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bonnie
I play a nice person on twitter.
I used this for several months to charge my X. It's not unsafe.
https://www.amazon.com/gp/product/B00STD8S7C/ref=pe_139950_229204750_em_1p_0_ti
https://www.amazon.com/gp/product/B00STD8S7C/ref=pe_139950_229204750_em_1p_0_ti
bonnie
I play a nice person on twitter.
As far as the extension cord goes, I'd talk to the folks at Conntek directly. They were a great help to me in figuring out how I was going to charge both the Roadster and the X with suboptimal choices.
thecloud
As rhythm raced inside, the ship came alive
Did you also need to manually lower the charging amps on the screen in the car?
The concern that @gaswalla is expressing (and which I also have) is that with this adapter, your Tesla will think it is plugged into a 14-50 receptacle. As such, it will try to draw 40 amps from a dryer outlet which probably can only provide 24 amps (on a 30 amp fuse) or 32 amps (on a 40 amp fuse). That's inherently unsafe.
Now, if you know the maximum amps your UMC adapter will draw, and the maximum continuous load that your outlet/breaker is capable of sustaining, and are aware of the need to dial down the amps in the car, then it's an OK solution for temporary charging. However, it's not a solution that will be safe in the long term if the UMC ever decides to draw more power than your outlet can provide.
bonnie
I play a nice person on twitter.
I've always had the car adjust down to the maximum current it can draw - not based on the plug type, but rather what's available. Certainly open to being educated on this. But I've never adjusted for low amperage at public chargers, for instance, and it's always dialed itself down.
bonnie
I play a nice person on twitter.
thecloud
As rhythm raced inside, the ship came alive
At "public chargers" you're probably using the J1772 adapter. J1772 has a safety protocol that negotiates and monitors the power output, so dialing down the amps manually is unnecessary.
For NEMA outlets, there's no such safety protocol. That's why there are separate UMC adapters, each of which has a built-in resistor to limit the maximum current it will draw continuously (40A for the 14-50 adapter, 24A for the 14-30 and 10-30 adapters, 16A for the 5-20, and 12A for the 5-15.) These are 80% of the rated values for each outlet.
I know that the car is smart enough to lower the amps itself if it detects that the power source can't provide the requested amount, but the concern is that it will not be able to detect that accurately with a 14-50 adapter. A 30A-rated outlet may actually be able to provide up to 30A for a while before heating up dangerously or blowing the fuse (if you're lucky).
I have actually blown a fuse this way, plugging in with a 10-30P-to-14-50R adapter, a Camco extension cord, and the UMC plugged into that. It's made me very aware of how much current the car can draw, and the need to know what size fuse is protecting the circuit.
I don't see an answer to your last question.
No, the TT-30 is a 120v plug and the ground pin is shaped differently to avoid placing it into a NEMA 10-30 240v outlet. IIRC, the plug can be forced into the outlet, and that is part of why the NEMA 14-30 is now used instead for dryers.
There are adapters for RVs to go from TT-30 to NEMA 14-50, but those are not wired correctly to use to charge the Tesla. Big RVs use the 240v Nema 14-50, but they use it differently and can run partially off of 120v, just not everything at once.
As far as a 50 amp extension cord, I bought one off eBay and you can shop for the best price. Camping world is too expensive. But if you are only going to run off your dryer a 10 gauge cord will work. If you plan on also possibly using campground 50 amp then get the 50 amp extension cord for sure.
The Tesla does not use one of the wires in the RV extension. If you can make it yourself (or, I assume, buy a custom one from some source), it will be significantly thinner cable. Just be sure to label it correctly as NOT being usable for an RV -- for Tesla use only.
That said, I personally carry an RV extension...
thecloud
As rhythm raced inside, the ship came alive
One thing that other folks have done is to cut off the neutral L-shaped prong on the 14-30 adapter so it will fit into either a 14-30 or 14-50 receptacle (remember, you can always draw less amps than an outlet's rated value, not more.) Then you can plug that into your 14-50 extension cord and not have to worry about manually setting the charging amps for the dryer outlet.
An alternative would be to use a short 14-50P-to-14-30R adapter that would go between the 14-50 extension cord and the 14-30 UMC adapter; have thought about doing this but haven't yet had the time or need for it.
Canuck
Well-Known Member
How to build a lightweight 50A extension cord
A lot of us here have made and use the lightweight one with no problems. The extra unneeded wire of the commercial ones makes them difficult to use because they don't bend very easily, aside from the unnecessary bulk and weight.
A lot of us here have made and use the lightweight one with no problems. The extra unneeded wire of the commercial ones makes them difficult to use because they don't bend very easily, aside from the unnecessary bulk and weight.
While you are correct that it makes a good cord, the one end (female) is a little more susceptible to water intrusion. I personally am also a guy who has made multitudes of adapters and cords for my 3 electric vehicles and friends etc. You really have to pay close attention to the cost of parts to make sure it does not cost more to make the cord/adapter than it does to buy it already pre-made and pre-molded.
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Canuck
Well-Known Member
I agree. I just used that thread as an example. When I made mine, I used these for the male and female ends:
Camco Power Grip Replacement Power Extension Cord Female Receptacle 50 Amp 55353 | eBay
The handle grips are nice. Water intrusion is not a concern to me but I only use mine for travel -- not everyday use.
thecloud
As rhythm raced inside, the ship came alive
As an additional source of information, I recommend reading @Cosmacelf 's excellent website:
CarCharging.us
PDF tutorial on homemade adapters
CarCharging.us
PDF tutorial on homemade adapters
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