Are steel galvanized boxes and GRC cosidered dissimilar metals?
I wouldn't think so.... the G in GRC stands for Galvanized.
And welcome to the forum!
As with 480sparky disimilar metals would be ferrous to non ferrous metals.
Dissimilar metals would also include non-ferrous to non-ferrous connections such as copper to aluminium.
Chris
So true my friend I should cover my self a bit better there. That is why you are a Moderator. Thanks Chris.