The earth differential relays range DER3, can be used on LV networks in alternate current, type TT and TN.
They guarantee an adequate selectivity of differential protection thanks to : wide adjustment of threshold current dispersion (until 30A) and threshold for delay intervention (until 10 sec).
DER3 Dossena are perfectly designed in accordance with strict regulations (CEI EN 60947-2:2007 annex M ed.8 and IEC 60947-2:2006 annex M ed.4) thus satisfying a double need: safety of facility and service continuity of industrial production.
Dossena offers a wide range of earth differential relays future-rich.
New technologies, easy to use, high reliability, simple installation and setting, performance and design “user friendly”.
Greatness and parameters are displayed on large screen dots matrix, very bright that change colour in relation of state device (Green=measurement/surveillance, Blue=setting, Red=alarm/intervention).
- 1intervention threshold
- 2contemporary contacts Na-c-Nc
- control of opening coil
- auto-diagnostic by display
-limit time of no-intervention 10 sec