Seg HighTECH Line User manual

MRI1
PROTECTION TECHNOLOGY
MADE SIMPLE
DIGITAL MULTIFUNCTIONAL RELAY FOR
TIME-OVERCURRENT PROTECTION
HighTECH Line
DIGITAL MULTIFUNCTIONAL RELAY FOR TIME-OVERCURRENT PROTECTION
Revision: A
Original document
English
MANUAL

2 TD_MRI1_06.05_GB
1 Introduction and application
2 Features and characteristics
3 Design
3.1 Connections
3.1.1 Analog input circuits
3.1.2 Output relays of MRI1-relays
3.1.3 Blocking input
3.1.4 External reset input
3.2 Relay output contacts
3.2.1 Parameter settings
3.3 LEDs
4 Working principle
4.1 Analog circuits
4.2 Digital circuits
4.3 Directional feature
4.4 Earth fault protection
4.4.1 Generator stator earth fault protection
4.4.2 System earth fault protection
4.5 Earth-fault directional feature
(ER/XR-relay type)
4.6 Determining earth short-circuit fault
direction
4.7 Demand imposed on the main current
transformers
5 Operation and setting
5.1 Display
5.2 Setting procedure
5.2.1 Pickup current for phase overcurrent
element (I>)
5.2.2 Time current characteristics for phase
overcurrent element (CHAR I>)
5.2.3 Trip delay or time multiplier for phase
overcurrent element (t
I>
)
5.2.4 Reset setting for inverse time tripping
characteristics in the phase current path
5.2.5 Current setting for high set element (I>>)
5.2.6 Trip delay for high set element (t
I>>
)
5.2.7 Relay characteristic angle RCA
5.2.8 Voltage transformer connection for residual
voltage measuring (3pha/e-n/1:1)
5.2.9 Pickup value for residual voltage U
E
(ER/XR-relay type)
5.2.10 Pickup current for earth fault element (I
E>
)
5.2.11 WARN/TRIP changeover
(E/X and ER/XR-relay type)
5.2.12 Time current characteristics for earth fault
element (CHAR IE; (not for ER/XR-relay type)
5.2.13 Trip delay or time multiplier for earth fault
element (t
IE>>
)
5.2.14 Reset mode for inverse time tripping in
earth current path
5.2.15 Current setting for high set element of earth
fault supervision (I
E>>
)
5.2.16 Trip delay for high set element of earth
fault supervision (t
IE>>
)
5.2.17 COS/SIN Measurement (ER/XR-relay type)
5.2.18 SOLI/RESI changeover (SR-relay type)
5.2.19 Circuit breaker failure protection t
CBFP
5.2.20 Nominal frequency
5.2.21 Display of the activation storage
(FLSH/NOFL)
5.2.22 Adjustment of the slave address
5.2.23 Setting of Baud-rate (applies for Modbus
Protocol only)
5.2.24 Setting of parity (applies for Modbus
Protocol only)
5.2.25 Blocking the protection functions and
assignment of the output relays
5.3 Setting value calculation
5.3.1 Definite time overcurrent element
5.3.2 Inverse time overcurrent element
5.4 Indication of measuring and fault values
5.4.1 Indication of measuring values
5.4.2 Indication of fault data
5.4.3 Fault memory (not for ER/XR types)
5.5 Reset
6 Relay testing and commissioning
6.1 Power-On
6.2 Testing the output relays and LEDs
6.3 Checking the set values
6.4 Secondary injection test
6.4.1 Test equipment
6.4.2 Example of test circuit for MRI1 relays
without directional feature
6.4.3 Checking the input circuits and measured
values
6.4.4 Checking the operating and resetting
values of the relay
6.4.5 Checking the relay operating time
6.4.6 Checking the high set element of the relay
6.4.7 Example of a test circuit for MRI1 relay
with directional feature
6.4.8 Test circuit earth fault directional feature
6.4.9 Checking the external blocking and reset
functions
6.4.10 Test of the CB failure protection
6.5 Primary injection test
6.6 Maintenance

