Electric safety lock

Electric safety lock — the electric device which is carrying out protective function. The safety lock protects an electric chain and its elements from an overheat and ignition at course of current of high force. [1] In a chain it is designated by the letters "FU" (the international designation, from the word English Fuse) or "Pr" (designation in the USSR) and a rectangle with the continuous line in the center. [2]

Most often mean its general purpose in protection of electric chains against overcurrents by the term "electric safety lock", than some concrete design. Safety lock insert usually disposable. To protection of electric chains devices of numerous operation (not collapsing element) usually use automatic switches. In low-voltage chains the self-repairing safety locks are also applied.