What gauge wire should be used to ground a fire alarm panel?

• A. 14 gauge
• B. 12 gauge
• C. 16 gauge
• D. 18 gauge

Answer: (A)

Grounding a fire alarm panel is governed by the equipment grounding conductor sizing in the NEC, based on the overcurrent device protecting the circuit. For a typical fire alarm panel fed by a 15-amp circuit, the minimum copper grounding conductor size is 14 AWG. This sizing ensures the ground conductor can carry fault current safely long enough to trip the overcurrent protection. If the circuit feeding the panel were 20A, the required size would be 12 AWG. Gauges smaller than that, like 16 or 18, would not meet code for a grounded path on a 15A circuit, and 12 AWG would be used only on a 20A circuit. So 14 gauge is the correct standard choice for most fire alarm panel grounding scenarios.