Service Calcs + Continuous Loads

[Keri_WW]

Hello everyone

Over the years I have noticed a few engineers who perform service calcs by applying 125% to continuous loads such as lighting and water heating. I've also noticed others, including myself, who do not apply this. I've found three code sections dealing with continuous loads, 210.19 (A), 210.20 (A), and 215.2 (A). All three of these deal with branch circuits and feeders only, not services.

Am I missing another code section somewhere that would make the continuous load application apply to the overall service calc? Their method isn't wrong per se, just overkill in my opinion, unless I've missed something.

Thanks,
Keri

 

[wwhitney]

For the case of a single service disconnect, the service OCPD is also the OCPD for the downstream feeder. And the feeder OCPD sizing will need to include a 125% factor for the continuous loads, unless you use a 100% rated OCPD. Then since the service OCPD also needs to protect the service conductors, the service conductors get upsized as well.

For service conductors supply multiple service disconnects, that aspect doesn't come into play, due to 230.90(A) Exception 3.

Cheers, Wayne