ABB SPAJ 131 C User Manual And Technical Description

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

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

0

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

with definite time or inverse time characteristic

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

Local numerical display of setting values, 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-

tection of distribution feeders, large low-voltage

motors, high-voltage motors, medium-sized and

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

output relays, of which four are freely configur-

able for the desired function. Two of the output

relays have heavy-duty contacts capable of di-

rectly controlling a circuit breaker.

The overcurrent relay SPAJ 131 C is a secondary

relay that is connected to the current transform-

ers of the protected object. The relay can be used

for single-phase, two-phase or three-phase over-

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, trips the circuit breaker or starts 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-

lated operate time t>, expires, the relay operates.

In the same way the high-set stage starts once its

set start value I>> is exceeded and, when the set

operate time t>> expires, the relay operates.

The low-set stage of the overcurrent relay can be

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

curve sets comply with the BS 142 and IEC 255

standards.

The start signals from the overcurrent relay are

obtainable as contact functions. The start signal

can be used, for instance, for blocking cooperat-

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

the ANSI (=American National Standards Institute) number of the concerned protection function.

4

Connections

Fig. 2. Connection diagram for the three-phase overcurrent relay SPAJ 131 C.

U

aux

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

1111

DC

BA

+-

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 I

L1

(I

n

= 5 A)

1-3 Phase current I

L1

(I

n

= 1 A)

4-5 Phase current I

L2

(I

n

= 5 A)

4-6 Phase current I

L2

(I

n

= 1 A)

7-8 Phase current I

L3

(I

n

= 5 A)

7-9 Phase current I

L3

(I

n

= 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. Under normal conditions the contact interval

70-72 is closed. When the auxiliary voltage disappears or an internal fault is detected,

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

17 or SPA-ZC 21. The bus connection module

is fitted to the D-type connector (SERIAL

PORT) on the rear panel of the relay. The opto-

connectors of the optical fibres are plugged into

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

output relay A and the trip signal of the I>> 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

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

0

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. The yellow LEDs (I

L1

,

I

L2

,

I

L3

) on the upper

black part of the front plate indicate, when lit,

that the value of the concerned phase current

is being displayed.

3. The red IRF indicator of the self-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. The green U

aux

LED on the front panel is lit

when the power supply module operates prop-

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.

The start and operation indicators, the function

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

concerned stage has started and red light that

the stage has operated (tripped).

With the SG2 software switchgroup the start

and trip indicators can be given a latching

function, which means that the LEDs and the

output relay remain lit, although the signal

that caused operation returns to normal. 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) is located behind the system front panel of

the protection relay and can be withdrawn from

the relay case after removal of the system front

panel. The power supply and I/O module incor-

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, the primary circuit and the secondary circuits

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 U

aux

LED

on the front panel is lit.

The power supply and I/O module is available

in two versions which have different input volt-

age ranges:

- type SPTU 240S1 U

aux

= 80...265 V ac/dc

- type SPTU 48S1 U

aux

= 18...80 V dc

The input voltage range of the power supply and

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 I

n

1 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 f

n

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 AgCdO

2

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 AgCdO

2

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 I

n

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 I

n

and ∞, 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. For reasons of clarity the remote control

Fig. 4. Overcurrent relay SPAJ 131 C applied for the protection of a distribution substation.

In example 1 the low-voltage switchgear is pro-

tected by an overcurrent relay SPAJ 131 C. The

trip signal is linked to the HV side circuit

breaker of the distribution transformer.

In example 2 the overcurrent relay SPAJ 131 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.

The short circuit protection is based on blockings

between successive protection stages. In such an

arrangement the relay located closer to the fault

gives, when starting, a blocking signal back-

wards to the relay that is closer to the object

supplying the short circuit current. If there is no

blocking, the relay perceives the fault as being in

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

1111

DCBA

+-

Uaux

E

+

-

(

~

)

(

~

)

5A

1A

5A

1A

5 81 68 661 23 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

circuit protection for the low-voltage switchgear

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. The setting of the low-set stage should be

selected so as to ensure that the protection

operates selectively together with the fuses on

the outgoing feeders. The high-set stage is set to

operate at close-by short circuits.

Separate protection for the low-voltage switch-

gear is important if there are several distribution

transformer along the same feeder. In particular

faults in low-voltage switchgear fed by the smaller

transformers of a system are not always capable

of starting the overcurrent relay of the distribu-

tion switchgear feeder.

Current asymmetry, if it appears, does not have

to be allowed for in the current settings, because

due to the peak-to-peak measurement method

employed by the overcurrent relay such asym-

metry does not affect the operation of the relay.

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,

the operate time is a function of the fault current

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, when time selectivity is concerned.

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-

rent of the feeder. When employing an extreme

inverse characteristic, the relay allows a tempo-

rary overload in the feeder, for instance, during

the run-up of a large motor.

In networks with large fault current variations a

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-

rent of the feeder only slightly. A normal inverse

characteristic does not permit very heavy over-

loads.

The very inverse characteristic is an intermedi-

ate form between normal inverse and extremely

inverse. In a short circuit situation the operate

time is rather short, even though the short

circuit current varies according to the switching

configuration. On the other hand, the "very

inverse" characteristic, too, allows temporary

overloading of the feeder.

The accuracy limit factor should be considered

when current transformers are selected, 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 I

n

0 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

1111

DCBA

+-

Uaux

E

+

-

(

~

)

(

~

)

5A

1A

5A

1A

5 81 68 661 23 4 6 7 89 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

operates as back-up protection for faults occur-

ring behind the distribution transformer.

Definite time characteristic has been employed,

but it is also possible to use inverse time opera-

tion characteristic of operation. 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 I

n

0 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

1111

DCBA

+-

Uaux

E

+

-

(

~

)

(

~

)

5A

1A

5A

1A

5 81 68 661 23 4 6 7 89 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. Overcurrent relay SPAJ 131 C used for protecting the infeeder cubicle and the busbar system.

The switch settings are shown on the next page

In the example in Fig. 7 the low-set stage backs

up the protection of the outgoing feeders, whereas

the high-set stage is used for protecting the

busbar system.

The operation of the busbar protection is based

on blocking signals received from the relay

modules of the outgoing feeders. If a fault occurs

on an outgoing feeder, the overcurrent relay

module of the feeder sends a blocking signal to

the overcurrent module of the infeeder 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

signal to the infeeder circuit breaker. In this way

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

wide setting range of the high-set stage makes it

well suited for starting the busbar protection.

16

Busbar system protection based on blockings

can also be used in the case of reverse supply on

the feeder, provided the reverse current does not

exceed the setting value of the high-set stage 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 by means of the SGR/1 switch on the front

panel and the SGB/5 switch on the PC board of

the overcurrent module. These switches have to

be in position 1.

The blocking circuit is easily tested through the

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

Trip test function (see manual "General charac-

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. For example in this application the high-

set stage of the overcurrent module on the

outgoing feeder is started, signal SS2. 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

stage of the overcurrent relay is based on definite

time characteristic, but inverse time characteris-

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 I

n

0 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.

Register 1 stores the highest current value meas-

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

moment of tripping is memorized. Any new trip

resets the old recorded value and updates the

register. The same thing happens if the meas-

ured current exceeds the previous recorded value.

The data stored in register 1 show the agreement

between the setting values and, on the one hand,

the actual current values that occur in a fault

situation and, on the other hand, the operation

values in normal situations.

If a short circuit occurs on the feeder, the over-

current module records the current value at the

moment of tripping and stores the value in

register 1. The level of the current indicates how

close the fault location is and also whether it is

a two-phase or three-phase fault. In addition,

the indicators on the front plate of the overcur-

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

is also stored in auxiliary register 1 and available

for the analysis of the fault situation.

The level of the fault current is directly indicated

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-

rence of the the overcurrents. Frequent starts on

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.

Registers 4 and 5 show the duration of the latest

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

resets the counter that starts counting from zero

again. When the stage trips, the register value is

100.

Registers 4 and 5 contain information about the

duration of, for instance, the connection inrush

current or the safety margin of the grading times

of the selective protection. If register 4 of the

busbar overcurrent relay operating as back-up

protection for an outgoing feeder has the value

75 when the overcurrent module of the feeder

has performed tripping, the selective protection

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

should be submitted to secondary injection test-

ing at five years’ intervals. These tests should

include the entire protection chain from the

instrument transformers to the circuit breakers.

The secondary testing described in this manual

is based on the relay’s setting values in the

concerned application. If necessary, the second-

ary testing can be extended by testing the pro-

tection stages throughout their setting ranges.

As switch positions and setting values may have

to be altered during the test the correct positions

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-

connectable terminal blocks or a test plug fitted

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-

duced by an open CT secondary circuit could

be lethal and may damage measuring instru-

ments and insulation.

When the auxiliary voltage is connected to the

protection relay, the relay performs a self-testing

program. The self-testing does not include the

matching transformers and the contacts of the

output relays. The operational condition of the

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-

former is to be selected on the basis of the rated

current, 1 A or 5 A, of the relay energizing input

to be tested. The energizing inputs are specified

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

1

11

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.

When the test connection has been finished and

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

measurements can be made at the rated current

of the relay. It should be noticed that the relay

shows the measured current as a multiple of the

rated current I

n

of the energizing input occu-

pied.

Checking of

matching

transformers

The matching transformers of the protection

relay are tested separately for each phase. A pure

sinusoidal current is fed to the relay. The current

value indicated in the display of the relay should

be equal to that indicated by the ammeter. The

The switches of switchgroup SGR should be set

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

accordance with Fig. 8. When required, the test

can be repeated separately for each phase. The

test current is slowly increased until the relay

starts (LED L2 is lit) and the value of the current

at starting is read on the ammeter.

Operate time

Definite time characteristic

The operate time of the overcurrent relay is

measured at a test current equal to 2 x the setting

value of stage I>. The timer is started by closing

switch S1 and stopped by contact 65-66 on

operation of output relay A.

The operation of output relay C is indicated by

lighting of LED L3.

When the relay starts, the yellow indicator I> in

the right bottom corner of the front panel of the

relay module is lit, and when the relay trips it

turns red.

Inverse time characteristic

At inverse time characteristic the operate time of

the relay is measured at two current values (2 x

I> and 10 x I>). The operate times thus received

are compared with the operate times shown in

the current/time curves for the corresponding

inverse time characteristic.

Blocking

Switches 4 and 5 of switchgroup SGB on the PC

board of the relay module are to be set in

position 1 (ON). Switch SGR/1 on the 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

closed and then the test current is encreased well

above the set start current level.The relay will

start, i.e. L2 is lit, but it must not operate, i.e. L3

remains dark.

Testing of low-set

current stage I>

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ABB SPAJ 131 C User Manual And Technical Description

ABB SPAJ 131 C User Manual And Technical Description

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