220v 30 amp - Advice, Charging Times

[Thirsty3]

I live in a house with a 100 amp service and an old panel. My electrician said that he could install a 220v/30 amp outlet that taps into my dryer outlet (or whatever the appropriate term is) on the other side of the house. I couldn't use both at the same time, but that's not a big issue since I only do laundry 1-2x per week.

I have searched, but haven't seen a lot of info on the 220v/30 amp setup (especially when the driveway and the dryer aren't in the same place) - so just a couple of questions:

1. Will the 10-30 adapter (purchased separately) do the trick? I noticed that there seem to be two versions for sale - which one should I buy/what outlet pattern should/will be installed?

2. Does the car automatically know to step down the charging based on 30 amp vs. 50 amp set up?

3. What is the typical charging speed on a LR AWD Model Y?

4. Anything else I should know/consider? My knowledge on this particular subject is (obviously) very limited.

Thanks!

 

[silverstoned83]

I live in a house with a 100 amp service and an old panel. My electrician said that he could install a 220v/30 amp outlet that taps into my dryer outlet (or whatever the appropriate term is) on the other side of the house. I couldn't use both at the same time, but that's not a big issue since I only do laundry 1-2x per week.

I have searched, but haven't seen a lot of info on the 220v/30 amp setup (especially when the driveway and the dryer aren't in the same place) - so just a couple of questions:

1. Will the 10-30 adapter (purchased separately) do the trick? I noticed that there seem to be two versions for sale - which one should I buy/what outlet pattern should/will be installed?

2. Does the car automatically know to step down the charging based on 30 amp vs. 50 amp set up?

3. What is the typical charging speed on a LR AWD Model Y?

4. Anything else I should know/consider? My knowledge on this particular subject is (obviously) very limited.

Thanks!

I don’t believe you want to use the 10-30 adapter since this is the size/limit of the circuit breaker/wiring according to the electrician, and it’s an old circuit. Generally, you always want the breaker to be slightly larger than the load your putting on it, especially for EV chargers since they draw a constant heavy load for hours. I believe you will be limited to the 6-20 adapter, which will keep the charger from exceeding the breaker’s rating. This will charge the MY at 14 mi/hr.

How many pins are on your drier plug?

 

[MountainRatMat]

I live in a house with a 100 amp service and an old panel. My electrician said that he could install a 220v/30 amp outlet that taps into my dryer outlet (or whatever the appropriate term is) on the other side of the house. I couldn't use both at the same time, but that's not a big issue since I only do laundry 1-2x per week.

I have searched, but haven't seen a lot of info on the 220v/30 amp setup (especially when the driveway and the dryer aren't in the same place) - so just a couple of questions:

1. Will the 10-30 adapter (purchased separately) do the trick? I noticed that there seem to be two versions for sale - which one should I buy/what outlet pattern should/will be installed?

2. Does the car automatically know to step down the charging based on 30 amp vs. 50 amp set up?

3. What is the typical charging speed on a LR AWD Model Y?

4. Anything else I should know/consider? My knowledge on this particular subject is (obviously) very limited.

Thanks!

1. Yes, but make sure you consult with your electrician on the type of outlet they will install and purchase the same adapter
2. Yes, the car steps down the current based on the adapter installed on the mobile charging cable
3. You should get around 20 MPH of charge rate
4. I would highly recommend either pulling new wire or putting in something like a dryer buddy on your dryer outlet. You don't want to make the mistake of running the dryer and charging the car at the same time on the same circuit. That could cause a dangerous situation, hopefully just a popped breaker but you don't want to risk it.

 

[patmurphey]

With a 30 amp circuit, the charger should be set to 24 amps, 80% of max for continuous load.

 

[jmaddr]

My electrician said that he could install a 220v/30 amp outlet that taps into my dryer outlet (or whatever the appropriate term is) on the other side of the house.

This part bothers me as it's likely against code. Based on your wording, I'm assuming the dryer is on the other side of the house, and the "other" side to that is your panel? And the panel is close to the area where you would like to have your EV outlet? If so, it sounds like he'll just tap it at the panel, which again, concerns me.

