ABB SPAJ 131 C Parts list manual

ABB Network Partner
User´s manual and
Technical description SPAJ 131 C
Overcurrent relay
RS 421 Ser.No.
SPAJ 131 C
2
5
1028D
f
n= 50Hz
60Hz
1
2
3
4
5/
>
tt
n
/
II
n
)(
>
I
n
)(
>>
I
>>
/
tt
%
[]
%
[]
U
aux
80...265V ~
–
18...80V –
n
I
=1A 5A
SPCJ 3C3
REGISTERS
0000
1
2
3
4
5
6
7
8
01
SGR
L1 IRF
>
I
L2
I
L3
I
I
1309
[ ]
s
k>
t
0.5
0.05 1.0
13
2.5
0.5
0.04 1.0
0.5
1.5
2.5 STEP
RESET
SG1
01
1
2
3
4
5
6
7
8
20
STEP
>>
I
n
I
>
I
n
I
>>
I
>>
t
[ ]
s
>
I
>>
I
SPCJ 3C3
B

2
1MRS 750660-MUM EN
Issued 97-02-24
Version A (replaces 34 SPAJ 20 EN1)
Checked
Approved
Data subject to change without notice
Station
Automation
SPAJ 131 C
Overcurrent relay
Contents Features .......................................................................................................................... 2
Application.....................................................................................................................3
Description of operation................................................................................................. 3
Connections ................................................................................................................... 4
Configuration of output relays ....................................................................................... 6
Start and operation indicators......................................................................................... 7
Combined power supply and I/O module ...................................................................... 7
Technical data ................................................................................................................ 8
Examples of application................................................................................................ 10
Secondary injection testing........................................................................................... 18
Maintenance and repair................................................................................................ 22
Spare parts.................................................................................................................... 22
Ordering numbers ........................................................................................................ 22
Dimensions and instructions for mounting .................................................................. 23
Order information........................................................................................................ 23
The complete manual for the three-phase overcurrent relay SPAJ 131 C includes
the following partial manuals:
Overcurrent relay SPAJ 131 C, general description 1MRS 750660-MUM EN
Three-phase overcurrent relay module SPCJ 3C3 1MRS 750602-MUM EN
General characteristics of C-type relay modules 1MRS 750328-MUM EN
Features Three-phase low-set phase overcurrent stage
withdefinite timeorinverse timecharacteristic
High-set phase overcurrent stage with definite
time characteristic
Both overcurrent stages can be blocked by an
external control signal
Output relay functions freely configurable for
desired operation
Flexible adaptation of relay to specific applica-
tions
Localnumericaldisplayofsettingvalues,meas-
ured values and recorded fault values
Serial interface for two-way data communica-
tion over fibre-optic bus between relay and
substation and/or remote control systems
Continuous self-supervision of hardware and
software, including auto-diagnostics

3
Application The overcurrent relay SPAJ 131 C is designed
to be used for two-stage phase overcurrent pro-
tectionofdistributionfeeders,largelow-voltage
motors,high-voltagemotors,medium-sizedand
large generators and power transformers. The
relay can be used both as main protection relay
and back-up protection relay.
The relay has two protection stages: a low-set
overcurrent stage I> and a high-set overcurrent
stage I>>. The low-set stage operates with defi-
nite-time characteristic or with inverse-time
characteristic, while the high-set stage operates
with definite time characteristic only.
The overcurrent relay is provided with five
outputrelays,of whichfourarefreely configur-
ableforthedesiredfunction.Twooftheoutput
relays have heavy-duty contacts capable of di-
rectly controlling a circuit breaker.
TheovercurrentrelaySPAJ131Cisasecondary
relaythatisconnectedtothecurrenttransform-
ersoftheprotectedobject.Therelaycanbeused
forsingle-phase,two-phaseorthree-phaseover-
current protection. The overcurrent relay con-
tinuously measures the phase currents of the
object to be protected. On the occurrence of a
fault the overcurrent relay generates an alarm
signal,tripsthe circuitbreakerorstarts external
auto-reclose functions, in accordance with the
current application.
When the phase current exceeds the set start
value I> of the low-set stage, the overcurrent
relay starts. When, at definite time operation,
the set operate time t> or, at inverse definite
minimum time (IDMT) operation, the calcu-
latedoperatetimet>,expires,therelayoperates.
Inthesamewaythehigh-setstagestartsonceits
setstart valueI>>is exceededand, whentheset
operate time t>> expires, the relay operates.
Thelow-setstageoftheovercurrentrelaycanbe
given either definite-time or inverse-time char-
acteristic. At inverse time characteristic four
inverse time curve sets with different slopes are
available: Normal inverse, Very inverse, Ex-
tremely inverse and Long-time inverse. These
curvesetscomplywiththeBS142andIEC255
standards.
The start signals from the overcurrent relay are
obtainableascontactfunctions.Thestartsignal
canbeused,forinstance,forblockingcooperat-
ing protection relays.
The relay contains one optically isolated logic
input for incoming external control signals,
generally blocking signals.
Description
of operation
Three-phase low-set overcurrent stage
with definite time or inverse definite
minimum time operation characteristic
Three-phase high-set overcurrent stage
with instantaneous or definite time
operation characteristic
Blocking of high-set and/or low-set overcurrent
stages by external control signal
Serial communication
51
50
Tripping 1
Tripping 2
Start 1
IRF
Signal 1
Serial port
Blocking
I
L1
I
L2
I
L3
Fig. 1. Protection functions of the overcurrent relay SPAJ 131 C. The encircled numbers refer to
theANSI(=AmericanNationalStandardsInstitute)numberoftheconcernedprotectionfunction.

