Earth-leakage protection relay DER4/1DL

current2 NO/NCthree-phase

The DER4 series differential toroid relays can be used on TT and TN type LV AC networks. The DER4/1DL relay is designed and built for use in environments where human presence is not necessary or absent (radio link switchboards, pumping stations, cold rooms, lighting systems, etc). They make it possible to achieve adequate selectivity and differential protection thanks to the wide regulation of the leakage current threshold (0.03÷30A) and of the trip delay threshold (instantaneous÷30 seconds). The DER4s comply with the stringent regulations in force (IEC 60947-2) thus satisfying a dual need: system safety and service continuity. Dossena offers a complete range of differential relays rich in functions. New technology, ease of use, great reliability, ease of installation and programming, performance and "user friendly" design. The quantities and parameters are displayed on a large, very bright dot matrix display which changes color in relation to the operating status of the instrument (Green=measurement/monitoring, Blue=programming, Red=alarm/intervention). - type A: - 1 trip threshold (Trip) with 2 output contacts (NO-C-NC) - continuous check of the correct functioning of the opening coil - continuous check of the correct functioning of the D series toroidal transducer - self-diagnosis with description of the problem on the display