14
Note:
▲
When the protective device is a residual current device
(RCD), Ia is the rated residual operating current I
n.
For instance in a TN system with a nominal mains voltage of
Uo = 230V protected by type gG fuses the Ia and maximum
Zs values could be:
If the prospective fault current is measured, its value must be
higher than the Ia value of the protective device concerned.
Rating
Disconnecting Time 5s Disconnecting Time 0.4s
(A)
Ia (A)
Zs (
Ω
)
Ia (A)
Zs (
Ω
)
6
28
8.20
47
4.90
10
46
5.00
82
2.80
16
65
3.60
110
2.10
20
85
2.70
147
1.56
25
110
2.10
183
1.25
32
150
1.53
275
0.83
40
190
1.21
320
0.72
50
250
0.92
470
0.49
63
320
0.71
550
0.42
80
425
0.54
840
0.27
100
580
0.39
1020
0.22
Fig 7
