What must be activated to prevent the elevator car from moving when working in the pit?

To ensure safety while working in the elevator pit, it is essential to activate two devices. These devices typically include a combination of the mainline disconnect switch and the hoistway door interlock or other safety devices. The mainline disconnect switch cuts power to the elevator system, preventing any accidental movement of the elevator car while maintenance or repairs are conducted in the pit. The hoistway door interlock ensures that doors cannot be opened when the elevator is not at a designated landing or when it is unsafe to do so.

Having both devices functioning provides a robust safety mechanism by ensuring that the elevator car remains stationary and that maintenance personnel are protected from potential hazards. Relying solely on one device may not provide adequate safety, while saying no devices are required would compromise worker safety. Thus, activating two devices is crucial for a safe working environment in the elevator pit.