New Construction - Conduit prep for future panels and PW setup

[UltralightBeam]

Currently entering the electrical phase of the build and we're most likely going to be able to fit one of tesla's larger system on our south facing and flat/uncomplicated roof (About 900sf area)

To keep things clean and easy for the installer, I was curious about what to have our electrician run for the conduit lines.
1. Our meter is outside of our garage - prob where the power walls, inverters/gateway etc would go...
2. Our electrical panel is in the basement

From what I've been hearing, people are saying that you may need 1 or 2 lines from the roof/attic down to the power walls depending on MPPTs but honestly, I wasn't sure what that was to begin with.

With that, would they go like this: Attic 2x 1" conduit to garage for inverters/powerwall etc, then I think it's all combined and then 1" conduit from garage to basement?

Any help appreciated as I tried Tesla chat and they just wanted me to place an order now saying that Tesla would install all of these items clean and behind the wall in conduit (Umm I wasn't sure about that).

 

[Vines]

Currently entering the electrical phase of the build and we're most likely going to be able to fit one of tesla's larger system on our south facing and flat/uncomplicated roof (About 900sf area)

To keep things clean and easy for the installer, I was curious about what to have our electrician run for the conduit lines.
1. Our meter is outside of our garage - prob where the power walls, inverters/gateway etc would go...
2. Our electrical panel is in the basement

From what I've been hearing, people are saying that you may need 1 or 2 lines from the roof/attic down to the power walls depending on MPPTs but honestly, I wasn't sure what that was to begin with.

With that, would they go like this: Attic 2x 1" conduit to garage for inverters/powerwall etc, then I think it's all combined and then 1" conduit from garage to basement?

Any help appreciated as I tried Tesla chat and they just wanted me to place an order now saying that Tesla would install all of these items clean and behind the wall in conduit (Umm I wasn't sure about that).

Sounds like you came to the right place, as Tesla generally isn't as helpful when looking for access to a designer.

If the meter that is on the garage has the main breaker as well that is a good thing, then you have many choices. This means the main service panel is located on the garage exterior wall. My advice is based on this assumption, that your meter and main breaker are on the same exterior enclosure.

I would recommend putting the PW inside the garage if you can in your climate.

You won't need any additional wiring to the loads in your basement unless you plan on having some of them not backed up. If you backup the whole home panel this design is simple. It is never a bad idea to have a couple of extra conduits through the concrete for unforeseen uses like network or future smart home signal or power.

Your basement subpanel will need to accept a main breaker installed inside it, rated with the circuit.

The (2) 1" conduit you are installing from the roof will be more than enough for the PV.

If the PW are going right there next to the service panel, you could hide that wire in the wall as much as possible. (2) PW conductor wiring plus the data wire will fit in a 1" EMT conduit. (3) Requires 1 1/4" EMT.

If you are intercepting a 200A main feed and need to run it in conduit, you should plan on 2" EMT, though 1.5" EMT will do in some circumstances. A 125A feed required 1 1/4" EMT.

You should run an additional 3/4" EMT conduit from the Gateway location to the main service panel if the Gateway will not be right next to it. This will allow you to add a button for rapid shutdown, or a different circuit if required in the future.

 

[mswlogo]

I’m running into a similar issue. I was told it needs metal conduit fit the DC stuff. But I have another complication that I have no attic. It’s all cathedral. The whole second floor. So I don’t know where to put the conduit. I prefer it not run outside.

 

[BGbreeder]

I’m running into a similar issue. I was told it needs metal conduit fit the DC stuff. But I have another complication that I have no attic. It’s all cathedral. The whole second floor. So I don’t know where to put the conduit. I prefer it not run outside.

If it is all cathedral, and you don't want it outside... then it is inside. It is your house.

However, I would point out that roof penetrations, like a conduit, are inherently a weak point in your roof membrane, and therefore a common site for leaks, so it would be prudent to have the penetration(s) occur somewhere that you will notice the leak sooner rather later. i.e. I wouldn't hide it in a wall or behind crown molding. You get real weather where you live, so I wouldn't take roof penetrations lightly.

Good luck.

All the best,

BG

 

[mswlogo]

If it is all cathedral, and you don't want it outside... then it is inside. It is your house.

However, I would point out that roof penetrations, like a conduit, are inherently a weak point in your roof membrane, and therefore a common site for leaks, so it would be prudent to have the penetration(s) occur somewhere that you will notice the leak sooner rather later. i.e. I wouldn't hide it in a wall or behind crown molding. You get real weather where you live, so I wouldn't take roof penetrations lightly.

Good luck.

All the best,

BG

On my current house with PV, They punched a hole in my roof under the panels. So the panels protect it. No snow or ice ever gets under the panels. It’s so neat and tidy. Many folks don’t know we have Solar. The only thing you see is a black rectangle of panels and nothing else.

