Home Charging in an Old Home

[saltsman]

We're all good. As I said, I know nothing about LA rates, but I did some basic estimation on parts and labor just for fun. The journeyman example was only to show the profit is already baked into the hourly charge.

I'm absolutely not doubting that cost in LA is more expensive. I just can't see how anyone arrives at $4000 from what I search (assuming a simple box swap as was shown in the picture and the additional 50 Amp circuit). What I pull up online says average cost for an electrician in LA is $100/hr. For example, this outfit is $99/hr and cost plus 20%. That's straightforward and fair. It makes it easy a direct apples-to-apple comparison. Are they any good, who knows...

What is surprising is how opaque many of the bids we see posted on this site are (like this one). In our part of the country, that would never fly - at least not with a knowledgable homeowner/landlord. A legitimate bid would include a detailed scope of work that lists parts, labor, and permitting. Typically there would be some wording that once started, something unexpected might come up that would require additional labor.

Your point regarding communication with the landlord is spot-on.

 

[MentalNomad]

Please let me know whether installing a 220V is possible in this scenario as I attached a picture of the panel.

Saltsman gave you great info on your panel and the fact that it ought to be replaced, regardless whether you get an EV, in this post:

That looks like an old GTE-Sylvania-Zinsco panel - most commonly called a Zinsco Panel.

As arnolddeleon notes, 240V will help even at low amperage:

Even just adding a 20A 240V would dramatically improve charging speed.

What I don't see anyone telling you is that yes, 240V is possible. It is.

You see those two main breakers that say 100Amps on them? One of them is -120V, the other is +120V. A single circuit made using both sides would be 240V (The distance between -120V and +120V.) How much power you pull through the line is dictated by both the voltage and the amperage... 20A 240V can handle twice as much as 20A 110V. (Also, 240V systems are slightly more efficient, on top of this.)

 

[MentalNomad]

This may be an option:

Let the landlord know that you looked into the panel because you're considering an EV and have learned it's a fire hazard and ought to be replaced. Tell them that if he's replacing it, you'd pay the extra amount necessary to run a 240V line to the parking, which would obviously stay behind when you leave and be a selling point for the next tenant.

If he doesn't, you can come back with an offer to pay some portion of the panel replacement, as well - it's something he will have to do, eventually, and he won't always have someone willing to share the cost.

Also, look into whether there are any gov't or utility incentives to upgrade the panel, especially if it's being done in order to accommodate an EV charging station - there may be a limited time for him to save on a necessary upgrade.

 

[EVNation]

Thank you for the reply!

I was thinking about that too but I do commute about 50 miles a day from Pasadena to Manhattan Beach for work. Do you think 120V is doable?

At first I was thinking of relying on superchargers as there is one near me but I heard it's not too good for the car to be constantly being put on a supercharger.

I’m in almost the exact same boat as you - rental house with Zinsco panel. I commuted to Manhattan Beach from Altadena off and on for almost 6 years in a Volt charging on 120V without triggering the Volt’s ICE. Now that I have my 3, I don’t even bother charging at home at all. It’s doable but you’ll have to really want it to work. It should be a little easier for you coming from Pasadena because you won’t have to climb the hill to the tippy top of Altadena. Going to Manhattan Beach is all downhill, so that’s in your favor. It’s going home that you’re going to use Wh/mi. I try to charge at work whenever I can, but I also use a lot of public chargers I found on the PlugShare app. Pasadena has a number of free ones, in addition to the new Superchargers. Try to be full (at least 80-90%) on Monday morning as your overnight charging may not recover every Wh you used on your commute, but by Friday you should still have enough range left to hit a public charger over the weekend and get caught up again. I’ve had my 3 for over 2 years now and while I would love 240V charging at home, I can live with only 120V. I rarely Supercharge, except on road trips.

 

[ACofNY]

Wrote everything I wanted to say originally and then some.

Panel upgrade in CA get pretty expensive pretty quickly. They seem start at around $3000 these days. I'm in the process of upgrading the panel on my rental property in Sunnyvale, CA and it almost $4000. If I owned this property that Zinsco panel would be gone already.

BTW I see some damage on the bus bar where it is open, there might be a reason that space is open.

Even just adding a 20A 240V would dramatically improve charging speed.

