Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Difficult situation with a Condo, advice appreciated...

This site may earn commission on affiliate links.
I am not an electrician, but I vaguely recall that the NEC allows rounding UP to the next larger breaker size(rather inexplicably, I must admit), if the ampacity of the circuit lands between two generally available breaker sizes. Unless there's something about 100 amp breakers having 90C rated lugs, it sounds like the 95 rounding up to 100 wouldn't apply here anyway.
Breakers have a max of 75C, so in theory they could round up to 90.
 
Hmm, good point. You know, when I have the other guy come over, I'll ask him about that and get it dealt with if it's not okay.



Yeah, so you're thinking even my main feeder has already got too high of a service level for my feeder wire? The 400 feet figure was the run distance from the meter to where my car is parked.

I don't know how long this 4 AWG wire is, but my apartment is near my car, so I guess it's also somewhere around 400 ft run inside the walls of my building. I do wonder if I've misidentified where my meter is... it's a possibility since I haven't actually *looked* at my own meter.



All the electricians I'm working with intend to pull a permit for the work, including the company that wants to upgrade my main breaker to 100A. So I assume this guy thinks it'll pass LA city inspection...
OK good, at least there is some amount of oversight to keep things from getting really silly.

I won't say the inspectors know everything, but at least they will have to sign off on the design pushing liability back to the insurance company. Scan those approvals and receipts and put them in your cloud storage vendor of choice. You also might need them when you sell the place to prove it was approved.

So the run from the meter to the panel is 320 feet. This is still long, but would bring the voltage drop under 5% at 61 amps on 4 AWG. The NEC code book changes over time, and when that was wired it might have met the requirements. It wouldn't now at those distances.

Consider this, 61 amps at 320 feet means that 4AWG wire would be creating 704 watts of heat for each hot lead, so a total of 1408 watts of heat in your conduit. That heat has to go somewhere, and a good chunk of it will end up in your breaker box at one end, and the disconnect at the other. This amount of heat is going to shorten the life of the components and cause terminals to loosen. Charging at night when your other loads are lower will help of course. Pulling only 24 amps through that wire would reduce that thermal load from 1248 to 118 watts! So what I am saying is that heat goes up non linearly as the load climbs.
40 amps would be 604 watts.
20 amps would be 150 watts.
60 amps would be 1363 watts of heat
 
Last edited:
  • Like
Reactions: MetricExpanse
OK good, at least there is some amount of oversight to keep things from getting really silly.

I won't say the inspectors know everything, but at least they will have to sign off on the design pushing liability back to the insurance company. Scan those approvals and receipts and put them in your cloud storage vendor of choice. You also might need them when you sell the place to prove it was approved.

So the run from the meter to the panel is 320 feet. This is still long, but would bring the voltage drop under 5% at 61 amps on 4 AWG. The NEC code book changes over time, and when that was wired it might have met the requirements. It wouldn't now at those distances.

Consider this, 61 amps at 320 feet means that 4AWG wire would be creating 704 watts of heat for eat hot lead, so a total of 1408 watts of heat in your conduit. That heat has to go somewhere, and a good chunk of it will end up in your breaker box at one end, and the disconnect at the other. This amount of heat is going to shorten the life of the components and cause terminals to loosen. Charging at night when your other loads are lower will help of course. Pulling only 24 amps through that wire would reduce that thermal load from 1248 to 118 watts! So what I am saying is that heat goes up non linearly as the load climbs.
40 amps would be 604 watts.
20 amps would be 150 watts.
60 amps would be 1363 watts of heat

Good idea to scan that stuff. I see what you're saying about the heat going up as the load increases. P=I^2*R, right? And while I appreciate that the permitting will help with the question of liability... I just don't want to cause a fire lol!

I'd love to get an empirical number on what my voltage drop is. Is there any easy way to do that?

Also, I just did this Google Maps calculation on the distance from my breaker (where I currently believe it to be) to my load center. It's a straight-line distance and it doesn't take into account the fact that I'm on the third floor, but it's kind of interesting. It does seem to be less than the 400 feet I was told be the electrician, somehow...

