SparkyNC
My 2 cents:
I would use a 2 wire twistlock plug and receptacle, and a "in-use cover.
My reasoning for the 2 wire twistlock is that it's not a "common" receptacle that someone could use if they removed the plug.
Did you think about "hard wiring" the heat tape, and using a snap switch?? We have PVC FS Boxes with a switch handle cover, that's lockable. A 30 amp, 2 pole spec switch fits without a problem.
As to the wiring methods, the only thing re: freezers in my memory bank is to seal the conduits going from the freezer to the adjacent area to prevent condensation, due to the temperature differentials.
I don't mean Exp Proof seals, just duct seal.
John
