If a circuit is non-power-limited, its maximum voltage is up to what value?

• A. 600 V
• B. 120 V
• C. 240 V
• D. 1000 V

Answer: (A)

In fire alarm circuit classifications, a non-power-limited circuit isn’t constrained by the lower power-limiting rules that apply to typical low‑voltage wiring. Because of that, equipment and conductors used in these circuits are rated up to 600 volts. This 600 V ceiling is a standard safety and compatibility limit for such circuits, ensuring components can handle the voltage while staying within established electrical codes. So, for a non-power-limited circuit, the maximum voltage is up to 600 V. Lower voltages like 120 V or 240 V are common in other contexts, but non-power-limited fire alarm circuits can go up to 600 V.