Screen Shot 2021-04-09 at 14.56.27.png
 
I was in a similar situation: condo building was not wired for high capacity circuits in the garage. I was able to run a new 40amp line from my central circuit breaker for a cost of $1600. The bigger challenge, which no one has mentioned, is that in California there are rules about how an HOA handle EV chargers. The good part: the HOA may not reasonable deny you installing the charger at your expense. The bad part: You must have the circuit permitted through your city planning department. This is where things get interesting.
You building has an over-all power capacity, as installed by the local electric utility. In my building, though each unit has 200 amp capacity at the breaker, the building is not able to meet the power demand, if a large number of vehicles are charging.

Here is what my building is doing:
1. Hire an outside electrical engineering firm to estimate the peak demand on the building. (Cost: $4000)
2. Hire an architect to update the buildings design documents to reflect the existing and new electrical installation.
3. Using these documents, the HOA gets a permit from the city planning department allowing the installation of chargers that don't over draw the utility line capacity.
4. Then, and only then, can you install the L2 EV charger.

Some of my neighbors in the building decided they could live with the L1 charging. The just plug in their cars each time they park them and start charging.

Our HOA is looking at installing a building wide charging network, like ChargePoints, EverCharge, and PowerFlex. Each essential creates a "bus" that all chargers ties into. The charging network then manages the load across the whole building and your individual condo unit's power is unaffected. So far, the cost has been prohibitive: $40,000 for common "bus" network, an average $2000 for each condo parking space to tie into the circuit. You pay the service a monthly fee and you are billed for electricity with an "uplift", about $.10 per kW.

The situation is a huge problem for all California cities because EV charging in multi-tenant buildings are such a barrier to adoption of EV...a strategic goal for the state.

One huge disappointment has been the local utility, SDG&E for me. They are of no help in solving the problem...even though they will sell more electricity if there was a simpler solution.

I hope that helps.
 
$1000 manlift... HA! I'd put the electrons in a bucket and lower them by a rope before I'd spend $1000 on a manlift for 30 feet!

Yeah, these are the guys who I have coming over next week. I figured they were stiffing me on the manlift. But the thing is, they're still overall cheaper ($3000 total) than the other guys (the ones who I had over today who want to upgrade my breaker) who just sent me an estimate for $4000 total! And at least they're not promising to upgrade me to 100A service which, after all the discussion so far, actually gives me more confidence that they'll do work that's actually safe.

I was in a similar situation: condo building was not wired for high capacity circuits in the garage. I was able to run a new 40amp line from my central circuit breaker for a cost of $1600. The bigger challenge, which no one has mentioned, is that in California there are rules about how an HOA handle EV chargers. The good part: the HOA may not reasonable deny you installing the charger at your expense. The bad part: You must have the circuit permitted through your city planning department. This is where things get interesting.
You building has an over-all power capacity, as installed by the local electric utility. In my building, though each unit has 200 amp capacity at the breaker, the building is not able to meet the power demand, if a large number of vehicles are charging.

Here is what my building is doing:
1. Hire an outside electrical engineering firm to estimate the peak demand on the building. (Cost: $4000)
2. Hire an architect to update the buildings design documents to reflect the existing and new electrical installation.
3. Using these documents, the HOA gets a permit from the city planning department allowing the installation of chargers that don't over draw the utility line capacity.
4. Then, and only then, can you install the L2 EV charger.

Some of my neighbors in the building decided they could live with the L1 charging. The just plug in their cars each time they park them and start charging.

Our HOA is looking at installing a building wide charging network, like ChargePoints, EverCharge, and PowerFlex. Each essential creates a "bus" that all chargers ties into. The charging network then manages the load across the whole building and your individual condo unit's power is unaffected. So far, the cost has been prohibitive: $40,000 for common "bus" network, an average $2000 for each condo parking space to tie into the circuit. You pay the service a monthly fee and you are billed for electricity with an "uplift", about $.10 per kW.

The situation is a huge problem for all California cities because EV charging in multi-tenant buildings are such a barrier to adoption of EV...a strategic goal for the state.

