Catalog Add On: BETA Low-Voltage Circuit Protection ...

4
BETA Protecting
SITOR Semiconductor Fuses
SITOR, LV HRC design
Series 3NC3 3
Size: 3
Operational class: aR
Rated voltage: 800 V AC, 1000 V AC
Rated current: 630 ... 1250 V
Time/current characteristic curves diagram Let-through characteristics
Virtual pre-arcing time t vs [s]
10 4
6
4
2
10 3
6
4
2
10 2
6
4
2
10 1
6
4
2
10 0
6
4
2
10 -1
6
4
2
10 -2
6
4
2
-3
10
Correction factor k A for breaking I 2 t value Peak arc voltage
2
2
Correction factor for breaking I t -value [A s]
1
0,8
0,6
0,4
0,2
4/16
Permissible
overload
Prearcing
1250 A
1100 A
1000 A
900 A
800 A
710 A
630 A
2 10 2 4 3 6 8 10 2 4 6 8 10 4 2 4 6 8 10 5
Prospective short-circuit current Ip
[A]
U n = 800 V
U n = 1000 V
0 200 400 600 800 1000
Recovery voltage U w [V]
Siemens ET B1 AO · 2008, Characteristic curves
I2_13407
© Siemens AG 2007
I2_13406
c [A]
I
Let-through current
[V]
Û s
Peak arc voltage
10 5
6
4
2
10 4
6
4
2
1250 A
1100 A
1000 A
900 A
800 A
710 A
630 A
3
10
10 3 2 4 6 8 10 4 2 4 6 8 10 5
Prospective short-circuit current Ip
[A]
2600
2400
2000
1600
1200
800
400
0
0 200 400 600 800 1000 1200
Recovery voltage U w [V]
I2_13408
I2_13409