Table 2 Comparison of impulse impedance of more than one vertical grounding rod with and without consideration of mutual coupling for \(\rho =\) 100 Ω.m
Current peak (kA) | Two vertical rods | Four vertical rods | ||||
|---|---|---|---|---|---|---|
Impulse impedance (Ω) | Relative difference (in %) | Impulse impedance (Ω) | Relative difference (in %) | |||
With mutual coupling | Without mutual coupling | With mutual coupling | Without mutual coupling | |||
10 | 13.40 | 13.00 | 2.98 | 8.00 | 7.80 | 2.50 |
20 | 12.10 | 11.60 | 4.13 | 7.60 | 7.30 | 3.94 |
50 | 9.20 | 8.70 | 5.43 | 7.30 | 700 | 4.11 |
100 | 8.20 | 7.70 | 6.10 | 6.80 | 6.40 | 5.88 |