Protection is the branch of electric power engineering concerned with the principles of design and operation of equipment (called 'relays' or 'protective relays') that detects abnormal power system conditions, and initiates corrective action as quickly as possible in order to return. Protection is the branch of electric power engineering concerned with the principles of design and operation of equipment (called 'relays' or 'protective relays') that detects abnormal power system conditions, and initiates corrective action as quickly as possible in order to return. Protective Relay Definition: A protective relay is an automatic device that senses abnormal conditions in electrical circuits and triggers actions to isolate faults. Types of Protective Relays: Protective relays are categorized by their mechanism (electromagnetic, static, mechanical) and function. Protective relays and devices have been developed over 100 years ago to provide “last line” of defense for the electrical systems. They are intended to quickly identify a fault and isolate it so the balance of the system continue to run under normal conditions. The selection and applications of. A Relay Engineer is a specialized professional within the electrical engineering field who is dedicated to the design, implementation, and maintenance of relay systems. Its main purpose is to safeguard electrical equipment like transformers, generators, and transmission lines from damage due to. The most common majors for this role are Electrical Engineering, Industrial Technology, Electrical Engineering Technology, Biology, and Electrical/Electronics Maintenance And Repair Technology. Notable schools that offer programs relevant to this field include California State University - Long.