What is the biggest amp outlet i could use? 125A sub-panel is full otherwise, but outlet would be only a few feet away and charge cable wouldn't need to be longer than 10 feet.
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What is the biggest amp outlet i could use? 125A sub-panel is full otherwise, but outlet would be only a few feet away and charge cable wouldn't need to be longer than 10 feet.
So the breakers are 40A? I would suggest installing a 10-30 or 14-30 so you'd be charging at 24A.
Great question. That makes me wonder about my unused electric dryer outlet too. Although I think dryers use less juice than ovens. How about it, anybody in the know?
What is the biggest amp outlet i could use? 125A sub-panel is full otherwise, but outlet would be only a few feet away and charge cable wouldn't need to be longer than 10 feet.
You cannot install a new NEMA 10-30R receptacle; you may only replace one that was installed/added prior to NEC 1996. Adding a new permanent NEMA 10 series receptacle (30A or 50A) will fail inspection. Furthermore, with only one exception -- 15A receptacles on 20A 120V circuits -- the overcurrent protection (breaker size) must be equal to or less than the receptacle's rating. You are not permitted to install a NEMA 14-30R on a branch circuit with a 40A circuit breaker, it will fail inspection.
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The NEC is fairly specific about certain appliance outlets. As Lloyd said, you may not share certain appliance circuits for another purpose like car charging. You may repurpose the breaker, and wiring accordingly to move the circuit if you need to. For general purpose use, you may wire multiple receptacles on a single branch circuit (for example, you are permitted to have 2 NEMA 14-50R's installed on a single branch circuit - but that breaker MUST be 50A and you couldn't draw more than that across both outlets). I would have to look deep in my NEC book about the dryer outlet, but I do know that a residential installed range/oven is not permitted to be shared with a second receptacle.
Your best bet -- if you don't use the electric dryer outlet -- is to run new wiring, use the dryer's breaker spot, and install a NEMA 14-50R in the garage.
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Oh goody... the engineer's answer: "it depends". This depends upon wire size that comes from the circuit. If the circuit is a 40A circuit, I'm guessing you either have a direct-wire appliance, or a 50A receptacle on it already. As noted you will not be permitted to share the oven circuit - so it will have to be repurposed, so does that mean you'll be reusing existing wiring (just perhaps reversing the box through the garage wall instead of the kitchen or something)? Or will you be running new wiring? If new wiring, just run 6/3 plus ground to the breaker box, replace the breaker with a 50A breaker (they're not too expensive), and install a NEMA 14-50R.
If you're using existing wiring:
If the wire is #6 copper, you can replace the breaker with 50A. If you have 3 jacketed conductors plus a bare ground (either via wire or metal conduit), use NEMA 14-50P. if you have 3 jacketed conductors without a bare ground, label the white wire ends with green tape and install a NEMA 6-50P, move the white wire in the panel to the bare bus bar and wrap the end with green tape. If you have 2 jacketed conductors with a bare ground, install a NEMA 6-50P.
If the wire is #8 copper, you will only be able to install a 30A receptacle even though the wire could handle 40A; this is because NEMA 40A receptacles/plugs aren't readily available. You will be required also to change the breaker to 30A. Like above, 3 jacketed conductors plus bare ground means you can use NEMA 14-30R, otherwise you'll need to use NEMA 6-30R. Keep in mind Tesla doesn't have the adapters for these outlets yet, they are currently supplying standard 120V, NEMA 14-50P, and NEMA 6-50P (to people who have HPWC's on order).
If the installation is older and uses aluminum wiring, you'll need one size larger (#4 AL instead of #6 CU, #6 AL instead of #8 CU). You'll need receptacles and breakers that are rated for AL wiring too - be sure it says that. Other local codes may apply. When in doubt, hire an electrician.
My dryer plug in garage turned out to be 50w similar to welding equipment and can be converted to the nema 6-50 plug per the Solar city electrician I had come. He thought the wires were fine. How do you know the gauge # wire? Is it labeled on wire supposedly?
