conductor

According to NEC NFPA-30 Is lightning Air Terminals and lightning conductors required to be tied with building ground grid? What is the acceptable ground resistance for lightning protection per code?

I had someone tell me that the new 4-022 of 2018 says you have to pigtail all identified conductors. Where I read it as the complete opposite, where it does not allow you to pigtail identified conductors. Thoughts?

Hi all: I just received two Yaskawa P1000 configured VFDs, with input rating of 460V, 207A, 3ph. The drives came with 400A disconnects and 500A fuses installed. My question is this, if the NEC requires conductors to be sized not less than 125% of rated input current, why does this have...

Help please. Transformer conductor protection confusion. Down below is example problem, with solution, from NEC Handbook, relates to Article/Section 240.4. Can anyone please comment as to the reasoning for the conclusions reached in the solution, including the conclusion that the 50 amp breaker...