MCGG82 Manual

Type MCGG 22, 42, 52, 53, 62, 63 & 82 Overcurrent Relay for Phase and Earth Faults

Type MCGG 22, 42, 52, 53, 62, 63 & 82 Overcurrent Relay for Phase and Earth Faults

Figure 1: Relay type MCGG 62 withdrawn from case.

Features • Choice of 4 inverse time curves and 3 definite time ranges by switched selection.

• Accurately follows time curves to BS142 and IEC60255. • High resetting ratio. • Fast resetting time.

• Wide setting range of 0.05 x In to 2.4 x In in steps of 0.05 x In.

• Positive, calibrated settings by means of switches.

• Time multiplier range 0.05 to 1 on all seven characteristics.

• Internal dc auxiliary power supply operating over a wide input range.

• Separate LED indicators provided on each measuring board to show time delayed and instantaneous operations. • LED start indicators provided to facilitate testing. • Separate output contacts provided for time delayed phase fault, instantaneous phase fault, time delayed earth fault and instantaneous earth fault operations. • Low ac burden. • Suitable for use with separate direction relay.

2

• Separate test mode with trip test feature. • Indication of power to the measuring board. • Non-volatile memory for time delayed and instantaneous LED indicators.

MCGG 53 Two phase overcurrent (with polyphase measurement) plus earth fault with instantaneous elements.

Models available MCGG 22 Single phase overcurrent with instantaneous element.

MCGG 62 Three phase overcurrent with instantaneous elements.

MCGG 42 Two phase overcurrent with instantaneous elements.

Associated publications: Midos System R6001 Directional Relay R6003

MCGG 63 Three phase overcurrent (with polyphase measurement), with instantaneous element.

MCGG 52 Two phase overcurrent plus earth fault with instantaneous elements.

3 phase 2 phase Single phase Measuring overcurrent overcurrent or earthfault boards † inst † inst † inst

Model MCGG MCGG MCGG MCGG MCGG MCGG MCGG

MCGG 82 Three phase overcurrent plus earth fault with instantaneous elements.

22 42 52 53 62 63 82

Application The relay can be used in applications where time graded overcurrent and earth fault protection is required. The relay can be used to provide selective protection for overhead and underground distribution feeders. Other applications include back-up protection for transformers, generators and HV feeder circuits and the protection of neutral earthing resistors. With all the current/time characteristics available on one relay, a standard relay can be ordered before detailed coordination studies are carried out – a distinct advantage for complex systems. Also, changes in system configuration can be readily accommodated.

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For applications where the instantaneous earth fault element is required to have a sensitive setting whilst remaining stable on heavy through faults the use of a stabilising resistor is recommended. The current transformers for this application must satisfy the criteria detailed under ‘Current transformer requirements’ in Technical Data. The total impedance of the relay and the series stabilising resistor is usually low enough to prevent the current transformers developing voltages over 2kV during maximum internal faults, but in some applications a non-linear resistor is required to limit this voltage. Non-standard resistance values and non-linear voltage limiting devices are available.

An instantaneous element with low transient overreach is incorporated within each phase or earth fault measuring board. This can be easily disabled in applications where it is not required.

3

1 2 3 2 3 1 4

Case size 4 6 8 8 6 6 8

Description This range of MCGG relays is designed so that versions are available with separate measuring boards for each phase or earth fault input; alternatively, phase inputs may be combined on to one board for polyphase measurement (see table). These boards, together with the other circuits of the relay, are contained in a single plug-in module which is supplied in a size 4, 6 or 8 Midos case. The case incorporates one or two terminal blocks for external connections. Removal of the module automatically short circuits the current transformer connections by means of safety contacts within the case terminal block. For added security, when the module is removed, the CT circuits are short circuited before the connections to the output contacts and the dc supply are broken. The relay uses solid state techniques, each measuring board utilising a microcomputer as a basic circuit element. The current measurement, whether performed on a single phase or polyphase input, is performed via an analogue-to-digital converter. Application diagrams are provided in Figures 2 to 8 (inclusive) showing typical wiring configurations.

Each measuring board has a built-in ‘power off’ memory feature for the time delayed and instantaneous LED indicators. Power to each measuring board may be tested whilst the relay is in service, without affecting the current measurement. A test mode is also available to carry out a trip test on the output relays. During this test, current measurement is inhibited. When required, directional control can be exercised over the relay by connecting an output contact from direction relay type METI to the terminals provided. Separate output contacts, capable of circuit breaker tripping, are provided for time delayed phase faults, instantaneous phase faults, time delayed earth fault and instantaneous earth fault operations.

