Tesla charger

J

JDB3

Senior Member
Location
San Antonio, Texas
Customer has bought a Tesla vehicle & charger. Instructions that he has given me so far, says to direct wire it & it takes 48 amps. Would this be considered continuous duty & would use #6 Copper with #8 ground, on a 50 amp circuit breaker ? I have never wired one of these before & I am pretty much retired. If not for an existing customer, I would have passed on this. Thanks
 
JDB3 said:
Customer has bought a Tesla vehicle & charger. Instructions that he has given me so far, says to direct wire it & it takes 48 amps. Would this be considered continuous duty & would use #6 Copper with #8 ground, on a 50 amp circuit breaker ? I have never wired one of these before & I am pretty much retired. If not for an existing customer, I would have passed on this. Thanks
Click to expand...

Yes read 625.41 calls for the branch circuit ocpd to be factored at 125% of the max load of the equipment
a 60 amp circuit is needed for a 48 amp charging station .
There’s no issue with supplying the charger with a 50 amp circuit either . But you’re charging speed will be 40 amps with a 50 amp ocpd


Sent from my iPhone using Tapatalk
 
infinity said:
How would the charger know that? Are you required to change a setting in the charger?
Click to expand...

1cbef4739a3922ba9b22590f02e8a657.jpg

Yes you go into the installation settings and adjust the charging speed to line up with the size of your Branch circuit ocpd


Sent from my iPhone using Tapatalk
 
infinity said:
So I'm guessing that you could leave this thing set to 48 amps on a 50 amp circuit without anything but a code issue.
Click to expand...

Yes . Unless the installer adjusts the charging speed the charger has the capability of charging at 48 amps , which is a violation but the charger will function properly


Sent from my iPhone using Tapatalk
 
Jaybone812 said:
Yes read 625.41 calls for the branch circuit ocpd to be factored at 125% of the max load of the equipment
a 60 amp circuit is needed for a 48 amp charging station .
There’s no issue with supplying the charger with a 50 amp circuit either . But you’re charging speed will be 40 amps with a 50 amp ocpd


Sent from my iPhone using Tapatalk
Click to expand...
Thanks, since I didn't know the length of the charging time, I wasn't sure about the 1255
infinity said:
How would the charger know that? Are you required to change a setting in the charger?
Click to expand...
That is what I was wondering. Just built in "smart" charger ?
 
Jaybone812 said:
Yes . Unless the installer adjusts the charging speed the charger has the capability of charging at 48 amps , which is a violation but the charger will function properly


Sent from my iPhone using Tapatalk
Click to expand...
When you say a violation, do you mean because of not applying the 125 % factor ?
 
JDB3 said:
When you say a violation, do you mean because of not applying the 125 % factor ?
Click to expand...

Yes. 625.42 says evse charging loads are continuous loads and 625.41 says the ocpd is factored at 125% of kw rating . Your 50 amp ocpd is not sized correctly for a 48 amp continuous load


Sent from my iPhone using Tapatalk
 
Jaybone812 said:
Yes. 625.42 says evse charging loads are continuous loads and 625.41 says the ocpd is factored at 125% of kw rating . Your 50 amp ocpd is not sized correctly for a 48 amp continuous load
Click to expand...
Yup but the charger would never know if it were connected to a 50 or 60 amp branch circuit.
 
infinity said:
Yup but the charger would never know if it were connected to a 50 or 60 amp branch circuit.
Click to expand...
As a 50A breaker is relatively common, I would have to guess that there are a lot of 48A chargers out there being supplied by them.

My thought would be a great deal of these chargers are installed and wired by homeowners with help from a YouTube video.

Just my useless .02 worth.
 
nizak said:
As a 50A breaker is relatively common, I would have to guess that there are a lot of 48A chargers out there being supplied by them.

My thought would be a great deal of these chargers are installed and wired by homeowners with help from a YouTube video.

Just my useless .02 worth.
Click to expand...

You’re definitely right , it’s extremely common . And recently every QR code I’ve scanned for a Tesla charging station has required access to the Tesla installer app to make any adjusted to the settings or register the device so it’s going to continue to happen




Sent from my iPhone using Tapatalk
 
Last edited:
nizak said:
As a 50A breaker is relatively common, I would have to guess that there are a lot of 48A chargers out there being supplied by them.

My thought would be a great deal of these chargers are installed and wired by homeowners with help from a YouTube video.

Just my useless .02 worth.
Click to expand...
Hence why we see so many reports of melted 50A receptacles LOL
 
Jaybone812 said:
You’re definitely right , it’s extremely common . And recently every QR code I’ve scanned for a Tesla charging station has required access to the Tesla installer app to make any adjusted to the settings or register the device


Sent from my iPhone using Tapatalk
Click to expand...
I’ve seen several brands that have a dip switch type set up that allows for physical changing of the charging levels.
 
infinity said:
So I'm guessing that you could leave this thing set to 48 amps on a 50 amp circuit without anything but a code issue.
Click to expand...
I'd wager you'd more likely get melted receptacles and/or tripped breakers, especially if the breaker terminal lugs aren't torqued properly.

What would probably only be a code issue is using 6awg NM instead of a 75C rated wiring method.
 
Thanks for all of the comments. As this is an older house (big house, don't know square footage), with a 200 amp service, I'm starting to wonder about the service size? Best that I remember, it has 2 electric water heaters, electric range & dryer, electric furnace (older one), etc. What do you'll think ?? Thanks, again !
 
JDB3 said:
Thanks for all of the comments. As this is an older house (big house, don't know square footage), with a 200 amp service, I'm starting to wonder about the service size? Best that I remember, it has 2 electric water heaters, electric range & dryer, electric furnace (older one), etc. What do you'll think ?? Thanks, again !
Click to expand...

My money is on the charger install will be okay even with it being used at the 48A with 60A breaker and 60A of wire.

I would suggest doing a quick NEC 220 optional method for all the existing and then add the EV charging load to that.

200A panel is pretty large in comparison to some of the "older" homes I have seen. If it was a 100A panel I would say you might just have to derate the output of the charger to whatever remainder you got left.
 
Elect117 said:
My money is on the charger install will be okay even with it being used at the 48A with 60A breaker and 60A of wire.

I would suggest doing a quick NEC 220 optional method for all the existing and then add the EV charging load to that.

200A panel is pretty large in comparison to some of the "older" homes I have seen. If it was a 100A panel I would say you might just have to derate the output of the charger to whatever remainder you got left.
Click to expand...
Thanks. The best that I recall about the entire service, is that an older 200 amp breaker is feeding, the entire inside panel. I have heard of the outside breaker being hard/un-able to be turned back on when turned off. Wish I had taken some pictures of the set-up years ago.
 
You must log in or register to reply here.
Top