4
Connections
Fig. 2. Connection diagram for the three-phase overcurrent relay SPAJ 131 C.
Uaux Auxiliary voltage
A,B,C,D,E Output relays
IRF Self-supervision function
BS Blocking signal
SS Start signal
TS Trip signal
SGR Switchgroup for configuring trip and alarm signals
SGB Switchgroup for configuring blocking signals
TRIP_ Trip output
SIGNAL1 Signal on relay operation
START1 Start signal or signal on relay operation
U1 Three-phase overcurrent relay module SPCJ 3C3
U2 Power supply and I/O module SPTU 240S1 or SPTU 48S1
U3 I/O module SPTE 3E4
SERIAL PORT Serial communication port
SPA-ZC_ Bus connection module
Rx/Tx Optical-fibre receiver terminal (Rx) and transmitter terminal (Tx) of the bus
connection module
L1
L2
L3
0
Ι
0
Ι
-
-
+
+
6
8
73 2 4
5A 1A
5
SGR/1
SPAJ 131 C
U2
U3
U3 1111
DCBA
+-
Uaux
E
+
-
( ~ )
(
~ )
≅
_
5A
1A
5A 1A
5 81 68 661 2 3 4 6 7 8 9 10 11 61 62 70 71 72 77 78 80 69 65
SGR
IRF
START1 SIGNAL1 TRIP2 TRIP1IRFBS
+
TS2
TS1
SGB
SS1
SS2
U1
5
4
I/O
3I>
t >>
t >,k
3I>>
SPA-ZC_
Rx Tx
SERIAL
PORT

5
Fig.3. Rear view of the overcurrent relay SPAJ 131 C
Specification of input and output terminals
Contacts Function
1-2 Phase current IL1 (In= 5 A)
1-3 Phase current IL1 (In= 1 A)
4-5 Phase current IL2 (In= 5 A)
4-6 Phase current IL2 (In= 1 A)
7-8 Phase current IL3 (In= 5 A)
7-9 Phase current IL3 (In= 1 A)
10-11 External blocking signal (BS)
61-62 Auxiliary power supply.
When DC voltage is used the positive pole is connected to terminal 61.
65-66 Trip output 1 for the I> and I>> stages (TRIP 1)
68-69 Trip output 2 for the I> and I>> stages (TRIP 2)
80-81 Signal on tripping of the I> and I>> stages (SIGNAL 1)
77-78 Signal on tripping of stage I>>, starting of the I> and I>> stages (START1)
70-71-72 Self-supervision(IRF)alarm output.Undernormal conditionsthecontact interval
70-72isclosed.Whentheauxiliaryvoltagedisappearsoraninternalfaultisdetected,
the contact interval 71-72 closes.
Protective earth terminal
Made in Finland
1
2
3
4
5
6
7
8
9
70
71
72
61
62
65
66
68
69
80
81
77
78
10
11
TTL
B470372
Rx
Tx
In single-phase applications it is recommended
that the energizing current is routed through
two energizing inputs of the relay connected in
series. This arrangement secures a faster opera-
tion time of the relay, in particular, at instanta-
neous operation.
The overcurrent relay SPAJ 131 C connects to
the fibre optic data communication bus by
means of the bus connection module SPA-ZC
17or SPA-ZC21. Thebusconnectionmodule
is fitted to the D-type connector (SERIAL
PORT)ontherearpaneloftherelay.Theopto-
connectorsoftheopticalfibresarepluggedinto
the counter connectors Rx and Tx on the bus
connection module.

6
In addition, the following functions can be
selected with the switches of the SGR switch-
group on the front panel:
Configuration of
output relays The trip signal of the I> stage is firmly wired to
outputrelayAandthetripsignaloftheI>>stage
is firmly wired to output relay B.
Switch Function Factory User's
settings settings
SGR/1 Routes the ext. blocking signal to the overcurrent module 1
SGR/2 Routes the start signal of the I>> stage to output relay D 1
SGR/3 Routes the start signal of the I> stage to output relay D 1
SGR/4 Routes the trip signal of the I>> stage to output relay D 1
SGR/5 Routes the trip signal of the I>> stage to output relay C 1
SGR/6 Routes the trip signal of the I>> stage to output relay A 1
SGR/7 Routes the trip signal of the I> stage to output relay C 1
SGR/8 Routes the trip signal of the I> stage to output relay B 1
The circuit breakers can be directly controlled
with output relay A or output relay B. Thus
either operation stage may have its own trip
output relay and two separate circuit breakers
can be controlled with the same overcurrent
relay.

