5-20 adapter

[Cellsaver]

Getting my P90D on Thursday and I'm psyched. So I'm a newbie and I see lots of posts about a NEMA 5-20 adapter for charging. In my garage I have what looks to me like a regular outlet, I checked the panel and the garage is on a 20 amp breaker. The only other thing connected is the garage door opener and it's built-in light. Does this mean I can charge at 20 amps? Doesn't look like I need any kind of adatper...

I'm getting a wall charger at work so I just need something at home to keep me topped off on the weekends.

TC

 

[NOLA_Mike]

NEMA 5-20 has one blade vertical and one blade horizontal (as opposed to both vertical on the 15A version).

 

[Cellsaver]

Right that's my question though, the panel has a 20 amp breaker but the outlet is just a regular one without the horizontal.

 

[Canuck]

The UMC will draw the amps as told to it by the adapter you put on the end (up to 40 amps max). So if you have a regular socket, you will only draw 12 amps from the 5-15 adapter. You could buy the 5-20 adapter

Tesla — NEMA 5-20

And then use a 5-15P to 5-20R Plug Adapter:

Amazon.com: NEMA 5-15P to 5-20R Plug Adapter - 1 Foot, 15A/125V, 14 AWG - IBX-1334-01: Home Audio & Theater

Since that will tell the car to draw 16 amps. You can also dial down the amps in the car -- but not up past what the adapter tells the car to draw.

I had to install an 100 amp fuse to draw 80 amps from my HPWC. So even though your fuse is 20 amps, you shouldn't be drawing the max 20 amps since you need a buffer, and the wiring itself may not support more than 12 amps even though your fuse is 20 amps. So I am not recommending you do anything I say here since you could burn your house down. I am just explaining to you how it works and how you can "fool" the system to draw more amps. I made an extension cord that uses the 14-50 adapter and I removed one pin (not used by Tesla) so I can plug it into both dryer and range outlets and the car will always draw 40 amps but I dial it down to 30 amps for a dryer outlet.

If the wiring and fuse supports it, you can just change the outlet to a 5-20 rather than use the 5-15 to 5-20 adapter.

I am not an electrician and I learned this just by having my vehicle a few years now, so do not do anything I say here without consulting an electrician first. Hopefully someone with more knowledge than me will chime in.

 

[GSP]

Cellsaver,

If I was in your situation I would consider the following options:

1) Just use the 5-15 adapter that comes with your car and charge at 12 Amps. This might be enough if you do not drive much on weekends.

2) Have an electrician upgrade one of your garage outlets to a 5-20, buy Tesla's 5-20 adapter, and charge at 16 Amps. That will be better, but not enough if you drove a lot on weekends

3) Have an electrican install a 14-50 outlet in your garage. You can charge at 40 Amps, and 240 V with the 14-50 Adapter that comes with your car. With much higher Voltage and current, this should handle about any driving you may do.

I would recommend just doing #3. Alternatively, you could just get a quote for #2 and #3, and try the 5-15 for a while to see how it works out.

GSP

 

[NOLA_Mike]

Right that's my question though, the panel has a 20 amp breaker but the outlet is just a regular one without the horizontal.

It's possible you could change the outlet to 5-20 but I wouldn't assume anything and I would verify all wiring is compatible first. I think it's quite possible that 5-15 are installed where 5-20 are acceptable but 5-15 is what the electricians buy in bulk and that's what gets put in everywhere.

Disclaimer: I am not an electrician I only stayed at a Holiday Inn Express one night...

 

[Solarman004]

I checked the panel and the garage is on a 20 amp breaker. The only other thing connected is the garage door opener and it's built-in light. Does this mean I can charge at 20 amps?

No. You can't draw 20 A continuous on a 20 A circuit. Your limit would be 0.8 x 20 = 16 Amps continuous.

 

[iwannam3]

The important part is the wire from the breaker to the outlet. It needs to be 12 gauge for a 20 amp circuit. You could have a 20 amp breaker and 14 gauge wire and an outlet for 15 amps. Just changing the outlet to 20 amp is not safe unless the wire is 12 gauge (thicker).

 

[Pwdr Extreme]

Although I personally am not an electrician, my best friend is a Master Electrician and I have learned a great deal from him. The main reason houses do not have 20 amp outlets installed is cost. A typical 15 amp outlet is 1/3 the price or less. Doesn't seem like a lot but when you multiply that by 100 outlets or so in a typical house, it becomes quite a bit of money. Code varies some state to state, but garages, bathrooms, kitchens and such require 12 gauge wiring. Bedrooms are allowed to have 14 gauge but most conscientious electricians will not use 14 gauge since it's quite possible a homeowner may install a window A/C or such in the bedroom.

So, to sum up a quick answer to your question, yes, you can most likely install a 20 amp outlet, but you should verify the electrician did in fact use 12 gauge wiring as he should have. Of course as stated you can only draw 16 amps from that outlet. Even more rules apply for situations that will be drawing maximum power for extended periods of time, but I won't get into that.

 

[gmtom1]

If you really only need the home charge to "top up" then the 5-15 should be okay, depending on how far you drive. I use the 5-15 as my daily charging source on my X and that usually covers the 36-40 miles I have on my daily commute with 9-10 hours of charging overnight while I'm at home. For longer trips, I find a free public charger, or if I cannot, then I just use the dryer outlet in my garage. I don't know how much additional charging speed the 5-20 would provide, but my guess is it's not much more for the additional hassle.

One factor to check first before you move forward with plans for 14-50 charging is your home's existing electric service capacity. If you have an older home, it's likely that your home electric service is only 100A or 120A, which may not provide enough to support an additional 50A circuit. An electric service upgrade can either be relatively inexpensive, or a huge cost, depending on your local utility and the infrastructure in place serving your home (overhead or underground lines). As noted above, best bet is to have an electrician come out for a consultation.

 

[balefire]

If you really only need the home charge to "top up" then the 5-15 should be okay, depending on how far you drive. I use the 5-15 as my daily charging source on my X and that usually covers the 36-40 miles I have on my daily commute with 9-10 hours of charging overnight while I'm at home. For longer trips, I find a free public charger, or if I cannot, then I just use the dryer outlet in my garage. I don't know how much additional charging speed the 5-20 would provide, but my guess is it's not much more for the additional hassle.

5/15 is extremely inefficient. It is OK for intermittent use but not for daily use. You will be wasting money and electricity bills. 5/20 is worth the hassle if you have no better options