The manual (see link) says that the MPPT controller must have wires run in grounded metallic conduit for "electromagnetic compatibility". I talked with tech support and they had to check and confirm that this requirement was in the manual. The manuals for their other controllers do not have this wording. Apparently they may add it. I suspect that this is a case of CYA or to meet some arcane local building codes for land use. RF noise can mess up HF reception so I'm paying attention here. I'll probably use regular cable but sprinkle some good quality ferrites here and there as needed, the HAM radio equivalent of seasoning to taste.

I haven't bought the hardware yet. What experience have others had with RF problems with solar installations on boats? If problems, what solutions?