ACB masterpact (Circuit Breakers)

Masterpact: presentation

035928PC

Masterpact circuit breakers are used to
protect and control low-voltage distribution
systems. They may be installed in main LV
switchboards (incoming units, main and
secondary outgoers). Masterpact is a
complete range offering a large selection of
performance levels:
c ratings from 800 to 6300 A AC,
from 1000 to 8000 A DC;
c breaking capacity from 40 to 150 kA rms;
c operational voltages 690 V AC,
1000 V DC.

Many versions
c 3 or 4 poles;
c fixed or drawout versions;
c current-limiting version up to 2500 A;
c wide range of control units offering
multiple functions.
Circuit breakers designed for all
applications
c 1000 V AC version;
c DC version;
c anti-corrosion version;
c source-changeover version;
c merchant-marine and military versions.
Masterpact circuit breakers comply with all

major international standards and meet
T2 tropicalisation criteria.

front face

2
5
1
6
12
13

4

E28760

7

c "charged"

charged

c "discharged"

discharged

13 main-contact position indicator
c "OFF" (O);

8

9

10

c "ON" (I).

3

11

E28761

14

1 opening push-button (O)
2 closing push-button (I)
3 keylock for "connected",
"disconnected" or "test" position
4 door interlock
5 stored-energy-mechanism charging
handle
6 operations counter
7 "open" position keylock
8 racking handle storage
9 functional position indicator:
"connected", "test" and "disconnected"
10 controls on fixed chassis (accessible
with cubicle door closed)
11 padlocking facilities for "connected",

"disconnected" or "test" position
12 stored-energy-mechanism status
indicator

O

OFF

I

ON

E28791

14 fault-trip indicator/breaker reset button
LV circuit-breaker: blue figures
Enclosure: red figures

M63

M50

M40

M08 àtoM32
M32
M08

IG

LI

L

G
off

LIG

I

reset V

push to reset

LG

MERLIN GERIN
masterpact
I

O

I3

I2

I1
90%

push OFF

I
push ON

STR 58 UE

M32 H1
Ui

1000V

50/60Hz

Ue 380/440V

480/690V

Icu 100kA

85kA

Ics 100kA

85kA

Icw 75kA 1s

50%

IEC 947-2

discharged

20%
Ir

Io
%Ir

.92
.95 60

1

.98 30

.85
1

0.5

105

.9

.8

.88

0.8

0.63

90

tr

xIo

xIn
Im

I
Ir :

t
Ir fault

.2

.1
0
.1
2
on I t off

.2

10

xIo
12

8

17

6

22
off

2

xIn
tr

th :

Ih

600
800

500

Ih

400

Im fault
tm

fault
th

T

th .4

.4
.3

.3

.2
.1
.1
2
on I t off

1000 .2
320
250

I

i
+S–

1200

A

Ic1 .9

.8

–T+

R

Ic2.8

.93
.95

.7

.98

.6

.85
.9

.86
.85

test

F

00000

.3

6 .3
8

4

Im :

480
15
at 1,5Ir

tm.4

5

4

3
2
1.5

120

O OFF

240

Reduced dimensions
c AC circuit breakers:
v a single frame size from 800 to 3200 A,
v common height and depth from 800 to
6300 A;
c DC circuit breakers:
v common height and length from 1000 to
8000 A for operational voltages of up to 500
V DC,
v common height and length from 1000 to
4000 A for operational voltages greater than
500 V DC.

1
xIr

.95
1

.5
xIr

test

connected

test
disconnected

2

Merlin Gerin


015159

1

2

3
4

6
7
8

5

10
9

drawout version
1
2
3

4
5
6
7
8
9
10

arc chute cover
auxiliary terminal shield
auxiliaries connection block
fixed chassis
safety shutters
arc chute
remote control voltage release
motor for electrical charging of
stored energy mechanism
control unit (AC system)
front cover

Merlin Gerin

3


E29490

Masterpact: presentation

safety and reliability

c reduced, simple maintenance (main
contacts easily accessible, with wear
indication feature);
c double insulation from the front face;
c positive contact indication;
c auxiliary devices can be fitted on site
without adjustment;
c fewer parts than conventional ranges (by a
factor of 5-10);
c a trip interlock ensures that the circuit
breaker is open during connection and
disconnection;
c connection to top or bottom terminals;
c fully tropicalised as standard.
STR 58 U

stored energy operating
mechanism

50%

20%

0.8

0.63

90

xIo

tm

Im

2
1.5

τ tr

I
Ir fault

8

Im :

4

Ih

th :

th

.2

.2

.1

0
off

8

.1
on I2t

10

14
19
22
Max.

xIn

Ih 1200A Max th .4
600
500
800 .3
400

Im fault
tm

fault

6 .3

xIr

12

Ir :

2
tr

.3

.4

5

4

3

320
250

I

i
overcurrent

+

–

–

+

test

A

Ic2

Ic1

.9

.86

.8

.93
.95

.7

.98

.6

1

xIr

T

.4
.3

1000 .2
.1
1200
on I2t

.85

ground

Masterpact circuit breakers are operated via
a stored energy mechanism for
instantaneous opening and closing.
The mechanism is charged either manually
or electrically. Closing and opening
operations can be initiated either from the
local pushbuttons on the circuit breaker front
face, or by remote control.

15
at 1.5Ir

1

.8

xIn

norm
min.

480

.98 30

.85

1

0.5

240

120
.92
.95 60

.9

.88

%Ir
105

tr

Ir

Io

.2
.1
off

R
.85
.9

.8

.95
.5

1

xIr

test

isolation renforcée

séparation totale

classe II insulation

double

entre phase
chaque phase
total
separation

035929

other possibilities

déclencheurs voltmétriques
accessibles
à l'avant
voltage
releases
accessible from the
front

c Fixed circuit breaker
The fixed circuit breaker is derived from the
moving part of the drawout circuit breaker by
adding a fixing bracket on each side.
c Switch version
The switch (unprotected) version is derived
directly from the standard circuit breaker, but
does not implement a control unit (or the
magnetic trip units used with the DC circuit
breakers). Available models are:
v standard: type HI and NI;

v high performance: type HF, equipped with
a protection system that instantaneously
opens the circuit breaker in the event of
closure under fault conditions.

