ÖVE EN 50123-5

Divisions 1, 2, 3 and 4 of EN 50123-5 cover particular requirements for surge arresters for specific use in fixed installations of d.c. traction systems. These are surge arresters consisting of one or more non-linear resistors which may be in series with single or multiple spark gaps. Low-voltage limiters are covered under division 5 of EN 50123-5. These are protective devices mainly used in fixed installations of d.c. traction systems to connect certain portions of the circuit, when, owing to an abnormal situation, the voltage across the device exceeds a predetermined limited value. They are not used in general toprovide surge protection. In particular the following main uses of low-voltage limiters (LVL) are envisaged: - connection to the rail of metallic masses;- protection of rail circuits; - earthing of rails in the substation; - protection of cathodic circuits; - protection of cable shields.