VMD258 3AC 500 V, voltage relay

Voltage relays

LINETRAXX ® VMD258Lower / Overvoltage relays for monitoring three-phase AC networks (window function) for power plant applications Product description The VMD258 voltage relays monitors three-phase AC networks on and over voltage (window function). It does not require a star point connection and is therefore universally suitable for 3AC systems. The device consists of pure analogue technology and is to be used for power plant applications due to its high availability. The supply voltage of the electronics is taken from the network to be monitored. The supply of the electronics, the relays and the connection for the external energy storage are separated from the grid with double insulation. Special input transformers dampen the transmission of interference factors from the system. The response values for the lower and overvoltage as well as the response delays are infinitely adjustable. Replaces devices of the series SUR35x.Function description When the voltage is within the set response values, the alarm relay K1 / K2 for the lower voltage in the rest current circuit (attracted) and the alarm relay K3 / K4 for the overvoltage in the working current circuit (relays dropped). If the power supply voltage is below the set response value < Un, the alarm LED "< U" will light up and the alarm relay K1 / K2 will switch on the default response delay. If the power supply voltage Un exceeds the set response value > Un, the alarm LED "> U" will light up and the alarm relay K3 / K4 will switch on the default response delay. If the response values are back within the set response values, the VMD258 switches to approx. 100 ms back to the initial position.