10-30 to 14-30 adapter and charging advise

[sumitkgarg]

something more sophisticated that can prevent your central A/C from running while you are charging your car. Interrupting the low voltage cable going to the A/C compressor unit that tells it to turn on is pretty easy to do. This is commonly used as a load management strategy for whole house backup generators.

I don't think that I want to hook it up to my AC. It would suck to pick between the car and AC on a hot night. Dryer buddy seems like the best option for me so far.

 

[sumitkgarg]

check if your 10-30 socket is actually wired with #10/3 wire (10 gauge + red + black + white + ground - in my case the ground was ground to the box and I used a multimeter to check that it was indeed grounded (+120 volts each phase to ground). So i just changed mine to 14-30 (I have a gas dryer). Then used the official 14-30 adapter. Works great charges at 18mi/hr which is totally fine.

So far have put off the 14-50 install which will require a new set of wires to be pulled (which reading the forums #6 gauge wire is recommended?)

Always double and triple check all power is indeed shutoff using a multimeter to test while it's on and confirm that it's off.

As for 14-30 extension cords there is one on amazon (AC Connectors NEMA 14-30 4 Prong Dryer SOOW 10/4 30A 250Volt Anti-Weather, Oils, Acids and Chemicals Rubber Extension Cord (10FT) - - Amazon.com) but I didn't like the rubbery smell plus I figured a 14-50 cord has much more versatility if I go on a roadtrip or do upgrade to 14-50 later on.

So I have this : 14-30 socket --> 14-30 to 14-50 pigtail from amazon --> 18' 14-50 cord --> 14-50 to 14-30 receptacle --> tesla 14-30 adapter to Tesla charger. (Kind of a mess but this ensures that the car will never attempt to charge more than 24A since using a genuine Tesla 14-30 adapter. I could hook directly to the wall but the cord is a bit short so that's why this extension). If anyone is interested in the parts I ordered I can list those from amazon.

I still haven't opened up my 10-30 to see how its wired. Thanks for offering the part links - I guess I should be able to find them on Amazon myself as well.

 

[MP3Mike]

This is the best answer ... safely share a 30A dryer outlet with your EVSE

Dryer Buddy

How does it make it "safe" to share? All it does is split the one outlet to two, and give you a meter to show how many amps you are using. You can still run both the car and dryer at full draw and trip your breaker.

 

[davewill]

How does it make it "safe" to share? All it does is split the one outlet to two, and give you a meter to show how many amps you are using. You can still run both the car and dryer at full draw and trip your breaker.

He was probably thinking of the Dryer Buddy Plus which only allows one outlet to be live at once.

 

[sumitkgarg]

He was probably thinking of the Dryer Buddy Plus which only allows one outlet to be live at once.

Yes, this is my current choice as well.

 

[FlatSix911]

Then the only code compliant solution is to either upgrade the panel and service or use special equipment to prevent two high-load devices from running simultaneously. This can be a Dryer-Buddy or something more sophisticated that can prevent your central A/C from running while you are charging your car. Interrupting the low voltage cable going to the A/C compressor unit that tells it to turn on is pretty easy to do. This is commonly used as a load management strategy for whole house backup generators.

Easy solution ... just install a load transfer switch.

 

[sumitkgarg]

Easy solution ... install a load transfer switch.

View attachment 241619

Any DIY instructions on this? Looks interesting.

 

[FlatSix911]

Any DIY instructions on this? Looks interesting.

I had my electrician install the switch to transfer loads as needed. Saved me from upgrading my 200A service to 400A

 

[miimura]

Easy solution ... install a load transfer switch.

Right you are. Here is another one suitable for a dryer circuit:

GE 30 Amp 240-Volt Non-Fused Indoor General-Duty Double-Throw Safety Switch-TC35321 - The Home Depot

Note the ON - OFF - ON positions instead of the normal ON - OFF switch positions that you find on a normal disconnect switch.

 

[sumitkgarg]

Any instructions on how to hook it up?