7
Start and
operation
indicators
RS 421 Ser.No.
SPAJ 131 C
2
5
1028D
f
n= 50Hz
60Hz
1
2
3
4
5/
>
tt
n
/
II
n
)(
>
I
n
)(
>>
I
>>
/
tt
%
[]
%
[]
U
aux
80...265V ~
–
18...80V –
n
I
=1A 5A
SPCJ 3C3
REGISTERS
0000
1
2
3
4
5
6
7
8
01
SGR
L1
IRF
>
I
L2
I
L3
I
I
1309
[ ]
s
k>
t
0.5
0.05 1.0
13
2.5
0.5
0.04 1.0
0.5
1.5
2.5
STEP
RESET
SG1
01
1
2
3
4
5
6
7
8
20
STEP
>>
I
n
I
>
I
n
I
>>
I
>>
t
[ ]
s
>
I
>>
I
SPCJ 3C3
B
2. TheyellowLEDs(IL1,IL2,IL3)ontheupper
blackpartofthefrontplateindicate,whenlit,
thatthevalueoftheconcernedphasecurrent
is being displayed.
3. TheredIRFindicator oftheself-supervision
system indicates, when lit, that a permanent
internal relay fault has been detected. The
fault code appearing on the display once a
fault has been detected should be recorded
and notified when service is ordered.
4. ThegreenUaux LED onthefront panelis lit
whenthepowersupplymoduleoperatesprop-
erly.
5. The LED indicator below a setting knob
indicates, when lit, that the setting value is
being displayed.
6. The LED of the SG1 switchgroup indicates,
when lit, that the checksum of the switch-
group is being displayed.
Thestartandoperationindicators,thefunction
of the SG2 software switchgroup and the func-
tions of the LED indicators during setting are
described more detailed in the relay module
manual for the three-phase overcurrent relay
module SPCJ 3C3.
1. Either overcurrent stage has its own opera-
tion indicator (I> and I>>), located in the
right bottom corner of the front plate of the
relay module. Yellow light indicates that the
concernedstagehasstartedandredlightthat
the stage has operated (tripped).
WiththeSG2softwareswitchgroupthestart
and trip indicators can be given a latching
function,whichmeansthattheLEDsandthe
output relay remain lit, although the signal
thatcausedoperationreturnstonormal.The
indicators are reset with the RESET push-
button. An unreset indicator does not affect
the operation of the relay.
Combined power
supply and I/O
module
The combined power supply and I/O module
(U2)islocatedbehindthesystemfrontpanelof
theprotectionrelayandcanbewithdrawnfrom
the relay case after removal of the system front
panel.ThepowersupplyandI/Omoduleincor-
porates a power unit, four output relays, the
control circuits of the output relays and the
electronic circuitry of the external control in-
put.
The power unit is transformer connected, that
is,theprimarycircuitandthesecondarycircuits
are galvanically isolated. The primary circuit is
protected by a slow 1 A fuse F1, placed on the
PC board of the module. When the power
source operates properly, the green Uaux LED
on the front panel is lit.
The power supply and I/O module is available
intwoversionswhichhavedifferentinputvolt-
age ranges:
- type SPTU 240S1 Uaux = 80...265 V ac/dc
- type SPTU 48S1 Uaux = 18...80 V dc
Theinputvoltagerangeofthepowersupplyand
I/O module incorporated in the relay on deliv-
ery is marked on the system front panel of the
relay.

8
Technical data Energizing inputs 1 A 5 A
Terminals 1-3, 4-6, 7-9 1-2, 4-5, 7-8
Rated current In1 A 5 A
Thermal withstand capability
Carry continuously 4 A 20 A
Make and carry for 10 s 25 A 100 A
Make and carry for 1 s 100 A 500 A
Dynamic current withstand capability,
half-wave value 250 A 1250 A
Input impedance <100 mΩ<20 mΩ
Rated frequency fn acc. to order 50 Hz or 60 Hz
Output contact ratings
Terminals 65-66, 68-69
Rated voltage 250 V ac/dc
Carry continuously 5 A
Make and carry for 0.5 s 30 A
Make and carry for 3 s 15 A
Breaking capacity for dc, when the manoeuvre
circuit time constant L/R ≤40 ms,
at the control voltages
- 220 V dc 1 A
- 110 V dc 3 A
- 48 V dc 5 A
Contact material AgCdO2
Signalling contacts
Terminals 70-71-72, 77-78, 80-81
Rated voltage 250 V ac/dc
Carry continuously 5 A
Make and carry for 0.5 s 10 A
Make and carry for 3 s 8 A
Breaking capacity for dc, when the signalling
circuit time constant L/R ≤40 ms,
at the control voltages
- 220 V dc 0.15 A
- 110 V dc 0.25 A
- 48 V dc 1 A
Contact material AgCdO2
External control input
Terminals 10-11
Control voltage level 18...265 V dc or
80...265 V ac
Current consumption when input activated 2...20 mA
Auxiliary supply voltage
Power supply and I/O modules and voltage ranges:
- type SPTU 240S1 80...265 V ac/dc
- type SPTU 48S1 18...80 V dc
Power consumption under quiescent/operating
conditions ~4 W/~6 W

