Do I need 400 amp service?

[voip-ninja]

@voip-ninja I'm far more oversubscribed than you, but had no concerns from the electricians or the building inspector. I just added a 50a breaker & HPWC. Was going to add 100a, but I was able to get unlimited off-hours charging for $30/mo if I keep it under 40a. They didn't think there was a problem with 100A either...

I have 200a main panel. 4600 sq ft house. 3 HVAC (propane heat), propane hot water, 2 electric ovens, microwave, fridge, electric dryer.

Most of the lighting has been converted to LED.

Thanks, that makes me feel a bit better. I have similarly converted all of my lighting over to LED bulbs about 5 or so years ago. Believe it or not I had over 30 can lights to do. Yikes.

I think I should be okay, but will crunch some more numbers just to be sure. If we eventually do the basement finish/remodel my wife is dreaming of then it could again become a problem, depending on what all went down there.

 

[voip-ninja]

And most garages have gas cars in them but that doesn't mean they are better. More and more gourmet home kitchens are installed with induction these days. The chef in my household went to culinary school (and got a degree) and prefers induction. Just like electric cars, we won't ever consider switching back to gas.

That's nice.

No sale though.

 

[brkaus]

Thanks, that makes me feel a bit better. I have similarly converted all of my lighting over to LED bulbs about 5 or so years ago. Believe it or not I had over 30 can lights to do. Yikes.

I think I should be okay, but will crunch some more numbers just to be sure. If we eventually do the basement finish/remodel my wife is dreaming of then it could again become a problem, depending on what all went down there.

I probably have 30 as well. I thought I was the only one.

I had 17 can light in my kitchen. Really helped the utility bill. Work from home and kitchen was on 12 hours a day (minimal natural light).

I think the risk is that it may be up to the descretion of the inspector. I don’t think anyone did load calcs for mine.

 

[voip-ninja]

I probably have 30 as well. I thought I was the only one.

I had 17 can light in my kitchen. Really helped the utility bill. Work from home and kitchen was on 12 hours a day (minimal natural light).

I think the risk is that it may be up to the descretion of the inspector. I don’t think anyone did load calcs for mine.

Worst thing that can happen is they fail me and make me do the load calcs.

Since I'm an engineer I will probably just break down and force my lazy ass to do them.

 

[Doug_G]

When I got my Roadster I wanted the 70A HPC. Expected to need to upgrade 100A panel to 200A. Got quotes.

First one quoted $14,000. Yeah, no.

Second one quoted $2000, and not upgrading the panel. Yeah, no.

Got two more, one for $5k and one for around $3k. Took the $3k and they did a great job.

Moral of the story: get more than one quote.

 

[mongo]

Worst thing that can happen is they fail me and make me do the load calcs.

Since I'm an engineer I will probably just break down and force my lazy ass to do them.

And that's why I have a 400 Amp meter and two mobile home feed through panels.

That... and I hit the service line with a back hoe... It was mis marked.

 

[Rocky_H]

I'm planning on doing my own installation of a 60 amp breaker that will run 6/3 Romex about 35 feet to a Tesla wall connector in an attached garage to power a Model 3 I am getting later this year.

I don't see anyone else mentioning this yet, but this wire type doesn't seem right. Romex naming convention has the second number listing how many large current carrying wires are in it, plus there is an additional bare wire for the ground. So 6/3 would be 4 total wires for Hot1, Hot2, Neutral, and Ground. You need that for an outlet like a 14-50, that needs to have the Neutral for the 120/240V dual function. But since you said wall connector, that only uses 240V. It doesn't use the Neutral at all, so that wire is unnecessary and would just be capped off with a wire nut. So the proper wire would be 6/2 Romex, to leave out the unused Neutral. That's cheaper too.