TD_MRI1_06.05_GB 3
7 Technical data
7.1 Measuring input circuits
7.2 Common data
7.3 Setting ranges and steps
7.3.1 Time overcurrent protection (I-Type)
7.3.2 Earth fault protection (SR-Type)
7.3.3 Earth fault protection (E/X-Type)
7.3.4 Earth fault protection (ER/XR-Type)
7.3.5 Switch failure protection
7.3.6 Interface parameter
7.3.7 Inverse time overcurrent protection relay
7.3.8 Direction unit for phase overcurrent relay
7.3.9 Determination of earth fault direction
(MRl1-ER/XR)
7.3.10 Determination of earth fault direction
(MRl1-SR)
7.4 Inverse time characteristics
7.5 Output contacts
8 Order form

4 TD_MRI1_06.05_GB
1 Introduction and application
The MRl1 digital multifunctional relay is a universal
time overcurrent and earth fault protection device in-
tended for use in medium-voltage systems, either with
an isolated/compensated neutral point or for networks
with a solidly earthed/resistance-earthed neutral point.
• The protective functions of MRI1 which are imple-
mented in only one device are summarized as fol-
lows:
• Independent (Definite) time overcurrent relay.
• Inverse time overcurrent relay with selectable charac-
teristics.
• Integrated determination of fault direction for appli-
cation to doubly infeeded lines or meshed systems.
• Two-element (low and high set) earth fault protection
with definite or inverse time characteristics.
• Integrated determination of earth fault direction for
application to power system networks with isolated
or arc suppressing coil (Peterson coil) neutral
earthing. (ER/XR-relay type).
• Integrated determination of earth short-circuit fault di-
rection in systems with solidly-earthed neutral point or
in resistance-earthed systems (SR-relay type).
Furthermore, the relay MRI1 can be employed as a
back-up protection for distance and differential protec-
tive relays.
A similar, but simplified version of overcurrent relay
IRI1 with limited functions without display and serial in-
terface is also available.
Important:
For additional common data of all MR-relays please
refer to manual "MR - Digital Multifunctional relays".
On page 41 of this manual you can find the valid soft-
ware versions.
2 Features and characteristics
• Digital filtering of the measured values by using dis-
crete Fourier analysis to suppress the high frequence
harmonics and DC components induced by faults or
system operations
• Selectable protective functions between:
definite time overcurrent relay and
inverse time overcurrent relay
• Selectable inverse time characteristics according to
BS 142 and IEC 255-4:
Normal Inverse
Very Inverse
Extremely Inverse
• Reset setting for inverse time characteristics select-
able
• High set overcurrent unit with instantaneous or de-
finite time function.
• Two-element (low and high set) overcurrent relay
both for phase and earth faults.
• Directional feature for application to the doubly in-
feeded lines or meshed systems.
• Earth fault directional feature selectable for either iso-
lated or compensated networks.
• sensitive earth fault current measuring with or without
directional feature (X and XR-relay type
• Determination of earth short-circuit fault direction for
systems with solidly-earthed or resistance-earthed
neutral point.
• Numerical display of setting values, actual mea-
sured values and their active, reactive components,
memorized fault data, etc.
• Withdrawable modules with automatic short circuit
of C.T. inputs when modules are withdrawn.
• Blocking e.g. of high set element (e.g. for selective
fault detection through minor overcurrent protection
units after unsuccessful AR).
• Relay characteristic angle for phase current direc-
tional feature selectable
• Dwell time selectable
• Switch failure protection
• Storage of tripping values and shut-down times
(not ER/XR versions) (t
CBFP
) of eight failure events
• Free assignment of output relays
• Serial data exchange via RS485 interface possible;
alternatively with SEG RS485 Pro-Open Data Proto-
col or Modbus Protocol
• Suppression of indication after an activation
(LED flash)

