Outgoing and return conductors of Class A, N, or X circuits should be separated by what vertical and horizontal distances?

• A. 2' vertically and 6' horizontally
• B. 1' vertically and 4' horizontally
• C. 3' vertically and 2' horizontally
• D. 4' vertically and 1' horizontally

Answer: (B)

Keeping outgoing and return conductors apart is about preventing interference between the circuits so the fire alarm signaling stays reliable. The required arrangement uses one foot of vertical separation and four feet of horizontal separation. This combination provides enough clearance to reduce inductive and capacitive coupling and minimizes the chance that a fault, arcing, or noise on one conductor induces issues in the other, even when cables run in close proximity along a shaft, conduit, or tray. The vertical offset discourages direct alignment in the vertical plane, while the larger horizontal spacing ensures long runs remain sufficiently separated to limit cross-talk. Other options either give too little horizontal separation or alter the proportions in a way that doesn’t achieve the same level of separation and protection.