If the handrail speed deviates from the step speed by more than what percentage for more than 2 seconds, the machine will stop?

In escalator systems, the synchronization of the handrail speed with the step speed is crucial for safety and operational efficiency. If the handrail speed deviates from the step speed by more than 15% for a duration exceeding 2 seconds, it triggers a safety mechanism that stops the machine. This percentage ensures that any significant discrepancy is addressed quickly to prevent potential accidents or malfunctions, as an out-of-sync handrail can lead to trips or falls for users.

The threshold is set at 15% because it provides a reasonable buffer for normal operational variations while still prioritizing safety. Exceeding this percentage for the specified time frame indicates a serious issue within the escalator's operation that requires immediate attention to avoid potential hazards.