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withdrawn from case.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 • Accurately follows time curves to

BS142 and IEC60255.
• Choice of 4 inverse time curves
and 3 definite time ranges by • High resetting ratio.
switched selection. • Fast resetting time.
• Wide setting range of 0.05 x In • Positive, calibrated settings by
to 2.4 x In in steps of 0.05 x In. means of switches.
• Time multiplier range 0.05 to 1 • Internal dc auxiliary power
on all seven characteristics. supply operating over a wide
• Separate LED indicators provided input range.
on each measuring board to • Separate test mode with trip test
show time delayed and feature.
instantaneous operations.
• Indication of power to the
• LED start indicators provided to measuring board.
facilitate testing.
• Non-volatile memory for time
• Separate output contacts delayed and instantaneous LED
provided for time delayed phase indicators.
fault, instantaneous phase fault,
time delayed earth fault and
instantaneous earth fault
operations.
• Low ac burden.
• Suitable for use with separate
direction relay.

2
Models available MCGG 53 MCGG 82
Two phase overcurrent (with Three phase overcurrent plus earth
MCGG 22 polyphase measurement) plus earth fault with instantaneous elements.
Single phase overcurrent with fault with instantaneous elements.
instantaneous element. Associated publications:
MCGG 62
MCGG 42 Midos System R6001
Three phase overcurrent with
Two phase overcurrent with Directional Relay R6003
instantaneous elements.
instantaneous elements.
MCGG 63
MCGG 52 Three phase overcurrent (with
Two phase overcurrent plus earth polyphase measurement), with
fault with instantaneous elements. instantaneous element.

3 phase 2 phase Single phase Measuring Case

Model overcurrent overcurrent or earthfault boards size
† inst † inst † inst
MCGG 22 ● ● 1 4
MCGG 42 ● ● 2 6
MCGG 52 ● ● ● ● 3 8
MCGG 53 ● ● ● ● 2 8
MCGG 62 ● ● 3 6
MCGG 63 ● ● 1 6
MCGG 82 ● ● ● ● 4 8

Application For applications where the Description

instantaneous earth fault element is
The relay can be used in required to have a sensitive setting This range of MCGG relays is
applications where time graded whilst remaining stable on heavy designed so that versions are
overcurrent and earth fault through faults the use of a stabilising available with separate measuring
protection is required. resistor is recommended. The current boards for each phase or earth fault
transformers for this application input; alternatively, phase inputs
The relay can be used to provide
must satisfy the criteria detailed may be combined on to one board
selective protection for overhead
under ‘Current transformer for polyphase measurement (see
and underground distribution
requirements’ in Technical Data. table). These boards, together with
feeders. Other applications include
the other circuits of the relay, are
back-up protection for transformers, The total impedance of the relay contained in a single plug-in module
generators and HV feeder circuits and the series stabilising resistor is which is supplied in a size 4, 6 or 8
and the protection of neutral usually low enough to prevent the Midos case. The case incorporates
earthing resistors. current transformers developing one or two terminal blocks for
With all the current/time voltages over 2kV during maximum external connections. Removal of the
characteristics available on one internal faults, but in some module automatically short circuits
relay, a standard relay can be applications a non-linear resistor is the current transformer connections
ordered before detailed co- required to limit this voltage. by means of safety contacts within
ordination studies are carried out – Non-standard resistance values and the case terminal block. For added
a distinct advantage for complex non-linear voltage limiting devices security, when the module is
systems. Also, changes in system are available. removed, the CT circuits are short
configuration can be readily circuited before the connections to
accommodated. the output contacts and the dc
An instantaneous element with low supply are broken. The relay uses
transient overreach is incorporated solid state techniques, each
within each phase or earth fault measuring board utilising a micro-
measuring board. This can be easily computer as a basic circuit element.
disabled in applications where it is The current measurement, whether
not required. 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.