One huge disappointment has been the local utility, SDG&E for me. They are of no help in solving the problem...even though they will sell more electricity if there was a simpler solution.

I hope that helps.

Ouch. Yeah, I'm kind of hoping that if I can avoid upgrading my 70A service by just installing a small 20A charging circuit (or maybe 30A with a DCC unit), that it'll get approved more easily without having to take the overall building power usage into account and do all the crazy stuff you're talking about.
 
Hi everyone! I recently took delivery of a Tesla Model 3 Long Range, and I love it!

Unfortunately, it seems that I should have done more homework when it comes to charging. I live in a 1970's condo unit in Los Angeles and I'm trying to get home charging installed. My HOA is receptive to me installing charging, so that's not an issue. My two issues are

1) My electrical meter is over 400 feet away from my parking spot. That means that my cabling might be expensive. However, my actual apartment (which has my electrical panel) is directly above my parking space.

2) My unit's main breaker is only 70A.

I spoke to two electricians so far. The first one came out and was the one who measured the distance. He said he would upgrade my main breaker to 100A and then run the power all the 400 ft to my space for $5700! That was a LOT and I'm also wonder if it's "okay" to just replace the breaker.

I then called another electrician over the phone (haven't had them come out yet) and asked if it was reasonable to just the power from my *panel* in my unit to the car. That would only be 80 ft, but he expressed concern over my 70A breaker. That said, he thinks it might be possible to do a slow 20A breaker. I do have air conditioning in this 650 sq ft unit.

So what's the deal here? Why is it that one guy is willing to upgrade the breaker but then wants to run the 400 ft wiring run, while the other guy is willing to run from the panel but is concerned about the amount of power I have available? What does you all think the best way to go is? Try to get power from my panel? Swallow the cost of a 400 ft run? Is it even safe to upgrade my breaker or to tap off my panel??

For reference, here's my breaker panel:

View attachment 651591
I charge a model S at 40A. More than enough to fill a vehicle overnight. I just used the electric dryer recepticle.
 
The paper on the photo says that the Main is rated at 125A, which then goes to “branch breakers” with 70A and 55A ratings. Are you sure that your “main” is only rated at 70A?

We did something similar for our condo, settled for 30A/220V in our case.
 
Hi everyone! I recently took delivery of a Tesla Model 3 Long Range, and I love it!

Unfortunately, it seems that I should have done more homework when it comes to charging. I live in a 1970's condo unit in Los Angeles and I'm trying to get home charging installed. My HOA is receptive to me installing charging, so that's not an issue. My two issues are

1) My electrical meter is over 400 feet away from my parking spot. That means that my cabling might be expensive. However, my actual apartment (which has my electrical panel) is directly above my parking space.

2) My unit's main breaker is only 70A.

I spoke to two electricians so far. The first one came out and was the one who measured the distance. He said he would upgrade my main breaker to 100A and then run the power all the 400 ft to my space for $5700! That was a LOT and I'm also wonder if it's "okay" to just replace the breaker.

I then called another electrician over the phone (haven't had them come out yet) and asked if it was reasonable to just the power from my *panel* in my unit to the car. That would only be 80 ft, but he expressed concern over my 70A breaker. That said, he thinks it might be possible to do a slow 20A breaker. I do have air conditioning in this 650 sq ft unit.

So what's the deal here? Why is it that one guy is willing to upgrade the breaker but then wants to run the 400 ft wiring run, while the other guy is willing to run from the panel but is concerned about the amount of power I have available? What does you all think the best way to go is? Try to get power from my panel? Swallow the cost of a 400 ft run? Is it even safe to upgrade my breaker or to tap off my panel??

For reference, here's my breaker panel:

View attachment 651591
It sounds as if it would not hurt to upgrade your panel anyway; it sounds way under and might pay for itself should you decide to sell. Which segues to my suggestion....Move! The only reason the streets are flooded E.V.s is because of apartment dwellers with your same problem. I think a lot of them find a supercharger somewhere close to a coffee shop, etc. and make a weekly sojourn to top off.
 