9
Three-phase overcurrent relay module SPCJ 3C3
Low-set stage I>
Start current I>, setting range 0.5...2.5 x In
Selectable modes of operation
- definite time characteristic
- operate time t> 0.05...100 s
- inverse definite minimum time (IDMT) characteristic
- curve sets acc. to IEC 255-4 and BS 142 Normal inverse
Very inverse
Extremely inverse
Long-time inverse
- time multiplier k 0.05...1.00
High-set stage I>>
Start current I>>, setting range 0.5...20 x Inand ∞, infinite
Operate time t>> 0.04...100 s
Data communication
Transmission mode Fibre optic serial bus
Data code ASCII
Selectable data transfer rates 300, 1200, 2400, 4800 or 9600 Bd
Fibre optic bus connection module,
powered from the host relay
- for plastic fibre cables SPA-ZC 21 BB
- for glass fibre cables SPA-ZC 21 MM
Fibre optic bus connection module with
a built-in power supply unit
- for plastic fibre cables SPA-ZC 17 BB
- for glass fibre cables SPA-ZC 17 MM
Test voltages *)
Dielectric test voltage (IEC 255-5) 2 kV, 50 Hz, 1 min
Impulse test voltage (IEC 255-5) 5 kV, 1.2/50 µs, 0.5 J
Insulation resistance (IEC 255-5) >100 MΩ, 500 V dc
Disturbance tests *)
High-frequency (1 MHz) disturbance test
(IEC 255-22-1)
- common mode 2.5 kV
- differential mode 1.0 kV
Electrostatic discharge test (IEC 255-22-2
and IEC 801-2), class III
- air discharge 8 kV
- contact discharge 6 kV
Fast (5/50 ns) transients
- IEC 255-22-4, class III
- IEC 801-4, level IV:
power supply inputs 4 kV
other inputs 2 kV
Environmental conditions
Specified ambient service temperature range -10...+55°C
Long term damp heat withstand acc. to IEC 68-2-3 <95%, +40°C, 56 d/a
Relative humidity acc. to IEC 68-2-30 93...95%, +55°C, 6 cycles
Transport and storage temperature range -40...+70°C
Degree of protection by enclosure
for panel mounted relay IP 54
Weight of relay including flush mounting case 3.0 kg
*) The tests do not apply to the serial port, which is used for the bus connection module only.

10
equipment and possible other protection relays
have been omitted.
Examples of
application Fig. 4 shows how the phase overcurrent relay
SPAJ 131 C can be applied for substation pro-
tection.Forreasonsofclaritytheremotecontrol
Fig. 4. Overcurrent relay SPAJ 131 C applied for the protection of a distribution substation.
Inexample1 the low-voltageswitchgear is pro-
tectedbyanovercurrentrelaySPAJ131C.The
trip signal is linked to the HV side circuit
breaker of the distribution transformer.
Inexample2 theovercurrent relay SPAJ131 C
is used for protecting the outgoing feeder of
medium voltage distribution switchgear and in
example 3 it is used for the busbar short circuit
protection.
Theshortcircuitprotectionisbasedonblockings
betweensuccessiveprotectionstages.Insuchan
arrangementtherelaylocatedclosertothefault
gives, when starting, a blocking signal back-
wards to the relay that is closer to the object
supplyingtheshortcircuitcurrent.Ifthereisno
blocking,therelayperceivesthefaultasbeingin
its own protection area and trips the circuit
breaker. As shown in Fig. 4 the busbar protec-
tion can be extended beyond the power trans-
former feeding the busbar system.
3I>
3I>>
3I>
3I>>
3I>
3I>>
3I>
3I>>
Exemple 1
Exemple 2
Exemple 3
110/20 kV
20 kV/380 V
Blocking signal
Tripping signal

