Voltage Relay VR-50 is a numerical multifunctional relay for monitoring busbars in low voltage or medium voltage grids. If the VR-50 detects a deviation of the voltage from the set values in accordance with the selected protection functions, it performs the signalling and / or tripp signal to shutdown the plant. The VR-50 Voltage Relay is used to protect and monitor the generator, transformer or the renewable power sources connection to the grid. The relay can achieve undervoltage and / or overvoltage protection, underfrequency and / or overfrequency protection. The VR-50 enables selecting of an additional vector shift detection function for preventing the islanding operation of a renewable power source.

• undervoltage and / or overvoltage protection
• underfrequency and / or overfrequency protection
• vector shift detection function for preventing the islanding operation of a renewable power source
• numerical signal processing
• galvanically separated measuring inputs and inputs from the power supply
• high accuracy of measurement (true RMS)
• time registration up to hundred events
• microprocessor processing of measured quantities
• RS485 or optical communication with the master system
• alphanumeric LCD with 2×8 digits and backlight for display of measured and registered quantities and parameters
• self-test function, local and remote signalling of availability
• protection signalling with bi-color LED elements (8 programmable LED elements)
• five programmable semiconductor outputs for signalling
• two digital inputs
• four programmable relay outputs
• small dimensions, mounting on the TS35 rail