Protection of Internal Parts of Electrical Equipment

Internal parts of electrical equipment, including _____, shall not be damaged or contaminated by foreign materials such as paint, plaster, cleaners, abrasives, or corrosive residues.

a) busbars
b) wiring terminals
c) insulators
d) all of the above

See answer and applicable Code reference

The correct answer is: d) all of the above

The general requirements for electrical installations are outlined in Art. 110. As per 110.12(B), "Internal parts of electrical equipment, including busbars, wiring terminals, insulators, and other surfaces, shall not be damaged or contaminated by foreign materials such as paint, plaster, cleaners, abrasives, or corrosive residues."