So an interesting development... I went to actually go look for my meter to make sure it is where I think it is. Even though I don't have access to the meters directly, it had just a metal gate surrounding it. So I got the idea to stick my hand in with my phone and grab pictures of all the meters that were there. So I did. And I didn't actually find my meter there (i.e. I didn't find a meter with the same meter number as what's on my power bill).

Unless the meter number on my bill is somehow different from what's actually written on it, I'm getting doubtful that my meter is actually in that distant location! Even more interesting, I noticed that underneath my apartment balcony, about 50ft from where my Tesla is parked, there's a small room that I can't get into. And it has these grey things next to it. Is it possible that this is another meeter room??

Here's a picture. I'm wondering if this is another electrical room with more meters. If that's really it, then the run for my Tesla would only be like 50ft from the meter, and I wouldn't even need a manlift...

Screen Shot 2021-04-09 at 16.16.51.png
 
So an interesting development... I went to actually go look for my meter to make sure it is where I think it is. Even though I don't have access to the meters directly, it had just a metal gate surrounding it. So I got the idea to stick my hand in with my phone and grab pictures of all the meters that were there. So I did. And I didn't actually find my meter there (i.e. I didn't find a meter with the same meter number as what's on my power bill).

Unless the meter number on my bill is somehow different from what's actually written on it, I'm getting doubtful that my meter is actually in that distant location! Even more interesting, I noticed that underneath my apartment balcony, about 50ft from where my Tesla is parked, there's a small room that I can't get into. And it has these grey things next to it. Is it possible that this is another meeter room??

Here's a picture. I'm wondering if this is another electrical room with more meters. If that's really it, then the run for my Tesla would only be like 50ft from the meter, and I wouldn't even need a manlift...

View attachment 652510
Sounds like you need to find your meter before getting more quotes! Can you get maintenance to give you that information?
 
Sounds like you need to find your meter before getting more quotes! Can you get maintenance to give you that information?

Yeah, it's been hard. I've called the HOA several times. And the far away location is the one the janitor opened for me, but maybe I need to ask them to specifically open this room for me. I feel like nobody I've talked to really knows where it is... looks like I have more phone calls to make on Monday when the HOA office opens up. I even called the power company to see if they have notes on where my meter is... and they didn't.
 
How many miles new charges do you need on your work day? I can't comment on the electrical requirements but after spending $650 for Tesla's big charging unit and then $2 grand for all the wiring in my Vallejo home I rethought what I needed for my Wisconsin lake home's new garage last summer. We are retired so we don't need a lot of miles/charging hour but we were not happy with the 2-4 miles per hour with the 110 charge we received from a standard outlet. So we spent about $35 on a plug that gave us about 20 miles/charging hr (maybe more I just don't remember) so that when charging from just after midnight to say 6:05 am we received at least 120 miles assuming we had a work commute. The new line ran out from our home just like your condo. It works great for us and because you likely would start charging at 12:05 am you home would not be drawing much power. There was a cost for upgrading the power box but that was minimal compared to the cost you mentioned even if adjusted to the high cost of CA electricians (who also have to pay California's ridicules housing costs). Anyway I suggest you work backward from the number of miles you need each commuting day. Also to be considered is the cost and how long you plan to stay it that small condo unit.
 
There are 90 amp breakers available.
However, this is what I'd do (yeah, it might be naive, but it's my 2 cents):
Install a 20 amp double pole (240V) breaker in your panel, have it feed a NEMA 14-50 outlet (so no 'pigtail' adaptor needed).
Program your car to only pull 16 amps whenever it is geolocated in your parking spot. 16 amps at 240 volts isn't bad. (If you are charging for less than 3 hours, you can pull the full 20 amps (code says to de-rate a service 20% for continuous draws of > 3 hours)).
Charge the first time at the full 20 amps for 15 minutes (make sure there are minimal other loads at the time), then put your palm on the 20 amp breaker. Is it warm? that's OK and expected. Is it hot? That's bad.
Then go put your palm on the 70 amp breaker. Is it warm? That's bad. If you were drawing 50 amps and it was warm, that'd be expected. Is it hot at 20 amps? Say "Oh S***" and get everything upgraded/replaced. If you did this test and the 70 amp breaker got hot even in the absence of charging, things need to be upgraded/replaced.
 
