What is the primary purpose of a disconnect switch?

The primary purpose of a disconnect switch is to isolate electrical equipment for maintenance. This is crucial for ensuring the safety of personnel working on or near the equipment. By providing a means to disconnect the electrical supply, it allows maintenance workers to perform their tasks without the risk of accidental energization, which could lead to serious injury or electrocution.

Disconnect switches are designed to be easily operable and identifiable, ensuring that they can be turned off quickly and efficiently. They are often placed in accessible locations to facilitate this process, reinforcing safe work practices in electrical maintenance. This function is a key aspect of electrical safety protocols and is heavily emphasized in the National Electrical Code (NEC), which lays out the requirements for safe electrical installations and maintenance practices.

The other options pertain to functions that are not the primary focus of a disconnect switch, emphasizing load control, circuit connection, and overload protection, which are functions associated with other devices like circuit breakers or relays and not the main role of a disconnect switch.