Any benefit of Tesla home charger vs 220 outlet?

[Rocky_H]

I am not disputing your knowledge but can you please explain why my double oven uses this exact same cord and is "legal"?

Because NEC now has an article numbered 625 that is specifically all about unique rules for electric vehicle supply equipment. Your oven is not electric vehicle supply equipment. See above, why regular people like you and I who don't work with this stuff all the time aren't always familiar with what sections of code apply. It is article 625.17 "Cords & Cables" Section A, subsection 3 (a).

"(a) When the interrupting device of the
personnel protection system specified in 625.22 is
located within the enclosure of the supply equipment or charging system, the power
supply cord shall be no more than 300 mm (12 in.) long"

http://mydocs.epri.com/docs/publicmeetingmaterials/1112/PDNNSH5Q3Z2/Day 1 PlugIn Electric Vehicle Codes Standards/D1_7C G Kissel Article 625 Restructure Proposal.pdf

I'm pretty sure @Cosmacelf has worked with this provision enough to know that it applies. Double check me? And notice how all of the Clipper Creek units that have cords always have a short cord less than a foot.

I would challenge your characterization of it being "illegal". I've never seen a law enforcement agency arrest someone for violating electrical code. Not per code, yes. Illegal? Not so much.

As to that, most(all?) states have a provision that does state it is illegal to do electrical installs on your home that violate electric code. Arrest you? Probably not, but fine you? Yes, for sure.

 

[cybergates]

I wrestled with should I buy a wall charger or not. I ended up buying a second UMC kit. I leave one in the trunk, and the other stays plugged into the garage.

there's a universal one that's as low as $300 in the model 3 section of the tesla site.

 

[Cosmacelf]

Public service announcement.

I’m not sure why @Rocky_H mentioned me in a post above, but just for the record, I’m not an electrician, never meant to imply I was one, and have even probably posted a few things that aren’t correct.

You can now go back to your regularly scheduled discussion

 

[Rocky_H]

Public service announcement.

I’m not sure why @Rocky_H mentioned me in a post above, but just for the record, I’m not an electrician, never meant to imply I was one, and have even probably posted a few things that aren’t correct.

You can now go back to your regularly scheduled discussion

Ah, did I get the wrong guy? Who's the one with the charging installation FAQ and how-tos on building adapters?

 

[Mickie]

I initially had a 14-50 installed, but was told adding a HPWC to that line was very simple as all the hard work was done. Are you not able to simply slap a HPWC onto your current setup?

Personally, I’d like to add a HPWC purely for convenience and streamlining—UMC always in the car and HPWC just looks great plus you’re able to eek out those extra 8 amps under your 50 amp breaker. I wouldn’t be upgrading service or unlocking the 72 amp feature on the car simply because it’s unnecessary for my purposes.

In short, I’d add a HPWC if it can be done easily with little cost because of above reasons. Or, just use the current 240 you’re blessed with, digest this all, and decide later without hurry.

 

[roblab]

For me, having the HPWC set at 72Amps/220Volt is great which gets about 40 miles/hour. This helps if you are doing multiple errands in a day. Otherwise, just a basic NEMA 14-50 connection is good since it will save you money from having to buy a Level 2 charger.

If someone could only afford a 60 KwH car, how can they afford the expense of a HPWC? Having a car that charges to near 300 miles means I don't have to have an L2 charger, and truth be told, the 50 amp plug adds enough to do "multiple errands" in a day. It's all I've ever used at home for five years.

 

[doubleohwhat]

If someone could only afford a 60 KwH car, how can they afford the expense of a HPWC?

Erm, because it's not an additional monthly cost and they saved $ by going with the lower model? That's like asking how someone who could only afford a $100k house how they can afford the expense of painting a few rooms.

 

[Racerx22b]

If someone could only afford a 60 KwH car, how can they afford the expense of a HPWC? Having a car that charges to near 300 miles means I don't have to have an L2 charger, and truth be told, the 50 amp plug adds enough to do "multiple errands" in a day. It's all I've ever used at home for five years.

