Pendant luminaires installed in Class II, Division 1 locations shall be suspended by threaded conduit stems, by chains with approved fittings, or by other approved means. Stems shall be provided with _____ or other effective means to prevent loosening.
a) set screws
b) welded joints
c) expansion joints
d) explosionproof flex
See answer and applicable Code reference
The correct answer is: a) set screws
Article 502 of the 2011 NEC cover