MRR1

Productomschrijving

The generator rotor protection relay MRR1 combines rotor earth fault protection, excitation over and undercurrent protection as well as rotating diode failure protection.
Thus providing a powerful protection regarding the rotor of synchronous generators, covering the following ANSI codes:
– 37 DC undercurrent relay
– 40 Field relay
– 58 Rectification failure relay
– 64 Ground detector relay
– 76 DC over current relay

The MRR1 is recommended for synchronous generators and motors above 1 MVA rating. The rotor earth fault element detects high- and low resistance earth faults of the rotor winding. It is equipped with two stages, one for alarm, one for trip.

The excitation current protection element super-vises the DC excitation current of brushless excitor machines. The protective functions are: Undercurrent, over current and ripple detection for diode failure protection.

Features
• Detection of high impedance earth faults with a test frequency of 0.5 Hz
• Short circuit and overvoltage proof measuring input for the earth fault protection
• Excitor current measurement galvanically isolated via Hall-transducer, measuring range to 20 A
• Display of insulation resistance
• Display of the excitation current
• Excitation current over- and undercurrent protection with independent settings for current nd delay time
• Detection of diode failures by supervision of the ripple component of the excitation current
• Two stage supervision of the rotor insulation resistance with independent settings for esistance and time delay
• Two trip relays, one for excitation under- and over current, one for diode failure detection
• Digital inputs for blocking and for remote reset
• Programmable function of the blocking input
• Programmable assignment of protective functions to output relays
• Remote interfacing via RS485