is there a distinction between "in-wall" vs "through wall" ?
BTW, I finally ran down the list of equipment requiring an equipment ground per the NEC and independent of manufacturer's requirements, it's in 250.114(3):
The following cord and plug connected equipment is required to be grounded unless protected by a system of double insulation:
A. Refrigerators, freezers, air-conditioners.
B. Clothes-washing, clothes drying, dishwashing machines; kitchen waste disposers; information technology equipment (your computer); sump pumps and electrical aquarium equipment
C. Hand-held motor-operated tools, stationary and fixed motor-operated tools, light industrial motor-operated tools
D. Motor-operated appliances of the following types: hedge clippers, lawn mowers, snow blowers, and wet scrubbers.
E. Portable handlamps.
So there is a requirement for computers, but not for home audio or video equipment unless it's stated in the manufacture's installation instructions.
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