Re: engine block heaters
I have to agree with Bob. We are in the process of installing 40 outdoor receptacles for block heaters. My design called for GFIC receptacles with "in use" covers.
My partner questioned using GFIC's because they are not required by the NEC. My reply . . . One mechanic, working on a bus, on the ground, on a rainy day, his trouble light plugged into the block heater receptacle . . . at that point he stopped me and ordered the GFIC receptacles.
The NEC is the minimum.