Electrical Inspection, Testing and Certification Practice Exam

In what unit is PFC measured?

1. Amperes

2. Volts

3. Kiloamps

4. Watts

The correct answer is: Kiloamps

The correct choice identifies PFC, which stands for Prospective Fault Current, expressed in kiloamps. PFC is a measure of the highest potential fault current that could flow in the event of a short circuit at a specific point in an electrical distribution system. This measurement is crucial for determining the necessary specifications of protective devices such as circuit breakers and fuses. Using kiloamps as the unit allows for the quantification of electrical currents that can reach significant levels during fault conditions. Since PFC can often be quite large, kiloamps, being a larger unit than amperes, provides a more manageable and understandable figure for utility and design purposes. In contrast, amperes measure electrical current in a more standard form; volts measure electrical potential, and watts represent the power in an electrical system based on the product of current and voltage. Each of these units has its specific application; however, they do not directly represent fault currents as kiloamps does in the context of PFC analysis.