Ok - I feel stupid but lesson learned and perhaps someone can avoid my mistake
I have a newer house with 400A service. 2 panels that are 200A - right? Well - the heat pumps are on the main outdoor panel. The 2 subs are in the basement. They are full size panels.
Well the breaker to the sub is 80A. I have 2 cars on the sub - a 20A charger and the 40A Tesla EVSE. I've had this set up for 4 months and charged both together many times.
Well, last night I forgot to plug the cars in. I have a TOU rate that ends at 6am and I have peak kw pricing so Tesla charging leads to a $50 surcharge if done during the day. I got up at 4:45 and plugged in both cars, ran the dishwasher (efficient as can be - .5A tops) and turned on the coffee maker - 1-2A tops for a few seconds here and there.
My egauge peaked at 16 kw - which I have exceeded many times before (although when I have been over 20 - it was hot water which is on the other panel).
Either way - not 80A - right? I'm guessing the refrigerator compressor fired up? 80% continuous I get so maybe that was it - 64A. But looking at the monitor I never really breached 16kw - if I did, it was seconds and not continuous. I did run at 15.8 for 10 minutes. I'm sure these things aren't exact but I would have thought the breaker could handle that.
Lesson learned - I can't use 200A from that panel. Don't push it in general. But still curious why it popped. I dialed down the Tesla to 20A. I am at 120 miles and I'll be fine - long day but have charging options. The Leaf isn't going far today - and wife can charge when the sun hits the panels....
I have a newer house with 400A service. 2 panels that are 200A - right? Well - the heat pumps are on the main outdoor panel. The 2 subs are in the basement. They are full size panels.
Well the breaker to the sub is 80A. I have 2 cars on the sub - a 20A charger and the 40A Tesla EVSE. I've had this set up for 4 months and charged both together many times.
Well, last night I forgot to plug the cars in. I have a TOU rate that ends at 6am and I have peak kw pricing so Tesla charging leads to a $50 surcharge if done during the day. I got up at 4:45 and plugged in both cars, ran the dishwasher (efficient as can be - .5A tops) and turned on the coffee maker - 1-2A tops for a few seconds here and there.
My egauge peaked at 16 kw - which I have exceeded many times before (although when I have been over 20 - it was hot water which is on the other panel).
Either way - not 80A - right? I'm guessing the refrigerator compressor fired up? 80% continuous I get so maybe that was it - 64A. But looking at the monitor I never really breached 16kw - if I did, it was seconds and not continuous. I did run at 15.8 for 10 minutes. I'm sure these things aren't exact but I would have thought the breaker could handle that.
Lesson learned - I can't use 200A from that panel. Don't push it in general. But still curious why it popped. I dialed down the Tesla to 20A. I am at 120 miles and I'll be fine - long day but have charging options. The Leaf isn't going far today - and wife can charge when the sun hits the panels....