Fixed circuit breaker

Auxiliaries
c accessible from the front, mounted in a
separate compartment insulated from power
circuits;
c secured by a single screw;
c adjustment-free;
c can be fitted on site.
c Source changeover system
Four solutions are available:
v mechanical interlocking for 2 or 3 circuit
breakers, adaptable to various sourcechangeover configurations;
v automatic source-changeover controller,
easy to implement on any two suitably
equipped circuit breakers (electrically
charged operating mechanism, etc.) (for 3
circuit breakers, consult us);
v complete assembly including 2 or
3 mechanically (rod assembly) interlocked
circuit breakers, adaptable to various
source-changeover configurations;
v complete assembly including
2 mechanically (rod assembly) interlocked
circuit breakers and an automatic sourcechangeover controller, adaptable to various

source-changeover configurations. Ready
for connection.

c 1000 V AC circuit breakers

053061

053058

053060

c Earthing switch
A special short-circuit and earthing switch is
available on request for the M08 to M32H
drawout types, 3 or 4 poles. Please consult
us.

common auxiliaries
from 800 A to 6300 A

Automatic source-changeover controller

4

Merlin Gerin


86094

DC circuit breakers

86096

Fixed Masterpact DC circuit breaker

Masterpact DC circuit breakers are available
in fixed and drawout versions. They benefit
from the AC range technology and
advantages.
c 5 available ratings from 1000 to 8000 A;
c 2 breaking capacities, 100 kA at 500 V,
50 kA at 750 and 1000 V;
c a circuit-breaker version offering
instantaneous short-circuit protection with
an adjustable, magnetic trip unit (DINA);
c a switch (unprotected) version.
note: up to 125 V DC, the devices in the AC
range (M08 to M63) may be used only in the
switch version, in which case a three-pole,
type HI device should be used, with:
c 1 pole for the positive polarity;
c 1 pole for the negative polarity;
c 1 pole not used.

Auxiliaries
All the auxiliaries designed for the
Masterpact AC circuit breakers may be used
on the DC versions, with the exception of the
position switches, indicating the connected
(CE), disconnected (CD) and test (CT)

positions.
Auxiliary connections are made via one or
two manually disconnectable plugs that
remain accessible from the front.
Accessories
Standard Masterpact DC range equipment
includes an arc-chute cover (CC) and, on
drawout versions, safety shutters (VO).
Interphase barriers (EIP) are not available
for the DC range.

Drawout Masterpact DC circuit breaker

device identification
M 20 H1
breaking capacity;
c N1: standard;
c H1: H2: high performance;
c L1: current limiting;
c DC: direct current.
rating
c rated current / 100.
family
c Masterpact: LV power air
circuit breaker.

Merlin Gerin

5

Masterpact circuit breakers are the product
of Merlin Gerin’s vast experience in the field
of power circuit breakers. They incorporate
all the qualities of traditional air circuit
breakers while drawing on certain of the
advantages specific to moulded-case circuit
breakers. In particular, they require no
preventive maintenance.

ease of installation

025179

2500 A Masterpact circuit breaker

Top: front connection
Bottom: rear vertical connection

Masterpact is a complete and rationally
designed range.
c 10 ratings;
c 4 breaking-capacity levels;
c 6 control units;
c a complete range of auxiliaries and
accessories;
c numerous versions (three and four-pole
devices, fixed and drawout versions, etc.).
Masterpact circuit breakers are easy to
incorporate in switchboards.

c a single frame size from 800 to 3200 A,
thus making for standardised columns;
c an upper safety clearance equal to zero
due to the arc-chute cover, on both the fixed
and drawout versions;
c built-in measurement functions in the
control units;
c auxiliaries are the same for the entire
range and may be easily implemented (only
a screwdriver is required).
Masterpact circuit breakers are easy to
connect to the main distribution system.
c all types of connections are available
(horizontal and vertical terminals, front and
mixed connections);
c connections are possible with bars of any
thickness;
c connection to the input power source is
possible on the upper or lower terminals of
the circuit breakers.
Due to their small size, Masterpact circuit
breakers can replace most existing
circuit breakers.

continuity of service
Masterpact circuit breakers are designed
with continuity of service in mind. The
result is:
c total time discrimination on the N1 and H1
circuit breakers and maximum discrimination

on H2 circuit breakers;
c factory pre-setting of Masterpact circuit
breakers which never require any periodic
maintenance;
c high electrical endurance: 10 000 cycles at
1600 A and 30 cycles at 50 kA, without
maintenance;
c preventive indications: load-shedding
indication switch, long-time threshold
overrun alarm, etc.;
c easy access to the main contacts fitted
with mechanical wear indicators. An optional
function on the STR68 control unit is the
remote indication of contact wear, thus
making possible continuous monitoring of
circuit breakers during their service life.
,

036634

Masterpact: presentation

operating safety
The insulating casing of Masterpact
circuit breakers provides for:
c user safety:
v double insulation on the front face
(class II),
v auxiliary circuits in a compartment
insulated from the power circuits;

c switchboard safety when the circuit
breaker is in the open position:
v each pole is effectively isolated in its own
housing,
v limitation of external disturbances.
Positive contact indication
The position indicator cannot indicate
«open» unless the poles are effectively
separated by the required distance.
The circuit breakers automatically open
during racking in and out.

reliability
c Masterpact circuit breakers comprise ten
times fewer parts than traditional devices.
They are easier to produce and more
reliable.
c the Masterpact circuit-breaker factory is
certified ISO 9002;
c the design of Masterpact circuit breakers
is modular with delayed differentiation
(highest possible number of common parts
on all models). The result is shorter delivery
times and enhanced reliability.

6

Merlin Gerin

Masterpact: functions and characteristics

general characteristics

E29049

conformity with standards

MERLIN GERIN
masterpact
M32 H2
Ui

1000V

50/60Hz

Ue 380/440V 480/690V
Icu 100kA

85kA

Ics 100kA

85kA

Icw 75kA 1s
IEC 947-2

Masterpact circuit breakers comply with all

the major international standards:
c International standard IEC 947-2;
c North American standards (please consult
us):
UL 489, ANSI C37-50, CSA C22-2,
NEMA AB1 et SG3;
c Japanese standards: JIS 160 and C 8372.
They also comply with the following national
standards:
c France NF C 63-120;
c Germany VDE 0660;
c United Kingdom BS 4752;
c Australia AS ;
c Italy CEI.
Masterpact circuit breakers comply with the
specifications of the marine classification
companies (Veritas, Lloyd's Register of
Shipping, Det Norske Veritas, etc.).

Standardised characteristics indicated on
the rating plate:
Ui: rated insulation voltage
Ue: rated operational voltage
Icu: ultimate breaking capacity, for various
values of the rated operational voltage Ue
Ics: service breaking capacity
Icw: short-time withstand current
: suitable for isolation

IEC 947-2

This standard replaces IEC 157-1,
applicable since 1973.
The circuit breaker selection criteria are
unchanged, but the new standard provides
the user with a better guarantee concerning
quality and performance.
Circuit breakers are subjected to tests that
are more representative of real operating
conditions.
IEC 947-2 also clarifies the notion of
breaking capacity.
c Icu : the ultimate breaking capacity, which
must be greater than or equal to the 3-phase
short-circuit current at the point of
installation of the circuit breaker, a value
unlikely to be reached under real conditions;
c Ics : the service breaking capacity,
generally expressed as a percentage of the
ultimate breaking capacity (25, 50, 75 or
100 % of Icu). It corresponds to a shortcircuit current that is more likely to be
reached under real conditions. The circuit
breaker must continue to operate normally
after having interrupted a current equal to
Ics several times;
c Icw : short-time withstand current for
circuit breakers belonging to category B
(category B refers to circuit breakers with
time discrimination and category A to those
without time discrimination).
Furthermore, IEC 947-2 takes into account

recent technological advances:
c suitability for isolation recognised for
circuit breakers having passed special
electrical and mechanical tests;
c industrial earth-fault circuit breakers
covered by an appendix;
c definition of tests designed to ensure
coordination between two circuit breakers.

tropicalisation
As standard, Masterpact circuit breakers
comply with NF C 63-100 standard level 2
conditions (95 % relative humidity at 45 °C
or 80 % at 55 °C, hot and humid climate
conditions). They also comply with the
following standards:
c IEC 68-2-30 damp heat;
c IEC 68-2-2 dry heat;
c IEC 68-2-11 salt spray;
c IEC 68-2-1 low temperatures during
storage.
Corrosive atmospheres: Special grease or
other surface coatings available (please
consult us).

pollution degree
Masterpact circuit breakers are certified for
operation in pollution degree IV
environments as defined by
IEC standard 947 (industrial environments).

