Table 7.
Coefficients of seasonal changes in equivalent soil resistivity according to2.
| Type of ground electrode | The value of the correction factor kp depending on the degree of soil moisture | ||
|---|---|---|---|
| Dry ground 1) | Damp ground 3) | Wet ground 2) | |
| Horizontal ground electrode buried at a depth of 0.6–1.0 m | 1.4 | 2.2 | 3.0 |
| Vertical ground electrode with a length of 2.5 m to 5 m | 1.2 | 1.6 | 2.0 |
| Vertical ground electrode with a length of more than 5 m | 1.1 | 1.2 | 1.3 |
| Compound ground electrode | It is recommended to determine the influence of the resistance of horizontal and vertical ground electrodes on the resultant groundingresistance | ||
1) Ground can be classified for the period from June to September inclusive. The exception is the three days after long-term heavy rainfall.
2) Ground can be classified in a period beyond the defined period in point 1).
3) Ground is classified in this category if the conditions cannot be assigned to cases 1) and 2).