3
Each measuring board has a built-in Switch position Operating
‘power off’ memory feature for the (0) (1) characteristic
time delayed and instantaneous LED ●
indicators. ● Trip test
●
Power to each measuring board
●
may be tested whilst the relay is in t= 0.14
● Standard inverse sec SI
service, without affecting the current ● (I0.02 – 1)
measurement. A test mode is also ●
t= 13.5
available to carry out a trip test on ● Very inverse sec VI
● (I – 1)
the output relays. During this test,
current measurement is inhibited. ●
80
● Extremely inverse t= sec EI
When required, directional control ● (I2 – 1)
can be exercised over the relay by ●
connecting an output contact from 120
● Long time earth fault t = sec LT
direction relay type METI to the ● (I – 1)
terminals provided. ●
● Definite time 2 seconds D2
Separate output contacts, capable ●
of circuit breaker tripping, are ●
provided for time delayed phase ● Definite time 4 seconds D4
faults, instantaneous phase faults, ●
time delayed earth fault and ●
instantaneous earth fault operations. ● Definite time 8 seconds D8
●

Table1: Operating time characteristics with corresponding switch positions.

Relay settings This acts as a conventional time

multiplier on the current dependent
Separate setting switches for each characteristics and gives the
measuring board are provided on following time ranges for the
the relay frontplate. These are used definite time characteristics.
to select the required time/current
characteristic, current and time Operating Time range
multiplier settings. characteristics
s s
Selection of time 2 0.1 to 2.0 in 0.05s steps
characteristics
4 0.2 to 4.0 in 0.1s steps
The current/time characteristic 8 0.4 to 8.0 in 0.2s steps
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
Current setting Trip test
Current measurement is inhibited by
Time delayed element
setting the curve selection switches
The current setting control is marked to 111. This causes all three LEDs to
Is = Σ x In where Is is the current flash once per second. If the reset
setting in amps, Σ is the sum of all push button is then pressed for
the switch positions and In is the approximately six seconds, both
relay rated current in amps. output relays associated with that
measuring board will operate.
Each measuring board provides a
setting range of 0.05 x In to 2.4 x Power supply healthy test
In in steps of 0.05 x In.
If, whilst the relay is in service, the
Instantaneous element reset button is pressed, all the LEDs
are illuminated, indicating that there
The setting control of the
is power to the measuring boards.
instantaneous element is marked
The LEDs are reset on releasing the
Iinst = Σ x Is where Σ is the sum of
push button. During this test, normal
the switch positions and Is is the
current measurement is not
time delayed element setting.
inhibited.
When all switches are set to the left
(at zero), or when the lowest switch
is set to infinity regardless of the
Figure 2: Type MCGG 22 nameplate
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
P2 P1
A
S2 S1
B
C B
C Phase rotation

Directional
control
PhA Indicator
24 TMS Inst Curve reset
setting setting selection
(See Note 4) 23
(See Note 2) 27 Time delayed trip
µC
IA Is Inst. trip
PhA RL1–1 7
28
6
Input Current Phase fault
circuit setting I>Is 5
time delayed
Ph Ph RL1–2 2 trip output
RL1 contacts
Case earth 2 1
13
1 2 +VE Power Output
Vx 14
supply
circuits RL2–1 8
–VE Ph
5 6 26 circuits 10
7 8 RL2 9 Phase fault
2 instantaneous
9 10 trip output
RL2–2 16
Case earth connection contacts
13 14 (See Note 3) 15
15 16
MCGG 22

