Woodward XRI1-ER User manual

XRI1-ER –Earth fault relay for isolated
and compensated mains
Manual XRI1-ER (Revision C)

Woodward Manual XRI1-ER
2 TD_XRI1-ER_12.03, Rev. C
Woodward reserves the right to update any portion of this publication at any time.
Information provided by Woodward is believed to be correct and reliable.
However, no responsibility is assumed by Woodward unless otherwise expressly undertaken.
© Woodward 1994–2019

Manual XRI1-ER Woodward
TD_XRI1-ER_12.03, Rev. C 3
Contents
1. Introduction and application........................................................................................5
2. Features and characteristics .......................................................................................6
3. Design............................................................................................................................7
3.1 Connections.............................................................................................................................................7
3.1.1 Analog input circuits.............................................................................................................................7
3.1.2 Blocking input.......................................................................................................................................7
3.1.3 External reset input..............................................................................................................................7
3.1.4 Output relays........................................................................................................................................7
3.1.5 Data communication............................................................................................................................8
3.2 Front plate................................................................................................................................................9
3.2.1 Indication and operation elements.......................................................................................................9
3.2.2 Display...............................................................................................................................................10
3.2.3 LEDs..................................................................................................................................................11
3.2.4 Parameter settings (see chapter 6) ...................................................................................................11
4. Working principle........................................................................................................12
4.1 Analog circuits .......................................................................................................................................12
4.2 Digital circuits.........................................................................................................................................12
4.3 Earth fault protection..............................................................................................................................13
4.3.1 Generator stator earth fault protection...............................................................................................13
4.3.2 System earth fault protection.............................................................................................................13
4.4 Earth-fault directional feature.................................................................................................................14
5. General operations and settings...............................................................................17
5.1 Push buttons..........................................................................................................................................17
5.1.1 Indication of measuring values and fault data...................................................................................18
5.2 Dip switches...........................................................................................................................................19
5.2.1 Function of the output relays .............................................................................................................19
5.3 Reset......................................................................................................................................................20
5.4 Password...............................................................................................................................................20
5.4.1 Password programming.....................................................................................................................20
5.4.2 Using the password ...........................................................................................................................20
5.5 Relay setting principle............................................................................................................................21
5.5.1 Setting of default parameters.............................................................................................................21
5.5.2 Blocking the protection function.........................................................................................................21
5.5.3 Assignment of the signal relays.........................................................................................................21
5.6 Display of software version and test-TRIP ............................................................................................22
5.7 Low/high range of functions blocking and reset ....................................................................................22
6. Operations and settings.............................................................................................23
6.1 Setting procedure ..................................................................................................................................23
6.1.1 Voltage transformer connection for residual voltage measuring (3pha/e-n/1:1) ...............................23
6.1.2 Pickup value for residual voltage UE..................................................................................................23
6.1.3 WARN/TRIP changeover...................................................................................................................23
6.1.4 Pickup current for earth fault element (IE>) ........................................................................................23
6.1.5 Tripping time for the earth overcurrent stage (tIE>) ............................................................................24
6.1.6 Pickup value for high set element (IE>>).............................................................................................24
6.1.7 Trip delay for high set element (tIE>>).................................................................................................24
6.1.8 Nominal frequency.............................................................................................................................24
6.1.9 Circuit breaker failure protection tCBFP ...............................................................................................25
6.1.10 Display of the activation storage (FLSH/NOFL) ............................................................................25
6.1.11 Adjustment of the slave address....................................................................................................25
6.1.12 Setting of Baud-rate (applies for Modbus Protocol only)...............................................................25
6.1.13 Setting of parity (applies for Modbus Protocol only)......................................................................25
6.1.14 Blocking the protection functions and assignment of the output relays ........................................26
6.2 Indication of measuring and fault values ...............................................................................................27
6.2.1 Measuring values...............................................................................................................................27
7. Relay testing and commissioning.............................................................................28
7.1 Power-On...............................................................................................................................................28

