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Panel full. Please help!

Big Earl

bnkwupt
Supporting Member
Jul 12, 2017
7,016
13,908
Springfield, VA
Check out the DCC-9. It allows you to power the EV without adding breakers to the panel and without affecting the load calculation. It works by monitoring real-time load and disconnecting the EV when total panel load exceeds 80% of the main breaker rating. Very clever solution for condos and homes with small panels such as yours.


 
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Sophias_dad

Active Member
Supporting Member
Jul 29, 2018
2,224
2,547
Massachusetts
Do you think it would be safer to just install a 6-20 instead? Tie into one of the 20amp breakers?
You are mixing two questions in one.... the maximum EV draw that panel will support, and the tie-into-old-breaker question.

Its not allowed to just tie into any of the breakers with a new 240V circuit(6-20 is a 240V circuit, maybe you meant 5-20). Assuming you meant 5-20... If something is already on a 20 amp breaker(especially in that panel), its probably because its expected to take 15-20 amps, and adding an EV which will take 16 amps continuously to that would be a guaranteed trip. Additionally, since you may be nearing the limit of the panel in 240V circuits any additional load on either 120V leg has a chance of tripping the main.

You(or your electrician) would have to do a load calculation to see what capacity is left in that panel. Its probably capable of taking a 30 amp circuit(24 amp EV load), but that depends on the ratings of the various items in play. Things like ACs are frequently over-breakered due to their motor-startup requirements, but other things like the dryer and stove are less so, but still sometimes have a decent amount of overhead. If you get model numbers(or nameplate ratings) of the big loads you can get a much better idea of what capacity is left.

In your position, I'd probably combine a couple lighting circuits(assuming you find the unlabeled breakers are actually in use!) and add a breaker to get 30 amps out to the subpanel in the garage, and figure out which type of breaker/outlet to put in the garage based on the aforementioned load calculation.
 

Sophias_dad

Active Member
Supporting Member
Jul 29, 2018
2,224
2,547
Massachusetts
In your position, I'd probably combine a couple lighting circuits(assuming you find the unlabeled breakers are actually in use!) and add a breaker to get 30 amps out to the subpanel in the garage, and figure out which type of breaker/outlet to put in the garage based on the aforementioned load calculation.
Actually in your position I'd probably replace the panel, upgrading it to 125 or 150A in the process if main feed could take it without replacing the wire.
 
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You are mixing two questions in one.... the maximum EV draw that panel will support, and the tie-into-old-breaker question.

Its not allowed to just tie into any of the breakers with a new 240V circuit(6-20 is a 240V circuit, maybe you meant 5-20). Assuming you meant 5-20... If something is already on a 20 amp breaker(especially in that panel), its probably because its expected to take 15-20 amps, and adding an EV which will take 16 amps continuously to that would be a guaranteed trip. Additionally, since you may be nearing the limit of the panel in 240V circuits any additional load on either 120V leg has a chance of tripping the main.

You(or your electrician) would have to do a load calculation to see what capacity is left in that panel. Its probably capable of taking a 30 amp circuit(24 amp EV load), but that depends on the ratings of the various items in play. Things like ACs are frequently over-breakered due to their motor-startup requirements, but other things like the dryer and stove are less so, but still sometimes have a decent amount of overhead. If you get model numbers(or nameplate ratings) of the big loads you can get a much better idea of what capacity is left.

In your position, I'd probably combine a couple lighting circuits(assuming you find the unlabeled breakers are actually in use!) and add a breaker to get 30 amps out to the subpanel in the garage, and figure out which type of breaker/outlet to put in the garage based on the aforementioned load calculation.
Thanks for this. I can only see the AC/EV being used at the same time during the summer months. Charging would only be done during the overnight hours, so basically any other major appliance such as stove or dryer wouldn’t be used.

I think from a load perspective, I don’t think I would run into an issue as charging would exclusively be done during the overnight hours.
 

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