 

[mongo]

I don't see anyone else mentioning this yet, but this wire type doesn't seem right. Romex naming convention has the second number listing how many large current carrying wires are in it, plus there is an additional bare wire for the ground. So 6/3 would be 4 total wires for Hot1, Hot2, Neutral, and Ground. You need that for an outlet like a 14-50, that needs to have the Neutral for the 120/240V dual function. But since you said wall connector, that only uses 240V. It doesn't use the Neutral at all, so that wire is unnecessary and would just be capped off with a wire nut. So the proper wire would be 6/2 Romex, to leave out the unused Neutral. That's cheaper too.

EDIT: The remarking rule is for individual wires in a raceway. NM-B white can be remarked at both ends and used at an ungrounded conductor.

Except that would then have white as a phase conductor. Remapping colors is only allowed on gauges about 6 (all black with colored tape to indicate usage) (other exception if using the neural as a traveler for a switched circuit).
If they ran THWN in conduit, 3 wires (black, black (or red), green) would be up to code.
So yes, 6/2 would work, but likely not pass inspection. For the extra 0.83 a foot * 35 feet $29, worth it to do it right.

 

[Rocky_H]

Except that would then have white as a phase conductor. Remapping colors is only allowed on gauges about 6 (all black with colored tape to indicate usage) (other exception if using the neural as a traveler for a switched circuit).
If they ran THWN in conduit, 3 wires (black, black (or red), green) would be up to code.
So yes, 6/2 would work, but likely not pass inspection. For the extra 0.83 a foot * 35 feet $29, worth it to do it right.

Code doesn't require including an empty disconnected wire, as you are suggesting. You have the right number of wires, but I think you are correct that there is the requirement of tagging it with tape if the color does not match the standard. That is code compliant and will pass inspection.

 

[mongo]

Code doesn't require including an empty disconnected wire, as you are suggesting. You have the right number of wires, but I think you are correct that there is the requirement of tagging it with tape if the color does not match the standard. That is code compliant and will pass inspection.

@voip-ninja
My mistake, the remarking rule is only for individual wires in a raceway. So remarking the white on NM-B (Romex) on both ends is legal.
Good call!
Corrected previous post.

 

[Rocky_H]

I got my reply out there before I found the reference for it. Man, that took a while to find. Yes, ideally, you would have cable with black, red, and a bare ground. But it is allowed for 240V-only appliances to use cable with black, white, and ground if you remark the white wire. Normally, the white wire can't be remarked because it must be used for Neutral anywhere there actually is a Neutral. Here is a page about it, though.
Understanding 120/240V Wiring Color Code | DoItYourself.com

Quote: "There is one case in which a white may be used to carry ungrounded potential that is still in conformity with the most recent cycle of the NEC. That is when a cable is used to feed a straight 240V load. If an appliance does not need or use 120V power, but only needs and uses 240V power, a standard 2-conductor cable, which has a black, white and bare set of wires, may be used to connect that appliance. In that case, the black wire is connected to one pole of the two-pole 240V breaker in the panel. The white wire is redesignated as an ungrounded conductor by using black or red (or any color except gray or green) electrical tape or permanent marker, and connected to the other pole of the breaker, and the bare ground wire is connected to the ground bus. At the appliance end, the white wire is marked again and the two insulated wires are connected to the two input terminals for ungrounded power on the appliance, or on its disconnect switch, and the ground wire is connected to the frame of the appliance, or the box that the disconnect is in."

 

[voip-ninja]

I don't see anyone else mentioning this yet, but this wire type doesn't seem right. Romex naming convention has the second number listing how many large current carrying wires are in it, plus there is an additional bare wire for the ground. So 6/3 would be 4 total wires for Hot1, Hot2, Neutral, and Ground. You need that for an outlet like a 14-50, that needs to have the Neutral for the 120/240V dual function. But since you said wall connector, that only uses 240V. It doesn't use the Neutral at all, so that wire is unnecessary and would just be capped off with a wire nut. So the proper wire would be 6/2 Romex, to leave out the unused Neutral. That's cheaper too.

