The DEB71 is an adjustable modular residual current relay which, in conjunction with the MCB and the CT, provides the protection of people against electrocution or protection of properties against fire, by interrupting the mains on faulty loads or lines. The set point of the leakage current is adjustable. The device is equipped with two changeover relay outputs. One output triggers at 60% of fault current set point value providing a warning to user, the other output is used to shut down the system to prevent accidents. The DEB is a flexible device and can be used for all the applications where the loss of insulation and/or grounding failure, of the loads or lines may cause injuries to people due to electrocution or ignite fires.