Settle a Bet on 220.12(A)

[winterovereverything]

Happy Friday Folks,

Before wrapping up work in the office today, a coworker and I shared a difference in opinion about the correct application of Table 220.12 in the 2020 NEC. As far as I am aware, 220.12 is used to calculate branch circuits with lighting loads so long as the actual fixtures themselves do not exceed the value of that which is calculated through the table. A coworker of mine shared a different perspective, that 220.12 supersedes the values of lighting fixtures installed in a branch circuit. The way that I have always performed my calculations is to consider both and that whichever load is higher (either 220.12 or lighting fixture load) is what would determine the branch circuit size. Am I wrong? By all accounts 220.10 and 220.12(A) seem to reiterate my point but I'm curious to hear your thoughts about this.

-WOVA

 

[tjdilly]

Table 220.12 in my opinion is out of date for most states for anything other than a conservative service sizing & branch circuit quantity. With the adoption of IECC 2015+ in the vast majority of states the wattage per square foot limitations are much lower than 220.12 when it comes to actual specified light fixture wattages. I always use the actual lighting loads for branch circuiting, and 220.12 in my service calculations.

I don't even think it's possible to exceed the values in 220.12 unless you are ignoring IECC/Ashrae 90.1/Title 24.