MI 3152(H) EurotestXC (2,5 kV)
Appendix A
– Impedance tables
116
Appendix A - Impedance tables
A.1 Impedance tables
- for fuses, circuit-
breakers and RCBO’s
The maximum loop impedances in the following tables are used for the pass/fail limits for
the measurement of loop impedance. The 1.0 Z factor setting maximum loop impedances
are in accordance with BS 7671 Amendment No. 3: 2015.
Fuses to BS 88-2
– fuse systems E & G
Fuses to BS 88-3
– fuse system C
Rated
current
(A)
Z factor setting
Rated
current
(A)
Z factor setting
1.0
0.8
1.0
0.8
Disconnection time (s)
Disconnection time (s)
0.4
5
0.4
5
0.4
5
0.4
5
Max. loop impedance (
)
Max. loop impedance (
)
2
33.10
44.00
26.48
35.20
5
9.93
14.6
7.94
11.68
4
15.60
21.00
12.48
16.80
16
2.30
3.90
1.84
3.12
6
7.80
12.00
6.24
9.60
20
1.93
3.20
1.54
2.56
10
4.65
6.80
3.72
5.44
32
0.91
1.60
0.73
1.28
16
2.43
4.00
1.94
3.20
45
1.00
0.80
20
1.68
2.80
1.34
2.24
63
0.68
0.54
25
1.29
2.20
1.03
1.76
80
0.51
0.41
32
0.99
1.70
0.79
1.36
100
0.38
0.30
40
1.30
1.04
50
0.99
0.79
63
0.78
0.62
80
0.55
0.44
100
0.42
0.34
125
0.32
0.26
160
0.27
0.22
200
0.18
0.14
Fuses to BS 3036
Fuses to BS 1362
Rated
current
(A)
Z factor setting
Rated
current
(A)
Z factor setting
1.0
0.8
1.0
0.8
Disconnection time (s)
Disconnection time (s)
0.4
5
0.4
5
0.4
5
0.4
5
Max. loop impedance (
)
Max. loop impedance (
)
5
9.10
16.80
7.28
13.44
3
15.60
22.00
12.48
17.60
15
2.43
5.08
1.94
4.06
13
2.30
3.64
1.84
2.91
20
1.68
3.64
1.34
2.91
30
1.04
2.51
0.83
2.01
45
1.51
1.21
60
1.07
0.86
100
0.51
0.41
