HVAC Contractor Practice Exam

The recommended device for preventing electrocution while using power tools is a Ground Fault Circuit Interrupter (GFCI). GFCIs are designed to automatically cut off electrical power in the event of a ground fault, which occurs when there is an unintended path between the electrical current and the ground. This can happen when a person comes into contact with water or a conductive surface, significantly increasing the risk of electric shock.

When a GFCI detects an imbalance in the electrical current (for example, if current is leaking through a person to the ground), it interrupts the flow of electricity within milliseconds, reducing the likelihood of serious injury or electrocution. This function is particularly important in environments where moisture is present, such as in outdoor workspaces, bathrooms, or kitchens where power tools might be used.

Other options, such as a voltmeter, a flat extension cord with ground, or an extension cord with large gauge wires, do not provide the same level of safety against electrocution. A voltmeter is used for measuring voltage, not for protection. While a flat extension cord with a ground does provide a safety feature, it does not actively disconnect power when needed. Similarly, using an extension cord with large gauge wires ensures reduced voltage drop