When are vision panels required in elevator doors?

Vision panels are required in elevator doors primarily for safety reasons. They allow both passengers and operators to see the elevator car’s interior and the area outside the door. This visibility helps prevent accidents by ensuring that individuals can see if the elevator is at the landing and whether it is safe to enter or exit.

Specifically, the requirement for vision panels applies to all swing doors in elevators. These doors, when opened, provide access to the elevator pit or lobby and must have visibility features that enhance passenger safety. The presence of vision panels helps in reducing the risk of collisions as passengers move in and out of the elevator.

The other options do not accurately reflect the scope of where vision panels are necessary. For instance, limiting the requirement to freight doors or new installations does not take into account existing elevators that may also need these panels for safety compliance. Similarly, width restrictions are not a criterion considered in vision panel requirements. Hence, it's the inclusion of vision panels on all swing doors that aligns with safety codes and regulations related to elevator design.