Woodward Manual XRI1-ER
4 TD_XRI1-ER_12.03, Rev. C
7.2 Testing the output relays and LEDs ......................................................................................................28
7.3 Checking the set values.........................................................................................................................28
7.4 Secondary injection test.........................................................................................................................29
7.4.1 Test equipment..................................................................................................................................29
7.4.2 Test circuit of XRI1-ER ......................................................................................................................29
7.4.3 Checking the input circuits and measured values.............................................................................31
7.4.4 Checking the operating and resetting values of the relay .................................................................31
7.4.5 Checking the relay operating time.....................................................................................................31
7.4.6 Checking the high set element of the relay .......................................................................................31
7.4.7 Checking the external blocking and reset functions..........................................................................32
7.4.8 Test of the CB failure protection........................................................................................................32
7.5 Primary injection test .............................................................................................................................33
7.6 Maintenance ..........................................................................................................................................33
8. Technical data.............................................................................................................34
8.1 Measuring input circuits.........................................................................................................................34
8.2 Common data ........................................................................................................................................34
8.3 Setting ranges and steps.......................................................................................................................35
8.3.1 Earth fault protection..........................................................................................................................35
8.3.2 Switch failure protection.....................................................................................................................35
8.3.3 Interface parameter ...........................................................................................................................35
8.4Output relays .........................................................................................................................................36
8.5 Power supply .........................................................................................................................................36
8.6 Inputs, Blockage and Reset...................................................................................................................36
8.7 System data and test specifications ......................................................................................................37
8.8 Relay case.............................................................................................................................................38
9. Order form...................................................................................................................39

Manual XRI1-ER Woodward
TD_XRI1-ER_12.03, Rev. C 5
1.Introduction and application
The XRI1-ER of the PROFESSIONAL LINE is an all-purpose protection against earth faults, used for electrical
machines, lines and isolated or compensated systems; it is mainly used in radial networks.
Relay variant XRI1-ER with directional current sensing is a selective earth-fault protection and is normally used
in ring systems, networks with parallel feeders and in complex meshed systems.
Very often the XRI1-ER can be found as backup protection at the central earthing point of the system. It detects
all earth faults occuring in the system. In this case the trip delay selected must exceed the longest time delay
setting of any other earthing protection used in the system.

Woodward Manual XRI1-ER
6 TD_XRI1-ER_12.03, Rev. C
2.Features and characteristics
Digital filtering of the measured values by using discrete Fourier analysis to suppress the
high frequence harmonics and DC components induced by faults or system operations.
High set overcurrent unit with instantaneous or definite time function
Sensitive earth fault current measuring with directional earth current measuring (XR-type).
Numerical display of setting values, actual measured 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 function of both earth current steps
Switch failure protection.
Free assignment of output relays.
Serial data exchange via RS485 interface possible; alternatively with Woodward RS485
Pro-Open Data Protocol and Modbus Protocol.
Suppression of indication after an activation (LED flash).

Manual XRI1-ER Woodward
TD_XRI1-ER_12.03, Rev. C 7
3.Design
3.1 Connections
Figure 3.1: Connection diagram XRI1-ER
3.1.1 Analog input circuits
The protection unit receives the analog input signals of the earth currents IE (1E1-1E2), phase voltages U1 (L1-
N1), U2 (L2-N2), U3 (L3-N3) each via separate input transformers. The neutral is bridged externally. The con-
stantly detected measuring values are galvanically decoupled, filtered and finally fed to the analog/digital con-
verter.
3.1.2 Blocking input
The blocking functions adjusted before will be blocked if an auxiliary voltage is connected to (terminals) C1/C1L
or C1/C1H. (See chapter 6.2.12)
3.1.3 External reset input
By applying the aux. voltage C2/C2L or C2/C2H, indication and output relays are reset. (see chapter 6.3)
3.1.4 Output relays
The XRI1-ER 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.
Except the self-supervision, all relays can be assigned to different functions. (see chapter 6.1.12).