But to answer your questions directly:
1. If he puts an outlet near your EV, it will likely be either a 10-30 or 14-30 (depends on 3 or 4 wire). Which one it doesn't really matter and your electrician should tell you which pigtail you will need
2. Yes, depending on which pigtail is installed.
3. The end result is you'll have 24 usable amps to charge (80% of 30A). This correlates to about 21mileage gained per hour according to:
NEMA Adapter Bundle
4. Yes, this is likely against code

 

[jeffbco]

I live in a house with a 100 amp service and an old panel. My electrician said that he could install a 220v/30 amp outlet that taps into my dryer outlet (or whatever the appropriate term is) on the other side of the house. I couldn't use both at the same time, but that's not a big issue since I only do laundry 1-2x per week.

I have searched, but haven't seen a lot of info on the 220v/30 amp setup (especially when the driveway and the dryer aren't in the same place) - so just a couple of questions:

1. Will the 10-30 adapter (purchased separately) do the trick? I noticed that there seem to be two versions for sale - which one should I buy/what outlet pattern should/will be installed?

2. Does the car automatically know to step down the charging based on 30 amp vs. 50 amp set up?

3. What is the typical charging speed on a LR AWD Model Y?

4. Anything else I should know/consider? My knowledge on this particular subject is (obviously) very limited.

Thanks!

Maybe this would be a solution:

Dryer Buddy™

 

[Rocky_H]

The bigger issues are about whether it complies with electric code--not just about whether it will work.
One of the main factors is that an outlet being installed for electric car charging must be dedicated--the only outlet on that circuit. You are not allowed to have those two outlets for the dryer and the car both active on the circuit. The way to comply with this that would fit your situation is putting an A/B throw switch in line, so it forces that only one outlet can be live at any time.

Also, you said it's a 10-30. The 10-XX series of outlets were disallowed in 1996. It's not allowed to install new ones--only replace existing ones that are already in place.

1. Will the 10-30 adapter (purchased separately) do the trick? I noticed that there seem to be two versions for sale - which one should I buy/what outlet pattern should/will be installed?

What you are seeing is that the adapter plugs are different for the older mobile connector (Generation 1) versus the newer mobile connector (Generation 2), which is the one that will be coming with your car. You would need the Gen2 kind.

2. Does the car automatically know to step down the charging based on 30 amp vs. 50 amp set up?

The type of adapter plug you have connected into the charging cable has a chip in it that signals the appropriate amp limit for that plug type, so you don't have to do anything or think about it.

I don’t believe you want to use the 10-30 adapter since this is the size/limit of the circuit breaker/wiring according to the electrician, and it’s an old circuit. Generally, you always want the breaker to be slightly larger than the load your putting on it, especially for EV chargers since they draw a constant heavy load for hours. I believe you will be limited to the 6-20 adapter, which will keep the charger from exceeding the breaker’s rating.

It sounds like you have heard a small piece of information that is correct, but getting a misunderstanding of how it's put into practice. All this is not true. What you are thinking of is the rule that for continuous loads, (which EV charging is) you can only draw 80% of the circuit's rating. But the factor you're missing is that Tesla is not dumb. They figure that into their charging adapters. The 10-30 plug they sell does not pull 30 continuous amps. It already tells the charging system to only pull 24 amps from that plug type to comply with that rule. That would be really terrible if they sold a 10-30 adapter you couldn't use on 10-30 outlets and instead had to hack up a hokey kludge 6-20 to 10-30 thing to comply with code.

 

[Pilot1226]

Dryer buddy would work assuming you had the length of cable to actually connect both the dryer wire and your mobile charger to it. The way it works is the main outlet gets priority and cuts off the secondary outlet as needed.

In my experience a band aid solution isn’t ideal.

You could consider some type of subpanel setup.

If you could get your dryer and the new EV outlet in a 50A subpanel you could designate a 6-20 circuit for the car and leave the dryer alone on a 30A whether it be a 10-30 or 14-30 (based on age of outlet typically).

Your 6-20 would charge at 16A and provide around 3.5 kW per hour of energy after the efficiency losses.

If you charged for 8 hours at a 250 Watts per mile efficiency, this would gain about 110 miles of range.

 

[jcanoe]

Determine your home charging needs based on your driving pattern. If you only drive less than 30 miles per day then even a 120V/15 amp receptacle would be adequate for your daily charging needs.Then start discussions with an electrician. Instead of trying for force your existing electrical service to accommodate an additional 230V/30 amp circuit find out if there is room in the panel and capacity for a 20 amp circuit. If the electrician determines that the existing electrical service in your would support an additional 230V/20 amp circuit that would enable you to charge your Model Y at up to 15 miles per hour; overnight that would easily add 120 miles of range to the vehicle's battery.

