Columns B and C in T220.55 (NEC2023)

[Abraham V]

When applying T220.55, we can get two different answers for the same scenario.
Ex. 1: 1 x 8kW range is @ 6.4 kW in Column B and 8 kW in Column C.
Ex. 2: 40 x 8kW ranges is @ 70.4 kW in Column B and 55 kW in Column C.

In these situations, should I be trying both methods and using the one that results in the smallest demand value? Or is there some secret about which is better after a certain number of units, eliminating the need to do that?

 

[wwhitney]

Don't have the table in front of me, but do the footnotes even allow the use of column B with ranges? We are instructed to use column C unless permitted otherwise in the footnotes.

Cheers, Wayne

 

[Dennis Alwon]

There has always been that situation in the code
The note 3 says we can use column A or B in lieu of C

 

[Dennis Alwon]

My thinking is that the smaller size should be used however there is no telling what the tester will want. Hopefully you wont get a question like that

 

[Abraham V]

The scenarios I wrote are from Example D4(b): Ex 1. from Application of Demand Factor and Ex 2. from Feeder Neutral Load of Main Feeder (Less House Load) (For 40 Dwelling Units). I don't see any rule they followed other than using what provided the smaller value. I suppose there is no other reason to use two different methods in the same question.

Thanks, gents.