GFCI receptacles are functional on which type of circuits?

GFCI (Ground Fault Circuit Interrupter) receptacles are designed to protect against ground faults by interrupting the electrical circuit if they detect an imbalance between the incoming and outgoing current. This function is crucial in preventing electrical shock, particularly in areas where water is present, such as kitchens and bathrooms.

GFCI receptacles can be installed on both 2-wire and 3-wire circuits. A 2-wire circuit consists of one hot wire and one neutral wire, which can adequately support a GFCI receptacle; the device can still monitor the flow of current between these two wires to ensure safety. On the other hand, a 3-wire circuit includes a hot, neutral, and ground wire, which further enhances electrical safety and allows the GFCI to function as designed while being able to provide a ground for additional protection.

This versatility in installation allows GFCI receptacles to be effectively utilized in a variety of settings, making them adaptable and essential for ensuring safety in electrical systems. Hence, the correct answer reflects that GFCI receptacles are functional on both 2-wire and 3-wire circuits.