Detail MFVU21 Frequency Relay Alstom
Application and Description The type MFVU 21 digital, definite time relay consists of two fully independent frequency monitoring circuits which can be used as either under or over frequency protection. In addition, the two operating circuits can be used together to provide pick-up and drop-off at different frequencies. The relay is suitable for any application in industrial plants and to generators where definite time under or over frequency protection is required. In addition multi-stage schemes using several relays can be provided for load shedding and reconnection applications. Integral timers are provided for each operating circuit and separate eletromagnetic auxiliary relays ensure maximum flexibility of application. Figures 2 and 3 are block diagrams showing relays suitable for use with ac and dc auxiliary power supply voltages respectively.