8

Merlin Gerin


positive contact indication

All Masterpact circuit breakers are also
disconnectors (suitable for isolation) as
specified by IEC 947-2. They bear the
corresponding symbol on the front cover:

All Masterpact circuit breakers offer positive
contact indication. The toggle position
rigorously reflects the position of the main
contacts. It can indicate the "OFF" position
only if the contacts are effectively open and
a suitable distance apart.

E18569

035932RC

maximum dependability

This characteristic considerably increases
the dependability of the circuit breaker.
The conditions specified by IEC 947-2 for
this function are:

c positive contact indication;
c impulse withstand: 8 kV at sea level;
c very low leakage current, checked on new
circuit breakers and on circuit breakers
subjected to tests representative of the end
of service life.
Moreover Masterpact circuit breakers have a
double-insulation front face (i.e. a class II
device) allowing control from the outside.

installation
Masterpact circuit breakers may be installed
on horizontal metal surfaces or on rails.
They are secured by four points accessible
at the bottom of the chassis (drawout
versions) or on either side of the circuit
breaker (fixed versions). A single door
cut-out is required for the entire range and
provides access to Masterpact controls
(see the description on page 2).
.

degree of protection
E28757

IP 30-5

circuit breaker installed in a cabinet with access
to controls through a door cut-out

IP 40-5

circuit breaker installed in a cabinet behind a door with
a cut-out fitted with a sealed, transparent cover

IP 54-9

E28763

circuit breaker installed free standing

E28758

(as defined by IEC 529)

Merlin Gerin

9


Masterpact: functions and characteristics

035928

circuit breaker selection

Masterpact circuit breakers
number of poles

electrical characteristics as per IEC 947-2 and EN 60947-2

In

40 °C

Ui
Uimp
Ue

AC 50/60 Hz

ultimate breaking capacity (1)
(kA rms)

Icu

AC 50/60 Hz

service breaking capacity
short-time withstand current
(kA rms)

Ics
Icw

(% Icu)
AC 50/60 Hz

making capacity (kA peak)

Icm

AC 50/60 Hz

electrodynamic withstand (kA peak)
utilisation category
suitability for isolation
break time
closing time
endurance (C-O cycles) x 1000

mechanical

with maintenance
no maintenance
no maintenance

rated current (A)
rating of 4th pole (A)
rated insulation voltage (V)
rated impulse withstand voltage (V)
rated operational voltage (V)

type of circuit breaker
Masterpact M16 H1

electrical

motor control (AC3-947-4) (2)

220/415 V

440 V
500/690 V
0.5 s
1s
3s
220/415 V
440 V
500/690 V

440 V - In
690 V - In
690 V

electrical characteristics as per standard Nema AB1
breaking capacity (kA)

480 V
600 V

protection (see following pages)
sensor ratings (A) (see page 12)
control unit
protection type

instantaneous
distribution
selective
universal

STR 18 M

STR 28 D
STR 38 S
STR 58 U
STR 68 U

installation and connections
connection
version

drawout
fixed

indication and measurement auxiliaries
auxiliary switches
electronic trip unit related functions

control auxiliaries
auxiliary releases (MN, MNR, MX, XF)
motor mechanism (MCH)
operation counter (CDM)

installation and connection accessories

(1) Defined for a power factor of 0.25 if 20 < kA rms
≤ 50 or 0.20 of kA rms > 50.
(2) Closing at 6 x Ie and opening at 0.17 x Un.
(3) For control unit STR 68 U, the minimum rating
In is 400 A.

6

locking by padlock or keylock/mismatch protection
safety shutters (VO)
interphase barriers (EIP)
partitioning fixture (AC)
arc-chute cover (CC)
terminal-block cover (CB)
door frame (CDP)
transparent cover (CCP)
Merlin Gerin


M08

M10

M12

M16

3, 4

3, 4

3, 4

3, 4

800
800

1000
8000
690

1000
1000
1000
8000
690

1250
1250
1000
8000
690

1600
1600
1000
8000
690

N1

N1

H1

H2

L1

N1

H1

H2

L1

40
65
100
130
40
65
100
130
40
65
100
110
40
65
100
110
40
65
85
65

40
65
85
65
100 % 100 % 100 % 100 % 100 % 100 % 100 % 100 %
40
65
65
12
40
65
65
12
30
50
50
12
30
50
50
12
22
32
32
12
22
32
32
12
84

143
220
286
84
143
220
286
84
143
220
242
84
143
220
242
84
143
187
143
84
143
187
143
84
143
143
24
84
143
143

24
B
B
B
B
B
B
B
B
c
c
25 to 30 ms without intentional time delay and 9 ms for type L1
70 ms
20
20
20
20
20
20
20
20
10
10
10
10
10
10
10
10
10

10
10
3
10
10
10
2.7
10
10
10
3
10
10
10
2.7
10
10
10
10
10
10
-

H1

40
40
40
100 %
40

30
22
84
84
84
84
B
c

65
65
65
100 %
65
50
32
143
143
143
143
B

100
100
85
100 %
65
50
32
220

220
187
143
B

130
110
65
100 %
12
12
12
286
242
143
24
B

40
40
40
100 %
40
40
22
84
84
84
84
B

c

65
65
65
100 %
65
50
32
143
143
143
143
B

100
100
85
100 %
65
50
32
220
220
187
143
B

130
110

65
100 %
17
17
12
286
242
143
34
B

20
10
10
10
10

20
10
10
10
10

20
10
10
10
10

15

10
2.5
2.5
-

20
10
10
10
10

20
10
10
10
10

20
10
10
10
10

15
10
2.2
2.2
-

40

40

-

40
40

65
65

100
65

-

40
40

65
65

100
65

-

c
c
c

200 to 1250 (3)
c
c
c
c
c
c
c
c
c
c

c
c
c

200 to 1600 (3)
c
c
c
c
c
c
c
c
c
c

c
c

c
c
c

c
c
c

65
65

200 to 800 (3)
c
c
c
c
c
c
c
c
c
c

H2

100
65

c
c

c
c
c

L1

N1

H1

-

40
40

65
65

c
c
c

200 to 1000 (3)
c
c
c
c
c
c
c

c
c
c

H2

100
65

c
c
c
c
c

L1

c
c
c
c
c

front and rear connections
c
c

c
c

c
c

c
c

c
c

c
c

c
c

c
c

c
c
c

c
c
c

c
c
c

c
c
c

c
c
c
c
c
c
c
c

c
c
c
c
c
c
c
c

c
c
c
c
c
c
c
c

c
c
c
c
c
c
c
c

Merlin Gerin

7


Masterpact: functions and characteristics

036635

circuit breaker selection (cont.)