23 24 Notes:
26 1. (a) CT shorting links make 2. When directional control is required the contacts
27 28 before (b) and (c) disconnect. of the directional relays should be connected as shown.
(b) Short terminals break before (c). Contacts must close to inhibit overcurrent relay.
(c) Long terminals 3. Earthing connections (CTs) are typical only.
Module terminal block
viewed from rear 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
 A P2 P1
A
S2 S1
B Directional Indicator
TMS Inst Curve reset
control setting setting selection
C PhA
49
C B
Phase rotation (See Note 4) 50
RL1
(See Note 2) 21 Time delayed trip 2
µC
IA Is PhA
Inst. trip Output RL1–1 35
22 circuits
Ph 33
23 Input Current Phase fault
circuit setting I> Is 34
RL2 time delayed
Ph Ph RL1–2 29 trip output
2
24 contacts
Directional 30
control
PhC TMS Inst Curve
45 setting setting selection
RL2–1 36
46 37
Case earth Time Phase fault
25 delayed trip 38
µC instantaneous
1 2 29 30 IC Inst. trip RL2–2 41 trip output
Is PhC
contacts
3 4 26
5 6 33 34 42
27 Input Current
7 8 35 36 circuit setting I> Is
9 10 37 38 Ph Ph
11 12 28
13
13 14 41 42 +VE Power
15 16 Vx –VE
14
supply
17 18 45 46 1 circuits
19 20 47 48
MCGG 42
21 22 49 50 Case earth connection
(See Note 3)
23 24
Notes:
25 26
1. (a) CT shorting links make 2. When directional control is required the contacts
27 28 before (b) and (c) disconnect. of the directional relays should be connected as shown.
(b) Short terminals break before (c). Contacts must close to inhibit overcurrent relay.
Module terminal block (c) Long terminals 3. Earthing connections are typical only.
viewed from rear
(with integral case earth strap) 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 P1
A
S2 S1 Directional Indicator
A control
B reset
PhA TMS Inst Curve
C 49 setting setting selection
50 RL1
C B (See Note 2) 21 Time delayed trip 2
(See Note 4) RL1–1 35
Phase rotation µC
IA Inst. trip
Is PhA Output 33
22 circuits Phase fault
Input Current Ph 34 time delayed
23 circuit setting I >I s RL2 trip output
RL1–2 29
Ph Ph 2 contacts
Directional
control 24 30
PhC TMS Inst Curve
45
setting setting selection RL2–1 36
46
37
25 Time
delayed trip 38 Phase fault
µC instantaneous
IC Is PhC
Inst. trip
RL2–2 42 trip output
26 contacts
Input Current 41
circuit setting I >I s
Case earth Ph Ph
Directional RL3–1 7
1 2 29 30 control 6
3 4 E/F TMS Inst Curve Earth fault
43 5
5 6 33 34 setting setting selection time delayed
44 RL3 RL3–2 2 trip output
7 8 35 36
27 2 contacts
9 10 37 38 Time delayed trip
µC 1
11 12 E/F Inst. trip Output
Is circuits
13 14 41 42 28 RL4–1 8
15 16 43 44 Input Current
13 circuit setting I >I s RL4 10
17 18 45 46 +VE Power 2 Earth fault
Vx 14 9
19 20 47 48 –VE supply instantaneous
21 22 49 50 17 circuits RL4–2 16 trip output
contacts
23 24
15
25 26 Case earth connection MCGG 52
(See Note 3)
27 28
Notes:
1. (a) CT shorting links make 2. When directional control is required the contacts 3. Earthing connections are typical only.
Module terminal block before (b) and (c) disconnect. of the directional relays should be connected as shown. 4. CT connections are typical only.
viewed from rear
(with integral case earth strap) (b) Short terminals break before (c). Contacts must close to inhibit overcurrent relay.
(c) Long terminals

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

6
 P2 P1
A
S2 S1 Directional Indicator
A control
B reset
PhA TMS Inst Curve
C 49 setting setting selection
50 RL1
C B (See Note 2) 21 Time delayed trip 2
(See Note 4) RL1–1 35
Phase rotation µC
IA Inst. trip
Is Ph Output 33
22 circuits Phase fault
Ph 34 time delayed
23 Current I >I s RL2
setting RL1–2 29 trip output
Ph 2 contacts
Directional 24 30
control
PhC RL2–1 36
45
46 37
38 Phase fault
25
instantaneous
IC RL2–2 41 trip output
contacts
26
42
Case earth
Input
circuit
Directional Ph RL3–1 7
1 2 29 30 control 6
3 4 E/F TMS Inst Curve Earth fault
43 5
setting setting selection time delayed
5 6 33 34
44 RL3 RL3–2 2 trip output
7 8 35 36
27 2 contacts
9 10 37 38 Time delayed trip
µC 1
11 12 E/F Inst. trip Output
Is circuits
13 14 41 42 28 RL4–1 8
15 16 43 44 13 Input Current I >I s RL4
+VE Power circuit setting 10
17 18 45 46
Vx 14 2 Earth fault
19 20 47 48 –VE supply 9
17 instantaneous
circuits RL4–2 16 trip output
21 22 49 50
contacts
23 24
Case earth connection 15
25 26 (See Note 3)
MCGG 53
27 28 Notes:
1. (a) CT shorting links make 2. When directional control is required the contacts 3. Earthing connections are typical only.
before (b) and (c) disconnect. of the directional relays should be connected as shown. 4. CT connections are typical only.
Module terminal block
viewed from rear (b) Short terminals break before (c). Contacts must close to inhibit overcurrent relay.
(with integral case earth strap (c) Long terminals