The best solution would also be the most expensive; upgrade your home's electrical service to 200 amps (known as a Heavy Up). This would require a new electrical panel.

 

[silverstoned83]

It sounds like you have heard a small piece of information that is correct, but getting a misunderstanding of how it's put into practice. All this is not true. What you are thinking of is the rule that for continuous loads, (which EV charging is) you can only draw 80% of the circuit's rating. But the factor you're missing is that Tesla is not dumb. They figure that into their charging adapters. The 10-30 plug they sell does not pull 30 continuous amps. It already tells the charging system to only pull 24 amps from that plug type to comply with that rule. That would be really terrible if they sold a 10-30 adapter you couldn't use on 10-30 outlets and instead had to hack up a hokey kludge 6-20 to 10-30 thing to comply with code.

Good to know, thanks for sharing this detail. I didn’t realize that the adapter already takes this into account as well. They should include those details on the website for those that have a basic understanding of electricity.

 

[captanzuelo]

With a 30 amp circuit, the charger should be set to 24 amps, 80% of max for continuous load.

Buy the Tesla adapter and you don't have to worry about setting the amps. It will set to 80% max by itself.

 

[Pilot1226]

Yes, I agree with above. Depending on how much you drive and how often you can charge, there are people that are just fine on 120V. And you have two options for 120V depending on your home setup (consult an electrician)...

5-15, which is a 120V15A circuit which charges at 12A,

or

5-20, which is a 120V20A circuit which charges at 16A.

The efficiency losses are there regardless of the amperage, because you’re going to lose energy converting wall AC to DC for the pack - I believe the amount is about 300 Watts.

But, 300 Watts is more detrimental in terms of percentage if you’re only adding 1.44 kW with a 5-15 or 1.92 kW with a 5-20.

This is why people suggest 240 regardless. Even if a lowly 6-15, it’s still going to provide 2.88 kW, and a 6-20 which is 3.84 kW.

Outdoor temps play a factor. There are a couple of videos out there with people charging overnight on 120V at 12A. It does still charge and add range but there are a few times where charging stops for range to use that energy to heat the battery pack if it drops too low.

One way around it is to charge as soon as you come home from a drive - the pack will be warm.

I agree that you should try what you have first before moving mountains. I am going to try 5-15 first to see what happens over winter. If it’s a problem I will probably jump to a 6-20 unless it is so close to working that I would go to a 5-20.

For me, the 240V would require a full panel replacement. So the 5-20 is the cheapest option if it works.

 

[Thirsty3]

Thanks so much, guys. This is all really, really helpful.
Update: So, of course this couldn't be easy - taking a closer look at my dryer ..it's 120v! My electrician and I came up with the shared circuit idea after he was back outside (we both just assumed the dryer was the typical 240 - but the previous owners were super cheap and clearly did everything they could to avoid replacing the panel, including getting a 120v dryer - which explains why it takes forever to do its job).

I already had a second electrician scheduled to come out tomorrow - just to be able to compare prices. But I'll share this new info and see what he says. I'm guessing I will end up with a 120-20/NEMA 5-20 that charges at 6 mph (unless we identify another 240v source to share with?). As for my driving habits - I'm working from home for at least the next several months and have no commute - some days I drive 10-20 miles to do errands. However, I regularly drive 120 miles (round-trip) to visit family/friends (about 1x per week). There's a supercharger very close that I can use if needed to leave home without an 80% charge. So, I could live with the 120v setup if needed, but would prefer something faster. Will keep you guys posted.

 

[1965Falcon]

I would strongly consider upgrading the panel. Consider it an investment in the future. It'll make ownership much more enjoyable, I wouldn't want to just rely on the 5-20 charging. I think the going rate seems to be $2500 to $3000.

 

[jcanoe]

One additional point with charging an EV using a 120V/15 amp circuit (typically a home outlet with a NEMA 5-15R; the "R" stands for receptacle, if there was a "P" this would be for the plug). On a 120V/15 amp circuit you can only safely charge at the 12 amp setting if there are no other appliances sharing the circuit. That means no freezers, attic fans, water filtration units, air compressors, garage door openers etc. on the same circuit. You would probably be ok with one or two light fixtures on the circuit especially with LED bulbs. Otherwise, you could only safely charge at the 8 amp rate.

