430.248 - Motors

[WA_Sparky]

Just looking for some clarification on this section. There is a list of hp @ different voltages and their respective current. In this table it shows 1hp at @115V =16A FLA... To this point I've used 1HP=745VA as an equivalent or if possible used the manufacturers cutsheet.

When is this table expected to be used? If there's not manufacturer provided cutsheet available?
Is this meant for upsizing disconnects, feeders, and breakers for inrush?

 

[tom baker]

Table is required to be used to size branch circuit conductors, disconnects, etc. Table values are multipled by motor duty cycle, normally but not always 125%. Table values are very conservative to allow for different motors.
Name plate data is used for overloads.
I have a great graphic from mike holt I can post later

 

[LarryFine]

To this point I've used 1HP=745VA as an equivalent . . .

There's a big difference between theoretical equivalencies and real-world mechanical equivalencies, with losses, inefficiencies, etc.

When is this table expected to be used? If there's not manufacturer provided cutsheet available?
Is this meant for upsizing disconnects, feeders, and breakers for inrush?

The tables take into consideration that replacement motors may have greater current requirements than originally-installed ones.

 

[WA_Sparky]

Table is required to be used to size branch circuit conductors, disconnects, etc. Table values are multipled by motor duty cycle, normally but not always 125%. Table values are very conservative to allow for different motors.
Name plate data is used for overloads.
I have a great graphic from mike holt I can post later

Ok good to know and that would be much appreciated.
Just so I have it clear...Hypothetically manufacturer has a 10HP motor 115V 1Ø. In their specifications it shows MOCP = 90A (assume power factors are 1 for this scenario). Table 430.248 recommends 100A. Would you stick with NEC, or rate per manufacturer MOCP values for warranty?

 

[tom baker]

You are required to use NEC tables.