11
Example 1.
Protection of
industrial low-
voltage switchgear
6
8
73 2 4
5A 1A
5
SGR/1
SPAJ 131 C
U2
U3
U3 1111
DCBA
+-
Uaux
E
+
-
( ~ )
(
~ )
5A 1A
5A
1A
5 81 68 661 2 3 4 6 7 8 9 10 11 61 62 70 71 72 77 78 80 69 65
SGR
IRF
START1 SIGNAL1 TRIP2 TRIP1IRFBS
+
SPA-ZC_
Rx Tx
0
Ι
0
Ι
-
-
+
+
L1 L3L2
TS2
TS1
SGB
SS1
SS2
U1
5
4
I/O
3I>
t >>
t >,k
3I>>
~
SERIAL
PORT
Fig. 5. Overcurrent relay SPAJ 131 C used to protect an outgoing feeder in industrial switchgear.
The switch settings are shown in the table on the next page.
The low-set stage of the overcurrent module
SPCJ 3C3 operates as overcurrent and short
circuitprotectionforthelow-voltageswitchgear
and as back-up protection for the outgoing
feeder of the distribution switchgear. The low-
set stage is set to extends to the next protection
stage.Thesettingof thelow-setstage shouldbe
selected so as to ensure that the protection
operates selectively together with the fuses on
theoutgoingfeeders.Thehigh-setstageissetto
operate at close-by short circuits.
Separate protection for the low-voltage switch-
gearisimportantifthereareseveraldistribution
transformeralongthesamefeeder.Inparticular
faultsinlow-voltageswitchgearfedbythesmaller
transformers of a system are not always capable
ofstarting theovercurrentrelay ofthe distribu-
tion switchgear feeder.
Currentasymmetry,ifitappears,doesnothave
tobeallowedforinthecurrentsettings,because
due to the peak-to-peak measurement method
employed by the overcurrent relay such asym-
metrydoesnotaffect theoperationof therelay.

12
The operation of the low-set stage of the over-
current relay can be based on definite time
characteristic or inverse time characteristic.
When the definite time characteristic has been
selected the operate time of the relay is inde-
pendent of the magnitude of the fault current.
At inverse time characteristic, on the contrary,
theoperatetimeisafunctionofthefaultcurrent
level: the greater the fault current, the shorter
the operate time. Therefore, the relay operate
time is short at close-by faults.
Due to the inverse time characteristic short
overloads, e.g. inrush currents, do not cause
spurious operations. If fuses with a high rated
current are used in the network, inverse time
characteristic has advantages over definite time
characteristic,whentimeselectivityisconcerned.
The low-set stage of the overcurrent relay has
four available inverse time characteristics. The
desired characteristic is selected with the SG1
switches.
In order to obtain selectivity in a network pro-
tected by fuses the characteristic "Extremely
inverse" is recommended. This characteristic is
also recommended to be used when, in every
switching configuration, the short circuit cur-
rent is several times greater than the rated cur-
rentofthefeeder.When employinganextreme
inverse characteristic, the relay allows a tempo-
raryoverloadin the feeder,for instance, during
the run-up of a large motor.
Innetworkswithlargefaultcurrentvariationsa
normal inverse characteristic is recommended.
In such a case the protection relay trips the
circuit breaker relatively quickly, even though
the short circuit current exceeds the rated cur-
rentofthefeederonlyslightly.Anormalinverse
characteristic does not permit very heavy over-
loads.
The very inverse characteristic is an intermedi-
ateformbetweennormalinverseandextremely
inverse. In a short circuit situation the operate
time is rather short, even though the short
circuitcurrentvariesaccordingtotheswitching
configuration. On the other hand, the "very
inverse" characteristic, too, allows temporary
overloading of the feeder.
The accuracy limit factor should be considered
whencurrenttransformersareselected,because
the use of instantaneous tripping, in particular,
requires current transformers with good capa-
bilities of reproducing high fault currents.
The selector switches of the phase overcurrent
relay SPAJ 131 C can be set as follows:
Switch SG1/SPCJ 3C3 SGB/SPCJ 3C3 SGR
1 0 0 not in use 0 no blocking signal
2 0 0 not in use 0 no I>> start to output relay D
3 1 IDMT characteristic 0 not in use 1 I> start to output relay D
4 0 no self-holding 0 no blocking to t> 0 no I> start to output relay D
5 0 no I>> doubling 0 no blocking to t>> 0 no I>> trip to output relay D
6 0 I>> = 2.5...20 x In0 not in use 1 I>> trip to output relay A
7 0 0 not in use 1 I> trip to output relay C
8 0 0 not in use 0 no I> trip to output relay B
∑4
t>> = 0.04...1 s
extremely inverse
}
}
With above switch settings the output relays of
SPAJ 131 C have the following functions:
Output relay (contact) Function
A (65-66) CB open (I>, I>>)
B (68-69) Signal on final trip (I>>)
C (80-81) Signal on final trip (I>)
D (77-78) Start of I> stage
E (70-71-72) Self-supervision alarm

13
Example 2.
Overvoltage
protection of
an outgoing feeder
in a distribution
substation.
I
II
0
Ι
0
Ι
-
-
+
+
6
8
73 2 4
5A 1A
5
SGR/1
SPAJ 131 C
U2
U3
U3 1111
DCBA
+-
Uaux
E
+
-
( ~ )
(
~ )
5A
1A
5A 1A
5 81 68 661 2 3 4 6 7 8 9 10 11 61 62 70 71 72 77 78 80 69 65
SGR
IRF
START1 SIGNAL1 TRIP2 TRIP1IRFBS
+
SPA-ZC_
Rx Tx
TS2
TS1
SGB
SS1
SS2
U1
5
4
I/O
3I>
t >>
t >,k
3I>>
1)
~
SERIAL
PORT
1) Blocking signal to the overcurrent module of the busbar system
Fig. 6. Overcurrent relay SPAJ 131 C protecting an outgoing feeder in a distribution substation.
The selector switch settings are shown in the table on the next page.

