MRN3 – Mains decoupling relay

The MRN3 is a universal mains decoupling device and covers the protection requirements from VDEW and most other utilities for the mains parallel operation of power stations.  Over/ and under voltage protection,  over/ and under frequency protection,  extremely fast decoupling of generator in case of mains failure (MRN3-1) or  rate of change of frequency df/dt (MRN3-2) Because of combination of three protection functions in one device the MRN3 is a very compact mains decoupling device. Compared to the standard used single devices it has a very good price/performance ratio. For applications where the single protection functions are required Woodward can offer the single MR-relays as follows:  MRU3-1 four step independent over-/ and under voltage protection (also used for generator earth fault protection).  MRU3-2 two step independent over-/ and under-voltage protection with evaluation of the symmetrical voltage components.  MRF3 four step independent over/ and under- frequency protection and two step frequency gradient supervision df/dt.  MRG2 generator mains monitor / vector surge detection.

FEATURES & FUNCTIONALITY

The MRN3 is a universal mains decoupling device and covers the protection requirements from VDEW and most other utilities for the mains parallel operation of power stations.  Over/ and under voltage protection,  over/ and under frequency protection,  extremely fast decoupling of generator in case of mains failure (MRN3-1) or  rate of change of frequency df/dt (MRN3-2) Because of combination of three protection functions in one device the MRN3 is a very compact mains decoupling device. Compared to the standard used single devices it has a very good price/performance ratio. For applications where the single protection functions are required Woodward can offer the single MR-relays as follows:  MRU3-1 four step independent over-/ and under voltage protection (also used for generator earth fault protection).  MRU3-2 two step independent over-/ and under-voltage protection with evaluation of the symmetrical voltage components.  MRF3 four step independent over/ and under- frequency protection and two step frequency gradient supervision df/dt.  MRG2 generator mains monitor / vector surge detection.