KYORITSU 6050 - Manual (Page 18)

̶ 16 ̶
Note:
● For a distribution circuit a disconnection time not exceeding 5s is
permitted.
● When the protective device is a residual current device (RCD),la is the
rated residual operating current I⊿n.
For instance in a TN system with a nominal voltage of Uo =230V
protected by type gG fuses the la and maximum Zs values could be:
6
10
16
20
25
32
40
50
63
80
100
Ia(A)
28
46
65
85
110
150
190
250
320
425
580
Zs(Ω)
8.2
5
3.6
2.7
2.1
1.53
1.21
0.92
0.71
0.54
0.39
Ia(A)
47
82
110
147
183
275
320
470
550
840
1020
Zs(Ω)
4.9
2.8
2.1
1.56
1.25
0.83
0.72
0.49
0.42
0.27
0.22
Rating
(A)
Disconnecting time 5s Disconnecting time 0.4s
If the prospective fault current is measured, its value must be higher than the
la value of the protective device concerned.
On 200A PSC range, for Loop impedance lower than 5 ohm (PSC greater
than 50A approx 230V) is not possible to obtain an accurate PSC reading
even if the unit will give a result. In these cases, for accurate PSC tests,
please use the 2000A or 20kA ranges.