What is the maximum angle at which nonmetallic sheathed cables can be secured to joists in dwelling units?

Nonmetallic sheathed cables, such as NM cable, are required to be secured properly to ensure they are protected from damage and do not create hazards. The maximum angle at which these cables can be secured to joists in dwelling units is 90 degrees. Securing the cables at this angle helps in maintaining a proper and safe installation, allowing for the cables to be run neatly along the framing without excessive bending or stress on the wires inside the sheathing.

This angle ensures that the cables run parallel or perpendicular to the structural components of the building, which is important for both aesthetics and safety, as it minimizes entanglement or snagging. When installed at angles greater than 90 degrees, the cable may be at risk of kinking, which can compromise the integrity and performance of the electrical system.

The other options propose angles that either restrict the securing method too much or introduce unnecessary complexities that could lead to improper cable support and potential hazards. The choice of 90 degrees balances the need for safety in installation with practical considerations in routing the cable through a dwelling unit.