Masterpact circuit breakers
number of poles

electrical characteristics as per IEC 947-2 and EN 60947-2
In

40 °C

Ui

Uimp
Ue

AC 50/60 Hz

ultimate breaking capacity (1)
(kA rms)

Icu

AC 50/60 Hz

service breaking capacity
short-time withstand current
(kA rms)

Ics
Icw

(% Icu)
AC 50/60 Hz

making capacity (kA peak)

Icm

AC 50/60 Hz

electrodynamic withstand (kA peak)
utilisation category

suitability for isolation
break time
closing time
endurance (C-O cycles) x 1000

mechanical

with maintenance
no maintenance
no maintenance

rated current (A)
rating of 4th pole (A)
rated insulation voltage (V)
rated impulse withstand voltage (V)
rated operational voltage (V)

type of circuit breaker
Masterpact M50 H1

electrical

motor control (AC3-947-4) (2)

220/415 V
440 V
500/690 V
0.5 s
1s
3s

220/415 V
440 V
500/690 V

440 V - In
690 V - In
690 V

electrical characteristics as per standard Nema AB1
breaking capacity (kA)

480 V
600 V

protection (see following pages)
sensor ratings (A) (see page 12)
control unit
protection type

instantaneous
distribution
selective
universal

STR 18 M
STR 28 D
STR 38 S
STR 58 U
STR 68 U

installation and connections
connection
version

drawout
fixed

indication and measurement auxiliaries
auxiliary switches
electronic trip unit related functions

control auxiliaries
auxiliary releases (MN, MNR, MX, XF)
motor mechanism (MCH)
operation counter (CDM)

installation and connection accessories

(1) Defined for a power factor of 0.25 if 20 < kA rms
≤ 50 or 0.20 of kA rms > 50.
(2) Closing at 6 x Ie and opening at 0.17 x Un.
(3) For control unit STR 68 U, the minimum rating
In is 400 A.
(4) 83% if Ue i 440 V.
(5) Consult us for full rated neutral.

8

locking by padlock or keylock/mismatch protection
safety shutters (VO)

interphase barriers (EIP)
partitioning fixture (AC)
arc-chute cover (CC)
terminal-block cover (CB)
door frame (CDP)
transparent cover (CCP)
Merlin Gerin


M20

M25

M32

M40

M50

M63

3, 4

3, 4

3, 4

3, 4

3, 4

3, 4

2000
2000
1000
8000
690

2500
2500
1000
8000
690

3200
3200
1000
8000
690

4000
4000
1000
8000
690

5000
2500 (5)
1000

8000
690

6300

N1

H1

H2

H1

H2

H1

H2

H1

H2

55
75
100
130
55
75
100

130
75
55
75
100
110
55
75
100
110
75
55
75
85
65
55
75
85
65
75
100 % 100 % 100 % 100 % 100 % 100 % 100 % 100 % 100 %
55
75
75
17
55
75
75
17
75

55
75
75
17
55
75
75
17
75
50
57
57
17
50
75
75
17
75
121
165
220
286
121
165
220
286
165
121
165
220

242
121
165
220
242
165
121
165
187
143
121
165
187
143
165
121
165
165
34
121
165
165
34
165
B
B
B
B
B
B

B
B
B
c
c
c
25 to 30 ms without intentional time delay and 9 ms for type L1
70 ms
15
15
15
15
15
15
15
15
15
10
10
10
10
10
10
10
10
10
9
9
9
2

8
8
8
1.8
4
7
7
7
2
6
6
6
1.8
2.6
7
7
7
6
6
6
2.6

100
100
85
100 %
75
75
75
220

220
187
165
B

75
75
75
100 %
75
75
75
165
165
165
165
B
c

100
100
85
100 %
75
75
75
220
220
187
165

B

100
100
85
100 %
100
100
100
220
220
187
220
B
c

150
150
85
100 % (4)
100
100
100
330
330
187
220
B

100

100
85
100 %
100
100
100
220
220
187
220
B
c

150
150
85
100 % (4)
100
100
100
330
330
187
220
B

15
10
4
2.6

2.6

80 ms
10
5
3
2.5
2.5

10
5
3
2.5
2.5

10
5
3
2.5
2.5

10
5
3
2.5
2.5

10
5
2

1.5
1.5

10
5
2
1.5
1.5

55
55

100
75

75
75

100
75

100
100

125
100

100
100

150
100

75
75

H2

100
75

200 to 2000 (3)
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c

L1

N1

H1

75
75

H2

-

55
55

100
75

c
c
c

300 to 2500 (3)
c
c
c
c
c
c
c
c

c
c
c
c
c
c
c

L1

H1

3200
1000
8000
690

-

75
75

c
c
c

600 to 3200
c
c
c

c
c
c
c
c
c
c

2000 to 4000
c
c
c
c
c
c
c
c
c
c

2000 to 5000
c
c
c
c
c
c
c
c
c

c

2000 to 6300
c
c
c
c
c
c
c
c
c
c

front and rear connections
c
c

c
c

c
c

rear connections
c
c

c
c (3P only)

c

c
c

c
c

c
c

c
c

c
c

c
c

c
c
c

c
c
c

c

c
c

c
c
c

c
c
c

c
c
c

c
c
c
c
c
c
c
c

c
c
c
c
c
c

c
c

c
c
c
c
c
c
c
c

c
c
c (3P only)
c
c
c
c
c

c
c

c
c

c
c
c

c
c

c
c
c
c
c

Merlin Gerin

9


Masterpact: functions and characteristics

052380

circuit breaker selection (cont.)
Masterpact 1000 V AC
Masterpact 1000 V AC circuit breakers
number of poles

electrical characteristics as per IEC 947-2 and EN 60947-2
In

40 °C

Ui
Uimp

Ue

AC 50/60 Hz

ultimate breaking capacity (1)
(kA rms)

Icu

AC 50/60 Hz

service breaking capacity
short-time withstand current
(kA rms)

Ics
Icw

(% Icu)
AC 50/60 Hz

making capacity (kA peak)

Icm

AC 50/60 Hz

electrodynamic withstand (kA peak)
utilisation category
suitability for isolation

break time
closing time
endurance (C-O cycles) x 1000

mechanical

with maintenance
no maintenance
no maintenance

rated current (A)
rating of 4th pole (A)
rated insulation voltage (V)
rated impulse withstand voltage (V)
rated operational voltage (V)

type of circuit breaker
Masterpact M20 H1 1000 V

electrical

motor control (AC3-947-4) (2)

220/415 V
440 V
500/690 V
1000 V
0.5 s
1s
3s

220/415 V
440 V
500/690 V
1000 V

440 V - In
690 V - In
690 V

protection (see following pages)
sensor ratings (A) (see page 12)
control unit
protection type

instantaneous
distribution
selective
universal

STR 18 M
STR 28 D
STR 38 S
STR 58 U
STR 68 U

installation and connections
connection
version

drawout

fixed

indication and measurement auxiliaries
auxiliary switches
electronic trip unit related functions

control auxiliaries
auxiliary releases (MN, MNR, MX, XF)
motor mechanism (MCH)
operation counter (CDM)

installation and connection accessories

(1) Defined for a power factor of 0.25 if 20 < kA rms
≤ 50 or 0.20 of kA rms > 50.
(2) Closing at 6 x Ie and opening at 0.17 x Un.
(3) For control unit STR 68 U, the minimum rating
In is 400 A.

