Electrician questioning installinig a 50 amp circuit

Thanks for the info. $350 sounds very reasonable. I have an electrician coming to my house tomorrow, so I will use the number as leverage. My plan was to install a dedicated 50A service in garage. But the garage being detached and conduite for 20A service to the garage is under asphalt driveway (and probably too small to fit a new wire), it may be too expensive. If that's the case, I may have to put the receptacle closer to the service panel on the house wall.

 

If you remove the old wire from the conduit I bet there would be room to put a new one through. There is likely a 10 or 12 gauge wire currently there. Putting an 8 gauge only adds about 20% diameter. And so on if you needed 6 gauge. (I'm no electrician though, but something to ask to your guy that comes out.)

 

That's an idea I will discuss with the electrician tomorrow as an option. I think conduit is only 1/2 inch, and it has single 12AWG wire in it already. Juicebox site says I need #6AWG copper wire with 3 conductors and a ground for the 40A unit. I have no idea how big this wire is and will it fit ALONG with existing 12AWG wire? I have to keep the service for lights and freezer in garage on separate 20A circuit. Fishing the new wire through the conduit under our driveway almost 20 feet away is going to add both labor and parts cost substantially I would think.

 

I'm just wondering. If we had wireless chargers available, we may not be considering all these?

I think there are companies online that sake those stuffs?

You basically need a charging pad, that's moveable (or permanent), and a charge receptacle on the vehicle.



Dxta

 

That's only if you plan on pulling 40 amps of juice (10 kW) which is gross overkill for Prime.

 

Nop, it's not for PRIME. I am currently perfectly happy with 120V L1 taking 5+ hrs of overnight charge. This is a step before I purchase our second car which I am hoping to be either LEAF or Clarity at this point. I will only need 32A for either of those two vehicles, but the price difference for 32A and 40A L2 chargers are minimal, so I am considering bigger one.

 

I have 8-gauge wire with the 40A charger set (via software) to a max of 32A on a 40A breaker.

 

Wireless charging isn't quite ready yet. Maybe in another 5-10 years. Still too much energy loss and heat buildup to be useful yet in EVs.

 

No the problem is actually worse. To get the same KW of charge wirelessly you need more input KWs. Which means a larger circuit. At current times, I believe "in the lab" we can get 20KW transmitted at 90% efficiency. In real life, the prototypes seem to be in the 80% to 85% range.

That means the OP's 50A circuit pulling 40A max could deliver 34A (85% efficiency, 8.1KW @ 240VAC) compared to the near 99% efficiency that nice low gauge wire can provide. Then note that The on board charger is again a charging loss. The Nissan Leaf can be as bad as 70% to 80%. If we say 80% again, That's 6.5KW delivered to the car for 9.6KW of power used if we go wireless versus 7.6KW delivered to the car for 9.6KW of power used.

If we wanted to deliver to the OBC the same 9.6KW so it would charge the same as a hardwire, we'd need 47A on the input, and a 60A circuit to supply it.

 

Well, if present conduit can only fit both 12 and 8 gauge wires together but not with 12 and 6 gauge wires, I will ask an electrician to put 40A circuit and buy 32A EVSE. OTOH, if it is impossible to put two wires together in current conduit, I am not going to tear up black top to lay down another conduit under the driveway. It all depends on how much it is going to cost.