14
The high-set stage operates rapidly on short
circuits on the feeder and the low-set stage
operatesasback-up protection forfaultsoccur-
ring behind the distribution transformer.
Definitetimecharacteristichasbeenemployed,
but it is also possible to use inverse time opera-
tioncharacteristic ofoperation. The difference
between the inverse time characteristics has
been explained in example 1.
On starting the I>> stage blocks the high-set
stage of the overcurrent relay.
The selector switches of the overcurrent relay
SPAJ 131 C can be set as follows:
Switch SG1/SPCJ 3C3 SGB/SPCJ 3C3 SGR
1 0 0 not in use 0 no blocking from feeders
2 0 0 not in use 1 I>> start to output relay D
3 0 Def. time charact. 0 not in use 0 no I> start to output relay D
4 0 no self-holding 0 no blocking to t> 0 no I>> trip to output relay D
5 0 no I>> doubling 0 no blocking to t>> 0 no I>> trip to output relay C
6 0 I>> = 2.5...20 x In0 not in use 1 I>> trip to output relay A
7 0 0 not in use 1 I> trip to output relay C
8 0 0 not in use 0 no I> trip to output relay B
∑0
t>> = 0.04...1 s
}t> = 0.05...1.00 s
}
With above switch settings the output relays of
SPAJ 131 C have the following functions:
Output relay (contact) Function
A (65-66) CB open (I>, I>>)
B (68-69) Signal on final trip (I>>)
C (80-81) Signal on final trip (I>)
D (77-78) Start of I>> stage, blocking signal to the overcurrent relay
module of the busbar system
E (70-71-72) Self-supervision alarm

15
Example 3.
Overcurrent
protection of
the busbar system
in a substation
I
II
0
Ι
0
Ι
-
-
+
+
6
8
73 2 4
5A 1A
5
SGR/1
SPAJ 131 C
U2
U3
U3 1111
DCBA
+-
Uaux
E
+
-
( ~ )
(
~ )
5A
1A
5A 1A
5 81 68 661 2 3 4 6 7 8 9 10 11 61 62 70 71 72 77 78 80 69 65
SGR
IRF
START1 SIGNAL1 TRIP2 TRIP1IRFBS
+
SPA-ZC_
Rx Tx
TS2
TS1
SGB
SS1
SS2
U1
5
4
I/O
3I>
t >>
t >,k
3I>>
1) 2)
~
SERIAL
PORT
1) Blocking signals from the overcurrent relays of the outgoing feeders
2) Blocking signal to the high-voltage side overcurrent relay of the power transformer
Fig.7.OvercurrentrelaySPAJ131Cusedforprotectingtheinfeedercubicleandthebusbarsystem.
The switch settings are shown on the next page
In the example in Fig. 7 the low-set stage backs
uptheprotectionoftheoutgoingfeeders,whereas
the high-set stage is used for protecting the
busbar system.
Theoperationofthe busbarprotectionis based
on blocking signals received from the relay
modulesoftheoutgoingfeeders.Ifafaultoccurs
on an outgoing feeder, the overcurrent relay
module of the feeder sends a blocking signal to
theovercurrentmodule oftheinfeeder cubicle.
Should, however, the fault be on the busbar
there will be no blocking and the overcurrent
module of the infeeder cubicle provides a trip
signaltotheinfeedercircuitbreaker. Inthisway
relay times of about 100 ms can be obtained at
a busbar short circuit. If required the blocking
succession can be extended to the overcurrent
module on the HV side of the power trans-
former (see Fig. 4). The trip signal, too, can be
linked from the busbar system to the HV side
circuit breaker of the power transformer. The
widesettingrangeofthehigh-setstagemakesit
well suited for starting the busbar protection.