@saltsman I couldn't decode FPE

If the circuit panel is near to the outlet for the car, I would definitely add a 20amp outlet and circuit. Unless there is a chance of having a dedicated 20 amp outlet already. Going with 20 amp will provide 30% faster charge from about 4 or 5 mi/hr to 6 or 7 mi/hour charge rate. With your daily range of 50 miles, and get a habit of plugging in all the time, it is very doable and economical. Also, you are in CA, there should be some charging stations nearby for the very occasional long trip. Even if you come back from a long trip and plug in overnight, you will have enough charge for the next day’s commute.
110v is more a problem in areas with very cold weather, it takes significant time for my M3 to warm up the battery before it starts charging.

I am changing my 15 outlet to 20 amps outlet, I do have a dedicated 20 amp line to these outlets for garage tools with 4 outlets. I will change it to 3 outlets and not charge the car when using tools. I have burnt the cheap 15 amp outlet from using a KillAWatt meter to see my energy usage.

I would not upgrade a rental unit’s power unless the owner pays for most of it.

 

[Phlier]

For example. I would imagine that the average californian is paying electrical service rates on a Time of Use plan, with an EV, of off - peak around 12-14 cents a kWh, to on peak (4pm to 9pm) somewhere between 40 and 55 cents a kWh. Its my understanding that in texas, "expensive" electricity is 15 cents a kWh, but I dont live there, so could be wrong on that.

Just.... wow. I honestly can't even fathom paying such high electrical rates. Here in the red rock desert, we pay 6 cents kW/h 24/7/365. I really want to put in a solar system, but with rates this low, I just can't get The Boss to approve. Our electrical rates are so low that it's actually cheaper to run electric appliances anywhere you'd typically put a natural gas one, but that's also because our NG rates are a bit high.

When we bought our Model 3, I had an electrician put in a 240v 100A circuit breaker, run metal conduit to the garage, run three conductors (can't remember the wire size off the top of my old head right now, but I had him go one size larger than the requirement, just cause I'm funny like that) 60 feet, install a junction box (for possible circuit expansion), then he did the actual installation of the Gen2 Tesla Wall Connector. All in, it was 800 bucks.

OP, you've been given a ton of great advice in this thread... let us know how it turns out?

 

[randynotcandy]

Wow! You guys sure know a whole lot!

Thank you so much for all the help and suggestions. I seriously got more than enough answers!

I think for now I'm going to just use regular 120V and see how it goes. I'm working from home for the time being but I'm hoping the office won't require me to go in for the whole week when the pandemic is over.

Thank you again for all the help guys! I hope all of you are staying safe!

 

[EVNation]

Working from home should give you a low stress opportunity to see how much energy it really takes to go from A to B, and how speed, weather, hills, traffic, etc impacts that. One suggestion to save your sanity: display your battery in percentage not miles. One can really obsess over how many miles one has left, how many one gained in a charging session, how many it displayed this time vs the other times one charged to the same state of charge, and so on... Once you get the hang of it, percentage is so much more relaxing

 

[adomanim]

But then again, most homeowners would rather not have their property burn down due to an electrical fire either. It all depends. If the landlord flat out refuses, I think I'd try to find one that was more accepting of the responsibility to maintain the property and my safety.

I still don't see the $4K cost. Just for fun, I ran the numbers on Square-D Homeline, shipped from Home Depot.
1 $104.93 40 circuit panel (20 spaces) 200 Amp Service HOM2040M200PC
10 $4.10 20 Amp breakers HOM120CP
2 $9.62 50 Amp 2-pole HOM250CP (includes a new 50 amp for the Tesla)
1 $9.62 20 Amp 2-pole HOM220CP
$174.79 Total

My guess is LA Country code would not require CAFCI on house this old. If you want to move to a full-on 2020 code compliant box with whole home surge supressor:
1 $104.93 40 circuit panel (20 spaces) 200 Amp Service HOM2040M200PC
10 $41.65 20 Amp CAFCI breakers HOM120PCAFIC
2 $9.62 50 Amp 2-pole HOM250CP (includes a new 50 amp for the Tesla)
1 $9.62 20 Amp 2-pole HOM220CP
1 $76.33 Square D Homeline 50 kA P Whole House Surge Protective Device HOM250PSPD
$626.62 Total

Labor would be three hours max. Looks like $100 per hour is the going rate in LA.
Add $100 for a Hubbell 9450a NEMA 14-50 receptacle and box installed at the panel.
I'm guessing $150 for permitting and inspection.

Even with the more expensive CAFCI breakers, with labor, permitting and 14-50 receptacle, you are scrabble word finder still under $1,500 and NFPA 70 compliant for NEW constriction. This isn't a difficult job.

