Viper67857 t1_ir3310p wrote on October 4, 2022 at 11:40 PM

Reply to comment by nocturnal311 in Wiring EV Charger by Loon610

>What would a disconnect have to do with the draw?

Would you bother with a big disconnect box for a 1A circuit running a small fan? Doubtful.. But I bet you have one going to your HVAC.

>Sub panel seems a little expensive and unnecessary

I agree.. This circuit isn't really big enough to split off additional loads unless the charger is taken out of the picture. Swapping the breaker feeding it from a 40A to a 50A and putting in a 50A subpanel would cost well over CA$100 and you could add what? A coffee maker? It's best not to run a circuit at capacity for long periods of time, especially over distance, and lv2 chargers take several hours to charge a dead EV. I wouldn't add anything to this circuit...

boxsterguy t1_ir3hylz wrote on October 5, 2022 at 1:36 AM

You're overestimating what a level 2 charger needs. 30A is more than enough to overnight charge anything less than a Hummer EV. Adding more is unnecessary and a little silly, but I wouldn't say it's necessarily unsafe.

rsfrisch t1_ir3vqqa wrote on October 5, 2022 at 3:29 AM

It depends, my gen3 Tesla charger requires a 60a 2p breaker and pulls 48a Max at 240v. You can set it lower... Either on the charger or the car. But there is still a big difference in charging times from 11kw to 5-6kw.

It's nice to have the flexibility to charge a little faster.

frollard t1_ir4h0bo wrote on October 5, 2022 at 7:37 AM

Sanity check, can support 60a breaker, not requires. You can program it to use a 15 amp if necessary.

rsfrisch t1_ir58ber wrote on October 5, 2022 at 1:03 PM

Your right, I misspoke

My point was that you should try to maximize your level 2 charger as much as possible. Charging a model y from like 20 to 90% shouldn't take more than 12hrs... And 8 hrs would be better. 30a at 240v will do that.

frollard t1_ir8f0g1 wrote on October 6, 2022 at 2:30 AM

Go for the most that is possible and reasonable, agreed to a point. There are very very few times in my 4 years I have needed to get home from a highway trip empty to need to turn around and do it again the next day. Overkill electrical is a convenience for sure but the price goes up way higher, and many people like me are stuck with 100 amp service. Jamming a current gen max spec continuous duty 60 breaker has ramifications for the whole home load calculations if I ever want a/c, heat pump, etc. Just the cost of the wire alone is astonishing these days. Upping my panel to 200a service would have long term consequences on my property tax bill for a super rare highway trip + turn around and do it again occurrence.

Viper67857 t1_ir3k6br wrote on October 5, 2022 at 1:53 AM

Transmission loss, AC/DC conversion, and keeping the battery temperature regulated draws more current than 30A to actually charge at 30A. Also, I didn't say it would be unsafe, because the breaker should trip if you're overloading the circuit, just that there isn't really room to bother adding anything.