What is the minimum distance between low-voltage alarm wiring and other 110/220 VAC wiring to avoid induced voltages and electrical noise?

• A. 2 inches
• B. 6 inches
• C. 0 inches
• D. 12 inches

Answer: (A)

Keeping low-voltage alarm wiring separated from high-voltage 110/220 VAC runs reduces the chance that mains power will induce voltages or create noise on the alarm circuit. The electromagnetic influence from power conductors drops with distance, so providing even a small clearance helps keep the alarm wiring clean and reliable. The smallest practical separation commonly used is about two inches, which gives enough distancing to minimize coupling in many installations without needing extra conduits. If runs must stay close for a longer distance or if extra noise margin is needed, greater separation or routing in separate conduits offers even better protection. So, two inches is the minimum distance that balances reliability and practicality in typical setups.