 

[Vines]

I’m running into a similar issue. I was told it needs metal conduit fit the DC stuff. But I have another complication that I have no attic. It’s all cathedral. The whole second floor. So I don’t know where to put the conduit. I prefer it not run outside.

You might need a dedicated chaseway from the roof in that case and just hide it in the construction.

Is there no insulation in your ceiling at all? If you used AC-PV panels you should hide ac conduit under just a couple of inches of foam or otherwise run it through structure. Last I checked DC conduit needs to be 10" under the roof deck when not exposed. Not sure if you could dado cut a channel and make a small wood addition to one of the cathedral beams to hide the conduit maybe?

 

[mswlogo]

You might need a dedicated chaseway from the roof in that case and just hide it in the construction.

Is there no insulation in your ceiling at all? If you used AC-PV panels you should hide ac conduit under just a couple of inches of foam or otherwise run it through structure. Last I checked DC conduit needs to be 10" under the roof deck when not exposed. Not sure if you could dado cut a channel and make a small wood addition to one of the cathedral beams to hide the conduit maybe?

I think the roof and walls is gonna be dense foam filled panels. It’s a Post and Beam home. For all electrical work they have to notch these panels. I might end up going external conduit.

 

[UltralightBeam]

If the meter that is on the garage has the main breaker as well that is a good thing, then you have many choices. This means the main service panel is located on the garage exterior wall. My advice is based on this assumption, that your meter and main breaker are on the same exterior enclosure.

I would recommend putting the PW inside the garage if you can in your climate.

You won't need any additional wiring to the loads in your basement unless you plan on having some of them not backed up. If you backup the whole home panel this design is simple. It is never a bad idea to have a couple of extra conduits through the concrete for unforeseen uses like network or future smart home signal or power.

Wow this is all great! I'm going to ask tomorrow. So one thing I know for sure is that we have 400Amp service and supposedly it will be into two 200amp panels in the basement. Again, I'm going to ask about this 'main breaker' that you're mentioning. I hope things work out for sure.

I wonder if this would have been even easier if Tesla actually supported 400amp service (sigh).

If people who have their house circuit breakers in their basements get solar, what does Tesla do to run the appropriate wires down there? I'm just wondering if I'm killing myself unnecessarily by overthinking everything. My electrical subcontractor is being unresponsive and the last thing he said was 3/4" conduit from attic to basement. (Which is not 1" nor is it 2 of them). Maybe I just let Tesla Install handle it? IDK. Any help appreciated.

 

[Vines]

Wow this is all great! I'm going to ask tomorrow. So one thing I know for sure is that we have 400Amp service and supposedly it will be into two 200amp panels in the basement. Again, I'm going to ask about this 'main breaker' that you're mentioning. I hope things work out for sure.

I wonder if this would have been even easier if Tesla actually supported 400amp service (sigh).

If people who have their house circuit breakers in their basements get solar, what does Tesla do to run the appropriate wires down there? I'm just wondering if I'm killing myself unnecessarily by overthinking everything. My electrical subcontractor is being unresponsive and the last thing he said was 3/4" conduit from attic to basement. (Which is not 1" nor is it 2 of them). Maybe I just let Tesla Install handle it? IDK. Any help appreciated.

If you have a 2x200 service, you may need to think on this with some diagrams, my advice above isn't as good unless you can confirm 1 thing:

-The Main Breaker only portion of the 2x200 will be the feed to your basement and your backup loads, this will be only partial home backup. There are no loads to backup which are landing in the main service panel 200A distribution bus bottom?

If you do need to move some loads from the main service panel distribution bus then you will want to try to get those loads to land in the basement panel which will be backed up, or you will have to get a little creative and add some equipment to support those loads on the backup system.

Your 2x PV conduit is overkill, overkill never hurts except the pocketbook.

 

[UltralightBeam]

If you have a 2x200 service, you may need to think on this with some diagrams, my advice above isn't as good unless you can confirm 1 thing:

-The Main Breaker only portion of the 2x200 will be the feed to your basement and your backup loads, this will be only partial home backup. There are no loads to backup which are landing in the main service panel 200A distribution bus bottom?

If you do need to move some loads from the main service panel distribution bus then you will want to try to get those loads to land in the basement panel which will be backed up, or you will have to get a little creative and add some equipment to support those loads on the backup system.

Your 2x PV conduit is overkill, overkill never hurts except the pocketbook.

I’ll ask that to confirm tomorrow re the main breaker etc.

So even with the 19kw system, 1x1” should be fine? I thought they could only do a certain number of MPPTs or whatever in one conduit which would then req 2.

But then again, just 1 conduit to basement most likely.

And yes, I know with the gateways, I can only backup partially. Probably just gonna back up as much as I can into one of the 200A units.

