© A

BB

ST

OT

Z K

ON

TA

KT

- 1

07

-05-

2002

MCB Tripping – Characteristics

MCB´s Knowhow

ABB STOTZ KONTAKT

© A

BB

ST

OT

Z K

ON

TA

KT

DE

ST

O/X

2 R

H -

2

MCB tripping characteristics

40 I1

40 I2

I3

I4

- Thermal non-tripping current rsp. Low test current

- Thermal tripping current rsp. High test current

- Electromagnetic non-tripping current rsp. test current: hold surges of I3

- Electromagnetic tripping current rsp. test current: trip at least at I4

General Time / current relationGeneral Time / current relation

1. Thermal tripping

2. Electromagnetic tripping

Basics:Basics:40 40

0,04

120

20

10

64

2

1

20

40

10

4

2

1

0,60,4

0,2

0,1

0,06

0,02

0,011 1,5 2 3 4 5 6 8 10 15 20 30

6

60

I3 I4

I1 I2

Tr i

pp

ing

tim

es

ec

on

ds

min

ute

s

© A

BB

ST

OT

Z K

ON

TA

KT

DE

ST

O/X

2 R

H -

3

MCB tripping characteristics

DC-current increases the magnetic tripping valuesby factor 1,5

40

0,04

120

20

10

64

2

1

20

40

10

4

2

1

0,60,4

0,2

0,1

0,06

0,02

0,011 1,5 2 3 4 5 6 8 10 15 20 30

6

60

AC

DC

Tri

pp

ing

tim

es

ec

on

ds

min

ute

s

Multiple of rated current

Basics:Basics:

Magnetic tripping:

AC, 100 Hz = factor 1.1

AC, 200 Hz = factor 1.2

AC, 400 Hz = factor 1.5

DC = factor 1.5

Thermal tripping is not dependent

on frequency

© A

BB

ST

OT

Z K

ON

TA

KT

DE

ST

O/X

2 R

H -

4

MCB tripping characteristics

"B"-characteristic"B"-characteristic

acc. EN 60898 rsp. IEC 898: standard for acc. EN 60898 rsp. IEC 898: standard for miniature circuit breakers to be used in miniature circuit breakers to be used in residential or similar applicationsresidential or similar applications

40 I1

40 I2

I3

I4

Thermal non tripping: 1,13 x In

Thermal tripping: 1,45 x In

Magnetic non tripping: 3 x In

Magnetic tripping: 5 x In

Applications:•low duty applications without starting or inrush currents

40

0,04

120

20

10

64

2

1

20

40

10

4

2

1

0,60,4

0,2

0,1

0,06

0,02

0,011 1,5 2 3 4 5 6 8 10 15 20 30

6

60

B

40 I1 40 I2

I3 I4

min

ute

ss

ec

on

ds

Tri

pp

ing

tim

e

Multiple of rated current

© A

BB

ST

OT

Z K

ON

TA

KT

DE

ST

O/X

2 R

H -

5

MCB tripping characteristics

““C"-characteristicC"-characteristic

acc. EN 60898 rsp. IEC 898: standard for acc. EN 60898 rsp. IEC 898: standard for miniature circuit breakers to be used in miniature circuit breakers to be used in residential or similar applicationsresidential or similar applications

40 I1

40 I2

I3

I4

Thermal non tripping: 1,13 x In

Thermal tripping: 1,45 x In

Magnetic non tripping: 5 x In

Magnetic tripping: 10 x In

Applications:•low duty applications with medium starting or inrush currents and low loop impendance

40

0,04

120

20

10

64

2

1

20

40

10

4

2

1

0,60,4

0,2

0,1

0,06

0,02

0,011 1,5 2 3 4 5 6 8 10 15 20 30

6

60

C

min

ute

ss

ec

on

ds

Tri

pp

ing

tim

e

Multiple of rated current

© A

BB

ST

OT

Z K

ON

TA

KT

DE

ST

O/X

2 R

H -

6

MCB tripping characteristics

““D"-characteristicD"-characteristic

acc. EN 60898 rsp. IEC 898: standard for acc. EN 60898 rsp. IEC 898: standard for miniature circuit breakers to be used in miniature circuit breakers to be used in residential or similar applicationsresidential or similar applications

40 I1

40 I2

I3

I4

Thermal non tripping: 1,13 x In

Thermal tripping: 1,45 x In

Magnetic non tripping: 10 x In

Magnetic tripping: 20 x In

Applications:•high duty applications with very high starting or inrush currents but low loop impendance

40

0,04

120

20

10

64

2

1

20

40

10

4

2

1

0,60,4

0,2

0,1

0,06

0,02

0,011 1,5 2 3 4 5 6 8 10 15 20 30

6

60

D

min

ute

ss

ec

on

ds

Tri

pp

ing

tim

e

Multiple of rated current

© A

BB

ST

OT

Z K

ON

TA

KT

DE

ST

O/X

2 R

H -

7

MCB tripping characteristics

"B,C;D"-characteristics"B,C;D"-characteristics

acc. EN 60898 rsp. IEC 898: Standard for acc. EN 60898 rsp. IEC 898: Standard for miniature circuit breakers to be used in miniature circuit breakers to be used in residential or similar applications.residential or similar applications.

