Install a 50amp or a 60amp breaker?

[ropogigio724]

We’re getting our first Tesla next week, a Model 3 Performance that is replacing my 2019 Audi S4 so I’m very excited! I have the electrician coming to install a 14-50 outlet in the garage and run it directly from the breaker box. In a couple of years we are thinking of getting a Model Y for the wife so I kind of want to prep so it’s just quick wiring for the second charger. So my question is do I have the electrician put in a 60amp breaker now or a 50amp and later upgrade it? Can the 14-50 run on a 60amp breaker? Once we get the second car I plan then to buy two Tesla wall chargers since it will make it more efficient and a smarter charging split when both are charging at the same time. My understanding is the wall chargers get hooked up to the same line coming from the breaker box. Any suggestions?

 

[Sophias_dad]

No, the 14-50 can't have a 60 amp breaker, but feel free to oversize the wiring to support 60A(48A continuous). Also realize that there is a limit to how large a wire the 14-15 outlets will take. Your electrician can deal with that.

And actually, the Gen3 HPWC expects two separate runs to two separate breakers. The Gen2's would share a single run. See page 24 of https://www.tesla.com/sites/default...ng/Gen3_WallConnector_Installation_Manual.pdf

If you are really expecting a second HPWC, it might be wise to put a small subpanel in the garage, or install two sets of wires(if its NMB wiring). If its being run through conduit, just make sure the conduit is big enough for a second set of wires or a change to larger wires for the potential subpanel.

 

[theothertom]

I'm pretty sure the 14-50 outlet is rated for 50 amps. Any breaker is rated for 80% of faceplate amps if you use it continuously. So a 60 amp breaker would be rated for 80% of 60, or 48 amps continuous use. A 14-50 outlet should be able to handle that. I'd be careful about splitting the line to add another wall charger. The wall charger doesn't "know" it's on a split line and will try to pull the full 48 amps, which means you'll have a load of 96 amps on the line. Maybe you can reduce the amps the wall charger will draw but you'd have to remember to do that. Plus, if you sell your house the next owner probably won't know that the line is split. Safest thing is to install two outlets, each on a separate line.

 

[ropogigio724]

No, the 14-50 can't have a 60 amp breaker, but feel free to oversize the wiring to support 60A(48A continuous). Also realize that there is a limit to how large a wire the 14-15 outlets will take. Your electrician can deal with that.

And actually, the Gen3 HPWC expects two separate runs to two separate breakers. The Gen2's would share a single run. See page 24 of https://www.tesla.com/sites/default...ng/Gen3_WallConnector_Installation_Manual.pdf

If you are really expecting a second HPWC, it might be wise to put a small subpanel in the garage, or install two sets of wires(if its NMB wiring). If its being run through conduit, just make sure the conduit is big enough for a second set of wires or a change to larger wires for the potential subpanel.

This is very helpful thank you!

 

[iluvmacs]

I'm pretty sure the 14-50 outlet is rated for 50 amps. Any breaker is rated for 80% of faceplate amps if you use it continuously. So a 60 amp breaker would be rated for 80% of 60, or 48 amps continuous use. A 14-50 outlet should be able to handle that. I'd be careful about splitting the line to add another wall charger. The wall charger doesn't "know" it's on a split line and will try to pull the full 48 amps, which means you'll have a load of 96 amps on the line. Maybe you can reduce the amps the wall charger will draw but you'd have to remember to do that. Plus, if you sell your house the next owner probably won't know that the line is split. Safest thing is to install two outlets, each on a separate line.

Sorry, this is not accurate. You can't pull 48A continuous on a 14-50 outlet. The outlet ratings are to match circuit sizing, not load sizing.
As for the "split line" scenario, that's where the wall charger-to-wall charger communication link comes in. Tesla's designed that in for exactly this scenario. You definitely don't want to "do it yourself".

 

[ucmndd]

I'm pretty sure the 14-50 outlet is rated for 50 amps. Any breaker is rated for 80% of faceplate amps if you use it continuously. So a 60 amp breaker would be rated for 80% of 60, or 48 amps continuous use. A 14-50 outlet should be able to handle that.

That’s not how it works. A 14-50 outlet installed with a 60 amp breaker is absolutely, unambiguously not code compliant. Ever.

 

[ropogigio724]

Sorry, this is not accurate. You can't pull 48A continuous on a 14-50 outlet. The outlet ratings are to match circuit sizing, not load sizing.
As for the "split line" scenario, that's where the wall charger-to-wall charger communication link comes in. Tesla's designed that in for exactly this scenario. You definitely don't want to "do it yourself".

So it’s posible to use one line for two wall chargers right? At least from what I have researched, when they communicate with each other and two cars are plugged in they automatically lower what they pull correct?

 

[jrweiss98020]

So it’s posible to use one line for two wall chargers right? At least from what I have researched, when they communicate with each other and two cars are plugged in they automatically lower what they pull correct?

Yes. From the installation manual:

The Wall Connector includes an automatic load management feature whereby Wall Connector to Wall Connector communication
allows you to split the maximum available load over a maximum of 4 Wall Connectors. The wire used for this local network must:
• Share the main power cable conduit or be housed in a separate conduit. In other words, the high voltage wires must be
branched to a junction box from each individual unit.
• Be at least 18 AWG, 2 conductor, shielded, twisted-pair wire.
Warning: When load sharing, high voltage (L1, L2, Neutral, Earth) cabling must be spliced in a separate NEMA rated enclosure.
Note: Take additional precautions into consideration to prevent water ingress at the Wall Connectors when installing them
outdoors.
Note: Consult with an electrician to ensure that the installation meets local regulations.

