This publication discusses general problems related to the structure of current overload protection systems in high voltage (HV) electrical installations and introduces a family of new devices based on reed switch contacts solid-state units hybrid technology and automatic systems based on these components. It highlights their application in high voltage (5 to 100 kV) power supplies power lasers and radar RF-generators and protection systems for class 6 to 24 kV distribution networks. The author also discusses applications in power engineering radio-electronic equipment and industrial high voltage devices.