Isolation Relay RI-R11 allow permanent monitoring of insulation of electrical networks in direct-current current isolated on earth (IT networks). It`s used for IT networks insulation control with 110~275 Vdc. These devices have two trip thresholds, which are adjustable by frontal micro switches . On the front, there are TEST and RESET buttons; test could be activated locally or by an external button; push button could be set manually or automatically, either with local button or with external push button . Borna niroo karan company(Bornika) is the representative of Contrel on buying , selling, consulting services for automation systems and protective relays including Industrial isolation Relay RI-R11.