I occasionally wire portable pumps with self-contained 3 ph. starters mounted on the unit. They are fed by plugging into 20 amp branch ckts. A typical size is 1.5 HP (3 amps @ 480 volt). Article 400-13(OC protection for the cords) refers to 240-4. 240-4(a) requires OC protection in accordance with the cords ampacity per table 400-5(A), which requires 12 gauge cord for 20 amps. However, 240-4 allows supplementary OC protection as in 241-10 to protect the cord. Is the OL relay in the starter considered to be this supplementary OC protection, and therefoe, can I use cord smaller than #12, based on OL heater size?
