post. I'm well aware of all the equipment involved. I have specific questions related to them, that the document does not cover. I'm not interested in a partial home back up and I'm not interested in one power wall. I can not back up my central A/C or hot water heater with one power wall.

I need specific information, as I plan for this electrical upgrade and future solar install. Thank you again for your response.

 

[roofsolartexas]

Let me rephrase one of several questions I had:

If I get two power walls, and want to back up 240 volt appliances, and also have a sub panel of stuff that I do not want to back up, can this be done?

A 2 ton A/C from a google search can use around 7,000 watts (7KW). Each powerwall is only rated for 5kw continuous. I don't have much room to play with. If I have something else big on the circuit, it will cause the Gateway to shut down due to over load. This is why it is going to be essential to wire certain large appliances on a sub panel that I don't want backed up.

It's much easier IMO, to back up the main panel, so every light and every outlet works in my house, rather then pull one here, or one there, to stick in a back up panel.

IF I do decide to do one powerwall, I know that I would have to use the sub panel as the back up panel, because there is only one leg and I can only do 120 volts. It just makes more sense to just do it all right the first time, and forget about it. Thanks.

 

[roofsolartexas]

If I could just see the inner workings of the Gateway it would really help answer my questions. I'm welcome to someone answering for me. I'm baffled at the lack of information provided by Tesla. Thanks.

 

[GenSao]

Let me rephrase one of several questions I had:

If I get two power walls, and want to back up 240 volt appliances, and also have a sub panel of stuff that I do not want to back up, can this be done?

A 2 ton A/C from a google search can use around 7,000 watts (7KW). Each powerwall is only rated for 5kw continuous. I don't have much room to play with. If I have something else big on the circuit, it will cause the Gateway to shut down due to over load. This is why it is going to be essential to wire certain large appliances on a sub panel that I don't want backed up.

It's much easier IMO, to back up the main panel, so every light and every outlet works in my house, rather then pull one here, or one there, to stick in a back up panel.

IF I do decide to do one powerwall, I know that I would have to use the sub panel as the back up panel, because there is only one leg and I can only do 120 volts. It just makes more sense to just do it all right the first time, and forget about it. Thanks.

1) Yes. For my system, Tesla relocated all the loads to a new panel. The old panel remained and can be used for non-backed up loads.

2) A Two ton AC unit should be able to be backed up. I have a 4 ton AC that is backed up. Check the LRA rating of the AC to be sure. A soft/hard start device may be required.
What does Powerwall Backup | Tesla

3) A single Powerwall will do both legs (L1 and L2).

If I could just see the inner workings of the Gateway it would really help answer my questions. I'm welcome to someone answering for me. I'm baffled at the lack of information provided by Tesla. Thanks.

Check out the installation manual. Figure 20 for Home House Back up and Figure 21 (Page 43) for Partial Home backup.
Installing Powerwall | Tesla

Here is a picture of my gateway for a whole home backup:

 

[CrazyRabbit]

Let me rephrase one of several questions I had:

If I get two power walls, and want to back up 240 volt appliances, and also have a sub panel of stuff that I do not want to back up, can this be done?

A 2 ton A/C from a google search can use around 7,000 watts (7KW). Each powerwall is only rated for 5kw continuous. I don't have much room to play with. If I have something else big on the circuit, it will cause the Gateway to shut down due to over load. This is why it is going to be essential to wire certain large appliances on a sub panel that I don't want backed up.

It's much easier IMO, to back up the main panel, so every light and every outlet works in my house, rather then pull one here, or one there, to stick in a back up panel.

IF I do decide to do one powerwall, I know that I would have to use the sub panel as the back up panel, because there is only one leg and I can only do 120 volts. It just makes more sense to just do it all right the first time, and forget about it. Thanks.

each powerwall is single phase 240 volt with L1 & L2 being 120v to neutral.
as stated earlier look at the label on the compressor, and note the LRA (locked rotor amps) this is the current required to start the unit. you will need head room for other thinks running in the house.

after you hit the buy now button, log into your tesla account and they will ask you to upload 3 electric bills and pictures of your electric panel, and AC compressor labels.

there is no reason not to use a referral code, it get you 250 bucks and the other person 250 bucks. the referal code is a url that you start your order with. please use mine if you don't have any other to use: Earn Free Supercharging Miles or a $250 Cash Award ( https: // ts . la / eric95695 remove spaces or click the link)

 

[roofsolartexas]

Very interesting. Thanks for the detailed response. The website says that I can't run an A/C with just one, I would need two. I did calculations, and discovered a 1.5 TON A/C unit would be fine for my house. Unless there is data that I'm missing, if I could get away with one Power wall to run that A/c and all the outlets and lighting in my small house, I would do it. Also, if one powerwall has two legs and makes 240 volts, I wonder what would happen if you tried to connect a 240 volt appliance that was too big for the battery? The RLA is 9, so around 2,000 watts for my calculation with the A/C going, and 47 LRA for when it starts. It may be too much for one, but again, Tesla says two for anything 220 volts.