Thanks for pointing this out, I did not realize the wall connector didn't use the neutral lead.

I will still run it and cap it so that if I end up switching it out later I'm not pulling wire again.

Now to figure out how hard a new conduit from my existing fuse box is going to be to put in for the home entry piece.

 

[voip-ninja]

@mongo @Rocky_H

So here's a thought.

Would I be better off just running the 60 amp circuit with 6/3 to a sub-panel in the garage? I could then throw a breaker in for the tesla wall connector just for that. This would also allow me to run bare wire to the wall connector through conduit rather than using Romex (would still use Romex for the main sub-panel run) and give me some more flexibility on where I put the wall connector.

I could then also put separate breakers in down the line if I wanted to run other outlets from the sub-panel... and if I ever no longer had a Tesla wall connector I could just pull the conduit junction out, pull out the breaker and cap it, and still have 220V in my garage ready to go.

 

[mongo]

@mongo @Rocky_H

So here's a thought.

Would I be better off just running the 60 amp circuit with 6/3 to a sub-panel in the garage? I could then throw a breaker in for the tesla wall connector just for that. This would also allow me to run bare wire to the wall connector through conduit rather than using Romex (would still use Romex for the main sub-panel run) and give me some more flexibility on where I put the wall connector.

I could then also put separate breakers in down the line if I wanted to run other outlets from the sub-panel... and if I ever no longer had a Tesla wall connector I could just pull the conduit junction out, pull out the breaker and cap it, and still have 220V in my garage ready to go.

A panel works, need the full 4 wire feed (check ground size) and isolated neutral bar in box. With the HPWC, you can crank down its draw and add other garage outlets. It is also nice to have a shut off for the HPWC right there.
For non-breaker box option, you can run the NM-B in conduit in the garage. An LB box would provide the right angle turn and protect the wire coming though the wall.

 

[voip-ninja]

A panel works, need the full 4 wire feed (check ground size) and isolated neutral bar in box. With the HPWC, you can crank down its draw and add other garage outlets. It is also nice to have a shut off for the HPWC right there.
For non-breaker box option, you can run the NM-B in conduit in the garage. An LB box would provide the right angle turn and protect the wire coming though the wall.

For non-breaker box installation I was planning on going directly out of the back of the wall charger, through my interior wall into my basement, then running it along the floor joists of the main floor back to the main breaker panel... that's how they did all of the other 220V circuits in the house.

 

[mongo]

For non-breaker box installation I was planning on going directly out of the back of the wall charger, through my interior wall into my basement, then running it along the floor joists of the main floor back to the main breaker panel... that's how they did all of the other 220V circuits in the house.

Sounds good. You had mentioned placement flexibility, so I wasn't sure on the set up.

 

[voip-ninja]

Okay, so I pulled the cover on my main panel (and I really really don't like this design) and it's now dawning on me that fishing another 6/3 through this tightly packed conduit is really going to suck. I know I can probably get it through with my fish tape and copious amounts of non-conductive lubricating gel but it's the "probably" part that has me nervous. If I put too much tension on the cables and pull things off the main entrance panel it's going to suck rewiring it all.

I get that for a pro this is a yawn but for a moderately skilled homeowner who has done some of his own electrical in the past still makes me nervous.

Now, option B is that I could replace the completely full sub-panel in my basement that has my PV tied into it with a higher capacity panel (unless someone makes slim GFI breakers and I could free up space that way)... it is currently on a 50 amp breaker from the main but is being serviced by 6/4 alumiflex cable which I believe is rated up to 55 amps. I couldn't run the wall charger at 48 amps but 30 amps should be no big whoop since during daylight hours it's being fed by my solar PV and at night all that's on it is some electronics and LED lighting.

The benefit of this option is that it's literally only about 15 feet from this sub-panel to the place in the garage I would put the charger.