 

[tga]

How will I plug the Tesla 14-30 adapter in a 14-50 receptacle? I think the connectors differ a little bit. I don't want to use the Tesla's 14-50 adapter because I may forget to set the charging amps down to 24Amps in the car. Don't want to risk anything there. I have Zinsco circuit breakers and from reading some other posts, I'd like to make sure that the car "never" tries to draw more than 24Amps.

You really, really, really want to get rid of those Zinsco breakers, Tesla or no Tesla. In the process, you can add in a service upgrade and a bigger panel with room to add more breakers later.

I installed a 14.50 in an hour. Go to home depot, buy 14.50 box complete, roll of 8.3, 50amp double breaker. Very easy
Watch ten you tube videos. Very easy.
Elementary Watson

Wrong!!! 8ga romex is good for 40A breaker (32A charging) max. You need 6/3 to be legal/code compliant with a 50A breaker (40A charging).

check if your 10-30 socket is actually wired with #10/3 wire (10 gauge + red + black + white + ground - in my case the ground was ground to the box and I used a multimeter to check that it was indeed grounded (+120 volts each phase to ground). So i just changed mine to 14-30 (I have a gas dryer). Then used the official 14-30 adapter. Works great charges at 18mi/hr which is totally fine.

Actually, most 10-30 outlets I've looked at are wired with 10/3 romex and can easily (and legally) converted to a 14-30. You can't (legally) wire a 10-30 with 10/2. The third pin on the 10-30 is a neutral (a current carrying conductor), not ground, and you can't use the 10/2's bare ground wire as a current carrying conductor. So you're stuck with 10/3 (black/red for hots, white for neutral, and bare unused/connect to a metal box). Therefore, easy to change to a 14-30.

Also, I'd consider changing the 14-50's on the cord to 14-30's (if you never want to extend a 14-50). You'll have fewer potential failure points with fewer connections.

 

[sumitkgarg]

So I opened up my 10-30 receptacle and the outlet box has a bare wire (aluminum) that seems to be somehow hooked to the metal outlet box itself. I assume that that wire can be used to properly convert this outlet to a 14-30. Is there any way I can tell if this ground wire is actually grounded properly?

 

[miimura]

Any instructions on how to hook it up?

You can use the safety switch to power one device from two different power sources or you can power either of two devices from one power source. All you have to do is wire the circuit from the panel to the middle of the switch (the moving blades) and wire each load to the top or bottom contacts. This particular unit may not include grounding blocks or any way to bond the Neutral wires together, so additional parts may be needed. If you are not comfortable doing this, please get an electrician or a skilled friend to do it for you.

 

[cybergates]

A multimeter is a great tool to have and cheap. Safety first. i checked my ground wire grounded to the box by checking voltage between it and the black or red wires (hot). If u have 120v it is properly grounded. Between black and white (neutral) or the red and white it should also be 120v

One could test the ground pin of a nearby 110 outlet for continuity to the ground wire of the 220 outlet just to be sure using the resistance setting of the multimeter- it should be close to 0.000 - no resistance i.e. Both grounds lead to the same point

Be careful as if u do this u are testing live wires. Use the same meter to make sure all power is definitely off before connecting or disconnecting the socket

Not sure about aluminum if any precautions need to be taken - maybe an electrician can comment. Mine was copper

So I opened up my 10-30 receptacle and the outlet box has a bare wire (aluminum) that seems to be somehow hooked to the metal outlet box itself. I assume that that wire can be used to properly convert this outlet to a 14-30. Is there any way I can tell if this ground wire is actually grounded properly?

 

[sumitkgarg]

Thanks for the info.

Safety first

Always!

 

[tga]

So I opened up my 10-30 receptacle and the outlet box has a bare wire (aluminum) that seems to be somehow hooked to the metal outlet box itself. I assume that that wire can be used to properly convert this outlet to a 14-30. Is there any way I can tell if this ground wire is actually grounded properly?

If you have Al wire, you really should get an electrician involved. IMHO, aluminum wire is above most DIY'ers ability (mine included - I won't mess with it).

Also, do some research on Zinsco (google it). The breakers can come loose from the bus bar and cause arcing and fire, even under normal loads. It's not just a "stuck on and not trip when overloaded" problem (although they can do that, too).

