Which item is NOT one of the three important specifications of fuses?

Which item is NOT one of the three important specifications of fuses?

• A. Voltage rating
• B. Overload rating
• C. Operating speed
• D. Current rating

Answer: (B)

The thing being tested is how fuse specifications are defined. Fuses are specified by current rating, voltage rating, and how quickly they operate (their time-current or operating speed). The current rating sets the maximum continuous current the fuse can carry before it blows. The voltage rating is the maximum voltage across the fuse that it can interrupt safely. The operating speed describes whether the fuse is fast-acting or slow-blow, i.e., how quickly it opens under overcurrent conditions. There isn’t a separate, standard spec called an “overload rating”—overload is simply exceeding the current rating, and the fuse’s response is determined by its time-current behavior. Therefore, overload rating is the item that is not a standard specification.

The thing being tested is how fuse specifications are defined. Fuses are specified by current rating, voltage rating, and how quickly they operate (their time-current or operating speed). The current rating sets the maximum continuous current the fuse can carry before it blows. The voltage rating is the maximum voltage across the fuse that it can interrupt safely. The operating speed describes whether the fuse is fast-acting or slow-blow, i.e., how quickly it opens under overcurrent conditions. There isn’t a separate, standard spec called an “overload rating”—overload is simply exceeding the current rating, and the fuse’s response is determined by its time-current behavior. Therefore, overload rating is the item that is not a standard specification.