 

[Rocky_H]

Good to know, thanks for sharing this detail. I didn’t realize that the adapter already takes this into account as well. They should include those details on the website for those that have a basic understanding of electricity.

I think quite the opposite. That is unhelpful. They need to keep this consumer friendly, and that includes not spelling out national electrical code details that will make most people's eyes glaze over. It is far better for people to just identify what kind of outlet they have, buy the plug that fits it, and plug it in. It manages itself automagically. No code knowledge needed.

Update: So, of course this couldn't be easy - taking a closer look at my dryer ..it's 120v!

Wow--I know they exist, but very few people have them.

I'm guessing I will end up with a 120-20/NEMA 5-20 that charges at 6 mph (unless we identify another 240v source to share with?).

Well, keep this in mind, though. If you are getting a separate line run for this, there is no reason to keep it as a 120V line. The load capacity calculations to see what fits into the 100A total your house has are about the amps, so if you can spare 20A for a circuit run to the garage, it makes no difference whether that line is connected as a 120V or a 240V, so you might as well give it twice the voltage and thereby twice the power, which is what scales the charging speed.

 

[jcanoe]

I would strongly consider upgrading the panel. Consider it an investment in the future. It'll make ownership much more enjoyable, I wouldn't want to just rely on the 5-20 charging. I think the going rate seems to be $2500 to $3000.

I agree. Electrical panels do get old and can literally wear out. It happened at my home when a 50 year old fuse panel failed. I spent many hours and $ trying to figure out what was happening with the power at my house. Half the house was experiencing low voltage and half was experiencing high voltage readings. The local electric company even ran a line monitor on my power where the power entered my home but could only say that there was nothing wrong with the utility power. About a year later I had my old panel replaced; the master electrician performing the work showed me the source of the problem. The neutral wiring in the house tied back to a single terminal tab in back of the old panel. This tab had broken off and was only being held in place by wires pressing against the tab. Lesson learned, replace panels when they get old or if you start to have unexplained electrical problems.

 

[jcanoe]

If your electrician determines that there is capacity for an additional 20 amp circuit you should ask the electrician to install a 230V circuit. The amperage does not change, only requires one additional 120V lead from the panel to the receptacle to make it a 6-20 (230V/20 amp.)

Another option that is not obvious; if you have an existing 120V circuit (could be 15 or 20 amp) an electrician can easily rewire the circuit to be a 230V circuit as long as the existing circuit terminates at only one outlet, i.e. is not shared. The receptacle would have to be changed to accept only a 230V plug.

Definitely have the electrician pull a permit for the work. That way, if there is ever an electrical fire in the home, the insurance company could not deny the claim if unapproved wiring was found to be the source of the fire.

 

[Pilot1226]

If you are getting a separate line run for this, there is no reason to keep it as a 120V line. The load capacity calculations to see what fits into the 100A total your house has are about the amps, so if you can spare 20A for a circuit run to the garage, it makes no difference whether that line is connected as a 120V or a 240V, so you might as well give it twice the voltage and thereby twice the power, which is what scales the charging speed.

This exactly. Modern code specifies 5-20 in garage applications anyway. But if you are going to pay labor to run the new circuit just go 240!

 

[jeffbco]

Thanks so much, guys. This is all really, really helpful.
Update: So, of course this couldn't be easy - taking a closer look at my dryer ..it's 120v! My electrician and I came up with the shared circuit idea after he was back outside (we both just assumed the dryer was the typical 240 - but the previous owners were super cheap and clearly did everything they could to avoid replacing the panel, including getting a 120v dryer - which explains why it takes forever to do its job).

I already had a second electrician scheduled to come out tomorrow - just to be able to compare prices. But I'll share this new info and see what he says. I'm guessing I will end up with a 120-20/NEMA 5-20 that charges at 6 mph (unless we identify another 240v source to share with?). As for my driving habits - I'm working from home for at least the next several months and have no commute - some days I drive 10-20 miles to do errands. However, I regularly drive 120 miles (round-trip) to visit family/friends (about 1x per week). There's a supercharger very close that I can use if needed to leave home without an 80% charge. So, I could live with the 120v setup if needed, but would prefer something faster. Will keep you guys posted.

Are you sure you don't have a gas dryer and that the 120 is just to turn the drum - doesn't seem like you could get enough heat to dry anything with 120 - it would take hours to dry a load of towels.