10

locking by padlock or keylock/mismatch protection
safety shutters (VO)
interphase barriers (EIP)
partitioning fixture (AC)
arc-chute cover (CC) (as standard on the 1000 V version)
terminal-block cover (CB)
door frame (CDP)
transparent cover (CCP)

Merlin Gerin


M08

M10

M12

M16

M20

M25

M32

3, 4

3, 4

3, 4

3, 4

3, 4

3, 4

3, 4

800
800
1000
8000
1000

1000
1000
1000
8000
1000

1250
1250
1000
8000
1000

1600
1600
1000
8000
1000

2000
2000
1000
8000
1000

2500
2500
1000
8000
1000

3200
3200
1000
8000
1000

H1

H1

H1

H1

H1

H1

H1

65
65
65

65
65
65
65
65
65
65
65
65
45
45
45
45
100 %
100 %
100 %
100 %
45
45
45
45
45
45
45
45
32
32
32
32
143

143
143
143
143
143
143
143
143
143
143
143
95
95
95
95
143
143
143
143
B
B
B
B
c
c
c
c
25 to 30 ms without intentional time delay and 9 ms for type L1
70 ms
20

20
20
20
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10

75
75
75
45
100 %
45
45
45
165
165

165
95
165
B
c

75
75
75
45
100 %
45
45
45
165
165
165
95
165
B
c

75
75
75
45
100 %
45
45
45

165
165
165
95
165
B
c

15
10
9
7
7

15
10
8
6
6

15
10
4
2.6
2.6

200 to 800 (3)
c
c
c

c
c

200 to 2000 (3)
c
c
c
c
c

300 to 2500 (3)
c
c
c
c
c

600 to 3200
c
c
c
c
c

rear connections only / supply by upstream terminals mandatory
c
c
c
c

c

c

c

c
c

c
c

c
c

c
c

c
c

c
c

c
c

c
c
c

c
c
c

c
c
c

c
c
c

c
c
c

c
c
c

c
c
c

c
c
c
c
c

c
c
c

c
c
c
c
c
c
c
c

c
c
c
c
c
c
c
c

c
c
c
c
c
c
c
c

c
c
c
c
c
c
c
c

c
c
c
c
c
c
c
c

c
c
c
c
c
c
c
c

Merlin Gerin

200 to 1000 (3)
c
c
c
c
c

200 to 1250 (3)
c
c
c
c
c

200 to 1600 (3)
c
c
c
c
c

11


Masterpact: functions and characteristics

052384

switch-disconnectors

Masterpact switch-disconnectors
number of poles

electrical characteristics as per IEC 947-2 and EN 60947-2
rated current (A)
rating of 4th pole (A)
rated insulation voltage (V)
rated impulse withstand voltage (V)
rated operational voltage (V)

In

40 °C

Ui
Uimp
Ue

AC 50/60 Hz

type of switch-disconnector
short-time withstand current
(kA rms)

Icw

AC 50/60 Hz

making capacity (kA peak)

Icm

AC 50/60 Hz

electrodynamic withstand (kA peak)
suitability for isolation
closing time
endurance (C-O cycles) x 1000

mechanical

with maintenance
no maintenance
no maintenance

Masterpact M10 NI

electrical

motor control (AC3-947-4) (1)

0.5 s
1s
3s
440 V
500/690 V

440 V - In
690 V - In
690 V

protection
STR 08 dummy unit (no protection)
STR 18I (protection against short-circuits when closing)

installation and connections
connection
version

drawout
fixed

indication and measurement auxiliaries
auxiliary switches

control auxiliaries
auxiliary releases (MN, MNR, MX, XF)
motor mechanism (MCH)
operation counter (CDM)

installation and connection accessories
locking by padlock or keylock/mismatch protection
safety shutters (VO)
interphase barriers (EIP)
partitioning fixture (AC)
arc-chute cover (CC)
terminal-block cover (CB)
door frame (CDP)
transparent cover (CCP)

(1) Closing at 6 x Ie and opening at 0.17 x Un.

12

Merlin Gerin


M08

M10

M12

M16

3, 4

3, 4

3, 4

3, 4

800
800
1000
8000
690

1000

1000
1000
8000
690

1250
1250
1000
8000
690

1600
1600
1000
8000
690

NI

HI

HF

NI

HI

HF

NI

HI

HF

NI

HI

HF

40
30
22
84
84
84
c
70 ms
20
10
10
10
10

65
50
32
105
105

143

65
50
32
143
143
143

40
30
22
84
84
84
c

65
50
32
105
105
143

65
50
32
143
143
143

40
30
22
84
84
84
c

65
50
32
105
105
143

65
50
32
143
143
143

40
30
22
84
84
84
c

65
50
32
105
105
143

65
50
32
143
143
143

20
10
10
10
10

20
10
10
10
10

20
10
10

10
10

20
10
10
10
10

20
10
10
10
10

20
10
10
10
10

20
10
10
10
10

20
10
10

10
10

20
10
10
10
10

20
10
10
10
10

20
10
10
10
10

c

c

c

c

c

c

c

c

c

c

c

c

front and rear connections
c
c

c
c

c
c

c
c

c

c

c

c

c
c
c

c
c
c

c
c
c

c
c
c

c
c
c
c
c
c
c
c

c
c
c
c
c
c
c
c

c
c
c
c
c
c
c
c

c
c
c
c
c
c
c
c

Merlin Gerin

13


Masterpact: functions and characteristics

052388

switch-disconnectors (cont.)

Masterpact switch-disconnectors
number of poles

electrical characteristics as per IEC 947-2 and EN 60947-2
rated current (A)
rating of 4th pole (A)
rated insulation voltage (V)
rated impulse withstand voltage (V)
rated operational voltage (V)
Masterpact M50 HI

In

40 °C

Ui
Uimp
Ue

AC 50/60 Hz

type of switch-disconnector
short-time withstand current
(kA rms)

Icw

AC 50/60 Hz

making capacity (kA peak)

Icm

AC 50/60 Hz

electrodynamic withstand (kA peak)
suitability for isolation
closing time
endurance (C-O cycles) x 1000

mechanical

with maintenance
no maintenance
no maintenance

electrical

motor control (AC3-947-4) (1)

0.5 s

1s
3s
440 V
500/690 V

440 V - In
690 V - In
690 V

protection
STR 08 dummy unit (no protection)
STR 18 I (protection against short-circuits when closing)

installation and connections
connection
version

drawout
fixed

indication and measurement auxiliaries
auxiliary switches

control auxiliaries
auxiliary releases (MN, MNR, MX, XF)
motor mechanism (MCH)
operation counter (CDM)

installation and connection accessories
locking by padlock or keylock/mismatch protection

safety shutters (VO)
interphase barriers (EIP)
partitioning fixture (AC)
arc-chute cover (CC)
terminal-block cover (CB)
door frame (CDP)
transparent cover (CCP)

(1) Closing at 6 x Ie and opening at 0.17 x Un.

