Over-voltage monitoring relay LINETRAXX® VMD258

under-voltagethree-phaseAC

Pure analogue technology for safety applications For nominal system voltages up to 690 V Undervoltage and overvoltage monitoring for 3 AC systems The voltage relay VMD258 monitors three-phase AC systems for undervoltage and overvoltage (window function). Neutral conductor connection is not required, therefore it is suitable for 3AC systems. The voltage to supply the electronics is taken from the system to be monitored. The supply of the electronics, the relays and the connection for the external energy storage device are isolated from the system by means of double isolation. Special input transformers attenuate interferences from the system. The response values for undervoltage and overvoltage as well as the response delays are continuously adjustable. Features Undervoltage and overvoltage monitoring for 3AC systems No separate supply voltage required Separate alarm relays for undervoltage and overvoltage with two potential-free changeover contacts Adjustable response value: 0.7…0.95 x Un/1.05…1.3 x Un Nominal system voltages: 3AC 690/500/480/440/400/230/110/100 V Adjustable response delay: 0…5 s LEDs for operation, overvoltage, undervoltage Applications Monitoring of the power supply of machines and electrical installations Monitoring of loads Switching electrical systems on and off at a certain voltage level Monitoring of stand-by and emergency supply systems Supply voltage monitoring of portable loads