Not everyone buys a car strictly based on what they can or can’t afford. I know many millionaires driving around in a Honda and many people buried in debt driving around in a Benz.

 

[Cosmacelf]

Ah, did I get the wrong guy? Who's the one with the charging installation FAQ and how-tos on building adapters?

I am the guy who wrote the how-tos on adapters. The faq is written by FlasherZ, who I believe, is an electrician, or at least knows a lot about the electrical code. FlasherZ actually mildly disapproves of my adapter how to since most home made adapters bypass a Tesla safety feature and aren’t code compliant.

Digressing a bit here. I wanted to make the Tesla Home Made Adapter guide a bit more broad (cover more than Tesla) and make it into a web site. The result is CarCharging.us. While I’m somewhat happy with the look and feel of the website, I don’t think it is as easy to use and follow as that 20 page pdf I wrote (http://cosmacelf.net/Home Made Adapters.pdf). Classic example, I think, of what happens when you change something from being very specific and step by step to something more general and universal. It loses ease of use. Or maybe I’m wrong and the website is fine?

 

[Yinn]

If someone could only afford a 60 KwH car, how can they afford the expense of a HPWC? Having a car that charges to near 300 miles means I don't have to have an L2 charger, and truth be told, the 50 amp plug adds enough to do "multiple errands" in a day. It's all I've ever used at home for five years.

I only afforded to buy a Model S 60 kwh car. I didn't find an issue affording the expense of a HPWC, nor the NEMA 14-50 I had installed when I purchased a Model X which was also a 60 kwh version.

To the OP, both work fine. 90% of the time, they'll both overnight charge and you won't notice a difference. The only time it does make one is if you've run it dry; the HPWC will help even more if you have the 72amp charging capability.

 

[Rocky_H]

I initially had a 14-50 installed, but was told adding a HPWC to that line was very simple as all the hard work was done. Are you not able to simply slap a HPWC onto your current setup?

"adding" is questionable. Replacing the 14-50 outlet with a wall connector on the ends of those wires is certainly very easy.

plus you’re able to eek out those extra 8 amps under your 50 amp breaker.

No, it doesn't work that way. The 40A current limit from a 50A circuit is an electrical code requirement, not just a limitation of the mobile cable. A wall connector has some convenience, but it would still be 40A on that same circuit.

 

[Rocky_H]

I am the guy who wrote the how-tos on adapters. The faq is written by FlasherZ, who I believe, is an electrician, or at least knows a lot about the electrical code.

Ah, yeah, that's it. I remembered whoever it was works with electricians and NEC frequently but may not actually be an electrician as a career.
@FlasherZ Could you help explain a little why wall mounted EVSEs with cord have to use the less than 1 foot length? 625.17 A 3 subsection (a) is the less than 1 foot and subsection (b) is more than 1 foot, but from reading the conditions, I don't quite get why they fall into (a). It is something about where the "personal protection system" is located in the device, but I'm not quite following what that is.

 

[Uncle Paul]

Think it is always a good idea to have a licensed electrican come to your place and give you his opinion options and and estimate.

In my case he found out the previous owner had wired up a plug for his welder and a 50 amp breaker. Simply needed to route some conduit to where I wanted and inst install the proper plug.

Trying to figure this out by yourself can often send you down an unsafe path.

Good idea to study your codes and get a couple bids, but totally doing it yourself can save you some $ in the beginning but maybe more expensive later on.

 

[Mickie]

"adding" is questionable. Replacing the 14-50 outlet with a wall connector on the ends of those wires is certainly very easy.

No, it doesn't work that way. The 40A current limit from a 50A circuit is an electrical code requirement, not just a limitation of the mobile cable. A wall connector has some convenience, but it would still be 40A on that same circuit.

Ok, replacing. Conversation with my electrician is vague today but it was along those lines. Thanks for that, and the 48A thing. News to me!

What is required to realize the 48A charging--a higher amp breaker more than 50A? I notice when I plug into Tesla's HPWC at their showrooms I'm getting 48A there.

