HH and -2 code

[Pcmaker]

What's the difference between HH and -2? They both mean that the insulation is rated for 90 degrees celsius, but why are they both printed? If it has HH, isn't that enough?

 

[Dennis Alwon]

-2 usually means the insulation is dual rated. It also makes the wire rated the same in dry and wet location if the wire can be used there.

I am assuming you are talking thhn/thwn-- Thus thwn-2 is rated 90C wet and dry

 

[Pcmaker]

thanks, that explains that