The L30 is a cost-effective line current differential protection relay intended for sub-transmission and medium voltage lines and cables providing reliable and secure operation even under the worst case power system conditions; provides secure high-speed fault detection and clearance suitable for three-pole tripping applications; supports inter-relay communications via direct fiber as well as standard RS422, G.703 and C37.94 telecommunication interfaces. Also provides synchrophasor measurements over Ethernet per IEEE C37.118.

Some of its applications are: Overhead lines and subway cables of different voltage levels; Circuits with transformer feeders with taps.