Which device is a primary safety device for protection against overcurrent in dwelling circuits?

• A. Fuses or circuit breakers
• B. GFCI
• C. AFCI
• D. Surge protector

Answer: (A)

Overcurrent protection in dwelling circuits is provided by the main safety devices in the electrical panel: fuses or circuit breakers. These devices monitor the current in each branch circuit and act to interrupt it if the current exceeds the circuit’s rated capacity. A fuse contains a metal link that melts when the current is too high, opening the circuit, while a circuit breaker trips a mechanism to disconnect power and can be reset afterward. This rapid interruption protects conductors, insulation, and equipment from overheating and possible fire.

Other devices have important safety roles but aren’t the primary protection against overcurrent. GFCIs guard against ground faults and shock by detecting imbalance between hot and neutral. AFCIs look for dangerous arcing conditions that can start fires. Surge protectors limit voltage spikes but are not the standard method for preventing overload currents in normal operation.

So, fuses or circuit breakers are the main devices used to protect dwelling circuits from overcurrent.