 

[Rocky_H]

What is required to realize the 48A charging--a higher amp breaker more than 50A? I notice when I plug into Tesla's HPWC at their showrooms I'm getting 48A there.

Yes, higher amp circuits, which is defined by the breaker size and having the appropriately sized wire. Electric code has two categories for how much current you can draw from a circuit--temporary loads and permanent loads (running for many hours at a time). For temporary loads, yes, you could draw up to the full rating of the circuit for a short time. Electric car charging is now specifically defined to always be considered a permanent load, though. So for whatever long-term current you will be drawing, the circuit size has to be 125% of that. So to draw 40A, you must have a 50A circuit. To draw 48A, you need a 60A circuit. To flip the math around, the current is 80% of the breaker rating.
So at the stores, they generally have those connectors on really big circuits, usually 100A, so they can easily supply more than the 48A that your car is capable of drawing.

 

[Mickie]

Yes, higher amp circuits, which is defined by the breaker size and having the appropriately sized wire. Electric code has two categories for how much current you can draw from a circuit--temporary loads and permanent loads (running for many hours at a time). For temporary loads, yes, you could draw up to the full rating of the circuit for a short time. Electric car charging is now specifically defined to always be considered a permanent load, though. So for whatever long-term current you will be drawing, the circuit size has to be 125% of that. So to draw 40A, you must have a 50A circuit. To draw 48A, you need a 60A circuit. To flip the math around, the current is 80% of the breaker rating.
So at the stores, they generally have those connectors on really big circuits, usually 100A, so they can easily supply more than the 48A that your car is capable of drawing.

This sounds very familiar, and correct. Thanks again

 

[cmaster]

The rule is using the 80% capacity rating of the circuit breaker to determine your input current. Example, if you want 72 amp enabled on the HPWC, use 90 amp circuit breaker. 0.80 X 90 amps = 72 amps.

 

[davewill]

The idea of an EVSE is to make it impossible to have a hot plug that is not connected to the vehicle, and secondarily to make it impossible to unplug while charging and cause arcing. Having a plug on the supply side of the EVSE breaks that second function as you could yank that out while charging. I expect that the the guys writing the specs minimized the length of the cord to help prevent snags from accidentally pulling the wall plug out. This can't happen with most appliances because the cord is buried behind the appliance.

Personally, I don't think a cord length of 4 ft or so is a big deal so long as the cord isn't hanging on the floor or across an aisle where someone could trip on it.

 

[EVrules]

I had the same dilemma. So, dug into the details that Tesla posts and found the at the best that I could do with a NEMA 14-50 (240V @ 50A) plug in my garage was 25 mph. However, with the Tesla wall charger, I was able to run a 240V 60A service and now I routinely charge at 34 mph! Since I have the 75D with a max charging of 48A, I did not run the more expensive 240V 100A cable. The cost of having an electrician install it was not bad ($300) given the smaller wire required for 60A.

In the long run, I recommend the Tesla Wall Charger as it has a thicker cable and is much more durable than the cable that comes with the car. You never need to get your cable out of your vehicle and you charge faster. During a typical day, I use about 60-75% of my battery. With the wall charger, the car must stay plugged in overnigh,t which is a problem if you want to do an evening trip. However, with the wall charger @ 60A, I am good to go in 4 hours!

Every decision is a trade-off. Do your research, do some planning on how you will drive the car (battery depletion), how long you can leave it plugged in to charge, and how many night trips you might make that will disrupt your charging. Then get a quote from a Tesla certified electrician in your area (if possible). Finally, make the decision that is best for you.

Remember that you should also check with your power company for Time of Use billing. In my area, charging during non-peak (if I am enrolled in their plan) costs only $0.03 per KWH!

 

[Jaws]

Thanks for all the great advice. After using the 240 circuit for awhile it seems perfectly capable for our needs. It charges around 25-30 mph which if plenty since we tend to run 30-50 miles a day. We now plug it in every three days or so and it charges up over night (midnight to 6:00am). Tesla was great about letting us return the charger since it hadn’t been removed from the box.