TD_MRI1_06.05_GB 5
3 Design
3.1 Connections
Phase and earth current measuring:
Figure 3.1: Measuring of the phase currents for over-current-
and short-circuit protection (I>,I>>)
Figure 3.2: Earth-fault measuring by means of ring-core C.T. (I
E
)
When phase-- and earth-fault current measuring are
combined, the connection has to be realized as per
Figure 3.1 and Figure 3.2.
Figure 3.3: Phase current measuring and earth-current
detection by means of Holmgreen-circuit.
This connection can be used with three existing phase
current transformers when combined phase and earth-
current measuring is required.
Disadvantage of holmgreen-circuit:
At saturation of one or more C.Ts the relay detects
seeming an earth current.
* This arrow shows the current flow in forward direction, for this LED →← lights up green

6 TD_MRI1_06.05_GB
Voltage measuring for the directional detection:
Figure 3.4: Measuring of the phase voltages for the directional
detection at overcurrent, short-circuit or earth-fault
protection (I>, I>>, I
E>
and I
E>>
).
For details on the connection of ER/XR-unit type c.t.s,
see para 4.5.
I>
I>
I>
A3 L1
U1
U2
A5 L2
A7 L3
A2 N
U3
L
1
L2
L3
a
b
c
Figure 3.5: Voltage transformer in V-connection for the
directional detection at overcurrent and short-circuit
protection.
The V-connection can not be applied at earth fault di-
rectional feature.
3.1.1 Analog input circuits
The protection unit receives the analog input signals of
the phase currents IL1 (B3-B4), IL2 (B5-B6), IL3 B7-B8)
and the current IE (B1-B2), phase voltages U1 (A3),
U2 (A5), U3 (A7) with A2 as star point, each via
separate input transformers.
The constantly detected current measuring values are
galvanically decoupled, filtered and finally fed to the
analog/digital converter.
For the unit type with earth fault directional features
(ER/XR-relay type) the residual voltage U
E
in the sec-
ondary circuit of the voltage transformers is internally
formed.
In case no directional feature for the phase current
path is necessary the residual voltage from the open
delta winding can directly be connected to A3 and
A2.
See Chapter 4.4 for voltage transformer connections
on isolated/compensated systems.
3.1.2 Output relays of MRI1-relays
The MRI1 is equipped with 5 output relays. Apart from
the relay for self-supervision, all protective functions
can be optionally assigned:
• Relay 1: C1, D1, E1 and C2, D2, E2
• Relay 2: C3, D3, E3 and C4, D4, E4
• Relay 3: C5, D5, E5
• Relay 4: C6, D6, E6
• Self-supervision C7, D7, E7
All trip and alarm relays are working current relays,
the relay for self supervision is an idle current relay.
3.1.3 Blocking input
The blocking functions adjusted before will be blocked
if an auxiliary voltage is connected to (terminals)
D8/E8. (See chapter 5.2.25)
3.1.4 External reset input
Please refer to chapter 5.5.

TD_MRI1_06.05_GB 7
3.2 Relay output contacts
Figure 3.6
Contacts at MRI1:
To prevent that the C.B. trip coil circuit is interrupted
by the MRI1 first, i.e. before interruption by the C.B.
auxiliary contact, a dwell time is fixed.
This setting ensures that the MRI1 remains in self hold-
ing for 200ms after the fault current is interrupted.

