A fused spur also known as a fused connection unit (FCU) is an electrical switch containing a fuse often used instead of a conventional electric plug socket. There are two different types of fused spurs, a switched that includes a manual switch for turning on or off, and a non-switched which does not have a manual switch. What are fused spurs used for? For maintenance and health and safety when installing appliances such as washing machines and dish washers or high powered electrical equipment on a separate cable from a ring main, you can use a fused spur. Can you connect a fused spur to an existing socket? You can connect a fused spur to an existing socket providing the socket does not already have a spur. The number of spurs used must not exceed the number of sockets. Caution All electrical equipment should be installed by a qualified electrician.