A nonfused safety switch with a voltage rating of 600 volts is:

A nonfused safety switch with a voltage rating of 600 volts is permitted to be used as the disconnecting means because it is designed to interrupt the circuit under normal operating conditions. Safety switches serve as disconnects that ensure electrical equipment can be safely isolated from the power source for maintenance or emergency situations.

In many installations, especially in commercial or industrial settings, these switches provide a reliable and safe means for disconnecting circuits and equipment placed at or below the rated voltage. When used appropriately and following relevant electrical codes, such switches can effectively handle the demands of various applications, ensuring both safety and compliance with regulations.

Utilizing a nonfused safety switch in this capacity allows for the safe maintenance of electrical systems, making it an integral part of electrical installations. The other options, while they may address different contexts or interpretations of usage, do not align with the practical applications and regulatory standards governing nonfused safety switches effectively functioning as disconnect means.