16
Busbar system protection based on blockings
canalsobeused inthecaseofreversesupplyon
thefeeder,providedthereversecurrentdoesnot
exceedthesetting valueof the high-setstage on
the feeder. In such a case the blocking signal is
generated by the high-set stage of the overcur-
rent relay of the feeder.
The blocking signals to terminals 10-11 are
linked to the high-set stage of the overcurrent
relay bymeansoftheSGR/1switchonthefront
panelandtheSGB/5switchonthePCboardof
theovercurrentmodule.Theseswitcheshaveto
be in position 1.
Theblockingcircuitiseasilytestedthroughthe
Trip test function of the relay modules and the
display. The blocking stage of the module to
generate the blocking signal is started via the
Triptestfunction(seemanual"Generalcharac-
teristics of C-type SPC relay modules"). Via
register 0 of the module to receive the blocking
signal it is checked that the blocking signal
arrives.Forexampleinthisapplicationthehigh-
set stage of the overcurrent module on the
outgoingfeederis started, signalSS2.Then the
left-most digit of register 0 of the overcurrent
module is 2, which means that the tripping of
the high-set stage is blocked.
In this example the operation of the low-set
stageoftheovercurrentrelayisbasedondefinite
timecharacteristic,butinversetimecharacteris-
tic is possible as well.
The selector switches of the phase overcurrent
relay SPAJ 131 C can be set as follows:
With above switch settings the output relays of
SPAJ 131 C have the following functions:
Switch SG1/SPCJ 3C3 SGB/SPCJ 3C3 SGR
1 0 0 not in use 1 blocking from outgoing feeders
2 0 0 not in use 1 I>> start to output relay D
3 0 def. time charact. 0 not in use 0 no I> start to output relay D
4 1 self-holding 0 no blocking to t> 0 no I>> trip to output relay D
5 0 no I>> doubling 1 blocking to t>> 0 no I>> trip to output relay C
6 0 I>> = 2.5...20 x In0 not in use 1 I>> trip to output relay A
7 0 0 not in use 1 I> trip to output relay C
8 0 0 not in use 0 no I> trip to output relay B
∑8
t>> = 0.04...1 s
}t> = 0.05...1.00 s
}
Output relay (contact) Function
A (65-66) CB open (I>, I>>)
B (68-69) Signal for final trip (I>>)
C (80-81) Signal for final trip (I>)
D (77-78) Start of I>> stage, blocking signal to the HV side
overcurrent module of the power transformer
E (70-71-72) Self-supervision alarm

17
Recorded data
and fault analysis The information stored in the registers of the
protection relay can be used for analysing fault
situations and situations during normal opera-
tion.
Register1storesthehighestcurrentvaluemeas-
ured on one of the phases L1, L2 or L3, as a
multiple of the rated value of the relay. If the
module performs tripping, the current value at
momentoftrippingismemorized.Anynewtrip
resets the old recorded value and updates the
register. The same thing happens if the meas-
uredcurrentexceedsthepreviousrecordedvalue.
Thedatastoredinregister1showtheagreement
betweenthesettingvaluesand,ontheonehand,
the actual current values that occur in a fault
situationand,on the otherhand, the operation
values in normal situations.
If a short circuit occurs on the feeder, the over-
currentmodulerecords thecurrentvalue atthe
moment of tripping and stores the value in
register1. Thelevelofthecurrentindicateshow
close the fault location is and also whether it is
a two-phase or three-phase fault. In addition,
theindicatorson thefrontplate oftheovercur-
rent module show in which phases the current
has exceeded the setting value of the tripping
stage.
Auxiliary register 1 of register 1 indicates the
current measured at the last tripping. A re-
corded value is reset only by a new trip that
simultaneously enters the new value into the
register.
A connection inrush current has a very short
duration, but the current level may be high
enough to start the relay and the value conse-
quently stored in register 1. In this case the
current value recorded at the previous tripping
isalsostoredinauxiliaryregister1andavailable
for the analysis of the fault situation.
Thelevelofthefaultcurrentisdirectlyindicated
by the register values. If, for instance, the value
is 5.0 after tripping, the highest value for a
separate phase at the moment of tripping was
five times the rated primary current of the
current transformers.
The number of starts of the various operation
stages, registers 2 and 3, illustrates the occur-
renceofthetheovercurrents.Frequentstartson
a feeder may, for instance, be due to too low
setting values of the relay, connection inrush
currents or a concealed fault, e.g. a defective
insulator.
Registers4and5showthedurationofthelatest
start situation of the operation stages, as a per-
centage of the preset operate time or, when
inverse time characteristic has been selected, of
the calculated operate time. A new start always
resetsthecounterthatstartscountingfromzero
again.When thestagetrips, theregister valueis
100.
Registers4and5containinformationaboutthe
durationof,forinstance,theconnectioninrush
currentorthesafetymarginofthegradingtimes
of the selective protection. If register 4 of the
busbar overcurrent relay operating as back-up
protectionforan outgoingfeeder has thevalue
75 when the overcurrent module of the feeder
hasperformedtripping,theselectiveprotection
has a safety margin of 25% of the operate time
of the low-set stage of the busbar overcurrent
protection.

