Sizing Cable: Motor FLA vs Continuous FLA

[TacoEngineer]

Trying to gain a better understanding of sizing Electrical Cable for Motors vs Continuous Loads.

Placing correction factors & Voltage Drop sizing aside, am i correct in saying we size a cable for 125% of a Motor Nameplate FLA and 100% of a continuous load FLA?

I wanted to make sure I am sizing cables correctly, and am currently looking at a 120VAC Continuous Load of 13.33Amps.
Per spec #12 is minimum so this may be a mute point but need to make sure i have the logic down. Would i size the cable to 13.33FLA or 1.25 * 13.33FLA?

 

[david luchini]

For a continuous load, the conductor would need to be sized not less than 125% of load before the application of any adjustment or correction factors.

 

[augie47]

430.24 Several Motors or a Motor(s) and Other Load(s). Conductors supplying several motors, or a motor(s) and other load(s), shall have an ampacity not less than the sum of each of the following
(1) 125 percent of the full-load current rating of the highest rated motor, as determined by 430.6(A)
(2) Sum of the full-load current ratings of all the other motors in the group, as determined by 430.6(A)
(3) 100 percent of the noncontinuous non-motor load (4) 125 percent of the continuous non-motor load.

 

[TacoEngineer]

Based on the responses above, it appears to be the conductor must be rated for no less than 125% of the FLA regardless of Motor or Continuous load. Does that sound correct?

 

[david luchini]

Based on the responses above, it appears to be the conductor must be rated for no less than 125% of the FLA regardless of Motor or Continuous load. Does that sound correct?

Yes

 

[Jraef]

am i correct in saying we size a cable for 125% of a Motor Nameplate FLA and 100% of a continuous load FLA?

Not quite. You do not use the motor NAMEPLATE amps, you must use the amps in the appropriate table in the NEC, article 430. Usually for 3 phase motors it is table 430-150.