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 P1
A
S2 S1 Directional Indicator
A control
B reset
PhA TMS Inst Curve
C 49 setting setting selection
50

C B (See Note 4) (See Note 2) 21 Time delayed trip

µC RL1–1 35
Phase rotation IA Inst. trip
Is PhA 33
22 Phase fault
Input Current RL1 34 time delayed
circuit setting I>Is trip output
2 RL1–2 29
Ph Ph contacts
Directional
control 30
PhB Output
47 TMS Inst Curve circuits
setting setting selection Ph RL2–1 36
48
37
23 Time
delayed trip RL2 38 Phase fault
µC instantaneous
IB Is PhB Inst. trip 2 RL2–2 41 trip output
24 contacts
Input Current I>Is
27 42
circuit setting
Case earth Directional Ph Ph
control 28
1 29 30 PhC
45 TMS Inst Curve
setting setting selection
33 34 46
35 36 25 Time delayed trip
37 38 µC
IC Is PhC
Inst. trip

26
13 14 41 42 Input Current
13 circuit setting I>Is
+VE Power Ph Ph
45 46 Vx 14
–VE supply
47 48 1 circuits
21 22 49 50
23 24 Case earth connection
25 26 (See Note 3) MCGG 62
Notes:
27 28
1. (a) CT shorting links make 2. When directional control is required the contacts 3. Earthing connections are typical only.
before (b) and (c) disconnect. of the directional relays should be connected as shown.
Module terminal block 4. CT connections are typical only.
(b) Short terminals break before (c). Contacts must close to inhibit overcurrent relay.
viewed from rear
(with integral case earth strap) (c) Long terminals

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

7
 P2 P1
A
S2 S1 Directional Indicator
A control
B reset
PhA TMS Inst Curve
C 49 setting setting selection
50 RL1
C B (See Note 2) 21 Time delayed trip 2
(See Note 4) RL1–1 35
Phase rotation µC
IA Inst. trip
Is Ph Output 33
22 circuits Phase fault
Ph 34 time delayed
Directional Current I> Is RL2
setting RL1–2 trip output
control 29
contacts
PhB Ph 2
47
30
48
23 RL2–1 36

IB 37
38 Phase fault
24 instantaneous
Directional RL2–2 41 trip output
control contacts
PhC 42
45
Case earth
46

1 2 29 30 25
3 4 IC
5 6 33 34
26
7 8 35 36 Input
27
9 10 37 38 circuit
11 12
13 14 41 42 28

15 16 13
+VE Power
17 18 45 46 Vx 14
–VE supply
19 20 47 48 1 circuits
21 22 49 50
23 24 Case earth connection
25 26 (See Note 3) MCGG 63
27 28 Notes:
1. (a) CT shorting links make 2. When directional control is required the contacts 3. Earthing connections are typical only.
before (b) and (c) disconnect. of the directional relays should be connected as shown. 4. CT connections are typical only.
Module terminal block
viewed from rear (b) Short terminals break before (c). Contacts must close to inhibit overcurrent relay.
(with integral case earth strap) (c) Long terminals