18
Testing, both primary and secondary, should
always be performed in accordance with na-
tional regulations and instructions.
The protection relay incorporates an IRF func-
tion that continuously monitors the internal
condition of the relay and produces an alarm
signal on detection of a fault. According to the
manufacturer’s recommendations the relay
shouldbesubmittedtosecondaryinjectiontest-
ing at five years’ intervals. These tests should
include the entire protection chain from the
instrumenttransformerstothecircuitbreakers.
The secondary testing described in this manual
is based on the relay’s setting values in the
concernedapplication.Ifnecessary,thesecond-
ary testing can be extended by testing the pro-
tection stages throughout their setting ranges.
Asswitchpositionsandsetting valuesmayhave
tobealteredduringthetestthecorrectpositions
of switches and the setting values of the relay
during normal operation conditions have to be
recorded, for instance, on the reference card
accompanying the relay.
To enable secondary injection testing the relay
has to be disconnected, either through dis-
connectableterminalblocksoratestplugfitted
on the relay.
DANGER!
Do not open the secondary circuit of a cur-
rent transformer during testing, if the pri-
mary circuit is live. The high voltage pro-
ducedbyanopenCTsecondarycircuitcould
be lethal and may damage measuring instru-
ments and insulation.
When the auxiliary voltage is connected to the
protectionrelay,therelayperformsaself-testing
program. The self-testing does not include the
matching transformers and the contacts of the
outputrelays. Theoperationalcondition ofthe
relay is tested by means of ordinary relay test
equipment and such a test also includes the
matching transformers, the output relays and
the accuracy of the operate values.
Equipment required for testing:
- adjustable voltage transformer 0...260 V, 1 A
- current transformer
- ammeter, accuracy ±0.5%
- stop watch or counter for time measurement
- dc voltage source for auxiliary supply
- switches and indicator lamps
- supply and pilot wires
- calibrated multimeter
The secondary current of the current trans-
formeristo beselected on thebasis oftherated
current,1Aor5A,oftherelayenergizinginput
tobetested.Theenergizinginputsarespecified
under the heading "Technical data, Energizing
inputs".
Secondary
injection testing

19
L1
+(~)
-
(~)
TRIP1
IRF
A
TIMER START
S1
N
TIMER STOP
S2 L2 L3
L1
6
8
73 2 4
5A
1A
5
SGR/1
SPAJ 131 C U2
U3
U3 1111
DCBA
+-
Uaux
E
≅
_
5A
1A
5A
1A
5 81 68 661 2 3 4 6 7 89 10 11 61 62 70 71 72 77 78 80 69 65
SGR
IRF
START1 TRIP2 TRIP1IRFBS
TS2 TS1
SGB
SS1 SS2
U1 I/O
3I>
t >> t >,k
SIGNAL1
A
4
5
3I>>
Fig. 8. Secondary injection test connection for the overcurrent relay SPAJ 131 C.
Whenthetestconnectionhasbeenfinishedand
the selector switches properly set, the auxiliary
voltage can be connected to the relay.
The correctness of the test connection can be
verified by using a multimeter.

20
measurementscan bemadeat therated current
of the relay. It should be noticed that the relay
showsthemeasured currentasamultipleofthe
rated current Inof the energizing input occu-
pied.
Checking of
matching
transformers
The matching transformers of the protection
relayaretestedseparatelyforeachphase.Apure
sinusoidalcurrentisfedtotherelay.Thecurrent
valueindicatedinthedisplayoftherelayshould
be equal to that indicated by the ammeter. The
TheswitchesofswitchgroupSGRshouldbeset
as follows:
Switch Position
11
20
31
40
50
60
71
80
Then the following signals are linked to the
output relays:
Output Function
(terminals)
A (65-66) Tripping of stage I>
B (68-69) (Tripping of stage I>>)
C (80-81) Signal on tripping of stage I>
(LED L3)
D (77-78) Start of stage I> (LED L2)
E (71-72) Signal on internal relay fault
(LED L1)
Starting
The start function for one phase is tested in
accordancewithFig.8.Whenrequired, thetest
can be repeated separately for each phase. The
test current is slowly increased until the relay
starts(LEDL2islit)andthevalueofthecurrent
at starting is read on the ammeter.
Operate time
Definite time characteristic
The operate time of the overcurrent relay is
measuredatatestcurrentequalto2xthesetting
valueofstageI>. Thetimeris startedbyclosing
switch S1 and stopped by contact 65-66 on
operation of output relay A.
Theoperationof outputrelay Cisindicated by
lighting of LED L3.
Whentherelaystarts,theyellowindicatorI>in
therightbottomcornerofthefrontpanelofthe
relay module is lit, and when the relay trips it
turns red.
Inverse time characteristic
Atinversetimecharacteristictheoperatetimeof
the relay is measured at two current values (2 x
I>and10xI>).Theoperatetimesthusreceived
are compared with the operate times shown in
the current/time curves for the corresponding
inverse time characteristic.
Blocking
Switches4and5ofswitchgroupSGBonthePC
board of the relay module are to be set in
position1(ON). Switch SGR/1onthe system
panel, too, has to be in position 1.
The blocking function is tested by applying a
control voltage of the auxiliary voltage level to
input 10-11 via switch S2. At first switch S2 is
closedandthenthetestcurrentisencreasedwell
above the set start current level.The relay will
start,i.e.L2islit,butitmustnotoperate,i.e.L3
remains dark.
Testing of low-set
current stage I>