How old was your panel? I will be having a new 200 AMP panel installed. I want to kinda try and verify that when they come out, they aren't trying to do things their way. I'm now considering having my electrician wire a sub panel in advance, so they don't have to come in and rewire all the fresh work.

I'm still trying to read the diagrams and understand how that bus bar works, and how power gets shut off from one panel and leaves power to the sub panel. I figured those lugs are connected together, unless I'm missing something.

I'm also wondering if it would just be best to get two, 200 AMP panels. I'd rather over do, then under do. Thanks, I really appreciate it.

 

[roofsolartexas]

I haven't purchased the system yet. On back up, I would have a 40 gallon hot water heater, which is around 4,500 watts running, all the outlets and lighting circuits in the house, and the central A/C. IF the water heater kicked on, it would over load. I would only be able to have the central A/C as the only back up, plus lighting circuits in the house. FYI, it would be a scroll compressor too and a Goodman unit. The only other concern would be heat strips, if it's too cold and heat strips are required. The other goal of this project is to cancel the gas service and be all electric. I have to pay almost $20.00 for the liberty to just be a customer of the gas company. Cooking with gas is cool, it has advantages, but free power with electric items sounds more interesting. Not worrying about carbon monoxide, gas leaks, gas explosions and a gas bill are even more interesting.

It lists the LRA/RLA for two, but nothing for one. I don't know if anyone is running 220 volt appliances on one power wall, or if and when they install it, they have the software and the voltage monitors set, so if someone did try to do something, it would sense the voltage and shut it down.

As far as the code goes, I will click on it. Please describe your system if you can, I see you're in the Fort Worth area too. My electrician and myself are new to the back up, he's as interested as I am. We have lots of questions. Thanks.

 

[aesculus]

Tesla can leave whatever you don't want backed up into your existing 200 amp panel.

They will then move whatever you do want backed up into a new backup panel. They run wire extenders from where your old circuit breakers were to the new backup panel.

So essentially you will be getting an additional 200 amp panel with the backup panel Tesla supplies.

 

[CrazyRabbit]

https://www.tesla.com/sites/default/files/pdfs/powerwall/Powerwall 2_AC_Datasheet_EN_NA.pdf

the powerwall will do 7KW for 10 seconds, which is 29 amps. i would believe the power wall would shut down when overloaded.

i have my home assessment this Wednesday. i signed up for a large system, but now want a x-large with 6 powerwalls. i can't get them to respond to my requests. also i'm building a deck onto my house and extending the roof over the deck and want the panels on that section of the roof (18 panels) which didn't show up on their satellite images, I want them to revise the layout. they also didn't want to backup my 3hp well pump which is a must for me. but i'm going to proceed with

the gateway has two power taps on it, one option would be to run your packup loads panel and the generation panel (PV and powerwall), my option will be to run my two 400 amp distribution panels to the gateway and connect my generation panels to my main panels. i can exceed the maximum by 20% for generation so that is a extra 80 amps per panel for my generation.

 

[roofsolartexas]

Crazyrabbit, you will have to call and email. Most emails don't get responses, so call. They tried to tell me all I could get was 4.3 KWH for my roof, I said no way, I need more than that. They said I couldn't with my design, I asked what the problem was and they told me I had vents in the way. I told them I will move or remove them, if that was the problem. I can't change this in the future, I need to max it out right now. This isn't like solar panels where I can ad more. Since I'm switching to electric appliances, I'm eliminating two flues from the roof and relocating a bathroom plumbing vent further up the roof. I'm going to be around 5.2-5.5 KWH.

Ask lots of questions. I'm not thrilled with the consulting. They just send you a design and expect you to sign it with out any further consultation, with no regard for you needs or plans for the future. For example, I'm switching from gas to electric, I may purchase an electric car in the future, get a jacuzzi, etc. They size it based on your current energy usage and your available roof space.

It wasn't easy to find literature, even with all my questions being ask, they couldn't point me in the right direction. I'm glad I came here and asked, or I'd still be in the dark not knowing.