Switch position (0) (1) ● ● ●

Operating characteristic Trip test

● ● ●

Standard inverse

t=

0.14 (I0.02 – 1)

sec SI

Very inverse

t=

13.5 (I – 1)

sec VI

●

Extremely inverse

t=

80 (I2 – 1)

sec EI

● ●

Long time earth fault t =

120 (I – 1)

sec LT

● ● ● ● ●

● ● ●

Definite time 2 seconds

D2

Definite time 4 seconds

D4

Definite time 8 seconds

D8

● ● ● ● ● ● ●

Table1: Operating time characteristics with corresponding switch positions.

Relay settings Separate setting switches for each measuring board are provided on the relay frontplate. These are used to select the required time/current characteristic, current and time multiplier settings. Selection of time characteristics

The current/time characteristic selection is carried out by means of three switches (identified by symbol on the nameplate). Table 1 gives the basic operating characteristic and the settings of the switches. Time multiplier setting

The time given by each of the operating characteristics must be multiplied by the time multiplier to give the actual operating time of the relay. This control is marked xt = Σ where Σ is the sum of all the switch positions. The range of multiplication is from 0.05x to 1.0x in steps of 0.025.

4

This acts as a conventional time multiplier on the current dependent characteristics and gives the following time ranges for the definite time characteristics. Operating characteristics s 2 4 8

Time range s 0.1 to 2.0 in 0.05s steps 0.2 to 4.0 in 0.1s steps 0.4 to 8.0 in 0.2s steps

Trip test

Current setting

Current measurement is inhibited by setting the curve selection switches to 111. This causes all three LEDs to flash once per second. If the reset push button is then pressed for approximately six seconds, both output relays associated with that measuring board will operate.

Time delayed element

The current setting control is marked Is = Σ x In where Is is the current setting in amps, Σ is the sum of all the switch positions and In is the relay rated current in amps. Each measuring board provides a setting range of 0.05 x In to 2.4 x In in steps of 0.05 x In.

Power supply healthy test

If, whilst the relay is in service, the reset button is pressed, all the LEDs are illuminated, indicating that there is power to the measuring boards. The LEDs are reset on releasing the push button. During this test, normal current measurement is not inhibited.

Instantaneous element

The setting control of the instantaneous element is marked Iinst = Σ x Is where Σ is the sum of the switch positions and Is is the time delayed element setting. When all switches are set to the left (at zero), or when the lowest switch is set to infinity regardless of the positions of the other five switches, the instantaneous feature is rendered inoperable. The range of adjustment of finite settings is from 1x to 31x in unity steps.

A

S2

A

P1

P2

B

Figure 2: Type MCGG 22 nameplate

S1 B

C

C

Phase rotation

Directional control PhA (See Note 4)

TMS setting

24

Inst setting

Curve selection

23

(See Note 2)

27

IA

Time delayed trip Inst. trip

µC PhA

Is

Indicator reset

RL1–1

28

Input circuit Ph

Current setting Ph

I>Is

5

RL1 2

Case earth 1

2

5

6

7

8

9

10

13

14

15

16

Vx

+VE –VE

13 14 26

Output circuits Ph

Power supply circuits

RL2 2 Case earth connection

23

24 26

27

(See Note 3)

28

Module terminal block viewed from rear

(b) (c)

RL1–2

2

CT shorting links make before (b) and (c) disconnect. Short terminals break before (c). Long terminals

2. When directional control is required the contacts of the directional relays should be connected as shown. Contacts must close to inhibit overcurrent relay. 3. Earthing connections (CTs) are typical only. 4. CT connections are typical only.

Figure 3: Application diagram (10 MCGG 22 02): static modular overcurent relay type MCGG 22. Single phase with instantaneous element. 5

Phase fault time delayed trip output contacts

1

RL2–1

8 10 9

RL2–2

16 15

MCGG 22

Notes: 1. (a)

7 6

Phase fault instantaneous trip output contacts

A

A

P2

P1

S2

B

S1

Directional control PhA

C C

B Phase rotation (See Note 4)

TMS setting

Inst setting

Curve selection

Indicator reset

49 50

(See Note 2)

