Woodward
Manual MRN3 GB
6
TD_MRN3_09.08_GB_Rev.New
2. Features and characteristics
•
Microprocessor technology with watchdog,
•
effective analog low pass filter for suppressing harmonics when measuring frequency and
vector
surge,
•
digital filtering of the measured values by using discrete Fourier analysis to suppress
•
higher harmonics and d.c. components induced by faults or system operations,
•
integrated functions for voltage, frequency and vector surge in one device as well as single
voltage, frequency and vector surge devices,
•
two parameter sets,
•
voltage supervision each with two step under-/and overvoltage detection,
•
frequency supervision with three step under-/or over frequency (user setting),
•
completely independent time settings for voltage and frequency supervision,
•
adjustable voltage threshold value for blocking frequency and vector surge measuring,
•
display of all measuring values and setting parameters for normal operation as well as
tripping via a alphanumerical display and LEDs,
•
display of measuring values as primary quantities
•
Storage of trip values and switching-off time (t
CBFP
) of 5 fault occurrences (fail-safe of
voltage),
•
recording of up to eight fault occurrences with time stamp
•
for blocking the individual functions by the external blocking input, parameters can be set
according to requirement,
•
user configurable vector surge measurement 1-of-3 or 3-of-3,
•
reliable vector surge measuring by exact calculation algorithm,
•
suppression of indication after an activation (LED flash),
•
free assignment for output relays,
•
display of date and time,
•
in compliance with VDE 0435, part 303 and IEC 255,
•
serial data exchange via RS485 interface possible; alternatively with SEG RS485
Pro-Open Data Protocol or Modbus Protocol.
Important:
For additional common data of all MR-relays please refer to technical description "MR - Digital Mul-
tifunctional Relays".