Hello saltsman.
Does the prices change from country to country ?
thank you

 

[jjrandorin]

Wow! You guys sure know a whole lot!

Thank you so much for all the help and suggestions. I seriously got more than enough answers!

I think for now I'm going to just use regular 120V and see how it goes. I'm working from home for the time being but I'm hoping the office won't require me to go in for the whole week when the pandemic is over.

Thank you again for all the help guys! I hope all of you are staying safe!

Thats a good choice, but you still want to know what else is on that circuit. Please dont ignore that part just because you are going to "plug it in to a standard outlet". Check the first post I made in this thread for reasons why, and purchase a cheap circuit tester ( less than $9) and perform the test I mentioned, so you can find out what else is on that circuit you are planning on plugging into.

You NEED to know this, ESPECIALLY if the panel is one that is a potential fire hazard. Dont ignore that part, or think I am fear mongering. People normalize electricity because " I just plug it in and it works" but there is danger there, which is why there are so many codes / rules etc... to protect people from burning their homes down.

Since you will be maxing out that circuit every time you plug in, for hours and hours and hours at a time, you NEED to know what else is on it, so you can, at a minimum, know not to use whatever else is on that circuit.

Charging at 120 is fine, and might work for what you want, its a good idea to try it, just dont take it for granted, especially with that old panel.

 

[LACALawyer]

Thank you for the reply!

I was thinking about that too but I do commute about 50 miles a day from Pasadena to Manhattan Beach for work. Do you think 120V is doable?

At first I was thinking of relying on superchargers as there is one near me but I heard it's not too good for the car to be constantly being put on a supercharger.

Pasadena to MB? Change jobs!!! Autopilot or not, that commute would make me go mental.

 

[SomeJoe7777]

Planet earth. With the right insulation (THHN) in the right pathway (a conduit of sufficient size): Ampacity Charts - Cerrowire

Just a bit of clarification on this: #10 wire for 40 Amps is doable with a lot of caveats:

1. The wire must be THHN insulation (or equivalent) in conduit.
2. NEC table 310.16 allows up to 3 current-carrying conductors up to 40 amps in appropriate-sized EMT conduit (which is up to 5 #10 wires in 1/2" EMT), but the ambient temperature where the conduit runs must be 30C or less. This probably precludes running the conduit in an attic or outside. If it's run in those locations, you'll have to derate the conductors and therefore will be below 40 amps.
3. Since there is no 40 amp NEMA outlet, a 50 amp outlet is allowed on a 40 amp circuit, but only for a "permanently installed appliance". This would mean that if you put in a NEMA 14-50R, the mobile charger would need to be "permanently installed" and plugged into the outlet, like a range would be. If the outlet doesn't have a device plugged into it all the time, that's not "permanently installed". Hard-wiring the circuit to a HPWC without an outlet is the better solution.
4. Regardless of the outlet installed, the breaker must be 40A to protect the #10 wires.
5. Allowing the temperature rise of the #10 THHN wires to 90C is what gives them the 40A rating. To do this per code, all outlet terminals and the breaker must also be rated for 90C. Not all outlets and breakers have this rating.
6. The 80% rule applies for continuous current draw. On a 40A circuit, the maximum current that can be drawn by the car is 32A. The Model 3/Model Y mobile connector maxes out at 32A, so this isn't a problem, but if a HPWC is installed, it must be configured internally to 40A circuit / 32A draw. If a Gen 1 (Model S/Model X) mobile connector is used, then you must turn down the amperage in the car to 32A because the Gen 1 mobile connector would allow up to 40A.

It's generally easier to use #8 conductors and therefore you don't have to worry about many of these. You can use
NM cable and not have to run conduit, and you don't have to worry about breaker and outlet terminal ratings.

 

[MentalNomad]

Hello saltsman.
Does the prices change from country to country ?
thank you

Yes, very much. Most of the supplies and equipment are not Tesla products, and price varies by country, and a big piece of the price is labor/permit/requirements, which also vary by country.

 

[tpoltron]

Something to keep in mind, that took us a while to appreciate: where you sleep you don't really need a fast charger.
As mentioned continuous loads like charger should not exceed 80 of the breaker and wire rating.
So a normal 120V socket on a 15 amp breaker delivers 120x15x.8=1440 watts which adds about 5 miles of range per hour of charging.
I'd ask the landlord to replace the dangerous panel but if he refused, I'd try to sneak a double 30A breaker into the panel to charge at 24Amps, double the voltage and double the amps gets you to 20 miles of range per hour of charge. If you thought that was pushing main breaker rating of 100A given your other loads, then even a double 20A 240v breaker charging at 16A would get you to 13mph so easily 150 miles of range per night.

