220.82 change proposals & EVSE's

[tortuga]

Now that we can view all the proposals I just came across this one Public Input No. 2407-NFPA 70-2023 from Generac of all people that proposed to treat EVSE loads differently in the residential Optional Calc.

The 2023 version of NFPA 70 (NEC) article 220, Part VI - Optional Feeder and Service Load Calculations in article 220.82 Dwelling Unit, paragraphs (A), (B), and (C) currently do not specifically address the inclusion of EVSE equipment loads. This proposes a revision of article 220.82(A) to include adding a new paragraph (D) which is to include EVSE loads into the Optional Feeder and Service Load Calculation – This corresponds with Public Input No. 2282-NFPA 70-2023. Per 2023 NEC Article 220, Part III. Feeder and Service Load Calculations: • Article 220.53 Appliance Load – Dwelling Unit(s). This demand factor shall not apply to: (5) Electric Vehicle Supply Equipment (EVSE). • Article 220.57 Electric Vehicle Supply Equipment (EVSE) Load. The EVSE load shall be calculated at either 7200 watts (volt-amperes) or the nameplate rating of the equipment, whichever is larger.

It is curious to me what is different about a EVSE load than any other residential continuous load?
A dwelling could have any number of large loads that run 3 hours or more and the optional calcs have historically taken that into account by where they set the demand factor cut off (10kw).

Mike has a different proposal 3204-NFPA 70-2023 [ Section No. 220.82(B) ]
That would lump EVSE's under B(3) and continue to allow the EVSE to be considered in the demand factor.

There are also a few other interesting proposals for 220.82 (and others in 220) such as 3239-NFPA 70-2023 [ Section No. 220.82(B) ]
from Lawrence Berkley National Labs (LBNL) that has been studying the effects of LED lighting on residential demand:

the treatment of the first 10 kW of load at 100% should be reduced to 8 kW at 100% based on analysis performed by LBNL on sub-metering data from 942 occupied US dwellings.

That is an actual funded study of almost 900 homes that shows the continuous demand is going down.

 

[jaggedben]

Good for LBNL. I almost wish that sort of thing were the threshold for a PI of this type to be submitted.

I surprised it took this long for the EV stuff to come up. Hope it doesn't end up stupid. Mike's proposal sounds okay. Still not sure why we have (A) and (B).

 

[tortuga]

Good for LBNL. I almost wish that sort of thing were the threshold for a PI of this type to be submitted.

I surprised it took this long for the EV stuff to come up. Hope it doesn't end up stupid. Mike's proposal sounds okay. Still not sure why we have (A) and (B).

LBNL has a ton of proposals for article 220 submitted its a pretty interesting read.

 

[brycenesbitt]

What this seems to be missing is EVLMS systems, which can moderate demand peaks.
For example a given circuit may be unable to handle space heating, an electric stove, hot water heater and an EVSE.
But somewhere between two and three of those loads can be interrupted for minutes or hours to level the load.
Interrupting a water for minutes is no problem, and demand rate programs will interrupt those for hours. For EVSEs the dwell time matters, yet that dwell time can readily be 10-15 hours even for a daily commuter, leaving ample time to avoid peak load.
EVSE loads start at 1440 Watts and in fact that's the most commonly used wattage for EV charging as of this writing.

 

[retirede]

EVSE loads start at 1440 Watts and in fact that's the most commonly used wattage for EV charging as of this writing.

I’m very skeptical of that. Do you have a source?

 

[brycenesbitt]

I’m very skeptical of that. Do you have a source?

I have the same interest in finding a reliable source. The carmakers through telematics have access to this data. And various California regulators have oft quoted that the majority of EV buyers end up sticking with the L1 charger that came with the car without citing a source, though there could well be one. JD Power has done some survey https://www.jdpower.com/business/pr...ic-vehicle-experience-evx-home-charging-study
What it would really take is getting access to the carmaker telematics data.

 

[retirede]

I have the same interest in finding a reliable source. The carmakers through telematics have access to this data. And various California regulators have oft quoted that the majority of EV buyers end up sticking with the L1 charger that came with the car without citing a source, though there could well be one. JD Power has done some survey https://www.jdpower.com/business/pr...ic-vehicle-experience-evx-home-charging-study
What it would really take is getting access to the carmaker telematics data.

Small sample size, but every person I know with an EV has level 2 charging capability, none less than 7 KW.