4 AWG and bigger

[Pinnie]

The Code starts making rules for wires 4 AWG and bigger. Like identification of grounded conductor, protective bushing in conduit, pull boxes with wire 4 AWG and bigger have to be sized differently.

Anyone know why that line in the sand was drawn? Is that something to do with manufacturing or ampacity of conductors or something else? Maybe available fault current at that wire gauge?

 

[TwoBlocked]

Good question. I've wondered the same thing. I don't argue with it, though, especially with box sizing.

 

[tom baker]

For reidentification of neutral and EGC, 4 and larger are sizes that will stay during life of building, so those can be reidentified

 

[Pinnie]

For reidentification of neutral and EGC, 4 and larger are sizes that will stay during life of building, so those can be reidentified

Ahhh that makes sense. Thank you Mr. Baker. Do you by chance know why they chose to start at 4 AWG?