Garlan Garner
Banned
Are you sure you are qualified to help him out? I mean your name is "Sparky"
Just kidding - I couldn't hold it.
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
Getting a home charger installed
- Thread starter thebeezknez
- Start date
-
- Tags
- Model 3
Are you sure you are qualified to help him out? I mean your name is "Sparky"
Just kidding - I couldn't hold it.
Mine is on a 125 A main, but my air conditioner is on 30 A, the dryer is 30 A and those are basically all I would need to worry about running at night besides the fridge. I can install 50 A easy.
You need far more info before saying 125 isn't enough.
Well not like worrying about it probably isn't worth the thousands of dollars it would cost to upgrade needlessly. If you already have a 200 A main breaker, great, but upgrading for the heck of it is silly.
SageBrush
REJECT Fascism
Am I reading correctly, that the electrician added up all the possible loads and concluded that an upgraded panel is required because max is > 125A ? Is that a code thing, or does the homeowner have a choice ?
I'm not sure about the codes, but the breakers on my panel already add up to more than the main. It's about load pulling at the same time. You don't have to be able to run everything in your house at once, and the legs should use less than 80% of the breaker value even when they are pulling their max.
An actual demand load calculation is a fairly complicated thing, but there are several websites that will estimate it for you. You put in the square footage of your house, number of bedrooms, various appliances, etc and it will spit out a rough demand load number. It’s should be enough to give you an idea if you’re nearing the threshold and need to have a more in-depth survey done (and possibly upgrade your service).
Example here: http://ask-the-electrician.com/residential-electrical-load-calculation.html
Example here: http://ask-the-electrician.com/residential-electrical-load-calculation.html
You really do need a load calculation and load test to see if 125 amp panel is enough to add a 50 amp breaker.
The double breakers count as a 240 V load, the single breakers count 50% as they should be some what balanced.
Right now your absolute max load is 180amps at 240V.
Your 125 amp service breaker, should be 80% de-rated, or a max continuous load of 100 amps.
Each of your "large" loads, such as AC and Dryer should only draw a max of 80%, but could peak above that for short periods of time (like when the AC first kicks on).
Once you get your overall load situation looked at, if it is still too high to comfortably add a 14-50 (with a 40amp draw), you may want to consider putting in a 14-30, which would have a 24amp draw, and would still charge a Model 3 at about 20 miles/hr (would charge a Model X at around 15-17 miles/hr). If you install a 14-30, put in a 30amp breaker, and the 14-30 outlet, but size the wire for 60 amps in case you upgrade the panel later, and want to put in a HPWC, or a 14-50 outlet. A 60 amp CB with the HPWC lets you charge a model S or X at 48 amps (and I presume model 3). The cost of the copper wire will be more expensive, but not as expensive as running it again if you upgrade.
The cost of a panel replacement may best be done when installing Solar, as your panel is not large enough, nor the right configuration for Solar, and the panel upgrade would probably count as part of the installation cost of the solar for tax incentives.
-Harry
The double breakers count as a 240 V load, the single breakers count 50% as they should be some what balanced.
Right now your absolute max load is 180amps at 240V.
Your 125 amp service breaker, should be 80% de-rated, or a max continuous load of 100 amps.
Each of your "large" loads, such as AC and Dryer should only draw a max of 80%, but could peak above that for short periods of time (like when the AC first kicks on).
Once you get your overall load situation looked at, if it is still too high to comfortably add a 14-50 (with a 40amp draw), you may want to consider putting in a 14-30, which would have a 24amp draw, and would still charge a Model 3 at about 20 miles/hr (would charge a Model X at around 15-17 miles/hr). If you install a 14-30, put in a 30amp breaker, and the 14-30 outlet, but size the wire for 60 amps in case you upgrade the panel later, and want to put in a HPWC, or a 14-50 outlet. A 60 amp CB with the HPWC lets you charge a model S or X at 48 amps (and I presume model 3). The cost of the copper wire will be more expensive, but not as expensive as running it again if you upgrade.
The cost of a panel replacement may best be done when installing Solar, as your panel is not large enough, nor the right configuration for Solar, and the panel upgrade would probably count as part of the installation cost of the solar for tax incentives.
-Harry
Similar threads
- Question
