When is a mechanic required to replace an escalator comb or comb plate?

A mechanic is required to replace an escalator comb or comb plate primarily when there are broken teeth. The comb or comb plate serves a critical role in ensuring the safe and smooth transition of passengers onto and off of the escalator steps. If teeth on the comb are broken, this can create a safety hazard by leading to potential misalignments or creating a gap that may cause passengers' footwear to get caught, potentially leading to accidents.

While signs of rust, looseness, or general wear and tear may indicate that maintenance is needed, these conditions may not necessarily require immediate replacement. For instance, rust can often be treated, and a comb plate that is slightly loose might only need adjustment rather than replacement. However, broken teeth compromise the functionality and safety of the escalator directly, mandating immediate action. Therefore, the requirement for replacement is focused on the integrity of the teeth to ensure passenger safety on the escalator.