It's not a requirement. The 14-50 is not installed with a GFCI after all. Probably the other outlet was miswired. It's worth tossing one of these in your UMC bag: https://smile.amazon.com/Power-Gear-3-Wire-Receptacle-50542/dp/B002LZTKIA - get it the next time you're at your local hardware store.
Ross608
Member
My 2013 Model S is on Maui. (Perfect island car). A longer trip for me is 70 miles. I have never bothered installing any charging in my garage. I simply plug into the 110 native to the garage. I never seem to get less than 40 miles overnight and much more if it is plugged in all evening too. I only charge my battery to about 160.
scsmx
Member
I carry this 20A extension with the Tesla 5-20 adapter and a 5-20 to 5-15 adapter that way I am prepared for both 15 and 20 amps receptacles.
One item worth mentioning that I don't think was brought up above was to use as short a run of cord as you can to get the job done. Meaning if you are just parked in your garage and can get by with a 10' cord, do that. Don't use a 50' cord when 10' will do. Also, if it is something like 75' go with a 50' and 25' as opposed to 100'. We recently were at a house on MArtha's vineyard and I had to run a 25' and 50' to get to the car. I got about 13 Amps at the car.
Snow Drift
Pirelli P Zero Winter
Lloyd, how has this held up? I ordered a single plug 12/3 version but Amazon has some negative reviews about quality.
Lloyd
Well-Known Member
gnuarm
Model X 100 with 72 kW chargers
The power cord won't drop the amps. It drops the voltage. A 50 ft, 14 gauge extension cord has about 0.25 ohms resistance and at 12 amps drops 3 volts. A 12 gauge cord will drop about 2 volts. A 16 gauge cord will drop about 5 volts and an 18 gauge cord will drop almost 8 volts. So your 120 VAC circuit shows up at the car as 117 volts which is what I often see. Sometimes it is 115 volts. Sometimes it is 112 volts. The actual voltage from the power line varies with the loads in your area. But the current drawn by your car is controlled by the car. That's why I'm surprised your car drew 13 amps on a 15 amp circuit. The car shouldn't draw more than 12 amps no matter what. Or was that a 20 amp circuit?
Until you start using very long power cords or cheap cords with too small wire, I wouldn't worry too much about the losses. Same with the house wiring. Unless you have long runs, I wouldn't bother running a heavier gauge than required.
gnuarm
Model X 100 with 72 kW chargers
Amazon and Walmart don't make the products. If you pick one you think is good it will have a brand and a model number. Search for that on the web and you will find a lot of places sell the same stuff. Once you've picked a brand you like, buy it from whoever you like, they won't ruin the quality.
A 12 gauge 50 foot extension cable is not really needed for 12 amps and is rated for 20 amp circuits. What current a wire can safely carry is complex because the ability to get rid of the heat generated has to be considered. The problem doesn't come from the wire overheating, it comes from the insulation getting too hot. So in house wiring the same gauge wire can carry higher currents if the insulation is rated for higher temperatures or it is in a location that has more heat conduction.
Extension cords usually have problems at the connectors, either because they are made poorly and have weak contact with the mating connector or they have weak connection with the wire in the cable. The only way to tell if one of those is occurring is to try it and see if it heats up. When run near their max ratings all connectors will become warm, but not hot. If you can hold it in your hand, it isn't too hot.
