Protection of Knob-and-Tube Wiring

Where knob-and-tube conductors pass through wood cross members in plastered partitions, conductors shall be protected by noncombustible, nonabsorbent, insulating tubes extending not less than _____ beyond the wood member.

a) 2 in.
b) 3 in.
c) 4 in.
d) 6 in.

See answer and applicable Code reference

The correct answer is: b) 3 in.

Article 394 covers the use, installation, and construction specifications for concealed knob-and-tube wirin

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