There are further instructions on how to set them up properly.

 

[mswlogo]

Do a 60amp Wall Connector.

 

[ropogigio724]

Yes. From the installation manual:

There are further instructions on how to set them up properly.

I think I will just make sure my electrician puts in wires big enough to support a 60amp breaker but use the 50amp breaker, use the 14-50 outlet for now until we get the second car and then at that point upgrade the breaker and just get a junction box to hook up the two wall connectors. Sound about right?

 

[Sophias_dad]

Yes. From the installation manual:

That is only correct for the Gen2 HPWC/manual, which is becoming harder to find, and won't talk to a Gen3. The Gen3 HPWC doesn't need ANY wiring between the HPWC's to coordinate charging.

One more thing for OP to consider... will your main electric service even support simultaneous high-amperage charging. I have 200 amp service and certainly couldn't reliably support 96 of that heading to Teslas simultaneously.

 

[nomis_nehc]

Glad I put in a 100amp circuit so I can use 2x of my HPWC2s to pull 40amp each simultaneously.

Definitely scoop up HPWC2s if you can. From everything I've read so far, ver. 3 is a step backwards. Added the useless wifi stuff, but took away the higher charging capacity, and load balancing.

 

[SigNC]

I'd recommend you install a gen2 wall connector at 60amp with the 24ft cable and then it can reach your current and future tesla. I have this setup with 2 teslas and never had a need for a 2nd charger. Only minor hassle is having to unplug if the cable is pulled behind the person trying to leave.

 

[tilt]

I think I will just make sure my electrician puts in wires big enough to support a 60amp breaker but use the 50amp breaker, use the 14-50 outlet for now until we get the second car and then at that point upgrade the breaker and just get a junction box to hook up the two wall connectors.

This is what I did when I installed the wiring for my vehicles. I used 6 AWG THHN in conduit, this will allow 60A (48 continuous) in the future. Right now I'm only pulling 32A and using the mobile EVSE that came with the car, so I installed a 50A breaker and a 14-50 outlet. I figure if I'm going to the effort and expense to run the wiring, may as well go bigger than I currently need because I'll definitely own more EVs in the future. And they will probably be no less power hungry than what we have now.

 

[ropogigio724]

This is what I did when I installed the wiring for my vehicles. I used 6 AWG THHN in conduit, this will allow 60A (48 continuous) in the future. Right now I'm only pulling 32A and using the mobile EVSE that came with the car, so I installed a 50A breaker and a 14-50 outlet. I figure if I'm going to the effort and expense to run the wiring, may as well go bigger than I currently need because I'll definitely own more EVs in the future. And they will probably be no less power hungry than what we have now.

Yeah this the same for us. Thanks for confirming my thoughts!

 

[ropogigio724]

That is only correct for the Gen2 HPWC/manual, which is becoming harder to find, and won't talk to a Gen3. The Gen3 HPWC doesn't need ANY wiring between the HPWC's to coordinate charging.
One more thing for OP to consider... will your main electric service even support simultaneous high-amperage charging. I have 200 amp service and certainly couldn't reliably support 96 of that heading to Teslas simultaneously.

I actually have two 200 amp breaker boxes coming in with two separate lines not piggy backed to each other just two completely separate lines. My electrician said I can power the whole block with what’s coming in to the house lol

 

[eric135i]

I actually have two 200 amp breaker boxes coming in with two separate lines not piggy backed to each other just two completely separate lines. My electrician said I can power the whole block with what’s coming in to the house lol

i also had a '19 S4 that i sold to Carvana, ordered an M3P on 08/03. should be taking delivery on 09/08. i was trying to get both a Tesla Wall Connector AND a 14-50 plug installed (backup), but the electrician said it would both be on one 50a breaker. so i ended up with just installing the HWPC gen 3 on a 60a breaker. and i would not be able to install both 50a & 60a breakers cause that would potentially overload my 200a panel which is almost full.

 

[ucmndd]

One more thing for OP to consider... will your main electric service even support simultaneous high-amperage charging. I have 200 amp service and certainly couldn't reliably support 96 of that heading to Teslas simultaneously.

What on earth is your house doing overnight drawing ~100 amps for other loads that would make this a problem?

 

[Sophias_dad]

What on earth is your house doing overnight drawing ~100 amps for other loads that would make this a problem?

AC(heat pump), pool pump, clothes dryer, well pump, oven(not overnight, usually). Not saying it wouldn't work... it just wouldn't work all the time.

 

[Gasaraki]

This is very helpful thank you!

Don't listen to that guy. TESLA themselves say for 48A charging, you need a 60A breaker.

https://www.tesla.com/sites/default...ng/Gen3_WallConnector_Installation_Manual.pdf

A 14-50 plug is a 50A plug. You can't just put a 50A breaker behind a 50A plug. Yes the car will only draw 38A with the gen3 mobile charger.

What happens if you plug something in to the 14-50 50A plug that actually tried to draw 50 amps? It will just trip your 50 amp breaker.