Transcript Choosing the right nominal current In

MCB´s Knowhow
© ABB STOTZ KONTAKT - 1
07-05-2002
ABB STOTZ KONTAKT
MCB
Tripping –
Characteristics
ABB
MCB tripping characteristics
120
60
40 1
I
I
40 2
Basics:
20
10
6
4
General Time / current relation
2
1
40
1. Thermal tripping
20
10
2. Electromagnetic tripping
6
4
2
1
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I
- Thermal non-tripping current rsp.
Low test current
I
- Thermal tripping current rsp.
High test current
I3
- Electromagnetic non-tripping current
rsp. test current: hold surges of I3
I4
- Electromagnetic tripping current
rsp. test current: trip at least at I4
40 1
0,6
0,4
40 2
0,2
0,1
0,06
0,04
I3
I4
0,02
0,01
1
1,5
2
3
4 5 6
8 10
15 20
30
ABB
MCB tripping characteristics
120
60
40
Basics:
minutes
20
10
6
4
Magnetic tripping:
AC, 100 Hz
= factor 1.1
AC, 200 Hz
= factor 1.2
AC, 400 Hz
= factor 1.5
DC
= factor 1.5
2
1
40
20
10
Thermal tripping is not dependent
6
4
on frequency
1
DC-current increases the
magnetic tripping values
by factor 1,5
0,6
0,4
Tripping time
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2
0,2
AC
0,1
0,06
0,04
DC
0,02
0,01
1
1,5
2
3
4 5 6
8 10
Multiple of rated current
15 20
30
ABB
MCB tripping characteristics
120
60
40 1
40
I
"B"-characteristic
I
40 2
20
acc. EN 60898 rsp. IEC 898: standard for
miniature circuit breakers to be used in
residential or similar applications
minutes
10
6
4
2
1
40
I
Thermal non tripping: 1,13 x In
I
Thermal tripping:
6
4
I3
Magnetic non tripping: 3 x In
2
I4
Magnetic tripping:
40 1
20
40 2
1
0,6
0,4
Tripping time
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10
5 x In
Applications:
B
0,2
1,45 x In
•low duty applications without
starting or inrush currents
0,1
0,06
0,04
0,02
I3
0,01
1
1,5
2
I4
3
4 5 6
8 10
15 20
Multiple of rated current
30
ABB
MCB tripping characteristics
120
“C"-characteristic
60
40
20
acc. EN 60898 rsp. IEC 898: standard for
miniature circuit breakers to be used in
residential or similar applications
minutes
10
6
4
2
1
40
I
Thermal non tripping: 1,13 x In
I
Thermal tripping:
6
4
I3
Magnetic non tripping: 5 x In
2
I4
Magnetic tripping:
40 1
20
40 2
1
0,6
0,4
Tripping time
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10
10 x In
Applications:
C
0,2
1,45 x In
•low duty applications with medium
starting or inrush currents and low
loop impendance
0,1
0,06
0,04
0,02
0,01
1
1,5
2
3
4 5 6
8 10
15 20
Multiple of rated current
30
ABB
MCB tripping characteristics
120
“D"-characteristic
60
40
20
acc. EN 60898 rsp. IEC 898: standard for
miniature circuit breakers to be used in
residential or similar applications
minutes
10
6
4
2
1
40
I
Thermal non tripping: 1,13 x In
I
Thermal tripping:
6
4
I3
Magnetic non tripping: 10 x In
2
I4
Magnetic tripping:
40 1
20
40 2
1
0,6
0,4
Tripping time
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10
20 x In
Applications:
D
0,2
1,45 x In
•high duty applications with very high
starting or inrush currents but low
loop impendance
0,1
0,06
0,04
0,02
0,01
1
1,5
2
3
4 5 6
8 10
15 20
Multiple of rated current
30
ABB
MCB tripping characteristics
120
"B,C;D"-characteristics
60
40
20
acc. EN 60898 rsp. IEC 898: Standard for
miniature circuit breakers to be used in
residential or similar applications.
minutes
10
6
4
2
1
40
• For low duty installations
• Rough leveled features for
average applications
• Restricted thermal protection,
allowing I3 : 1,45 x In
• Extreme high I4 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“.
20
10
6
4
1
0,6
0,4
Tripping time
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2
BC D
0,2
0,1
0,06
0,04
0,02
0,01
1
1,5
2
3
4 5 6
8 10
15 20
Multiple of rated current
30
ABB
MCB tripping characteristics
120
“STOTZ“
„Z“„K“characteristics
60
40
20
minutes
10
6
4
acc. EN 60947-2 rsp. IEC 947-2:
standard for industrial switchgear
2
1
40
„The
tailormade solution for
commercial and industrial
applications“
20
10
6
4
1
Z
0,6
0,4
Tripping time
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2
0,2
K
Compared to tripping characteristics „B“,“C“, „D“
the STOTZ characteristics „K“ and „Z“
offer a higher degree of protection.
BC D
0,1
This means a higher degree of safety
0,06
0,04
in both, planning and operation
0,02
0,01
1
1,5
2
3
4 5 6
8 10
15 20
Multiple of rated current
30
ABB
MCB tripping characteristics
120
“Z"-characteristic
60
40
20
acc. EN 60947-2 rsp. IEC 947-2:
standard for industrial switchgear
minutes
10
6
4
I
Thermal tripping:
I3
Magnetic non tripping: 2 x In
I4
Magnetic tripping:
1
40
40 2
10
6
4
2
1
Z
0,6
0,4
Tripping time
Thermal non tripping: 1,05 x In
40 1
20
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I
2
0,2
BC D
•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
0,06
0,04
0,02
0,01
1,5
2
3
3 x In
A sensitive characteristic to
protect highly sensitive equipment such as:
0,1
1
1,2 x In
4 5 6
8 10
15 20
Multiple of rated current
30
ABB
MCB tripping characteristics
120
“K"-characteristic
60
40
acc. EN 60947-2 rsp. IEC 947-2:
standard for industrial switchgear
Thermal non tripping:
1,05 x In
40 I1
20
minutes
10
6
4
2
20
10
6
4
2
1
Thermal tripping:
1,2 x In
I3
I4
Magnetic non tripping S270:
Magnetic tripping S270:
8 x In
12 x In
I3
I4
Magnetic non tripping S280:
Magnetic tripping S280:
10 x In
14 x In
The right choice for high duty application
with high starting or inrush currents:
K
0,6
0,4
Tripping time
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I
40 2
1
40
BC D
0,2
0,1
0,06
0,04
0,02
0,01
1
1,5
2
3
4 5 6
8 10
15 20
Multiple of rated current
30
•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
ABB
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MCB tripping characteristics
ABB