 

[SMAlset]

We sent our photos in and spoke to them about what we had equipment wise drawing power and what we wanted to do with the system. The team prepared a solar panel layout and also provided the product info for what they were spec'ing. We looked it over, had lots of questions (first time ever looking at solar, let alone PW) and wanted a different panel arrangement than what was shown in our initial layout. The vents and a solar attic fan on our S/SW roof section was the reason they gave us the layout they did. BTW my husband also said he was willing to remove the solar attic fan (had it for a number of years and it stopped working anyway). The removal and reroofing of that section would have to be done before the install.

Then my husband asked if we could arrange the panels slightly differently and fit the two panels that were initially placed elsewhere onto that section instead. There is some required spacing from the roof hips and ridge. I think because of some code issues. They also like to have the panels arranged more together than not for I think aesthetics but might also be for making connections and ease of any later adjustments/repairs. Anyway in our case they were able to fit the two panels onto that roof section laid out a bit differently and still avoid our vents and the attic fan. Not as nice of an overall look but we were fine with it and other solar paneled roofs in our neighborhood weren't perfectly laid out either. I will add that it won't be easy for anyone to work on the attic fan in the future likely, but it got us the 12 panels on that section that we really wanted. Tesla was fine with sending the layout back to the solar panel team after we reviewed it the first time and we were able to accept the design after the revision.

Whatever you do if you are in the pre-design stage, have some idea how you want to use your system--do you want to back up somethings (if so what) or everything, do you want any outlets added maybe for an EVSE, and since the systems are designed for use for like 15+ years only you can anticipate what things you might want to add to your house later that need to be figured in now. Like for example maybe you plan to add a hot tub or BBQ island with overhead quartz heater. Think about trees you might plant, their height and placement and shading on your roof where the panels will be. Yes, ask questions if you don't understand what they spec'd before signing any contract. Now is the time to get informed. Check over the layout and verify it's marked correctly. Ours was derived from a google overhead photo, not an onsite assessment. Read up on the various components ahead of time so you have a basic understanding. We took several weeks to think about our system and how we would use it, wrote up all our questions on the equipment, warranties, servicing if a problem occurred and contract terms and language, and then had another pre-contract signing conversation with them where everything got answered to our satisfaction.

We still don't understand all the electrical aspects of how this will get wired and set up but have been assured they will work with us as far as the placement of things and having seen our photos of the outside panel wall and garage and how we'd like to see the conduit run and equipment placed in general have been told it all sounds doable.

 

[CrazyRabbit]

Crazyrabbit, you will have to call and email. Most emails don't get responses, so call....
They just send you a design and expect you to sign it with out any further consultation, with no regard for you needs or plans for the future..

I've been calling three times a week, they have attached my emails to my file.... they say it is complicated and takes time, lol.

my sentiments exactly... expect you to sign...

i will call again Monday, but expect it won't be until my assessment.

 

[SMAlset]

@CrazyRabbit have your questions written down and ready to ask during the assessment. They can probably answer a lot then. You'll undoubtedly have more afterwards . We strictly went by submitting photos and phone calls/emails.

BTW something else people should think to ask about is panel/conduit routing, what areas of your house will need accessing, how will conduit be run from the roof to your panel, what about painting it if outside and visible, if conduit is running in your garage is surface mounting okay or are you willing to pay extra for in wall run if possible. There are many other questions about the install you might want to think about ahead of time like time without electricity, how the gateway will talk to your wifi etc.

 

[SMAlset]

"I'm reading conflicting stories. For example, one guy posted on the Tesla forum they wanted him to pay $4,200.00 to upgrade his 200 AMP load center to a new load center. Why, I don't know. I'm also hearing about dishonesty, either intentionally or through mis-information, I do not know."

Our city required us to upgrade our outdoor 200A main panel when they went to review Tesla's permit. City gave them two reasons: 1) our panel had a center feed and they want to see it be a top/bottom and 2) the panel the developer put in back in 2003/4 timeframe did not have a bus bar rating of 225A, which the city wanted to see for the addition of Solar based I think on our existing load then not meeting some calculation. Tesla quoted us something similar to that price to do the extra work but their guy was booked out for months (this was before CV shut things down), so we asked if our electrician could do the work and they said great. Our guy actually charged us more than what we would have paid Tesla BTW. He was going to fit us in after his current job and we would have been all ready to go in like a week (then the City shut down their permit/inspection office).

