Moving EV Circuit from Backed Up to Non-Backed Up

[jhn_]

Things like this seem to add a lot of complexity to things as you say, you have but have never needed

This is why I think software option in the Tesla app could help the OP and I.

Tesla already has a setting when the grid is down to not charge a Tesla EV if Powerwalls reach a set % charge.

If we had a “do not charge Tesla EV from Powerwall when Powerwall below x% SOC” setting in the app for when the grid is up, we could charge without draining powerwalls. Maybe a sub option if you turned this on would be a choice to charge the EV from grid or stop charging the EV.

Anyone want to tweet my idea to @elonmusk?

 

[wwhitney]

Hopefully I can answer your questions without messing it up.

Your second photo didn't load, and I can't zoom in enough to read the details in your first photo.

But, if you are saying that all the breakers inside are disconnected except for the ones with the black stickers (that the others could be removed and replaced with the filler covers), and that the bottom service disconnect is 200A, but the top "main" disconnect is 100A, then your situation is a bit atypical. Basically your install used the strategy of "the service is 200A, but the load calc is under 100A, so let's just put the whole house on a 100A feeder to save the trouble and expense of upgrading this meter main combo that won't accept any branch circuit breaker bigger than 100A".

So if that's correct, based on the rule I paraphrased for you, you can put up to 100A of (double pole) breakers for non-backed up loads into that service panel. It should have a sticker on it saying something like "Warning sum of breakers excluding service disconnect must not exceed bus bar rating of 200A" (the exact wording is in the NEC). Which would only make sense if you removed the unused breakers.

Cheers, Wayne

 

[h2ofun]

Your second photo didn't load, and I can't zoom in enough to read the details in your first photo.

But, if you are saying that all the breakers inside are disconnected except for the ones with the black stickers (that the others could be removed and replaced with the filler covers), and that the bottom service disconnect is 200A, but the top "main" disconnect is 100A, then your situation is a bit atypical. Basically your install used the strategy of "the service is 200A, but the load calc is under 100A, so let's just put the whole house on a 100A feeder to save the trouble and expense of upgrading this meter main combo that won't accept any branch circuit breaker bigger than 100A".

So if that's correct, based on the rule I paraphrased for you, you can put up to 100A of (double pole) breakers for non-backed up loads into that service panel. It should have a sticker on it saying something like "Warning sum of breakers excluding service disconnect must not exceed bus bar rating of 200A" (the exact wording is in the NEC). Which would only make sense if you removed the unused breakers.

Cheers, Wayne

Is it to code to leave unused breakers in a panel and not put in filler?

 

[wwhitney]

Things like this seem to add a lot of complexity to things as you say, you have but have never needed

It's design complexity, but the additional installation complexity in my case was minimal as everything is next to each other. It just meant adding a 5' feeder, 2 circuit breakers, and the manual interlock cover on the non backed up panel cover.

Cheers, Wayne

 

[wwhitney]

Is it to code to leave unused breakers in a panel and not put in filler?

Let me say that it is not prohibited, therefore it is allowed. But I find it a bit cheesy. On the other hand, is it worth another truck roll to change? No. It was a failing on the person lining up the materials who didn't provide enough filler covers for the crew. The panel schedule should label them all as "spares".

Cheers, Wayne

 

[h2ofun]

Let me say that it is not prohibited, therefore it is allowed. But I find it a bit cheesy. On the other hand, is it worth another truck roll to change? No. It was a failing on the person lining up the materials who didn't provide enough filler covers for the crew. The panel schedule should label them all as "spares".

Cheers, Wayne

I noticed they were still labeled with stuff, which again is why I asked about code. It all seemed cheesy and at risk for something to do something against code and then if a fire or something, who is responsible? Not something I want in my house. Would I have the truck back to take out the breakers, put in fillers, and any other labels needed, you bet I would force it.

 

[GHTech]

Your second photo didn't load, and I can't zoom in enough to read the details in your first photo.

But, if you are saying that all the breakers inside are disconnected except for the ones with the black stickers (that the others could be removed and replaced with the filler covers), and that the bottom service disconnect is 200A, but the top "main" disconnect is 100A, then your situation is a bit atypical. Basically your install used the strategy of "the service is 200A, but the load calc is under 100A, so let's just put the whole house on a 100A feeder to save the trouble and expense of upgrading this meter main combo that won't accept any branch circuit breaker bigger than 100A".

So if that's correct, based on the rule I paraphrased for you, you can put up to 100A of (double pole) breakers for non-backed up loads into that service panel. It should have a sticker on it saying something like "Warning sum of breakers excluding service disconnect must not exceed bus bar rating of 200A" (the exact wording is in the NEC). Which would only make sense if you removed the unused breakers.