Or, I could cut the Alumiflex (obviously after disconnecting the PV and the main breaker) and use the tail of it to back haul new 2 gauge wire that would handle up to 100 amps on the sub panel. Of course if it then turned out that they nailed something behind the wall where I can't see it I am screwed.

Thoughts? Also, I see that I've got 2 200amp disconnects from the utility, so I have 400 amp service already?

I even provided pictures this time.

the first two pictures are of the main entrance service. It's weird to me that there are two two pole 200 amp breakers but it looks like only the lugs on the 2nd breaker are populated? Weird. The 3rd picture is of the packed sub-panel in my basement.

 

[mongo]

Also, I see that I've got 2 200amp disconnects from the utility, so I have 400 amp service already?

What is model number on meter? And what does the label on the inside panel cover say?
It looks like the breakers are paired to the internal bus bars. Bottom pair left bus, top pair right bus.

Edit: from research, it looks like a 200A panel.


That is a filled pass through! If the GFCI feed outlets, you may be able to replace the first one with a combo receptacle/ GFCI. Or attach a box to the panel with GFCI only unit (no receptacle) and route through that. A double will free up your breaker position.
6 awg copper is rated for 55 Amp @ 60C. 6 aluminum is only 40A @60C , 50A @75C.

Wire to sub is likely fastened somewhere. Even if not, the holes it runs through should be too small and fire caulked.

Can you run a new conduit down from main panel and then through brick into basement. Or what is on the other side of the wall?

Edit: or is that Novik?

 

[voip-ninja]

What is model number on meter? And what does the label on the inside panel cover say?
It looks like the breakers are paired to the internal bus bars. Bottom pair left bus, top pair right bus.

Edit: from research, it looks like a 200A panel.


That is a filled pass through! If the GFCI feed outlets, you may be able to replace the first one with a combo receptacle/ GFCI. Or attach a box to the panel with GFCI only unit (no receptacle) and route through that. A double will free up your breaker position.
6 awg copper is rated for 55 Amp @ 60C. 6 aluminum is only 40A @60C , 50A @75C.

Wire to sub is likely fastened somewhere. Even if not, the holes it runs through should be too small and fire caulked.

Can you run a new conduit down from main panel and then through brick into basement. Or what is on the other side of the wall?

Edit: or is that Novik?

The meter was swapped out 5 years ago when I got solar, I can take a photo of the front of it tomorrow, but I don't see any markings that are obvious match-ups for the model #.

The current entrance from the panel comes in about 12 or so inches above the foundation apron into the basement. Theoretically I could cut a new hole through the stone facade (AFAIK it's natural stone) glue in a conduit for entry, then run ROMEX through it and along to the destination... I recall something about it not being to code to run Romex through an exterior conduit though and I don't want to run separate conductors. Will have to re-check the code. I definitely am nervous due to my lack of visibility into the interior side entrance of drilling anything since I don't want to damage any of the existing wire.

The sub panel feeder wire is Aluminum 6/4 that has a jacket rating of 90C. From this chart it looks like it is actually good to 55 amps.

http://www.southwire.com/ProductCatalog/XTEInterfaceServlet?contentKey=prodcatsheet3

If it truly was good to 55 amps I would just swap out the breaker at the head end if that's to code with a 60 and probably collapse my sub-panel with a couple of single slot GFCI 15 amp breakers since they do seem to exist.

That would free up a slot to then run the Tesla wall connector.

Based on how much of a PITA this is turning out to be I just might have to settle for lower speed 30 amp charging.

Or hiring a professional. I can just see the $$$ for this job.

 

[rocksphoto]

I have 200 AMP main service. Central A/C, electric -Oven and dryer. Electrician ran a 100 AMP circuit to the garage (2-2-2-4 SER cable). to a sub-panel. In the sub-panel there is a 60 AMP breaker that feeds the HPWC. 100% inspected. No problems, no issues.