Two ways - you can look on the insulation, where it's typically embossed or printed, or you can measure the diameter of the wires (the conductors only, not including insulation).
#8 is 3.25 mm, #6 is 4.11 mm in diameter.
If the breaker is already 50A, and you have a 50A receptacle on it, your wire size should be fine. Otherwise you'll need to look at the wire size before determining maximum breaker size you can put on it.
Oh goody... the engineer's answer: "it depends". This depends upon wire size that comes from the circuit. If the circuit is a 40A circuit, I'm guessing you either have a direct-wire appliance, or a 50A receptacle on it already. As noted you will not be permitted to share the oven circuit - so it will have to be repurposed, so does that mean you'll be reusing existing wiring (just perhaps reversing the box through the garage wall instead of the kitchen or something)? Or will you be running new wiring? If new wiring, just run 6/3 plus ground to the breaker box, replace the breaker with a 50A breaker (they're not too expensive), and install a NEMA 14-50R.
If you're using existing wiring:
If the wire is #6 copper, you can replace the breaker with 50A. If you have 3 jacketed conductors plus a bare ground (either via wire or metal conduit), use NEMA 14-50P. if you have 3 jacketed conductors without a bare ground, label the white wire ends with green tape and install a NEMA 6-50P, move the white wire in the panel to the bare bus bar and wrap the end with green tape. If you have 2 jacketed conductors with a bare ground, install a NEMA 6-50P.
If the wire is #8 copper, you will only be able to install a 30A receptacle even though the wire could handle 40A; this is because NEMA 40A receptacles/plugs aren't readily available. You will be required also to change the breaker to 30A. Like above, 3 jacketed conductors plus bare ground means you can use NEMA 14-30R, otherwise you'll need to use NEMA 6-30R. Keep in mind Tesla doesn't have the adapters for these outlets yet, they are currently supplying standard 120V, NEMA 14-50P, and NEMA 6-50P (to people who have HPWC's on order).
If the installation is older and uses aluminum wiring, you'll need one size larger (#4 AL instead of #6 CU, #6 AL instead of #8 CU). You'll need receptacles and breakers that are rated for AL wiring too - be sure it says that. Other local codes may apply. When in doubt, hire an electrician.
Thanks, and let me clarify based on your answer. I'd run all new wire and get a new outlet. Your answer is great and I'm just left with one question: Can I keep using the same breaker with a 14-50 or what could I use with the current breaker? I believe I just need to get at least 8 miles/hour of charge.
I'm worried about maxing out the sub-panel, but I didn't know about the need to tell the car about the reduced Amp *EVERY* time I charge the car. That would be a huge red flag. Do I just add up all the breakers in the sub-panel to see how close I'm at to maxing it out? Also, I don't have access the main panel as I'm in a townhouse and really don't know which main panel services my unit.Just curious -- any reason you want to keep the existing breaker?
I'm worried about maxing out the sub-panel, but I didn't know about the need to tell the car about the reduced Amp *EVERY* time I charge the car. That would be a huge red flag. Do I just add up all the breakers in the sub-panel to see how close I'm at to maxing it out? Also, I don't have access the main panel as I'm in a townhouse and really don't know which main panel services my unit.
The breaker you need is a Murray MP250 2-pole 50 amp circuit breaker. Amazon sells it for $11.57.
You have room for an additional breaker! There is one slot available at the bottom of each row. You don't need to re-purpose your range! Just buy a breaker, move two 1/2 's to the other side and you are good to go!
Or Square D
Right, I missed the two top slots.
I'm worried about maxing out the sub-panel, but I didn't know about the need to tell the car about the reduced Amp *EVERY* time I charge the car. That would be a huge red flag. Do I just add up all the breakers in the sub-panel to see how close I'm at to maxing it out? Also, I don't have access the main panel as I'm in a townhouse and really don't know which main panel services my unit.
You have room for an additional breaker! There is one slot available at the bottom of each row. You don't need to re-purpose your range! Just buy a breaker, move two 1/2 's to the other side and you are good to go!