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

A P2 P1
A Directional
S2 S1 control Indicator
B reset
PhA
C 49 TMS Inst Curve
setting setting selection
C B N 50 RL1
Phase rotation (See Note 2) 21 2
Time delayed trip
(See Note 4) µC RL1–1 35
IA Inst. trip
Is PhA Output
33
22 circuits
Input circuit Current setting Ph Phase fault
I>Is 34 time delayed
Ph Ph RL2
Directional trip output
control 2 RL1–2 29
contacts
PhB
Case earth 47 TMS Inst Curve 30
setting setting selection
48
1 2 29 30
RL2–1 36
3 4 23 Time delayed trip
µC 37
5 6 33 34 IB Inst. trip
Is PhB Phase fault
7 8 38
35 36 24 instantaneous
9 10 37 38 Input circuit Current setting RL2–2 41 trip output
Ph Ph I>Is contacts
11 12 Directional
13 14 41 42
control 42
phase PhC
15 16 43 44 45 TMS Inst Curve
setting setting selection RL3–1 7
17 18 45 46 46
6
19 20 47 48 25 Time delayed trip Earth fault
21 22 49 50 µC 5
time delayed
IC Inst. trip
Is PhC
RL3–2 2 trip output
23 24 26
Input circuit Current setting
contacts
25 26 Ph Ph I>Is 1
27 28 Directional
control E/F RL4–1 8
43 TMS Inst Curve RL3
Module terminal block setting setting selection 10
44 2
viewed from rear Earth fault
(with integral case earth strap) 9
27 Time delayed trip Output instantaneous
µC circuits RL4–2 16 trip output
Inst. trip
Is E/F E/F contacts
Notes: 28 RL4
Input circuit Current setting 15
1. (a) CT shorting links make 13 E/F E/F I>Is 2
before (b) and (c) disconnect. +VE Power MCGG 82
Vx 14
(b) Short terminals break before (c). supply
–VE
(c) Long terminals. 17 circuits
2. When directional control is required the contacts (See Note 3)
of the directional relays should be connected as shown. Case earth connection
Contacts must close to inhibit overcurrent relay.
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
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 Relay type
rating
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 Nominal Accuracy Accuracy Limiting lead
secondary rating output class limit current resistance –
(A) (VA) (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
Setting ranges Time delayed settings (Is), phase/
earth fault measuring range: 5% to
240% of In in 5% steps.
Instantaneous setting (Iinst)
1 x –31 x Is in 1 x 1s steps

Operating time
Time delayed element Shown in Figure 10
Operating characteristics
selectable to give: 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:
<35ms at 2x instantaneous setting

Accuracy – reference conditions

Current setting (Is) Reference range 0.05In to 2.4In for
MCGG 22, 42, 52, 62, 82 and
E/F element of MCGG53.
0.2In to 2.4In for phase fault
elements of MCGG 53 and 63.
Input current Time Reference
characteristic range
Standard inverse
Very inverse 2 x Is to 31 x Is
Long time inverse
Extremely inverse 2 x Is to 20 x Is
Definite time 1.3 x Is to 31 x Is
Ambient temperature 20°C
Frequency 50Hz to 60Hz
Time multiplier setting 1x
DC auxiliary voltage Reference ranges 24V to 54V
48V to 125V
110V to 250V

10
 100

10
Definite 8 seconds

Operating time t (seconds)

Definite 4 seconds
Longtime standby
earth fault
120
Definite 2 seconds t=
I–1
Standard inverse
0.14
t = 0.02
I –1
1.0

Very inverse
13.5
t=
I–1

Figure 10: Time delayed overcurrent element – Extremely inverse

operation time characteristics. t= 2
80
I –1
0.1
1 10 100
I( x Is)
Current (multiple of setting)

240

220

200

180

160

140
Operating time (ms)

120

100
Iinst = 1Is
80

60 2Is
3Is
40 5-31Is 4Is

20

0
1 10 100
Current (multiple of instantaneous setting)

Figure 11: MCGG instantaneous operating times (various settings).