Woodward Manual XRI1-ER
8 TD_XRI1-ER_12.03, Rev. C
3.1.5 Data communication
For data communication with a central control system the XRI1-ER relay is provided with a serial interface
RS485. Simplified and fast reading and changing of parameters and measuring values can be achieved by
HTL/PL-Soft4, which will be provided on request together with the relay.
The XRI1-ER can be connected to other units of
PROFESSIONAL LINE via interface. If there is more than 1 relay in the system, the last relay of the chain has to
be provided with a resistor line termination.
Figure 3.2: Connection example with 3 users, XR ... as linked device
Figure 3.3: Connection example with 3 users, XR ... as last device

Manual XRI1-ER Woodward
TD_XRI1-ER_12.03, Rev. C 9
3.2 Front plate
3.2.1 Indication and operation elements
The front plate of protection relays comprises the following operation and indication elements:
Alphanumerical display (4 Digits)
Push buttons for setting and other operations
LEDs for measured value indication and setting
Figure 3.4: Front plate XRI1-ER

Woodward Manual XRI1-ER
10 TD_XRI1-ER_12.03, Rev. C
3.2.2 Display
Function
Display shows
Pressed push button
Corresponding
LED
Normal operation
WW
Measured operating values
Actual measured
values,
<SELECT/RESET>
one time for each
E IP/IQwith regard
to directional fea-
ture
Measuring range overflow
max.
<SELECT/RESET>
E
Setting values: (IE>; UE>; tIE>; IE>>;
tIE>>)
Current settings Trip
delay Characteristics
<SELECT/RESET> one
time for each parameter
IE>; tIE>; IE>>; tIE>>;
LED →←
Warning or Trip at earth fault
measuring (E- and ER/XR-types)
TRIP WARN
<SELECT/RESET><+><->
IE>
Measured method of the residual
voltage UE
3 PHA ; E-N ; 1:1
<SELECT/RESET><+><->
UE>
residual voltage setting
voltage in volts
<SELECT/RESET><+><->
UE>
changeover of isolated (sin φ) or
compensated (cos φ) networks
SIN COS
<SELECT/RESET><+><->
Tripping protection switch failure
protection
CBFP
After fault tripping
Nominal frequency
f=50 / f=60
<SELECT/RESET><+><->
Switch-over LED flash No LED
flash
FLSH NOFL
<SELECT/RESET><+><->
Blocking of function
EXIT
<+> until max. setting
value
LED of blocked
parameter
Slave address of serial interface
1 - 32
<SELECT/RESET><+><->
RS
Recorded fault data
Tripping currents
and other fault data
<SELECT/RESET>
one time for each phase
L1, L2, L3, E IE>,
IE>>, UE>
Save parameter?
SAV?
<ENTER>
Save parameter!
SAV!
<ENTER>
for about 3 s
Software version
First part (e.g. D01-)
Sec. part (e.g. 8.00)
<TRIP>
one time for each part
Manual trip
TRI?
<TRIP> three times
Inquire password
PSW?
<TRIP><ENTER>
Relay tripped
TRIP
<TRIP>
or after fault tripping
Secret password input
XXXX
<SELECT/RESET><+><-
><ENTER>
System reset
WW
<SELECT/RESET>
for about 3 s
Table 3.1: Possible indication messages on the display

Manual XRI1-ER Woodward
TD_XRI1-ER_12.03, Rev. C 11
3.2.3 LEDs
The LED left from the display, E is partially bi-colored, the green indicating measuring, and the red fault indica-
tion.
XRI1-ER with directional feature have a LED (green- and red arrow) for the directional display. At pickup/trip
and parameter setting the green LED lights up to indicate the forward direction, the red LED indicates the re-
verse 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 earth fault overcurrent indicate the corresponding menu point
selected.
3.2.4 Parameter settings (see chapter 6)
Short overview
Relay type XRI1-ER
Unit
Setting range
1:1/3pha/e-n
UE>; 3pha/e-n
V
1-70; 2-160; 5-300*
UE>;1:1
V
1-120; 2-300; 5-500*
IE> ER-type
XR-type
x IN
%
0.01 –0.45
0.1 –4.5
WARN/TRIP
tIE>V/tIE>R
s
0.05 - 260
IE>> ER-type
XR-type
x IN
%
0.01 –0.45
0.1 –4.5
tIE>>V/tIE>>R
s
0.05 –2.00 s
SIN/COS
tCBFP
s
0.1 –2 s
50/60 Hz
FLSH/NOFL
RS485/Slave
Baud rate**
1200, 2400, 4800, 9600
Parity**
even, add, no
Blockage function
Assignment of the relays
* Setting is depended on rated voltage
** only with Modbus Protocol
Table 3.2: Parameter values