• For low duty installations• Rough leveled features for average applications• Restricted thermal protection, allowing : 1,45 x In • Extreme high of „D“ characteristic may lead to delayed tripping time, damaging conductors and equipment• Using „D“, low loop impedances, meaning larger cross sections of conductors is a „must“.

I3

I4

40

0,04

120

20

10

64

2

1

20

40

10

4

2

1

0,60,4

0,2

0,1

0,06

0,02

0,011 1,5 2 3 4 5 6 8 10 15 20 30

6

60

DCB

min

ute

ss

ec

on

ds

Tri

pp

ing

tim

e

Multiple of rated current

© A

BB

ST

OT

Z K

ON

TA

KT

DE

ST

O/X

2 R

H -

8

MCB tripping characteristics

““STOTZ“STOTZ“„„Z“„K“characteristicsZ“„K“characteristics

acc. EN 60947-2 rsp. IEC 947-2:acc. EN 60947-2 rsp. IEC 947-2:standard for industrial switchgearstandard for industrial switchgear

„The tailormade solution for commercial and industrial applications“

40

0,04

120

20

10

64

2

1

20

40

10

4

2

1

0,60,4

0,2

0,1

0,06

0,02

0,011 1,5 2 3 4 5 6 8 10 15 20 30

6

60

DCBZ K

min

ute

ss

ec

on

ds

Tri

pp

ing

tim

e

Multiple of rated current

Compared to tripping characteristics „B“,“C“, „D“ the STOTZ characteristics „K“ and „Z“offer a higher degree of protection.

This means a higher degree of safety

in both, planning and operation

© A

BB

ST

OT

Z K

ON

TA

KT

DE

ST

O/X

2 R

H -

9

MCB tripping characteristics

““Z"-characteristicZ"-characteristic

acc. EN 60947-2 rsp. IEC 947-2:acc. EN 60947-2 rsp. IEC 947-2:standard for industrial switchgearstandard for industrial switchgear

40 I1

40 I2

I3

I4

Thermal non tripping: 1,05 x In

Thermal tripping: 1,2 x In

Magnetic non tripping: 2 x In

Magnetic tripping: 3 x In

A sensitive characteristic to protect highly sensitive equipment such as:

•0,14mm2 cable sets•applications with limit switches•reed contacts in burglar alarm systems•sensor technology•actuators in bus systems•printed boards with its semiconductors

40

0,04

120

20

10

64

2

1

20

40

10

4

2

1

0,60,4

0,2

0,1

0,06

0,02

0,011 1,5 2 3 4 5 6 8 10 15 20 30

6

60

DCBZ

min

ute

ss

ec

on

ds

Tri

pp

ing

tim

e

Multiple of rated current

© A

BB

ST

OT

Z K

ON

TA

KT

DE

ST

O/X

2 R

H -

10

MCB tripping characteristics

40

0,04

120

20

10

64

2

1

20

40

10

4

2

1

0,60,4

0,2

0,1

0,06

0,02

0,011 1,5 2 3 4 5 6 8 10 15 20 30

6

60

DCBK

““K"-characteristicK"-characteristicacc. EN 60947-2 rsp. IEC 947-2:acc. EN 60947-2 rsp. IEC 947-2:standard for industrial switchgearstandard for industrial switchgear

40 I1

40 I2

I3

I4

Thermal non tripping: 1,05 x In

Thermal tripping: 1,2 x In

Magnetic non tripping S270: 8 x In

Magnetic tripping S270:12 x In

Magnetic non tripping S280: 10 x In

Magnetic tripping S280:14 x In

I3

I4

The right choice for high duty applicationwith high starting or inrush currents:

•Motors, fan sets•Power supply units: i.e 24V DC supply for intelligent building automation systems •Charging sets; i.e for electrical forklift trucks•Extra low voltage lamps, high performance tools, electronic ballasts•Welding- and control power transformer

min

ute

ss

ec

on

ds

Tri

pp

ing

tim

e

Multiple of rated current

© A

BB

ST

OT

Z K

ON

TA

KT

DE

ST

O/X

2 R

H -

11

MCB tripping characteristics