When sizing a motor disconnect for horsepower, can I use the design letter or the LRC calculated from the table 430.7(B) to find the horsepower of disconnect in table 430.251 a or b. OR, do I have to use the largest of the two values based on design letter or code letter.
I have been taught that if the code letter is beyond F or G then the LRC should be calculated using the table 430.7(B) then go to 430.251 tables to size the disconnect. Can I use the design letter to do this regardless of the code letter on the nameplate instead?
Thanks
I have been taught that if the code letter is beyond F or G then the LRC should be calculated using the table 430.7(B) then go to 430.251 tables to size the disconnect. Can I use the design letter to do this regardless of the code letter on the nameplate instead?
Thanks