 

[Dmagyar]

Planet earth. With the right insulation (THHN) in the right pathway (a conduit of sufficient size): Ampacity Charts - Cerrowire

Your understanding of the application of the National Electrical Code is seriously lacking...You evidently failed to note the double asterisks alongside the #10 wire, if you had looked that up, it might have indicated to you along with countless others your incorrect assumption... The double asterisks directs you to Section 240.4 D, where you will read #10 wire copper is limited to 30 amps... The second incorrect aspect in your assumption is you can’t use the 90ºC column wire as the lugs in your circuit breakers are only rated 75ºC, that limited the ampacity of those conductors back to 30 and is only used where you need headroom for derating capacity...Sorry but you’re wrong on both points....

 

[Lectric_Agent]

I have a 100amp Zinsco (same as your panel I believe). And I’ve been paranoid about the panel so I have used an infrared temp gun to check the panel when charging over many amp ranges and time frames. Anything 32a/240v (on a 60a breaker and 14-50nema) or less has been just fine to charge overnight. That should give you enough range

Just know that those panels can definitely be a problem. If your bus bar is corroded it can arc and cause problems. Also, sometimes the breakers won’t trip when overheated. You can actually order a replacement bus bar from Home Depot for around $60-70 if needed, but don’t ever do any of this work unless you know what you’re doing.

I have background in engineering and some electrical so I felt ok testing the limits of my panel from 1970 and it’s worked out fine for the past 2 yrs, but I still check the panel with my infrared thermometer all the time lol (it’s indoor and technically a sub panel, I currently live in a townhome)

Unless your bus bar is corroded or scarred, you should be able to swap out a breaker and charge at 24a/240v safely all night (30a breaker min, 40 would work, 80% rule). If you go that route just make sure to monitor the panel/breaker temp for the first 1hr+ of charging and make sure it levels out at a safe temp (less than 120 deg or so). And I would do this for the first couple weeks when you can, just to make sure.

I’m moving to a new house with a brand new 200a panel so i can’t wait to not worry about the panel overheating again.

Good luck! And disclaimer- I’m definitely not an electrician, but have had years of experience getting to know my zinsco lol

Oh and also I’m in SoCal so my dryer, oven and water heater run on gas. All of my lights are led. The only large draw is AC, and I rarely run it at night. I pretty much only charge between 12-6am when the best rates are available, plus most of the home is off

 

[arnolddeleon]

Your understanding of the application of the National Electrical Code is seriously lacking...You evidently failed to note the double asterisks alongside the #10 wire, if you had looked that up, it might have indicated to you along with countless others your incorrect assumption... The double asterisks directs you to Section 240.4 D, where you will read #10 wire copper is limited to 30 amps... The second incorrect aspect in your assumption is you can’t use the 90ºC column wire as the lugs in your circuit breakers are only rated 75ºC, that limited the ampacity of those conductors back to 30 and is only used where you need headroom for derating capacity...Sorry but you’re wrong on both points....

Thanks, you are correct per NEC. Learned something new.

The beginning of the this particular point and conversation was the Menlo Park city's guide to for EV charging: https://www.menlopark.org/DocumentC...ential-Electric-Vehicle-EV-Charger-Guidelines
where they specified the minimum conductor size for THHN wire for a circuit with a 40A was #10. If I understand correctly they're basically saying that #10 THHN would be good for 32A continuous. Other information suggests that 32A is plausible for continuous use. I'm guessing their local code allows it under right circumstances.