Our panel upgrade was just completed this week after some restrictions were lifted on residential electrical. Took him two days to do the electrical work. First day he cut through our stucco outdoor wall to gain access to the panel. He then replaced the box and meter area with the new equipment and worked on establishing the new breakers/wiring to get us power back inside the house that first day. We have a lot of outdoor backyard patio electrical for our bbq island/dining pergola area and he saved wiring that for the second day. He had to access the panel from inside our garage to connect some of the outdoor wiring and do some drywall work as a result. Our roughed in inspection was the third day when he met with the inspector. The fourth day his stucco guy came out, took out a bit more of the stucco to be able to lay in the wire mesh, flashing and whatever else they do, taking photos for the inspector at various stages. Then the multiple layers of stucco were applied and texturized. That was Friday. Monday is our final inspection with our electrician and inspector. Hopefully he's happy and signs off on it. Our panel upgrade project costs included the panel box, breakers, wiring, city permit, time applying in person (that was in person back in February) and times meeting with the inspector. We also incurred a city license fee for him since he hadn't worked in our city before and needed it to do so. Also included was the labor/materials for the stucco work of the two guys who came. Not a simple in/out replacement. I was surprised at all the work that needed to be done. So IMO given all the time and work involved in this upgrade I didn't think our quote was that bad. It is also the Bay area.

FWIW our outdoor panel and meter box was an Eaton Model #MBE2040PV200BTF, 200A, 40-circuit solar ready combo, with 225A bus. He bought it from an electrical supplier but here's pictures of it on HD's site for anyone interested. It is flush mounted. We already had a SmartMeter installed a few years back so that part is good to go.

 

[jboy210]

"I'm reading conflicting stories. For example, one guy posted on the Tesla forum they wanted him to pay $4,200.00 to upgrade his 200 AMP load center to a new load center. Why, I don't know. I'm also hearing about dishonesty, either intentionally or through mis-information, I do not know."

Our city required us to upgrade our outdoor 200A main panel when they went to review Tesla's permit. City gave them two reasons: 1) our panel had a center feed and they want to see it be a top/bottom and 2) the panel the developer put in back in 2003/4 timeframe did not have a bus bar rating of 225A, which the city wanted to see for the addition of Solar based I think on our existing load then not meeting some calculation. Tesla quoted us something similar to that price to do the extra work but their guy was booked out for months (this was before CV shut things down), so we asked if our electrician could do the work and they said great. Our guy actually charged us more than what we would have paid Tesla BTW. He was going to fit us in after his current job and we would have been all ready to go in like a week (then the City shut down their permit/inspection office).

Our panel upgrade was just completed this week after some restrictions were lifted on residential electrical. Took him two days to do the electrical work. First day he cut through our stucco outdoor wall to gain access to the panel. He then replaced the box and meter area with the new equipment and worked on establishing the new breakers/wiring to get us power back inside the house that first day. We have a lot of outdoor backyard patio electrical for our bbq island/dining pergola area and he saved wiring that for the second day. He had to access the panel from inside our garage to connect some of the outdoor wiring and do some drywall work as a result. Our roughed in inspection was the third day when he met with the inspector. The fourth day his stucco guy came out, took out a bit more of the stucco to be able to lay in the wire mesh, flashing and whatever else they do, taking photos for the inspector at various stages. Then the multiple layers of stucco were applied and texturized. That was Friday. Monday is our final inspection with our electrician and inspector. Hopefully he's happy and signs off on it. Our panel upgrade project costs included the panel box, breakers, wiring, city permit, time applying in person (that was in person back in February) and times meeting with the inspector. We also incurred a city license fee for him since he hadn't worked in our city before and needed it to do so. Also included was the labor/materials for the stucco work of the two guys who came. Not a simple in/out replacement. I was surprised at all the work that needed to be done. So IMO given all the time and work involved in this upgrade I didn't think our quote was that bad. It is also the Bay area.

FWIW our outdoor panel and meter box was an Eaton Model #MBE2040PV200BTF, 200A, 40-circuit solar ready combo, with 225A bus. He bought it from an electrical supplier but here's pictures of it on HD's site for anyone interested. It is flush mounted. We already had a SmartMeter installed a few years back so that part is good to go.

Best of luck on your inspection.

Can I ask if Tesla is coordinating the inspection? We need our final inspection and have talked to the Tesla project coordinator, but not heard anything from the Tesla inspection team. This team is supposed to arrange for the inspection and walk the city inspector through the inspection.

 

[roofsolartexas]

Depending who you talk to, there are phone issues where you will hear your self echo. Some of the people are working from home and doing other things. I had one guy that was doing something else and moving his phone or mic piece from his face and I had to tell him multiple times to move the mic because I can't hear what you're saying.

I whacked every tree at my house several years ago when I moved in. I also noticed the Power Wall 2, you can get 3 for 12k with a Tesla Solar system, but if you go with the solar roof they are 2 for 14k, 3 for triple that. I'm waiting to call tomorrow to find out why I can't get more for less with my Tesla solar roof, and why the solar panels are getting that deal.