21

IA

Is

RL1 2

Time delayed trip Inst. trip

µC PhA

Input circuit Ph

23

Current setting Ph

I> Is

45

25 29

30

6

33

34

7

8

35

36

9

10

37

38

11

12

13

14

41

42

15

16

1

2

3

4

5

IC

Inst setting

Curve selection

18

45

46

19

20

47

48

21

22

49

50

23

24

25

26

27

28

Input circuit Ph

27

+VE –VE

28 13

1

38

RL2–2

41

Phase fault instantaneous trip output contacts

I> Is

MCGG 42

CT shorting links make before (b) and (c) disconnect. Short terminals break before (c). Long terminals

(b) (c)

36

42

Current setting Ph

Case earth connection

Module terminal block viewed from rear (with integral case earth strap)

Phase fault time delayed trip output contacts

Power supply circuits

14

(See Note 3) Notes: 1. (a)

29

37

Time delayed trip Inst. trip

µC PhC

Is

RL2–1

26

Vx

17

34

RL1–2

30 TMS setting

46 Case earth

35 33

RL2 2

24

Directional control PhC

RL1–1

Output circuits Ph

22

2. When directional control is required the contacts of the directional relays should be connected as shown. Contacts must close to inhibit overcurrent relay. 3. Earthing connections are typical only. 4. CT connections are typical only.

Figure 4: Application diagram (10 MCGG 42 03): static modular overcurent relay type MCGG 42. Two phase with instantaneous element.

P2

A A

P1 S2

B

S1

C

Directional control PhA

TMS setting

49

Inst setting

Curve selection

Indicator reset

50

B

C

(See Note 2)

(See Note 4)

Phase rotation

21

IA

Is 22

Input circuit Ph

23

Directional control PhC

Current setting Ph

RL1 2

Time delayed trip

µC PhA

Inst. trip

I >I s

RL1–1

Output circuits Ph

33

RL2 2

34

RL1–2

TMS setting

45

Inst setting

Curve selection

RL2–1

IC

Is

26

29

Directional control E/F

30

2

3

4

5

6

33

34

7

8

35

36

9

10

37

38

11

12

Input circuit Ph

13

14

41

42

16

43

44

17

18

45

46

19

20

47

48

21

22

49

50

23

24

25

26

27

28

38

RL2–2

RL3–1 Inst setting

Curve selection

Notes: 1. (a) (b) (c)

–VE

7

5

13 14 17

Power supply circuits

Input circuit

Current setting

Inst. trip

RL3–2

I >I s

RL4–1 RL4 2

8

9 16 15

3. Earthing connections are typical only. 4. CT connections are typical only.

Figure 5: Application diagram (10 MCGG 52 03): static modular overcurent relay type MCGG 52. Two phase plus earth fault with instantaneous elements. 6

Earth fault time delayed trip output contacts

10

MCGG 52

2. When directional control is required the contacts of the directional relays should be connected as shown. Contacts must close to inhibit overcurrent relay.

2 1

Output circuits

RL4–2

Case earth connection

CT shorting links make before (b) and (c) disconnect. Short terminals break before (c). Long terminals

RL3 2

Time delayed trip

µC

Is 28

Vx

Phase fault instantaneous trip output contacts

6

27

+VE

42 41

I >I s

44

(See Note 3)

Module terminal block viewed from rear (with integral case earth strap)

Current setting Ph

TMS setting

43

E/F

15

µC PhC

36 37

Time delayed trip Inst. trip

25

1

29

Phase fault time delayed trip output contacts

30

24

46

Case earth

35

Earth fault instantaneous trip output contacts

P2

A A

P1 S2

B

Directional control PhA

S1

C

49

TMS setting

Inst setting

Is

µC Ph

Indicator reset

Curve selection

50

B

C

(See Note 2)

(See Note 4)

Phase rotation

21

IA

RL1 2

Time delayed trip Inst. trip

22

Current setting Ph

23

Directional control PhC

RL1–1

35

Output circuits Ph

I >I s

33

RL2 2

34

RL1–2

29 30

24

RL2–1

45

36 37

46

38

25

RL2–2

IC

41

26

29

30

6

33

34

7

8

35

36

9

10

37

38

11

12

13

14

41

42

15

16

43

44

17

18

45

46

19

20

47

48

2

3

4

5

21

22

23

24

25

26

27

Directional control E/F

RL3–1 Inst setting

27

Curve selection

5

RL3 2

Time delayed trip

µC

E/F

49

Inst. trip

Is 13

+VE

14

–VE

17

50

Module terminal block viewed from rear (with integral case earth strap

CT shorting links make before (b) and (c) disconnect. Short terminals break before (c). Long terminals

