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.
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