Cheers, Wayne

Hi Wayne,

Thank you for the feedback. My load at home is not that much at the moment. My water heater, dryer, range and furnace is on natural gas. I plan to move some of these over to electric. Therefore, if I do move the EV to the non-backed up panel, and later on add the circuits for some of the stuff mentioned above to the backed up panel, would I have to change the Main Disconnect breaker? Anything else?

Thanks,

GHTech

 

[GHTech]

I noticed they were still labeled with stuff, which again is why I asked about code. It all seemed cheesy and at risk for something to do something against code and then if a fire or something, who is responsible? Not something I want in my house. Would I have the truck back to take out the breakers, put in fillers, and any other labels needed, you bet I would force it.

Hi h2ofun,

I did purchase the blanks and was planning to swapping it out when my electrician comes by next Wed. to take care of some other work. I plan to relabel the breakers with properly printed labels.

Regards,

GHTech

 

[wwhitney]

Therefore, if I do move the EV to the non-backed up panel, and later on add the circuits for some of the stuff mentioned above to the backed up panel, would I have to change the Main Disconnect breaker? Anything else?

You've got two limitations if you don't want to change your main service panel:

- I believe that panel is limited to a max 100A branch breaker. (You could check the fine print label to confirm)
- The sum of the breakers other than the bottom service disconnect must not exceed the bus rating, which I believe is 200A (again check the label).

So I suggest you figure out where you want to be ultimately with your electrification, and do a load calculation with the planned new electric appliances. You can pick up to 100A (non-continuous) of your loads to be in the backed up panel behind the Gateway.

If that covers everything except one or two circuits (maybe the EVSE and, say, the water heater), just use the spaces in your service panel for the 1 or 2 non backed up loads. But if you end up needing 3 or more circuits to be not backed up, then I would suggest you add a second 100A breaker to your service panel for a new non-backed up panel, and add all the loads there. That will give you more flexibility--you could have a number of larger circuits where the breakers add up to over 100A, but the load calc for them is under 100A.

Cheers, Wayne

 

[gpez]

@GHTech what EV charger are you using? Make/model/version and plug type (ie 14-30/14-50)? There may be a way to integrate the Powerwall with your charger in some way, even if maybe it's a bit hacky, to avoid the problem of your EV charging off of (and draining) your Powerwalls during a grid outage.

 

[GHTech]

You've got two limitations if you don't want to change your main service panel:

- I believe that panel is limited to a max 100A branch breaker. (You could check the fine print label to confirm)
- The sum of the breakers other than the bottom service disconnect must not exceed the bus rating, which I believe is 200A (again check the label).

So I suggest you figure out where you want to be ultimately with your electrification, and do a load calculation with the planned new electric appliances. You can pick up to 100A (non-continuous) of your loads to be in the backed up panel behind the Gateway.

If that covers everything except one or two circuits (maybe the EVSE and, say, the water heater), just use the spaces in your service panel for the 1 or 2 non backed up loads. But if you end up needing 3 or more circuits to be not backed up, then I would suggest you add a second 100A breaker to your service panel for a new non-backed up panel, and add all the loads there. That will give you more flexibility--you could have a number of larger circuits where the breakers add up to over 100A, but the load calc for them is under 100A.

Cheers, Wayne

Hi Wayne,

Attached is the label. Please advice.

Thanks,

GHTech

 

[wwhitney]

OK, I had a chance to look at your label, but doubt I'll be able to respond further today after this post. Please confirm I'm reading the following text correctly from the picture:

"Bus Rating: 225 Amps Max."
"Any 80-100 Amp max circuit breaker must be installed i the lowest position in the branch panel. All other positions are limited to 70 Amp max. circuit breakers."

This information changes my advice.

First, your "main disconnect" was installed in the wrong place. It should be directly above the service disconnect, as that is the only space rated for a 100A breaker. You should get your installer out to fix that. Apparently they didn't read the label properly. [And "main disconnect" is a weird term for that feeder.]

Second, you obviously can't add another 100A breaker. But with the 225A bus rating, you can add up to 125A of breakers in addition to your 100A feeder to the Gateway. So when you do your future configuration load calc, hopefully you'll find that the breakers you need to kick out of your 100A backed up panel to keep that portion of the load calc below 100A will total to less than 125A, and you can just put them all in this panel.