(b) (c)

Input circuit

Current setting

I >I s

2

RL4–1

Earth fault time delayed trip output contacts

8

RL4 2

10 9

RL4–2

Case earth connection

(See Note 3)

28

Power supply circuits

RL3–2

1

Output circuits

28

Notes: 1. (a)

7 6

TMS setting

43 44

Vx

Phase fault instantaneous trip output contacts

42

Input circuit Ph

Case earth 1

Phase fault time delayed trip output contacts

16

Earth fault instantaneous trip output contacts

15

MCGG 53

2. When directional control is required the contacts of the directional relays should be connected as shown. Contacts must close to inhibit overcurrent relay.

3. Earthing connections are typical only. 4. CT connections are typical only.

Figure 6: Application diagram (10 MCGG 53 02): static modular overcurent relay type MCGG 53. Two phase (with polyphase measurement), plus earth fault with instantaneous elements.

P2

A A

P1 S2

B

S1

C

Directional control PhA

TMS setting

49

Inst setting

Curve selection

Indicator reset

50

B

C

(See Note 2)

(See Note 4)

Phase rotation

21

IA 22

Directional control PhB

Input circuit Ph

Current setting Ph TMS setting

47

Time delayed trip

µC PhA

Is

RL1–1

Inst. trip

Inst setting

33

RL1 2

I>Is Curve selection

Output circuits Ph

48 23

IB 24

Case earth 1

13

14

29

30

33

34

35

36

37

38

41

42

45

46

47

48

49

50

Directional control PhC

Input circuit Ph

Current setting Ph

34

RL1–2

TMS setting

38

RL2–2

I>Is

Inst setting

25

IC 26

Vx

22

23

24

25

26

(See Note 3)

27

28

Notes: 1. (a) (b) (c)

+VE –VE

13 14 1

Power supply circuits

Input circuit Ph

Current setting Ph

Case earth connection

Time delayed trip Inst. trip

I>Is

MCGG 62

CT shorting links make 2. When directional control is required the contacts before (b) and (c) disconnect. of the directional relays should be connected as shown. Short terminals break before (c). Contacts must close to inhibit overcurrent relay. Long terminals

3. Earthing connections are typical only. 4. CT connections are typical only.

Figure 7: Application diagram (10 MCGG 62 03): static modular overcurent relay type MCGG 62. Three phase with instantaneous element. 7

41 42

Curve selection

µC PhC

Is

36 37

RL2 2

28 45

29

Phase fault time delayed trip output contacts

30

RL2–1

46

21

Module terminal block viewed from rear (with integral case earth strap)

µC PhB

Is

27

Time delayed trip Inst. trip

35

Phase fault instantaneous trip output contacts

P2

A A

P1 S2

B

Directional control PhA

S1

C

49

TMS setting

Inst setting

Is

µC Ph

Indicator reset

Curve selection

50

B

C

(See Note 2)

(See Note 4)

Phase rotation

21

IA

RL1 2

Time delayed trip Inst. trip

22

Directional control PhB

Current setting Ph

47

RL1–1

Output circuits Ph

I> Is

35 33

RL2 2

34

RL1–2

29

Phase fault time delayed trip output contacts

30

48

RL2–1

23

38

24

Directional control PhC Case earth

36 37

IB RL2–2

41

Phase fault instantaneous trip output contacts

42

45 46

29

25

30

1

2

3

4

5

6

33

34

7

8

35

36

9

10

37

38

11

12 41

42

IC

13

14

15

16

17

18

45

46

19

20

47

48

21

22

49

50

23

24

25

26

27

28

26

Input circuit

27

28

Vx

+VE –VE

13 14 1

Case earth connection

(See Note 3) Notes: 1. (a)

Module terminal block viewed from rear (with integral case earth strap)

Power supply circuits

CT shorting links make before (b) and (c) disconnect. Short terminals break before (c). Long terminals

(b) (c)

MCGG 63

2. When directional control is required the contacts of the directional relays should be connected as shown. Contacts must close to inhibit overcurrent relay.

3. Earthing connections are typical only. 4. CT connections are typical only.

Figure 8: Application diagram (10 MCGG 63 02): static modular overcurent relay type MCGG 63. Three phase (with polyphase measurement) with instantaneous element.

