Millwright Level 1 Practice Exam

What are the three protections offered by a GFCI?

1. Voltage spike, overload, ground fault protection

2. Overload, overcurrent, ground fault protection

3. Overcurrent, short circuit, voltage spike

4. Ground fault, insulation, overcurrent protection

The correct answer is: Overload, overcurrent, ground fault protection

A Ground Fault Circuit Interrupter (GFCI) is designed to protect against electrical hazards by continuously monitoring the flow of electricity in a circuit. The key protection offered by a GFCI is ground fault protection, which is essential in preventing electrical shocks by detecting any discrepancy between the outgoing and incoming current. When a fault occurs, such as when electricity unintentionally flows to the ground due to moisture or damaged insulation, the GFCI interrupts the circuit, thereby minimizing the risk of electrocution. Overcurrent protection is another vital aspect of a GFCI, which includes any situation where the current exceeds the rated capacity of the circuit. While a GFCI does not directly protect against overloads or provide circuit breaker functions like some other devices, it contributes to safety by cutting off power during a ground fault condition and helping to prevent potentially unsafe currents. Choosing two specific protections—ground fault protection and overcurrent protection—provides a comprehensive level of safety that's crucial in environments where exposure to electricity and moisture is a hazard, like kitchens and bathrooms.