12

Merlin Gerin


M20

M25

M32

M40

M50

M63

3, 4

3, 4

3, 4

3, 4

3, 4

3, 4

2000
2000
1000
8000
690

2500
2500
1000
8000
690

3200
3200
1000
8000
690

4000
4000
1000

8000
690

5000
2500
1000
8000
690

6300
3200
1000
8000
690

NI

HI

HF

NI

HI

HF

HI

HF

HI

HF

HI

HF

HI

HF

55
55
50
84
84
121
c
70 ms
15
10
9
7
7

75
75
57

105
105
165

75
75
57
165
165
165

55
55
50
84
84
121
c

75
75
75
105
105
165

75
75
75
165

165
165

75
75
75
105
105
165
c

75
75
75
165
165
165

75
75
75
165
165
165

100
100
100
187
187

220
c

100
100
100
220
220
220

100
100
100
187
187
220
c

100
100
100
220
220
220

15
10
9
7
7

15
10
9
7
7

15
10
8
6
6

15
10
8
6
6

15
10
8
6
6

15
10
4
2.6
2.6

15
10
4
2.6
2.6

75
75
75
105
105
165
c
80 ms
10
5
3
2.5
2.5

10
5
3
2.5
2.5

10
5
3

2.5
2.5

10
5
3
2.5
2.5

10
5
2
1.5
1.5

10
5
2
1.5
1.5

c

c

c

c

c

c
c

c
c

c
c

c
c

c

front and rear connections
c
c

c
c

c
c

rear connections
c
c

c

c (3P only)

c

c

c

c

c

c

c

c
c
c

c
c
c

c
c
c

c
c

c

c
c
c

c
c
c

c
c
c
c
c
c
c
c

c
c
c
c
c
c
c
c

c
c

c
c
c
c
c
c

c
c
c (3P only)
c
c
c
c
c

c
c

c
c

c
c
c
c
c

c
c

c
c
c

Merlin Gerin

13


Masterpact: functions and characteristics

dimensions and weights

Masterpact circuit breakers and switch-disconnectors
type
dimensions and weights
dimensions W x H x D
(mm)

drawout

3P
4P
3P
4P
3P
4P
3P
4P

fixed
maximum weight
(kg)

drawout
fixed

Masterpact circuit breakers and switch-disconnectors
type
dimensions and weights
dimensions W x H x D
(mm)

drawout

3P
4P
3P
4P
3P
4P
3P
4P

fixed
maximum weight
(kg)

drawout
fixed

Masterpact 1000 V circuit breakers
type
dimensions and weights
dimensions W x H x D
(mm)

drawout

maximum weight
(kg)

drawout

3P
4P
3P
4P

sensor selection
In (A)
Ir threshold
settings (A)
In (A)
Ir threshold
settings (A)

200
80
to 200

1250
500
to 1250

250
100
to 250
1600
640
to 1600

320
125
to 320
2000
800
to 2000

400
160
to 400
2500
1000
to 2500

500
200
to 500
3000
1200

to 3000

600
240
to 600
3200
1280
to 3200

630
250
to 630
4000
1600
to 4000

800
320
to 800
5000
2000
to 5000

1000
400
to 1000
6000
2400
to 6000

1200
480
to 1200
6300
2500
to 6300

The table above indicates:
c all the available sensor ratings In;
c the limits of the long time Ir settings.

12

Merlin Gerin


M08

M10

M12

M16

M20

M25

M32

N1/H1/H2/L1
NI/HI/HF

N1/H1/H2/L1
NI/HI/HF

N1/H1/H2/L1
NI/HI/HF

N1/H1/H2 L1
NI/HI/HF

N1/H1/H2 L1
NI/HI/HF

N1/H1/H2 L1
NI/HI/HF

H1/H2
HI/HF

435 x 439 x 367
550 x 439 x 367
422 x 356 x 290
537 x 356 x 290
65
80
43
54

435 x 439 x 367
550 x 439 x 367
422 x 356 x 290
537 x 356 x 290
65
80
43
54

435 x 439 x 367
550 x 439 x 367
422 x 356 x 290
537 x 356 x 290
65
80
43
54

435 x 439 x 367
550 x 439 x 367
422 x 356 x 290
537 x 356 x 290
69
82
85
102
46
55
58
69

435 x 439 x 367
550 x 439 x 367
422 x 356 x 290
537 x 356 x 290
82
130
102
150
55
80
69
90

435 x 439 x 367
550 x 439 x 367
422 x 356 x 290
537 x 356 x 290
82
130
102
150
55
80
69
90

435 x 439 x 367
550 x 439 x 367
422 x 356 x 290

537 x 356 x 290
130
150
80
90

M40

M50

M63

H1/H2
HI/HF

H1/H2
HI/HF

H1/H2
HI/HF

550 x 439 x 367
815 x 484 x 367
537 x 356 x 290
801 x 356 x 290
150
200
90
110

815 x 484 x 367
1045 x 484 x 367
802 x 356 x 290

1045 x 484 x 367
1045 x 484 x 367

215
230
110

245
265

M08

M10

M12

M16

M20

M25

M32

H1

H1

H1

H1

H1

H1

H1

435 x 439 x 367
550 x 439 x 367
65
80

435 x 439 x 367
550 x 439 x 367
65
80

435 x 439 x 367
550 x 439 x 367
65
80

435 x 439 x 367
550 x 439 x 367
69

85

435 x 439 x 367
550 x 439 x 367
82
102

435 x 439 x 367
550 x 439 x 367
82
102

435 x 439 x 367
550 x 439 x 367
130
150

Merlin Gerin

13


Masterpact: functions and characteristics

control unit selection

Masterpact M08 to M63 circuit breakers are
equipped with microprocessor-based
electronic control units.

80

160

400

E31218

All the protection functions are powered by
the AC system and no auxiliary power
supply is required. The same is true for most
of the complementary functions.

current settings (A)

1250

1600

2000

2500

3200

4000

5000

6300

STR 18 M
STR 28 D
STR 38 S

Each control unit of the Masterpact range
corresponds to a certain type of application
(instantaneous, distribution, selective,
universal).
All the STR control units measure the true
rms value of the current and are therefore
not affected by harmonics that may be
present on the system.

STR 58 U
STR 68 U
instantaneous protection
distribution protection
selective protection
universal protection

protection

push to reset

1

E31219

E30703

STR 18 M

Key:

t

3

1

reset button: pops out when the circuit
breaker has tripped on a fault and must
be pressed (reset) before the circuit
breaker can be closed again.

2

maximum protection rating.

3

instantaneous pick-up.

4

test connector.

5

holes for sealable cover plate screws.

STR 18 M

2
5
0

I

I

other functions
c fault indication.
I 12 14
8

19
22
max

4
2

+
test

3

xIn

–

4
5

14

Merlin Gerin


protection
1

push to reset

E31220

E30704

STR 28 D

t

Key:

6

2
I1

I2

I

I3

3
STR 28 D

4

50%

Io
0.63

90

Ir
0.8

%Ir
105

7

11

20%

8

1

0.5

.88

.9 .92
.95

.85

.98
.8

xIn
Im

xIo

0

6

1

6

c
c
c
c

7

2
8
1.5 xIr 10
t

Ir :

Ir

2

ammeter digital display.

