For devices with screw shells, which conductor should be connected to the screw shell?

The connection of the conductor to the screw shell in devices is important for safety and proper electrical functioning. When dealing with devices that have a screw shell, the correct conductor to connect is the grounded conductor. This connection ensures that the screw shell, which may be accessible or touched by users, is safely bonded to the grounding system of the electrical installation.

The grounded conductor helps to prevent electric shock by providing a path to ground in the event of a fault. If the device were to develop a fault where live voltage is exposed, having the screw shell connected to the grounded conductor would allow electrical current to safely flow to ground, thus tripping protective devices like circuit breakers or fuses and minimizing the risk of electric shock.

This practice is part of ensuring that equipment is properly earthed, which is critical in maintaining electrical safety standards. The other types of conductors such as neutral, hot, or service conductors do not fulfill this protective role and therefore are not appropriate choices for connection to the screw shell.