1. The supplier or user shall cause -
a. The minimum clearances of electric conductors and other wires of power lines, excluding overhead service connections and line conductors having a voltage not exceeding 1.1 kV r.m.s. consisting of insulated wire of a type which complies with a safety standard incorporated for this purpose in these regulations under section 36 of the Act, to be not less than the clearances indicated in the following table:
|
|
|
Minimum clearance in metres | ||||
|
Max voltage for which insulation is designed kV r.m.s phase to phase cradles. |
Minimum safety clearance |
Above ground outside townships |
Above ground in townships |
Above roads, railways, tramways |
To communication lines, power lines, |
To buildings & structures not part of power lines. |
|
1.1 or less |
- |
4.9 |
5.5 |
6.1 |
0.6 |
3.0 |
|
7.2 |
0.15 |
5.0 |
5.5 |
6.2 |
0.7 |
3.0 |
|
12 |
0.20 |
5.1 |
5.5 |
6.3 |
0.8 |
3.0 |
|
24 |
0.32 |
5.2 |
5.5 |
6.4 |
0.9 |
3.0 |
|
36 |
0.43 |
5.3 |
5.5 |
6.5 |
1.0 |
3.0 |
|
48 |
0.54 |
5.4 |
5.5 |
6.6 |
1.1 |
3.0 |
|
72 |
0.77 |
5.7 |
5.7 |
6.9 |
1.4 |
3.2 |
|
100 |
1.00 |
5.9 |
5.9 |
7.1 |
1.6 |
3.4 |
|
145 |
1.45 |
6.3 |
6.3 |
7.5 |
2.0 |
3.8 |
|
245 |
1.85 |
6.7 |
6.7 |
7.9 |
2.4 |
4.2 |
|
300 |
2.35 |
7.2 |
7.2 |
8.4 |
2.9 |
4.7 |
|
362 |
2.90 |
7.8 |
7.8 |
9.0 |
3.5 |
5.3 |
|
420 |
3.20 |
8.1 |
8.1 |
9.3 |
3.8 |
5.6 |
|
800 |
5.50 |
10.4 |
10.4 |
11.6 |
6.1 |
8.5 |
|
533 kV d.c.* |
3.70 |
8.6 |
8.6 |
9.8 |
4.3 |
6.1 |
* Maximum voltage to earth for which insulation is designed.
Provided that these figures are base on the assumption that clearances shall be determined for a minimum conductor temperature of 50°C and a swing angle corresponding to wind pressure of 500 Pa: Provided further that where under normal conditions power line conductors operate at a temperature above 50°C, the clearance at the higher temperature at which the conductors operate shall be in accordance with the clearance indicated in the table;
b. the clearances of conductors and other wires over the normal high-water level of power lines crossing over water to be not less than the values for power lines above the ground outside townships: Provided that if the owner of the land on which the water is situated requires a greater clearance and no agreement can be reached, the dispute shall be referred to the chief inspector for a decision; and
c. the distance of any power line from an explosives magazine to comply with the requirements of the Explosives Act, 1956 (Act 26 of 1956).
c. No person shall construct any road, railway, tramway, communication line, other power line, building or structure or place any material or soil under or in the vicinity of a power line which will encroach on the appropriate minimum clearances prescribed in terms of subregulation (1).
3. No person shall encroach in person or with objects on the minimum safety clearances prescribed in subregulation (1) or require or permit any other person to do so except by permission of the supplier or user operating the power line.
4. The supplier or user, of power lines shall control vegetation in order to prevent it from encroaching on the minimum safety clearance of the power lines and the owner of the vegetation shall permit such control.