3

bar graph indicating load level (% Ir).

4

maximum protection rating.

Im :

Ir

I

I

8

overcurrent indicator LED.

9

noted settings.

10 test connector.
11 holes for sealable cover plate screws.

other functions

4 5

3

reset button: pops out when the circuit
breaker has tripped on a fault and must
be pressed (reset) before the circuit
breaker can be closed again.

5-6 long-time current setting as a function of:
Io x Ir x In.

7 instantaneous pick-up.

90%

5

1

9

fault indication;
indication of LT overrun;
ammeter;
self-monitoring (internal overheating).

Im

i
+

–

10

test

11

protection

E33950

E31221

STR 38 S

t

Key:
I2t ON

1

push to reset

1

reset button: pops out when the circuit
breaker has tripped on a fault and must
be pressed (reset) before the circuit
breaker can be closed again.

2

ammeter digital display.

3

bar graph indicating load level (% Ir).

4

maximum protection rating.

5

overcurrent indicator LED.

7
I2t OFF

2
I1

I2

I

I3

90%

12

3
50%

4

20%

16
Ir
0.8

%Ir
105

1

0.5

6

.85
1
xIo

8

2
1.5
xIr
t

tm

4 5

3

6

.3

8
10

.2

.2

.1
0
.1
on I2t off

Ir fault

9
11

Im :

tr
Ih
fault
th

14

16

max. off
xIn
th :
Ih
T
th
500 600
.4 .4
Im fault
400
tm
800 .3
.3
I
320
1000 .2
.2
.1
250 1200
.1
i
A
on I2t off
overcurrent
+

–

–

+

12
13

I

I

short-time delay.

10 noted settings.
11 instantaneous pick-up.

other functions

12 earth fault pick-up.

c
c
c
c
c

13 earth fault delay.

fault indication;
indication of LT overrun;

ammeter;
self-monitoring (internal overheating);
indication of type of fault (F).

14 LEDs indicating tripping on long-time,
short-time or earth fault.
15 test connector.
16 holes for sealable cover plate screws.
17 battery supplying backup power for fault
indication.
18 fault indication reset and/or battery test.

15

test

Im

.4 .3

I

Ir :

Ir

7

.98
.8

Im

0

.9 .92
.95

.88

xIn

10

9

11
Io
0.63

90

6-7 long-time current setting as a function of:
Io x Ir x In.
8 short-time pick-up.

9

13

STR 38 S

5

8

ground

19 re-indication of last fault.

F
test

17

19
18
Merlin Gerin

15


Masterpact: functions and characteristics

control unit selection (cont.)

protection
E31222

E30705

STR 58 U
V

1

I+T L+I
L+I+T
reset V
L+T
T
L off

push to reset

I

Key:

t
I2t ON

2

1

8
I2t OFF

9

3
I1

I2

I

I3

10

90%

14

4
STR 58 U

11

15

5

50%

21
20%

6

7
12
10
16

19
21
24

Io
0.63

Ir

tr
120 240
.9 .92
0.8
90
.88
.95 60
%Ir
480
30
.85
.98
105
1
0.5
1

15
.8
xIn
at 1.5Ir
xIo
Max.
Im
tm
4 5
.4 .3
τ tr
3
.3
6
.2
2
.2
norm
8
.1
0
1.5 10
.1
2
on I t off
xIr
I 12 14
t
Ir :
8

19
Ir fault
4
22
Im :
2 off
tr
xIn
th :
Ih 1200A Max th
T
Ih
500 600
.4 .4
fault
Im fault
400
800 .3
.3
tm
th
320
1000 .2
.2
I
.1
250 1200
.1
i
A

on I2t off
overcurrent Ic1
Ic2
R
+ –
.8 .85
.9 .93
test
.86
.9
.95 .7
.85
– +
.95
.98 .6
ground
1
.5
8 1
xIr
xIr
F
test

23

13

8
0

9

Ir

Im

I

I

other functions
c
c
c
c
c
c

fault indication;
indication of LT overrun;
ammeter;
self-monitoring (internal overheating);
fault type indication (F);
segregated alarm switch for selected
fault type (V);
c zone selective interlocking (Z);
c load monitoring (R);
c communication (COM).

11
13
14
15
17
18
20
22

protection
1

reset

E31223

E33949

STR 68 U

I2t ON

t

Key:
1

V
N

1

2

3

LT setting
(Ir)

2

Hz

I2t OFF

Cos ϕ

LT time delay
(tr)

kW
MWh

2

ST pick-up
(Im)
ST time delay
(tm)

STR 68 U

earth fault
pick-up (Ih)
685812
A
KA
S
test

1

2

3

3

earth fault
time delay (th)

0

instantaneous
pick-up (I)

Ir

Im

I

max

other functions
fault

s

4

tr

tm
th
Ih

Ir

Im

I

2

11

maintenance

1

6

–
no trip
test

5

load monitoring

10
8

A

%

trip

reset button: pops out when the circuit
breaker has tripped on a fault and must
be pressed (reset) before the circuit
breaker can be closed again.
2 selection of fault type for segregated
alarm: Ir and/or Im and/or Ih
L: long-time fault (Ir)
I: short-time fault (Im/l)
T: earth fault (Ih)
3 ammeter digital display.

4 bar graph indicating load level (% Ir).
5 maximum protection rating.
6 overcurrent indicator LED.
7-8 long-time current setting as a function of:
Io x Ir x In.
9 long-time trip delay
10 short-time pick-up.
11 short-time delay.
12 adjustment of thermal memory after
tripping.
13 instantaneous pick-up.
14 earth fault pick-up.
15 earth fault delay.
16 noted settings.
17-18 load monitoring settings.
19 test connector.
20 battery supplying backup power for fault
indication.
21 holes for sealable cover plate screws.
22 fault indication reset and/or battery test.
23 re-indication of last fault.
24 LEDs indicating tripping on long-time,
short-time or earth fault.

MEM

+
24 V DC

c

c
c
c
c
c
c

fault indications and memorisation;
maintenance indicator;
ammeter;
integrated test;
power measurement;
load monitoring (R);
self-monitoring (internal overheating,
malfunction of the microprocessor);
c zone selective interlocking for earth
faults.

I

reset button: pops out when the circuit
breaker has tripped on a fault and must
be pressed (reset) before the circuit
breaker can be closed again.
2 selection of displayed value (voltage,
power, energy, power factor, frequency).
3 display of current or interrupted current
(when flashing).
4 local fault indication and indication reset.
5 selection and indication of protection

parameter to be set.
6 selection and indication of load
monitoring parameters.
7 adjustment and saving of parameter
settings.
8 holes for sealable cover plate screws.
9 test connector.
10 test.
11 maintenance indicator.

