EV Chargers and Optional Service Calculation

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SoFloBuc

SoFloBuc

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South Florida
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Manager for Electrical. plumbing and AC shop
Building department down here in South Florida is giving me an issue for including an EV charger in my load calculation (using optional method 220.83) under the fixed appliance section and told i cant use the demand factor and have to include the full load @100%. I Call Bull Spit!! See plan review comment....

EV charger is considered a continuous load as per NEC 625.42EV charger load needs to be calculated at 100% and not part of the demand reduction.

This is for branch circuit load not feeder! I even included the extra 25% in the calculation bringing the EV charger from 9600 KV to 12000 KV before adding the Load Factor. PS I use the Mike Hold Residential Load Calc on the app, its awesome!! I am posting this it is because it does make a difference whether the customer can have a charger installed legally or not with his current service.
 
SoFloBuc said:
Building department down here in South Florida is giving me an issue for including an EV charger in my load calculation (using optional method 220.83) under the fixed appliance section and told i cant use the demand factor and have to include the full load @100%. I Call Bull Spit!! See plan review comment....

EV charger is considered a continuous load as per NEC 625.42EV charger load needs to be calculated at 100% and not part of the demand reduction.

This is for branch circuit load not feeder! I even included the extra 25% in the calculation bringing the EV charger from 9600 KV to 12000 KV before adding the Load Factor. PS I use the Mike Hold Residential Load Calc on the app, its awesome!! I am posting this it is because it does make a difference whether the customer can have a charger installed legally or not with his current service.
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What code edition are you on?
 
While there was a change in the 2023 that addresses EVSE in the standard calculation, there was no change and not even an Public Input to address it in the optional calculation.
However, it appears to me that 625.42 in the 2020 code requires the feeder and service to be calculated based on the rated load of the EVSE.
The language in that section in the 2017 does not really address the issue like it does in the 2020.
 
don_resqcapt19 said:
However, it appears to me that 625.42 in the 2020 code requires the feeder and service to be calculated based on the rated load of the EVSE.
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Are you referring to the sentence "Service and feeder shall be sized in accordance with the product ratings"?

That doesn't seem specific enough to overrule the optional load calc's 40% factor on loads over 10 kVA. It just says to use the product rating as the input to your calculation; it doesn't say the final result needs to reflect that input with a coefficient of 1.0.

Cheers, Wayne
 
don_resqcapt19 said:
While there was a change in the 2023 that addresses EVSE in the standard calculation, there was no change and not even an Public Input to address it in the optional calculation.
However, it appears to me that 625.42 in the 2020 code requires the feeder and service to be calculated based on the rated load of the EVSE.
The language in that section in the 2017 does not really address the issue like it does in the 2020.
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We are still 2017 here, he even referenced that fact in another comment that was pretty picky too, but I did it.
 
SoFloBuc said:
17
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EV Chargers appear to meet the definition of an Appliance in article (100). 220.83(A)(3)(a) All appliances that are fastened in place, permanently connected, or located to be on a specific circuit.
Where is the building department getting their information on how to calculate it otherwise?
 
wwhitney said:
Are you referring to the sentence "Service and feeder shall be sized in accordance with the product ratings"?

That doesn't seem specific enough to overrule the optional load calc's 40% factor on loads over 10 kVA. It just says to use the product rating as the input to your calculation; it doesn't say the final result needs to reflect that input with a coefficient of 1.0.

Cheers, Wayne
Click to expand...
It can be read a number of ways.
 
SoFloBuc said:
Building department down here in South Florida is giving me an issue for including an EV charger in my load calculation (using optional method 220.83) under the fixed appliance section and told i cant use the demand factor and have to include the full load @100%. I Call Bull Spit!! See plan review comment....

EV charger is considered a continuous load as per NEC 625.42EV charger load needs to be calculated at 100% and not part of the demand reduction.

This is for branch circuit load not feeder! I even included the extra 25% in the calculation bringing the EV charger from 9600 KV to 12000 KV before adding the Load Factor. PS I use the Mike Hold Residential Load Calc on the app, its awesome!! I am posting this it is because it does make a difference whether the customer can have a charger installed legally or not with his current service.
Click to expand...
After taking another look at 220.83 I might be a little more inclined to go with the building department on this one. Even though it is not really totally clear in this section about Electrical Vehicle Chargers. You Stated that you took the original 9,600 * 1.25 to get 12,000 before applying 220.83…..if you took 40% of the remaining load you are actually cutting the actual rating 9,600 in half! 12,000 * 40% = 4,800 Watts. So a continuous load is only counting as half of its actual rating. I do not have all the calculations that you have in front of me so I am just simplifying the information I have! I know that this can be debated ….but the building department has some accountability also! Just throwing this out there. Not necessarily saying my opinion is the answer. Hopefully in the 2026 NEC….it will be clearer on how to calculate these !
 
I've had an AHJ or two do that same thing.

I can kind of see their point. An EV charger runs continuously for a long time without cycling on and off like most other loads. If it ever runs at the same time as an air conditioner those things will likely exceed the 8 or 10kw that the optional methods count at 100%.
 
Is the EV charger really an appliance? The charger is in the car, and the car is certainly not fixed in place
 
HEYDOG said:
After taking another look at 220.83 I might be a little more inclined to go with the building department on this one. Even though it is not really totally clear in this section about Electrical Vehicle Chargers. You Stated that you took the original 9,600 * 1.25 to get 12,000 before applying 220.83…..if you took 40% of the remaining load you are actually cutting the actual rating 9,600 in half! 12,000 * 40% = 4,800 Watts. So a continuous load is only counting as half of its actual rating. I do not have all the calculations that you have in front of me so I am just simplifying the information I have! I know that this can be debated ….but the building department has some accountability also! Just throwing this out there. Not necessarily saying my opinion is the answer. Hopefully in the 2026 NEC….it will be clearer on how to calculate these !
Click to expand...
I added the 25% after the factor as a separate line item with the AC load
 
To clarify I added the appliance load (with factor) the AC loads and then the 25% of the EV. Not originally but now
 
SoFloBuc said:
Building department down here in South Florida is giving me an issue for including an EV charger in my load calculation (using optional method 220.83)
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Are you really using NEC 2017 220.83 existing dwelling unit? Or 220.82 Optional calc?
 
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