 

[SomeJoe7777]

Just a bit of clarification on this: #10 wire for 40 Amps is doable with a lot of caveats:

1. The wire must be THHN insulation (or equivalent) in conduit.
2. NEC table 310.16 allows up to 3 current-carrying conductors up to 40 amps in appropriate-sized EMT conduit (which is up to 5 #10 wires in 1/2" EMT), but the ambient temperature where the conduit runs must be 30C or less. This probably precludes running the conduit in an attic or outside. If it's run in those locations, you'll have to derate the conductors and therefore will be below 40 amps.
3. Since there is no 40 amp NEMA outlet, a 50 amp outlet is allowed on a 40 amp circuit, but only for a "permanently installed appliance". This would mean that if you put in a NEMA 14-50R, the mobile charger would need to be "permanently installed" and plugged into the outlet, like a range would be. If the outlet doesn't have a device plugged into it all the time, that's not "permanently installed". Hard-wiring the circuit to a HPWC without an outlet is the better solution.
4. Regardless of the outlet installed, the breaker must be 40A to protect the #10 wires.
5. Allowing the temperature rise of the #10 THHN wires to 90C is what gives them the 40A rating. To do this per code, all outlet terminals and the breaker must also be rated for 90C. Not all outlets and breakers have this rating.
6. The 80% rule applies for continuous current draw. On a 40A circuit, the maximum current that can be drawn by the car is 32A. The Model 3/Model Y mobile connector maxes out at 32A, so this isn't a problem, but if a HPWC is installed, it must be configured internally to 40A circuit / 32A draw. If a Gen 1 (Model S/Model X) mobile connector is used, then you must turn down the amperage in the car to 32A because the Gen 1 mobile connector would allow up to 40A.

It's generally easier to use #8 conductors and therefore you don't have to worry about many of these. You can use
NM cable and not have to run conduit, and you don't have to worry about breaker and outlet terminal ratings.

Your understanding of the application of the National Electrical Code is seriously lacking...You evidently failed to note the double asterisks alongside the #10 wire, if you had looked that up, it might have indicated to you along with countless others your incorrect assumption... The double asterisks directs you to Section 240.4 D, where you will read #10 wire copper is limited to 30 amps... The second incorrect aspect in your assumption is you can’t use the 90ºC column wire as the lugs in your circuit breakers are only rated 75ºC, that limited the ampacity of those conductors back to 30 and is only used where you need headroom for derating capacity...Sorry but you’re wrong on both points....

You are correct, I thus have to revise my post above in that #10 conductors would not be allowed in a 40A application due to rule 240.4(D)(7). 30A protection is the maximum.

My recommendation for #8 conductors still stands as posted.

The beginning of the this particular point and conversation was the Menlo Park city's guide to for EV charging: https://www.menlopark.org/DocumentC...ential-Electric-Vehicle-EV-Charger-Guidelines
where they specified the minimum conductor size for THHN wire for a circuit with a 40A was #10. If I understand correctly they're basically saying that #10 THHN would be good for 32A continuous. Other information suggests that 32A is plausible for continuous use. I'm guessing their local code allows it under right circumstances.

I think they overlooked the same thing we did, in that 240.4(D)(7) limits the overcurrent protection on #10 wire to 30A. In any case, local regulations can be more strict than the NEC, but not less strict.

If you wanted to use #10 wire for EV charging, you would be bound by the following:

1. 240.4(D)(7) limits the overcurrent protection (breaker) to 30A.
2. 210.19(A)(1)(a) states that the circuit ampacity shall be 125% of the continuous load (this is the "80% rule"). For the 30A ampacity of the circuit, the continuous load can thus be no more than 24A. The same rule applies to the receptacle as given by 210.21(B)(2). And the same rule applies to any cord-and-plug connected equipment in 210.23(A)(1).
3. 210.21(B)(2) requires that with cord-and-plug connected loads, the receptacle must be selected in accordance with table 210.21(B)(2), which specifies that on a 30A circuit, the receptacle rating must be 30A. The NEMA 6-30R or 14-30R would then be the only receptacles permitted.
4. The charging limit for the car must be set to 24A either by automatic or manual means. Using the Mobile Connector with a proper 14-30R adapter will cause the mobile connector to automatically limit the charging current to 24A. If a non-Tesla adapter is used, then the charge current must be set to 24A manually in the car.

One further note on using smaller conductors: Don't forget that voltage will drop along the conductors when they are under load. This effect is greater for smaller conductors and longer runs. The car will back off the charging rate if the voltage drops too low. This means that if you have a long run of wire from the breaker panel to the receptacle, upsizing the wire to the next higher gauge may be needed anyway to prevent excessive voltage drop.

 

[Bradlyrt]

Thanks for this such an excellent post! Keep up!

 

[TheRFMan]

Anything 32a/240v (on a 60a breaker and 14-50nema) or less has been just fine to charge overnight. That should give you enough range

A NEMA 14-50 receptacle is only rated to 50A (for intermittent loads) and 40A for continuous loads; the breaker should also be 50A max, regardless of the draw you pull from it.