Vector surge relay is used to protect the transformer / generator / alternator from grid disturbance such as grid failure, grid interruption, vector surge etc. The invention is applicable to the technical field of power and provides a device and a method for checking relay protection vectors and testing functions of a power distribution network, wherein the device comprises the following components: a variable current device and an analog load; the input. In the design of electrical power systems, the ANSI Standard Device Numbers denote what features a protective device supports (such as a relay or circuit breaker). These can be used for example to switch various signal paths in a test system, to realize a switch matrix, or to generate errors like short-circuits. VT2820 – General-purpose relay module for HIL testing with the Vector VT System. It has many features such as under voltage protection, over. ding or loss-of-mains conditions of distributed generation units, the relay shall have vector shift protection (78V). The relay. Learn vector diagrams for relay protection & automation. A practical textbook for electrical engineering students.