What component helps escalate motion during repair or maintenance?

The service switch is a crucial component in the operation of escalators during repair or maintenance. It allows technicians to control the escalator's movement, providing the ability to run the escalator at reduced speeds or even stop it completely during maintenance tasks. This controlled operation is essential for safety, as it enables workers to safely access parts of the escalator that need attention without the risk of the escalator unexpectedly moving at full speed.

In contrast, the other components mentioned play different roles: the handrail contributes to user safety by offering support and stability during normal use, while the step chain is responsible for driving the escalator's steps, providing the necessary movement but not directly aiding in maintenance operations. The brake system is fundamental for safety, ensuring that the escalator can halt promptly when needed, but it does not facilitate motion during repairs. Thus, the service switch is specifically designed to assist during maintenance by providing controlled operation, making it the correct choice.