8 TD_MRI1_06.05_GB
3.2.1 Parameter settings (see chapter 5)
Relay-type MRI1- IIE
IX
IRE
IRX
IR IER
IXR
IRER
IRXR
ER
XR
E
X
ISR IRSR SR
I> X X X X X X X X
CHAR I> X X X X X X X X
t
I>
X X X X X X X X
0s / 60s
3)
X X X X X X X X
I>> X X X X X X X X
t
I>>
X X X X X X X X
RCA X X X X
1:1 / 3 pha / e-n X X X
U
E
X X X
I
E>
X X X X X X X X X
warn/trip X X X X X X
CHAR I
E
X X X X X X
t
IE
X X X X X X X X X
0s/60 s
4)
X X X X X X
I
E>>
X X X X X X X X X
t
IE>>
X X X X X X X X X
sin/cos X X X
soli/resi XXX
tCBFP X X X X X X X X X X X
50/60 Hz X X X X X X X X X X X
LED-Flash X X X X X X X X X X X
RS485/Slaveaddress X X X X X X X X X X X
Baud-Rate
3)
X X X X X X X X X X X
Parity-Check
3)
X X X X X X X X X X X
Table 3.1: Parameters of the different relay types.
1)
Reset setting for inverse time characteristics in phase current path
2)
Reset setting for inverse time characteristics in earth current path
3)
Only devices with Modbus-Protocol
Additional parameters:
Relay-type MRI1- I IE
IX
IRE
IRX
IR IER
IXR
IRER
IRXR
ER
XR
E
X
ISR IRSR SR
Blocking mode X X X X X X X X X X X
Relay parameterising X X X X X X X X X X X
Fault recorder X X X X X X X X

TD_MRI1_06.05_GB 9
SELECT/RESET
ENTER
TRIP
t
I
MRI1-I
PHASE
tI>>
I>>
tI>
CHAR I>
I>
L1 L2 L3
RS DISPLAY
Figure 3.7: Front panel MRI1-I
MRI1-E
SELECT/RESET
ENTER
TRIP
t
I
I >
E
CHAR I
tE
I >
I >>
EtI >>
EEARTH
E
RS
E
DISPLAY
Figure 3.8: Front panel MRI1-E/X
SELECT/RESET
ENTER
TRIP
t
I
I>
CHAR I>
tI>
I>>
tI>> PHASE
MRI1-IR
L1 L2 L3
RS
Q
I
P
IDISPLAY
Figure 3.9 Front panel MRI1-IR
MRI1-ER
t
I >
E
U >
E
tI >
E
I >>
E
tI >>
EEARTH
I
E
RS
QP
II
SELECT/RESET
ENTER
TRIP
DISPLAY
Figure 3.10: Front panel MRI1-ER/XR

10 TD_MRI1_06.05_GB
SELECT/RESET
ENTER
TRIP
t
I
I >
E
CHAR IE
tE
I >
I >>
EtI >>
EEARTH
MRI1-SR
E
RSIQ
IPDISPLAY
Figure 3.11: Front panel MRI1-SR
SELECT/RESET
ENTER
TRIP
t
I
MRI1-IRER
L1 L2 L3 E
RS
Q
I
P
I
PHASE
EARTH
I >
E
I >>
E
tI >>
E
tI>>
I>>
I>
t
CHAR I>
I>
tI >
E
U >
E
Figure 3.12: Front panel MRI1-IRER/IRXR
and MRI1-IER/IXR
3.3 LEDs
The LEDs left from the display are partially bi-colored,
the green indicating measuring, and the red fault indi-
cation.
MRI1 with directional addition have a LED (green- and
red arrow) for the directional display. At pickup/trip
and parameter setting the green LED lights up to indi-
cate the forward direction, the red LED indicates the
reverse direction.
The LED marked with letters RS lights up during setting
of the slave address of the device for serial data com-
munication.
The LEDs arranged at the characteristic points on the
setting curves support the comfortable setting menu se-
lection. In accordance with the display 5 LEDs for
phase fault overcurrent relay and 5 LEDs for earth-fault
relay indicate the corresponding menu point selected.
SELECT/RESET
ENTER
TRIP
t
I
MRI1-IRSR
L1 L2 L3 E
RS
Q
I
P
I
PHASE
EARTH
I >>
E
I>>
I>
I >
E
CHAR I
t
I >
E
I >>
E
t
t
I>>
I>
t
CHAR I>
E
Figure 3.13: Front panel MRI1-IRSR; MRI1-IRE/IRX
and MRI1-ISR