Which component typically remains stationary while piped flexibly for adjustment?

The limit switch is the correct answer because it is a component that is designed to detect the position of the machine parts and typically remains in a fixed location within the elevator system. In many applications, limit switches need to be positioned in relation to moving parts, but they can be piped flexibly to allow for adjustments to the exact position without needing to relocate the entire switch. This flexibility is essential during installation or maintenance because it provides the ability to fine-tune the switch's alignment as needed to ensure proper operation of the elevator system.

The other components mentioned either require more rigid mounting due to their functions or do not have the same flexibility associated with their installation. For instance, a control panel usually needs to be mounted securely and is not designed to be adjusted once installed. Similarly, a wiring harness is generally fixed in place and wires are typically routed in specific locations. A relay box also requires secure mounting, as its function hinges on stable connections for reliable electrical circuitry.