Woodward Manual XRI1-ER
12 TD_XRI1-ER_12.03, Rev. C
4.Working principle
4.1 Analog circuits
The incoming current from the main current transformer on the protected object is converted to voltage signals
in proportion to the currents via the input transformers and burden. The noise signals caused by inductive and
capacitive coupling are suppressed by an analog R-C filter circuit.
The analog voltage signals are fed to the A/D-converter of the microprocessor and transformed to digital signals
through Sample- and Hold-circuits. The analog signals are sampled at 50 Hz (60 Hz) with a sampling frequency
of 800 Hz (960 Hz), namely, a sampling rate of 1.25 ms (1.04 ms) for every measuring quantity. (16 scans per
period).
4.2 Digital circuits
The essential part of the XRI1-ER relay is a powerful microcontroller. All of the operations, from the analog digi-
tal conversion to the relay trip decision, are carried out by the microcontroller digitally. The relay program is lo-
cated in an EPROM (Electrically-Programmable-Read-Only-Memory). With this program the CPU of the micro-
controller calculates the three phase currents and ground current in order to detect a possible fault situation in
the protected object.
For the calculation of the current value an efficient digital filter based on the Fourier Transformation (DFFT -
Discrete Fast Fourier Transformation) is applied to sup-press high frequency harmonics and DC components
caused by fault-induced transients or other system disturbances.
The calculated actual current values are compared with the relay settings. If a phase current exceeds the pickup
value, an alarm is given and after the set trip delay has elapsed, the corresponding trip relay is activated.
The relay setting values for all parameters are stored in a parameter memory (EEPROM - Electrically Erasable
Programmable Read-only Memory), so that the actual relay settings cannot be lost, even if the power supply is
interrupted.
The microprocessor is supervised by a built-in "watch-dog" timer. In case of a failure the watchdog timer re-sets
the microprocessor and gives an alarm signal, via the output relay "self supervision".

Manual XRI1-ER Woodward
TD_XRI1-ER_12.03, Rev. C 13
4.3 Earth fault protection
4.3.1 Generator stator earth fault protection
With the generator neutral point earthed as shown in figure 4.1 the XRI1-ER picks up only to phase earth faults
between the generator and the location of the current transformers supplying the relay.
Earth faults beyond the current transformers, i.e. on the consumer or line side, will not be detected.
Figure 4.1: Generator stator earth fault protection
4.3.2 System earth fault protection
With the generator neutral point earthed as shown in figure 4.2, the XRI1-ER picks up only to earth faults in the
power system connected to the generator. It does not pick up to earth faults on the generator terminals or in
generator stator.
Figure 4.2: System earth fault protection

Woodward Manual XRI1-ER
14 TD_XRI1-ER_12.03, Rev. C
4.4 Earth-fault directional feature
A built-in earth-fault directional element is available for applications to power networks with isolated or with arc
suppressing coil compensated neutral point.
For earth-fault direction detection it is mainly the question to evaluate the power flow direction in zero sequence
system. Both the residual voltage and neutral (residual) current on the protected line are evaluated to ensure a
correct direction decision.
In isolated or compensated systems, measurement of reactive or active power is decisive for earth-fault detec-
tion. It is therefore necessary to set the relays to measure according to sin φor cos φmethods, depending on
the neutral-point connection method.
The residual voltage UErequired for determining earth fault direction can be measured in three different ways,
depending on the voltage transformer connections. (refer to Table 4.1:)
Total current can be measured by connecting the unit to a ring core C.T.
The pick-up values IE> and IE>> (active or reactive cur-rent component for cos φor sin φmethod) for relays can
be adjusted from 0.01 to 0.45 x IN. For relay type XRI1-XR these pick-up values can be adjusted from 0.1 to 4.5
% IN.
Adjustment
possibility
Application
Voltage transformer con-
nections
Measured
voltage at
earth fault
Correction
factor for
residual
voltage
“3pha”
3-phase voltage trans-
former connected to
terminals L1, L2, L3,
N1, N2, N3
√x UN= 3
x U1N
K = 1/3
“e-n”
e-n winding connected
to terminals L1, N1
UN= √x
U1N
K = 1/√
“1:1”
Neutral-point voltage
(= residual voltage)
terminals L1, N
U1N = UNE
K = 1
Table 4.1:

Manual XRI1-ER Woodward
TD_XRI1-ER_12.03, Rev. C 15
Figure 4.3: Phase position between the residual voltage and zero sequence current for faulted and non-faulted lines in
case of isolated systems (sin φ)
UE- residual voltage
IE- zero sequence current
IC- capacitive component of zero sequence current
IW- resistive component of zero sequence current
By calculating the reactive current component (sin φadjustment) and then comparing the phase angle in rela-
tion to the residual voltage UE, the ER/XR-relay type determines whether the line to be protected is earth-
faulted.
On non-earth-faulted lines, the capacitive component Ic(a) of the total current precedes the residual voltage by an
angle of 90°. In case of a faulty line the capacity current IC(b) lags behind the residual voltage at 90°.

Woodward Manual XRI1-ER
16 TD_XRI1-ER_12.03, Rev. C
Figure 4.4: Phase position between the residual voltage and zero sequence current for faulted and non-faulted lines in
case of compensated systems (cos φ)
UE- residual voltage
IE- zero sequence current
IL- inductive component of zero sequence current (caused by Petersen coil)
IC- capacitive component of zero sequence current
IW- resistive component of zero sequence current
In compensated mains the earth fault direction cannot be determined from the reactive current components be-
cause the reactive part of the earth current depends upon the compensation level of the mains. The ohmic
component of the total current (calculated by cos φadjustment) is used in order to determine the direction.
The resistive component in the non-faulted line is in phase with the residual voltage, while the resistive compo-
nent in the faulted line is opposite in phase with the residual voltage.
By means of an efficient digital filter harmonics and fault transients in the fault current are suppressed. Thus, the
uneven harmonics which, for instance, are caused an electric arc fault, do not impair the protective function.

Manual XRI1-ER Woodward
TD_XRI1-ER_12.03, Rev. C 17
5.General operations and settings
For adjustment of the unit the transparent cover has to be opened as illustrated. Do not use force! The trans-
parent cover has two inserts for labels.
Figure 5.1: How to open the transparent cover
5.1 Push buttons
Push buttons are used for calling up the parameters to be processed, for selection of measuring parameters to
be indicated and for changing and storing the parameters.
The individual setting and measuring values can be selected one after another by pressing push button
<SELECT/RESET>. This push button is also used for re-setting the display by pressing approx. 3s.
As for an individual case (relay version D) the push button can also be operated when the front cover of the re-
lay is closed and sealed with lead.
Push buttons <+> <-> are used for in-/decrementing of the parameter indicated on the display. They can be
pressed step-by-step or continuously.
After the selected parameter is set by the <+> <-> push button it may be stored using the <ENTER> push but-
ton.
Through the push button <ENTER> the set value indicated on the display will be transferred to the internal pa-
rameter memory. An unintented or unauthorized change of the selected parameter is avoided by means of a
password identification (see 5.4.2).
The <TRIP>-push button is used to test the output relay circuits both for tripping and signaling. During normal
operation it is also interlocked by means of the pass-word identification.