11
Accuracy – influencing quantities
Time multiplier On settings 0.05 to 1.0 ±2% or
±30ms whichever is the greater
Ambient temperature
operative range –25°C to +55°C
Variations over this range
Setting current ±5%
Time characteristic Time variation
Standard inverse
Very inverse ±5%
Long time inverse
Extremely inverse ±7.5%
Definite time ±3%
Frequency
Setting current ±1% over the range 47 – 62Hz
Operating time ±2% or ±30ms whichever is the
greater, over the range 47–52Hz or
57–62Hz.
DC auxiliary voltage Vx dc(V) Operative range (V)
24/54 19 – 60
48/125 37.5 – 150
110/250 87.5 – 300
Variations over these ranges
Setting current ±1%
Operating time ±2% or ±30ms whichever is greater

Accuracy – general
Current setting
Time delayed element 1.0 x Is to 1.1 x Is
Instantaneous elements Iinst = 1 x Is 1.0 x Iinst to 1.1 x Iinst
All other settings Iinst ±5%
Operating time
Time characteristic Accuracy
Standard inverse
Very inverse ±5%
Long time inverse
Extremely inverse ±7.5% ±30ms whichever is greater
Definite time ±3%
Repeatability
(within basic accuracy claim)
Pick-up current Better than ±1%
Operating time Better than ±2% or ±30ms
whichever is greater.
Overshoot time Less than 30ms (when the input
current is reduced from any value
within the operative range to zero).

12
Resetting current Time delayed and instantaneous
elements: not less than 95% of time
delayed current setting.
Resetting and disengaging times Less than 70ms (when the input
current is reduced from any value
within the operative range to zero).
Transient overreach System time constant up to 30ms:
5%
(instantaneous elements) System time constant up to 100ms:
12%

Thermal withstand
Continuous withstand 2 x Is or 2.6 x In whichever is
lower, with a minimum of 1 x In
Short time withstand For 1s: 100 x In with 400A
maximum
For 3s: 57 x In with 230A
maximum

Operation indicators
Each measuring board is fitted with
two red LED indicators, one showing
time delayed operation and the
other showing instantaneus
operation. The reset button provided
on the frontplate resets all the
operation indicators.
The green timer start indicator
illuminates when the input current
exceeds the setting current Is to
facilitate testing of the module.
This indicator is self resetting.
LED covers are available to
eliminate any undesired LED
indication.

Contacts
Changeover Make
MCGG 52, 53, 82 Phase fault time delayed element 1 1
Phase fault instantaneous element 1 1
Earth fault time delayed element 1 1
Earth fault instantaneous element 1 1
MCGG 22, 42, 62, 63 Time delayed element 1 1
Instantaneous element 1 1

13
Contact ratings
Make and carry for 0.2s 7500VA subject to maxima of 30A
and 300V ac or dc
Carry continuously 5A ac or dc
Break ac – 1250VA subject to
dc – 50W resistive maxima of
25W, L/R = 0.04s 5A and 300V
Durability
Loaded contact 10,000 operations minimum
Unloaded contact 100,000 operations minimum

Directional control
Directional control can be exercised
over each pole individually by
connecting the output contact of a
relay type METI across appropriate
case terminals.
Relay type Direction control terminals
MCGG 22 23,24
MCGG 42 45, 46, 49, 50
MCGG 52, 53 43 to 46, 49, 50
MCGG 62, 63 45 to 50
MCGG 82 43 to 50
Note: The directional control circuits are isolated from all other circuits but
are electrically connected to the relay case. These circuits must not,
therefore, be insulation or impulse tested to the case.

High voltage withstand

Dielectric withstand
IEC 60255-5: 1977 2kV rms for 1 minute between all
case terminals connected together
and the case earth terminal, with the
exception of the directional control
terminals.
2kV rms for 1 minute between
terminals of independent circuits,
with terminals on each independent
circuit connected together.
1kV rms for 1 minute across open
contacts of output relays.
High voltage impulse
IEC 60255-5: 1977 Three positive and three negative
impulses of 5kV peak, 1.2/50µs,
0.5J between all terminals and case
earth and between adjacent
terminals, with the exception of the
directional control terminals,
(see note).

