Table of delimitation radius of free areas, controlled areas and risk zones.
Voltage range Nominal electrical installation in kV |
Rr – Delimitation radius in meter, between risk zone and controlled area |
Rc – Delimitation radius in meter, between controlled area and free area |
< 1 ≥ 1 e < 3 ≥ 3 e < 6 ≥ 6 e < 10 ≥ 10 e < 15 ≥ 15 e < 20 ≥ 20 e < 30 ≥ 30 e < 36 ≥ 36 e < 45 ≥ 45 e < 60 ≥ 60 e < 70 ≥ 70 e < 110 ≥ 110 e < 132 ≥ 132 e < 150 ≥ 150 e < 220 ≥ 220 e < 275 ≥ 275 e < 380 ≥ 380 e < 480 ≥ 480 e < 700 |
0,20 0,22 0,25 0,35 0,38 0,40 0,56 0,58 0,63 0,83 0,90 1,00 1,10 1,20 1,60 1,80 2,50 3,20 5,20 |
0,70 1,22 1,25 1,35 1,38 1,40 1,56 1,58 1,63 1,83 1,90 2,00 3,10 3,20 3,60 3,80 4,50 5,20 7,20 |
Figure 1 – Distances in the air radially demarcating the free areas, controlled areas and risk zones.
Figure 2. Distances in the air radially demarcating the free areas, controlled areas and risk zones, with interposition of surfaces of adequate physical separation.

ZL = Free are ZC = Controlled area, restricted to authorized workers ZR = Risk zone, restricted to authorized workers with techniques, tools, equipments appropriate to the task. PE = Point of energized installation SI = Insulating surface constructed with resistant material and endowed with all safety devices.