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18 TD_XRI1-ER_12.03, Rev. C
5.1.1 Indication of measuring values and fault data
Indication in faultless condition
In normal operation the display always shows WW. After pressing the push button <SELECT/RESET> the dis-
play switches cyclically to the next measuring value. After the measuring values had been indicated the set-ting
parameters are displayed. Hereby the LEDs in the upper section signalize which measured value is indicated,
the LEDs in the lower section signalize which setting parameter is indicated on the display. Longer actuating the
push button resets the relay and the display changes into normal operation (WW).
Indication after pickup/tripping
All of the faults detected by the relay are indicated on the front plate optically. Here not only the faults are indi-
cated but also the faulty phase(s) and the protection function in operation. At pickup the LEDs are flashing, after
tripping this changes to continuous light.
In tripped condition "TRIP" appears on the display and the LEDs of the operating measuring data light up red
together with the LEDs of the tripping parameter. All operating data, which were measured at the moment of
tripping, can now be called one after another by pressing push button <SELECT/RESET>. If in this condition
setting parameters are to be indicated, push but-ton <ENTER> has to be pressed.
The graphic below shows again the difference between the different display modes.
Figure 5.2: Switching over of the display in dependence of the operating mode

Manual XRI1-ER Woodward
TD_XRI1-ER_12.03, Rev. C 19
5.2 Dip switches
Behind the front plate of the XRI-ER relay there is one dip switch to preset the following functions:
Password programming
Output relay functions
The following table 5.1 shows the position and designation of the code jumpers:
5.2.1 Function of the output relays
The alarm relays are activated according to the preset-ting:
Dip switch 1 OFF
The actual password is active.
Dip switch 1 ON:
After switch on the supply voltage the password can be correct. (see chapter 5.4)
Dip switch 3 OFF:
All output relays will be reset automatically after the fault has been cleared, (e.g. when the fault current is inter-
rupted).
Dip switch 3 ON:
All output relays remains activated and must be reset after fault clearance.
Manually: By pressing push button <SELECT/RESET>
External: By connecting aux. voltage to C2/C2L or C2/C2H
Via RS 485 interface
To let the parameter change take effect, the auxiliary voltage has to be switched on and off again after the dip
switches are plugged or unplugged.
Dip switches
Function
Code jumper
position
Operation mode
1
Password
OFF
Normal position
ON
Password programming
2
none
3
Reset
OFF
Output relays will be reset automatically
ON
Output relays will be reset manual/external/via
software
4
none
Table 5.1: Summary of coding possibilities

Woodward Manual XRI1-ER
20 TD_XRI1-ER_12.03, Rev. C
5.3 Reset
Manual reset
By pressing push button <RESET/SELECT> for some time (about 3 s).
External reset-input C2/C2L or C2/C2H
The external reset input has the same function as the <SELECT/RESET> push button on the front plate. Con-
necting auxiliary voltage to this input, the unit can be reset, provided that the fault is removed.
Software reset via serial interface RS 485
Software reset has the same function as push button <SELECT/RESET>. Please refer to open data protocol of
RS 485 interface named RS485-PRO.
5.4 Password
5.4.1 Password programming
The XRI1-ER-relay is delivered with the preset password "++++", it can be programmed new with dip switch 1:
Switch on dip switch 1. After power on and pressing any push button, the relay XRI1-ER inquires for a new
password. The text "PSW?" appears on the display. The new password is entered by any combination of the
push buttons <SELECT> <-> <+> <ENTER>. After the new password is given, the dip switch 1 must be
switched off.
5.4.2 Using the password
Step by step, a new relay setting is made according to the following sequence:
After the present setting value is changed with <+><-> push button, <ENTER> push button
should be pressed.
A message "SAV?" appears on the display to inquire if the new setting value is really
wanted to be stored.
After pressing the <ENTER> push button again, the password will be inquired by means of
the message "PSW?" on the display.
After the password is given correctly, which is prompted by message "SAV!" on the display,
the new setting value can be stored by pressing the <ENTER> push button for about
3 seconds.
The new setting value for the selected parameter appears on the display again.
A password consists of four push button operations. The pressed push buttons and their sequences define the
password.
<SELECT/RESET> = S
<-> = -
<+> = +
<ENTER> = E
then a password "-E+S" means pressing push buttons according to the following sequence:
<-> <ENTER> <+> <SELECT/RESET>