The SK symbol in electrical systems represents what type of component?

The SK symbol in electrical systems is an abbreviation for a keyed switch. This type of switch allows for a controlled mechanism where access or operation of the switch is limited to individuals who have the appropriate key. Keyed switches are commonly used in applications where security and control are paramount, preventing unauthorized personnel from being able to operate the system.

In contrast, the other options represent different components: emergency breakers are designed for safety to shut off power in emergencies; fuse holders are used to hold fuses that protect circuits; and disconnect switches are employed to isolate a circuit or equipment for maintenance. Each alternative serves a distinct role in electrical systems, highlighting the unique purpose of the keyed switch as indicated by the SK symbol.