Arc chutes typically absorb greater than 80% of the energy released during the interruption of current flow as the contacts open. This is described as:

• A. less than 80%
• B. about 60%
• C. greater than 80%
• D. exactly 80%

Answer: (C)

Arc chutes are designed to take the bulk of the energy released when a current is interrupted, by giving the arc a path that stretches, cools, and divides it. This arrangement absorbs the arc’s energy as heat and light within the chute’s metal plates, protecting the contacts and insulation from damage and reducing erosion of the contact surfaces. In practice, the energy absorbed by the arc chute is typically more than 80% of the total interruption energy, which is why this description—more than 80%—best fits what arc chutes do. The remaining energy is handled by the other parts of the breaker, but the arc chute’s large energy absorption is what makes interruption more reliable and safer.