Mra4

HighPROtec
Mra4

Protection tecHnoloGy
Made siMPle
Protection relay for feeder,
Grid and Generator aPPlications

aPPlic ation
the Mra4 is a protection relay which uses the latest dual-coreProcessor technology to provide precise and reliable protective
functions and is very easy to operate. its various protective functions are specifically tailored to the protection of incoming andoutgoing feeders in MV systems. it also can be used for grid and
generator protection.

all incluSive:
all protection features without
extra charge
Parameter setting and evaluation
software
disturbance record analysis software

t wo StaGeS reSiDual
voltaGe Protec tion
Ve>

SiX StaGeS PHaSe overcurrent Protec tion
directional and non-directional
overcurrent/short-circuit protectiontripping characteristics:
deft
ansi: ninV, VinV, einV
iec: ninV, VinV, linV, einV
thermal flat, it, i2t, i4t
Voltage controlled and restraint

Four StaGeS eartH Fault
Protec tion
directional and non-directional
earth fault protection
tripping characteristic:
deft
ansi: ninV, VinV, einV
iec: ninV, VinV, linV, einV
thermal flat, it, i2t, i4t
Voltage controlled and restraint

t woStaGeS unBal anceD
loaD Protec tion
supervision by definite time or
tripping characteristic

SiX StaGeS voltaGe
Protec tion
Under- and overvoltage
Programmable undervoltage
time depending characteristic

SiX StaGeS voltaGe
aSYmmetrY SuPerviSion
Under- and overvoltage in positive
phase sequence system, overvoltage
in negative phase sequence system

DiSturBance recorDer
120 s nonvolatile,
32 samples per cycles

a DDitional HiGHliGHtS
automatic reclosing
inrush
thermal replica
four stages external protection
Plausibility checks
adaptive parameter sets
energy counters
status display
comprehensive measured values
and statistics
Masking of unused functions

Par ameter Set tinG
SuPPort BY SoFt ware
copy parameter sets
compare parameter sets
setting files are upand down
convertible (across versions)

comPreHenSive
FreQuenc Y
Protec tion PacK aGe
each of the six stages can be used as:
f< or f> (over- and
underfrequency supervision)
df/dt (rocof)
(f< and df/dt) or (f> and df/dt)
combination of over-, under- and rate
of change of frequency (rocof)
(f< and df/dt) or (f> and df/dt)
combination of over-, underand increase of frequency
delta Phi(Vector surge)

Power Protec tion
PacK aGe
six stages power protection
each can be used as P>, P, Q, s<
two stages power factor (Pf)

Q(v) Protec tion
Undervoltage directional reactive power
protection with reclosing disengaging

S uPerviSion
current transformer supervision
Voltage transformer supervision
circuit breaker failure protection
trip circuit supervision
cold load pickupswitch onto fault
Breaker Wear

MRA4

Protection relay for feeder,
Grid and Generator aPPlications

Func tional over vie w
elements

anSi

6

50P, 51P, 67P

Protective Functions
i, time overcurrent and short circuit protection, all stages can be configured for
directional or non-directional supervision. tremendous reset options
(instantaneous, definite time, resetcharacteristics according to iec and ansi).

51c
51V
51Q

Voltage controlled overcurrent protection by means of adaptive parameters.
Voltage dependent overcurrent protection.
negative phase sequence overcurrent protection

46

i2>, unbalanced load protection with evaluation of the negative phase sequence currents

2

iB, overload protection with thermal replica and separate pick-up valuesfor alarm and trip functions

1

49

iH2/in, inrush detection with evaluation of the 2nd harmonic

1

inrush

iG, earth overcurrent and short circuit protection, all stages can be configured for
directional or non-directional supervision. tremendous reset options
(instantaneous, definite time, reset characteristics according to iec and ansi).

4

50n, 51n, 67n

Voltage...