Which device must not be connected to the lighting circuit in the elevator hoistway pit?

The device that must not be connected to the lighting circuit in the elevator hoistway pit is the ground-fault circuit interrupter (GFCI). While GFCIs are crucial in providing protection against electrical shock in wet or damp locations, in elevator pit applications, a GFCI is not specified for use in the lighting circuit primarily for safety and operational reasons.

Elevator pits are classified as potentially hazardous areas due to water ingress and other environmental factors. The use of a GFCI in this context may introduce unnecessary risks. This is largely because GFCIs can trip under conditions that are typically not problematic for other types of devices, leading to situations where lighting could be lost in the pit area when it is most needed for maintenance or emergency situations.

On the other hand, it is acceptable to have a light switch, receptacle, and emergency light in the elevator hoistway pit, as these devices can operate effectively without the complications that a GFCI may introduce in that particular environment.