FAQ on Motor Sizing and Grounding part 2

Another video on my most common questions. I this video I explain where the 25% comes from when sizing the largest motor in a standard service calculation. Also sizing the service grounding conductor and what table to use in article 250.

[Fabhdumans]

This is clearer explanation, I can explain my apprentice now where the 25% comes from (100+25%)... But I don’t see why not calculate 125% for the compactor then sum 100% for the rest?? The result number come the same and like I said, my apprentices can not find anything in the NEC that show a break of (100% then 25%), maybe you can guide me where in the NEC I can found “your method “... thank you for all those great informative videos, much appreciated 👍

[albertomencia]

thanks for you great tips.also can you explain in a video about those 2 chart 250.66/122 wend or how identify to used and wich one to use to bounding please

[Fabhdumans]

Very important video to make when you get a chance, about motor calculation base on FLA (not FLC) for NONCONTINUOUS duty ( intermittent, short time, etc) from 430.32(E). Cause those kids are missing “ the motor nameplate current rating “ from this article. And they see it like Table 430.52 which is base on FLC. Hope you get my point. Thank. Oh !! although, about the fuse size from (FLA) for OL, it can not be size up!! Because Those guys always think to size up everything... have a great day.

[Fabhdumans]

About “Main” bonding jumper? Is it this third tables 250.102(c)(1)? All grounding wire calculations are base on 75C? Nothing on 60C, what if the terminal is rated 60C on the equipment, are we still using 75C? 250.122 is only for OCPD?? Again, thank you for your follow up videos from my last question, it’s truly appreciate.

[mikebronc]

So this is calculating residential service loads? What's unclear to me is elimination of smaller of two appliances that won't be used at the same time (heater, ac)

[israelsantana]

Don’t the water heater which is 5000 watts is the bigest motor ?

[MNDMNE]

isnt it 250.102c and 250.66 that are the same?