Cheers, Wayne

 

[GHTech]

OK, I had a chance to look at your label, but doubt I'll be able to respond further today after this post. Please confirm I'm reading the following text correctly from the picture:

"Bus Rating: 225 Amps Max."
"Any 80-100 Amp max circuit breaker must be installed i the lowest position in the branch panel. All other positions are limited to 70 Amp max. circuit breakers."

This information changes my advice.

First, your "main disconnect" was installed in the wrong place. It should be directly above the service disconnect, as that is the only space rated for a 100A breaker. You should get your installer out to fix that. Apparently they didn't read the label properly. [And "main disconnect" is a weird term for that feeder.]

Second, you obviously can't add another 100A breaker. But with the 225A bus rating, you can add up to 125A of breakers in addition to your 100A feeder to the Gateway. So when you do your future configuration load calc, hopefully you'll find that the breakers you need to kick out of your 100A backed up panel to keep that portion of the load calc below 100A will total to less than 125A, and you can just put them all in this panel.

Cheers, Wayne

Hi Wayne,

Yes, the info you read is correct. I have attached a screen shot of the details. Please respond when you ahve the time. I really appreciate the info. So, should I ask Tesla to come out to move the 100 amp breaker to the correct location?

So, if I want to move out the EV charger to the non-backed up panel, and put all the other items (water heater, dryer, range and furnace) on the backed up panel, I assume that it would not be doable, right? Any suggestions?

Thanks,

GHTech

 

[wwhitney]

So, if I want to move out the EV charger to the non-backed up panel, and put all the other items (water heater, dryer, range and furnace) on the backed up panel, I assume that it would not be doable, right? Any suggestions?

Only a load calculation will tell you that. It depends on the size of the water heater, dryer, range and furnace (heat pump). If the load calc including those (but excluding the EVSE) exceeds 100A, you need to kick one or more of those big appliances over to the non-backed up service panel to get the back up panel load calc down below 100A.

Cheers, Wayne

 

[GHTech]

@GHTech what EV charger are you using? Make/model/version and plug type (ie 14-30/14-50)? There may be a way to integrate the Powerwall with your charger in some way, even if maybe it's a bit hacky, to avoid the problem of your EV charging off of (and draining) your Powerwalls during a grid outage.

Hi gpez,

I have a GE WattStation. I am honestly not too concern about the EV charging, as I have rarely charged at home, in the last 5 years I have had an EV (Ford FOcus Electric and now the Honda Clarity Electric).

Regards,

GHTech

 

[h2ofun]

Only a load calculation will tell you that. It depends on the size of the water heater, dryer, range and furnace (heat pump). If the load calc including those (but excluding the EVSE) exceeds 100A, you need to kick one or more of those big appliances over to the non-backed up service panel to get the back up panel load calc down below 100A.

Cheers, Wayne

Technically is there anything wrong with having more stuff in the backed up panel than things can support? I just assume a person is smart enough to not turn all the stuff on our they just blow a breaker.

 

[GHTech]

Only a load calculation will tell you that. It depends on the size of the water heater, dryer, range and furnace (heat pump). If the load calc including those (but excluding the EVSE) exceeds 100A, you need to kick one or more of those big appliances over to the non-backed up service panel to get the back up panel load calc down below 100A.

Cheers, Wayne

Hi Wayne,

If I have someone do a proper load calculation, and can get some of the of the appliances under the 100A limit, would I still need Tesla to get involved? Or can a qualified electrician run the circuits?

Regards,

GHTech

 

[gpez]

Hi gpez,

I have a GE WattStation. I am honestly not too concern about the EV charging, as I have rarely charged at home, in the last 5 years I have had an EV (Ford FOcus Electric and now the Honda Clarity Electric).

Regards,

GHTech

Maybe I missed something because earlier you mentioned you didn't want the EV charging when the grid was out and draining the battery? I was just suggesting that if preventing your EV from draining your Powerwall while the grid was down there are other ways to do so other than moving your charger over to a non-backed up panel.

 

[SMAlset]

Do you have a nearby SC that you could go to for I assume the few times you described where you want to charge after a long trip? Would seem cheaper than redoing your electrical set up and only take up 40 minutes or so of your time?

 

[GHTech]

Maybe I missed something because earlier you mentioned you didn't want the EV charging when the grid was out and draining the battery? I was just suggesting that if preventing your EV from draining your Powerwall while the grid was down there are other ways to do so other than moving your charger over to a non-backed up panel.

Hi gpez,

Yes, it would be nice to be able to charge at home when I really need it. But, things are starting to sound pretty expensive to move things around. I appreciate all the suggestions.

Thanks,

GHTech