Be careful as if u do this u are testing live wires. Use the same meter to make sure all power is definitely off before connecting or disconnecting the socket

If you are using an ohm meter on wires, make sure all power is off (turn off the main breaker). If the circuits are powered up, you'll either get false readings or trash your meter (been there, done that).

 

[cybergates]

Thanks for the info.


Always!

I think you should get that panel upgraded. I had to get my 70's panel changed out for solar last year (not zinsco). Also see @tga comments above about aluminium - maybe you should get a dedicated run of cable installed.

Lots of bad stuff i read on here about zinsco panels and breakers (google it) as your car is going to be charging like 12 hrs on a 14-30 circuit for example daily.

 

[KJD]

The Home charging FAQ has this.
FAQ: Home Tesla charging infrastructure Q&A

MY FAMILY MEMBERS HAVE ONLY AN OLD-STYLE NEMA 10-30 ELECTRIC DRYER OUTLET AVAILABLE, CAN I MAKE AN ADAPTOR CORD TO THE TESLA’S 14-50 UMC PLUG FOR IT?

This is not recommended, because it has a medium safety risk associated with it. Instead, use the appropriate Tesla adapter for the UMC which will properly restrict the maximum amount of current drawn by the car.

DO NOT make this type of adaptor cord under any circumstances if you have a Federal-Pacific Electric or Zinsco/Zinsco-Sylvania circuit breaker panel – CHECK THIS! The potential for the car accidentally drawing too much current, and the high failure rate of breakers in these panels is of high risk!

 

[FlatSix911]

The Home charging FAQ has this.
FAQ: Home Tesla charging infrastructure Q&A

I wish people would not selectively quote the FAQ and just tell the complete story...

MY FAMILY MEMBERS HAVE ONLY AN OLD-STYLE NEMA 10-30 ELECTRIC DRYER OUTLET AVAILABLE, CAN I MAKE AN ADAPTOR CORD TO THE TESLA’S 14-50 UMC PLUG FOR IT? This is not recommended, because it has a medium safety risk associated with it. Instead, use the appropriate Tesla adapter for the UMC which will properly restrict the maximum amount of current drawn by the car.

DO NOT make this type of adaptor cord under any circumstances if you have a Federal-Pacific Electric or Zinsco/Zinsco-Sylvania circuit breaker panel – CHECK THIS! The potential for the car accidentally drawing too much current, and the high failure rate of breakers in these panels is of high risk!

If you insist upon making a cord, follow the same instructions for the 10-50 adapter cord but use a 10-30P plug instead, and you may use 10/4 cable instead of 6/4. Follow the instructions above for using adaptor cords.

You will need to set the charge current down to a maximum of 24A in the Tesla (80% of rated circuit) and ensure it remains there when you charge. While technically you could set it to 30A, plugs and receptacles rated for 30A are not intended to be used for continuous loads at full rated capacity, and members of the forum have reported burned/destroyed plugs from running the circuits this hot. If the car is not set down to a lower charging current, it is likely that the circuit breaker will trip if the car tries to draw the full 40A across the circuit. Again, this carries a medium risk, and in case of fire you are likely to find that your homeowner’s insurance company will not cover you in case of a fire, regardless of whether or not the cord is the cause.

 

[sumitkgarg]

Thanks to so much great info in these forums from you guys, this is what my current plan is:

At a high level, my plan is to use the 10-30r (or 14-30r) receptacle in the wall with Tesla's official 14-30p adapter on the other end. I think that takes care of the accidental current overdraw and because of that, I don't think that I need to do anything special with my Zinsco breakers. The risk with the Zinsco breakers, as I understand, for me remains the same as before.

At a little bit detailed level, the in wall receptacle will be hooked to Dryer Buddy Plus so that the car charging can be shared with my dryer. The "plus" part of the Dryer Buddy will ensure that there is only one outlet powered at a time. In addition to this, I will be using an extension cord (14-30p to 14-30r with proper gauge for indoor use only) to comfortably reach the car from the Dryer Buddy Plus location.

Btw - why are extension cords frowned upon? Is there anything I can do to ensure safety with this extension cord in my situation?