Which of the following is NOT a type of protective equipment commonly found on a distribution line?

Transformers are primarily used for changing the voltage levels within the electrical distribution system and do not serve a protective function. Their main purpose is to step up or step down voltage for efficient transmission and distribution of electricity, ensuring that the voltage is suitable for either long-distance transportation or for use in homes and businesses.

On the other hand, protective equipment such as fused cutout switches, voltage regulators, and lightning arrestors each serve specific safety and protection roles within the distribution system. Fused cutout switches are essential for isolating sections of the network and providing fault protection by allowing the circuit to disconnect when an overload occurs. Voltage regulators help maintain stable voltage levels, protecting equipment from fluctuations, while lightning arrestors protect distribution lines from surges caused by lightning strikes, preventing potential damage to infrastructure and maintaining system integrity.

Thus, while transformers are integral components of the electrical grid, they are not categorized as protective equipment like the other options listed, making them the correct choice in this context.