  • Disagree
Reactions: Dmagyar and Rocky_H
Install a 20 amp double pole (240V) breaker in your panel, have it feed a NEMA 14-50 outlet
No electrician would allow that to be installed. a 40 amp breaker on a 50 amp outlet is allowed, but only because there are no 40 amp standard outlets. Once you step below 40 amps, there's a decent number of outlets to choose from.

OP, if you go down this path(and there's nothing at all wrong with only having a 20 amp 240 volt charger!), just get the right outlet and a $35 adapter from Tesla to feed it. If nothing else it'll keep some rando from plugging their (EV or arc welder or kiln) into your 50 amp-looking plug and instantly tripping your breaker.
 
I charge a model S at 40A. More than enough to fill a vehicle overnight. I just used the electric dryer recepticle.
Do you have an electric dryer? If so you might be able to share the breaker & outlet and have an automatic unit like a "dryer buddy" that only allows one item at a time to run off the breaker/outlet. Then you're not increasing draw from the breaker box at all and don't even have to ask the utility for permission to increase you box's capacity. Perhaps ask the electrician to wire in something similar to lock out one when the other is in use. Something might already exist for the commercial market. Then you just have to get the wire from your breaker box to the parking space. No need to run it from the meter. 20 amps 220v is plenty. Electrician can tell you if you'll exceed the box's capacity if you added one more dedicate 16amp 220V breaker. If you don't you can also get away from having to involve the utility and installing a higher capacity line to your meter and from there to your panel. You'll add about 16 miles per hour. Every 10 hour overnight charge and you pick up 160 miles. So if you run between 90% top end charging and 20% bottom you're really using and replenishing 70% of the range each time, around 175 miles per day, out of a theoretical 250 miles 100% charge. Your daily commute will be the most important factor.
 
Do you have an electric dryer? If so you might be able to share the breaker & outlet and have an automatic unit like a "dryer buddy" that only allows one item at a time to run off the breaker/outlet. Then you're not increasing draw from the breaker box at all and don't even have to ask the utility for permission to increase you box's capacity. Perhaps ask the electrician to wire in something similar to lock out one when the other is in use. Something might already exist for the commercial market. Then you just have to get the wire from your breaker box to the parking space. No need to run it from the meter. 20 amps 220v is plenty. Electrician can tell you if you'll exceed the box's capacity if you added one more dedicate 16amp 220V breaker. If you don't you can also get away from having to involve the utility and installing a higher capacity line to your meter and from there to your panel. You'll add about 16 miles per hour. Every 10 hour overnight charge and you pick up 160 miles. So if you run between 90% top end charging and 20% bottom you're really using and replenishing 70% of the range each time, around 175 miles per day, out of a theoretical 250 miles 100% charge. Your daily commute will be the most important factor.
I do not have an electric dryer. But my place was wired for one.
 
PS think efficiency. Is it possible to replace your A/C unit, dishwasher and clothes washer/dryers with something that's new and uses much less electricity? You might be able to cut your electric usage in half, have nice new working appliance and free up capacity so you can do a dedicated 20amp 220V line to charge in your parking space. The cost of the new appliances would still equal your expensive option. Then running a 20amp line from the breaker box to your parking space wouldn't cause any load problems. We live in a 100year old house and have 2 electric vehicles, 2013 Smart ED and 2018 Model 3. the two cars share an Eaton EVSE on a 40 amp breaker but the Smart's charger (in the car) can only charge at 3.3kw so anything over 20 amps it can't use. In the winter I'll keep them plugged in charging as slow as possible as the cars are outdoors. Over the last 7 years we've replaced 4 window A/C units, one of the roll around vented a/c units and the dishwasher. Our usage remained steady. Essentially driving on "free fuel" since we don't pay Public Service more than we used to.