7
9

adjustments

8
16

Merlin Gerin


options for STR control units

"earth fault" protection
(T or W)

E31225

zone selective interlocking
(Z)

A number of circuit breakers are
interconnected one after another by a pilotwire. In the event of a short-time or earth
fault, the control unit applies the set time
delay only if it receives a signal from a
downstream circuit breaker. If not, it trips
instantaneously (tripping time as 0.1 shorttime setting). In this way, the fault is cleared
rapidly by the nearest circuit breaker. The
thermal stresses in the installation are
minimised while maintaining time
discrimination throughout the entire

installation.
Opto-electronic outputs
The use of opto-transistors ensures total
isolation between the internal circuits of the
control unit and the circuits wired by the
user.

t

This earth fault protection is designed to
protect the installation against the risks of
fire due to high earth faults (not to be
confused with schemes designed for the
protection of persons against electrical
shock).
Two types of earth protection are available
for Masterpact:
c residual current type (T): the control unit

calculates the vector sum of the phase and
neutral (if distributed) currents;
c source ground return type (W): the control
unit acts directly on the signal received from
an external current transformer installed on
the source earthing circuit.

I2t ON

I2t OFF

Ih
Th

0

I

load monitoring (R)

E26037

earth fault curves for the STR 58

Remote indication of threshold overrun for
load-shedding or load-reconnection
purposes.

t

Ic2
Ic1

0

I

load monitoring curves for the STR 58

communication: STR 58 U
transmission: STR 68 U

Transmission of the control unit settings,
circuit breaker position and current, voltage
and power measurements.

Other information that can be transmitted
includes the value of the interrupted current,
the state of the thermal memory and the
maintenance indications

indication and
measurement

c ammeter (I): a digital display
continuously indicates the current of the
phase with the greatest load (Imax). By
pressing a scroll button, it is also possible to
display successively the readings of I1, I2,
I3, Ineutral and Ih.

In addition, three bargraphs provide an
immediate visual indication of the load on
each of the three phases.

c indication of type of fault (F);

Merlin Gerin

c segregated alarm switch for selected
fault type (V), wired in parallel with the
opening button (MX), it disables circuit
breaker closing for the selected type of fault.

17


Masterpact: functions and characteristics

048449

control unit selection (cont.)
STR 18 M to STR 58 U
control unit
type of circuit breaker

basic protection
long time protection LT
current setting (Ir) as a function of Io and Ir
settings tripping between 1.05 and 1.20 x Ir
time delay (tr)

accuracy: + 0 - 20 %

short-time protection ST
pick-up (Im) adjustable by Im setting
time delay (tm)

Io = In x ...
Ir = Io x ...
tr at 1.5 Ir (s)
tr at 6 Ir (s)
tr at 7.2 Ir (s)
Im = Ir x ...
tm setting with I2t OFF
tm setting with I2t ON
max. overcurrent time before tripping (ms)
max. break time (ms)

instantaneous protection I
pick-up setting
setting range
accuracy
OFF switch on front face

STR 58 U

basic functions
fault indication
for tripping on a fault
for LT setting overrun

self-monitoring

indicator button on front face
fault trip alarm contact (SDE)
LED (lights up at 0.9 Ir and flashes at 1.05 Ir)
LT overrun alarm contact (optional)
self-powered
internal overheating

optional functions

(1) Plus the uncertainty of the built-in transformers:
± 3 %.
(2) Max = In x ...
630 A
800 - 1000 A
1200 - 1600 A
2000 A
2500 A
3000 - 3200 A
4000 - 6300 A

N1/H1
22
22
22
17
12
10
8

H2
28
28
24
20
14
12
10

L1
14
10
8
6
6
–
–

(3) Continuous display for the phase with the
greatest load.
(4) 0.2 x In to 1200 A without external power
supply or 0.1 x In with external power supply.
(5) Accuracy with respect to the long time LT
protection.

ammeter (I)
display between 0.2 and 1.20 In
current readings with an accuracy of ± 1.5 % (1) (3)
bargraph indication of current levels with a resolution of 10 %

self-powered
earth fault protection: residual current (T) or source ground return (W) type on request
pick-up adjustable by Ih setting
Ih = In x ...
time delay (th)
th setting with I2t ON and I2t OFF
max. overcurrent time before tripping (ms)
max. break time (ms)
indication of type of fault (F) (LT - CT/Inst. - Earth) by LEDs on front face
power supply
with battery module
with external power supply by AD module
segregated alarm switch for selected fault type (V) (LT - CT/Inst. - Earth)
output via relay contact
power supply by AD module
zone selective interlocking (Z)
by opto-electronic contact on ST and earth (T/W) fault
load monitoring (R)
adjustment of load limit thresholds by Ic1 and Ic2 settings Ic1 = Ir x ... / Ic2 = Ir x ...
time delay tr1 at 1.5 Ic1
time delay tr2 at 1.5 Ic2
output via opto-electronic contact 0.1 A / 240 V
time delay for load reconnection
communication (COM)
2 outputs for data transmission to Digipact module
transmitted values
all control unit settings
alarms: Ir warning, fault type, self-monitoring
load monitoring thresholds
current values I1, I2, I3, IN

power supply by AD module

(6) Resettable maximum ammeter.

18

Merlin Gerin


STR 18 M

STR 28 D

STR 38 S

STR 58 U

N1, H1, H2

N1, H1, H2

N1, H1, H2, L1

N1, H1, H2, L1

c
0.5 to 1 (4 settings)
0.8 to 1 (8 settings)
fixed
120

7.5
5.2

c
0.5 to 1 (4 settings)
0.8 to 1 (8 settings)
fixed
120
7.5
5.2
c
1.5 to 10 ± 15 %
0
0.1
0.2
0.3
0.1
0.2
0.3
0
80
140
230
80
140
230
350
c
I = In x ...
fixed at high set (Max) (2)

± 20 %
on types N1 and H1

c
0.5 to 1 (4 settings)
0.8 to 1 (8 settings)
adjustable
15
30
60
120
0.94 1.88 3.75 7.50
0.65 1.30 2.60 5.20
c
1.5 to 10 ± 15 %
0
0.1 0.2 0.3
0.1 0.2 0.3
0
80
140 230
80
140 230 350
c
I = In x ...
2 x In to Max (2)
± 15 %
on types N1 and H1

0.4

350
500

240
15
10

480
30
21

0.4
350
500

c
Im = In x ...
2 x In to Max (2)
± 15 %
on types N1 and H1

c
Im = Ir x ...
1.5 to 10 x Ir
± 15 %

c
c

c

c
c
c
c
c

c
c
c
c
c
c

c
c
c
c
c
c

c
I1, I2, I3, IN, Imax (6)
I1, I2, I3
c

c
I1, I2, I3, IN, Ih, Imax (6)
I1, I2, I3
c
c

0.1 at 1 (max 1200 A) (4) ± 15 %
0.1
0.2
0.3
0.4
60
140
230
350
140
230
350
500
c
c
c

c
I1, I2, I3, IN, Ih, Imax (6)
I1, I2, I3
c
c
0.1 at 1 (max 1200 A) (4) ± 15 %
0.1 0.2 0.3 0.4
60
140 230 350
140 230 350 500
c
c
c

c
c
c
0.8 to 1 (8 settings) ± 1 % (5)
0.5 x tr
0.25 x tr
c
fixed at 10 s
c
c
c
c
c
c

Merlin Gerin

19