14
Electrical environment
High frequency disturbance
IEC 60255-22-1: 1988 Class III 2.5kV peak between independent
circuits and case earth.
1kV peak across terminals of the
same circuit.
Note: The directional control
terminals comply with class II and
will withstand 1kV peak between all
independent circuits, and 500V
peak across the directional control
terminals.
DC supply interruption
IEC 60255-11: 1979 The unit will withstand a 10ms
interruption in the auxiliary supply,
under normal operating conditions,
without de-energising.
AC ripple on dc supply
IEC 60255-11: 1979 The unit will witstand 12% ac ripple
on the dc supply.
Fast transient disturbance
IEC 60255-22-4: 1992 Class IV 4kV, 2.5kHz applied directly to
auxiliary supply.
4kV, 2.5kHz applied directly to
all inputs.
Electrostatic discharge
IEC 60255-22-2: 1996 Class II 4kV discharge in air with cover
in place
4kV contact discharge with cover
removed.
Surge immunity
IEC 61000-4-5: 1995 Level 4 4kV peak, 1.2/50µs between all
groups and case earth.
2kV peak, 1.2/50µs between
terminals of each group.
EMC compliance
89/336/EEC Compliance with the European
Commission Directive on EMC is
claimed via the Technical
Construction File route.
EN50081-2: 1994 Generic Standards were used to
EN50082-2: 1995 establish conformity.
Product safety
73/23/EEC Compliance with the European
Commission Low Voltage Directive.
EN 61010-1: 1993/A2: 1995 Compliance is demonstrated by
EN 60950: 1992/A11: 1997 reference to generic safety
standards.

15
Atmospheric environment
Temperature
IEC 60255-6: 1988 Storage and transit
–25°C to +70°C
Operating –25°C to +55°C
IEC 60068-2-1: 1990 Cold
IEC 60068-2-2: 1974 Dry heat
Humidity
IEC 60068-2-3: 1969 56 days at 93% RH and 40°C
Enclosure protection
IEC 60529: 1989 IP50 (dust protected)

Mechanical environment
Vibration
IEC 60255-21-1: 1988 Response Class 1
Endurance Class 1

16
Cases
52
MCGG 22 Size 4
97 4 holes Ø4.4
23.5
MCGG 42 Size 6
MCGG 62 Size 6
All dimensions in mm.
MCGG 63 Size 6
168 159
MCGG 52 Size 8
MCGG 53 Size 8
Push button
MCGG 82 Size 8 projection 10 max. 99

The dimensions of the cases are Panel cut-out:

Flush mounting fixing details.
shown in Figures 12, 13 and 14.
32 212
25 min.

177 157 max.

103 11
Flush mounting.

Figure 12: Case outline size 4.

103.6
149 4 holes Ø4.4
23.5

All dimensions in mm.

168 159

Push button
151
projection 10 max.
Panel cut-out:
Flush mounting fixing details.

32 212
25 min.

177 157 max.

155
Flush mounting. 11

Figure 13: Case outline size 6.

17
 155.4
200 4 holes Ø4.4
24

168 159

Push button
203
projection 10 max.
Panel cut-out:
Flush mounting fixing details.

32 212
25 min.

177 157 max.

206 11
Flush mounting.
All dimensions in mm.

Figure 14: Case outline size 8.

Information Required
with Order
Relay type (see models available).
Rated current and frequency.
DC auxiliary voltage range.
Requirement for LED cover part
GJ0280 001.
(These self adhesive LED covers can
be supplied to cover the
instantaneous LED when used in
auto-reclose applications as the
LEDs remain on during normal use).

18
19
 ALSTOM T&D Protection & Control Ltd St Leonards Works, Stafford, ST17 4LX England
Tel: 44 (0) 1785 223251 Fax: 44 (0) 1785 212232 Email: pcs.enquiries@tde.alstom.com Internet: www.alstom.com
©1999 ALSTOM T&D Protection & Control Ltd

Our policy is one of continuous development. Accordingly the design of our products may change at any time. Whilst every effort is made to produce up to date literature, this brochure should
only be regarded as a guide and is intended for information purposes only. Its contents do not constitute an offer for sale or advice on the application of any product referred to in it.
ALSTOM T&D Protection & Control Ltd cannot be held responsible for any reliance on any decisions taken on its contents without specific advice.

Publication R6054X 089920 CPS Printed in England.