A

A B

P2 S2

P1 S1

C C

B

Directional control PhA

TMS setting

50

N

Phase rotation

Indicator reset 49

(See Note 2) 21 (See Note 4)

IA

Is 22

Directional control PhB

Case earth 29

30

6

33

34

7

8

35

36

9

10

37

38

11

12

13

14

41

42

15

16

43

44

17

18

45

46

19

20

47

48

21

22

49

50

1

2

3

4

5

23

24

25

26

27

28

Is 24

TMS setting

25

IC

Is

43

28

2. When directional control is required the contacts of the directional relays should be connected as shown. Contacts must close to inhibit overcurrent relay.

(See Note 3)

–VE

34

RL1–2

29

Phase fault time delayed trip output contacts

30 36 37

Inst. trip

38

RL2–2

I>Is

13 14 17

Inst setting

Power supply circuits

RL3–1

41

Phase fault instantaneous trip output contacts

Is

µC E/F

5

Inst. trip

RL3–2

Time delayed trip Inst. trip

RL3 2

RL4–1

Earth fault time delayed trip output contacts

8 10 9

Output circuits E/F

MCGG 82

Case earth connection

3. Earthing connections are typical only. 4. CT connections are typical only.

Figure 9: Application diagram (10 MCGG 82 03): static modular overcurent relay type MCGG 82. Three phase plus earth fault with instantaneous elements (4 wire system). 8

2 1

Curve selection

I>Is

7 6

Time delayed trip

I>Is Inst setting

Input circuit Current setting E/F E/F

Curve selection

µC PhC

TMS setting

27

Vx

RL2 2

Time delayed trip

µC PhB

35 33

Curve selection

Inst setting

Input circuit Current setting Ph Ph

44

+VE

RL1–1 Output circuits Ph

42 45

26

CT shorting links make before (b) and (c) disconnect. Short terminals break before (c). Long terminals.

Inst. trip

I>Is

Input circuit Current setting Ph Ph

46

Directional control E/F

RL1 2

Time delayed trip

RL2–1

IB

Notes:

(b) (c)

TMS setting

23

Module terminal block viewed from rear (with integral case earth strap)

1. (a)

47

Curve selection

µC PhA

Input circuit Current setting Ph Ph

48

Directional control phase PhC

Inst setting

RL4–2 RL4 2

16 15

Earth fault instantaneous trip output contacts

Technical Data Ratings

AC current (In)

1A or 5A

Frequency

50/60Hz

DC supply (Vx)

24/54V, 48/125V or 110/250V

Burdens

AC Burden

Less than 0.25 VA for 1A relays and less than 0.5VA for 5A relays, at unity power factor and at rated current on any setting. The impedance of the relays over the whole of the setting range (5% to 240% rated current) is less than 0.25Ω for 1A relays and less than 0.02Ω for 5A relays and is independent of current.

DC burden

Relay rating

Relay type MCGG

MCGG

MCGG

MCGG

22, 63

42, 53

52, 62

82

24/54

1.5W

2.5W

3.0W

4.0W

48/125

2.0W

3.0W

3.5W

4.5W

110/250

2.5W

3.5W

4.0W

5.0W

The figures above are maxima under quiescent conditions. With output elements operated they are increased by up to 2.5W per element. Current transformer requirements

Relay and CT secondary rating (A)

Nominal output (VA)

Accuracy class

Accuracy Limiting lead limit current resistance – (X rated current) one way (ohms)

1

2.5

10P

20

1

5

7.5

10P

20

0.15

Note: For 5A applications with longer leads, the CT rating can be increased in steps of 2.5VA where each step of 2.5VA is equivalent to additional 0.06Ω lead resistance. Instantaneous earth fault element

For installations where the earth fault element is required to have a sensitive setting whilst remaining stable on heavy through faults, the use of a stabilising resistor is recommended, the value of which will vary according to the specific application. If assistance is required in selecting the appropriate value, please consult the Applications Department of ALSTOM T&D Protection & Control Ltd.

9

Time delayed settings (Is), phase/ earth fault measuring range: 5% to 240% of In in 5% steps.

Setting ranges

Instantaneous setting (Iinst) 1 x –31 x

Is in 1 x 1s steps

Operating time

Time delayed element Operating characteristics selectable to give:

Shown in Figure 10 Standard inverse IDMT Very inverse IDMT Extremely inverse IDMT Long time earth fault IDMT Definite time 2s, 4s, 8s

Time multiplier setting

0.05 to 1.0 in 0.025 steps (applicable to all time characteristics)

Instantaneous elements

Shown in Figure 11 For settings of 5 x Is and above: