An isolator is a mechanical switch used to disconnect equipment or circuits from their power supply. It ensures that electrical equipment can be safely isolated for maintenance, repairs, or in emergencies.

Isolators are commonly used in industrial settings, commercial buildings, and sometimes in residential applications where equipment or circuits need to be safely isolated from the electrical supply.

There are several types of isolators, including:

• Main Switch: This isolates the entire installation from the mains supply.
• Individual Circuit Isolator: These isolate specific circuits within the installation.
• Rotary Isolators: These are used for more robust isolation and often have lockable handles for security.

In many cases, isolators are required by electrical regulations (such as BS 7671 in the UK) to ensure safe working conditions and compliance with safety standards. They are particularly important for isolating equipment before carrying out maintenance or repairs.

A switch fuse combines the functions of a switch and a fuse in a single unit. It provides a means of switching a circuit on and off manually, as well as protecting the circuit against overcurrents by means of a fuse.