 

[Vines]

I’ll ask that to confirm tomorrow re the main breaker etc.

So even with the 19kw system, 1x1” should be fine? I thought they could only do a certain number of MPPTs or whatever in one conduit which would then req 2.

But then again, just 1 conduit to basement most likely.

And yes, I know with the gateways, I can only backup partially. Probably just gonna back up as much as I can into one of the 200A units.

Always take the advice of the designer or installer of your particular system first. They have to own their work and follow their orders. I am just giving you advice over the internet and do not know your site conditions or your plans.

Once you get to this very large PV size, the number of strings matters. I can't sit here without more information and promise you anything 100%.

A single 1" EMT conduit will take 4 strings easily, and that is about 19 kW depending on module size.

Practically you could make (5-6) 20A strings work through the single 1" conduit, though I am not sure Tesla will use the 90C rated #10 AWG wire it takes.

 

[Rocket_man]

You may be wasting your time and money. Without the full design of the system you won't really know where all the PV will end up. The installers are not going to want to vouch for the work your electrician did, even if you think it is saving time. You are already paying for this as part of the install. Depending on the structure between your garage and basement (like a concrete floor) you could think about putting a nipple through there for them to run their conduit. They don't seem to like going through attic space even if it looks better. I think it is just faster to go over the roof and probably less leaks this way.

 

[Rocket_man]

Installers are at my house today. After looking at the roof and the attic they decided it is easier to go through the attic. They just made the call real time. The installation crew has some leeway to make adjustments. If I asked Tesla for this it might have cost me more. I'm sure this must vary by location and crew. I also put some painters tape on the garage wall last night where I wanted the PW+'s. Even marked the stud locations. They are putting them exactly where I marked them. They also told me that they can adjust the layout on the roof to optimize things. A few of my roof penetrations they can work around to move the panels a little higher on the roof and delay the shadow line that my neighbor's house puts on the roof in the afternoon. This same crew installed my co-workers panels a few months ago. They seem like a good crew.

 

[Electrph]

Installers are at my house today. After looking at the roof and the attic they decided it is easier to go through the attic. They just made the call real time. The installation crew has some leeway to make adjustments. If I asked Tesla for this it might have cost me more. I'm sure this must vary by location and crew. I also put some painters tape on the garage wall last night where I wanted the PW+'s. Even marked the stud locations. They are putting them exactly where I marked them. They also told me that they can adjust the layout on the roof to optimize things. A few of my roof penetrations they can work around to move the panels a little higher on the roof and delay the shadow line that my neighbor's house puts on the roof in the afternoon. This same crew installed my co-workers panels a few months ago. They seem like a good crew.

this is probably the conensus you'll read on these boards .. crews are often amazing usually at least very good .. Tesla itself is usually a S show

 

[Rocket_man]

The crew finished day one. All the electrical is done. They did a great job. There is no way that an independent electrician is going to run the conduit exactly where they want it. Plus they get inspected at the end of the job which is reflected on them, so I doubt they want to be judged on someone else's work.

The roof guys attached all the roof anchors and started on the rails. I have a fairly large system with 37 400W panels. They will be back in the morning to finish the solar panel install and connect them to the inverters.

I can see the two powerwalls in my app and he took the house off grid and the batteries (only 20% charge) took over the load without even a flicker. Nice. They won't charge until the solar is connected. Then I get the fun of trying to get inspections and PTO.

 

[Counciltucky]

This post is a little dated but in reference to having an electrician run conduits, I was just told by Tesla Solar that they are no longer allowed to use existing empty conduit. Tesla has to run their own. This is kind of insane to me as I ran an empty one from the back of my house to my crawlspace during a remodel for future expansion. I guess if I had an empty chaseway it would be fine.....

 

[BGbreeder]

This post is a little dated but in reference to having an electrician run conduits, I was just told by Tesla Solar that they are no longer allowed to use existing empty conduit. Tesla has to run their own. This is kind of insane to me as I ran an empty one from the back of my house to my crawlspace during a remodel for future expansion. I guess if I had an empty chaseway it would be fine.....

Tesla solar's viewpoint is reasonable in my opinion. If you didn't run the conduit, you don't know how well it was assembled, and whether there are defects like burrs inside that can damage or short wiring.

All the best,

BG

 

[preilly44]

Just to give my experience with Tesla and building a new construction....

Tesla came out to my home 6 times while it was being built. On one of those visits they told our builder what type of conduit to use. My builder installed the conduit where they said to (using the conduit they said to). Before the builder put up the drywall, Tesla was out again (for something unrelated). They confirmed everything looked good with the conduit. Fast forward 9-10 months, Tesla comes out to do the installation and tells me it's not the right conduit and they need to cut up our walls and do trench work. Very frustrating.