PRECAUTIONS TO BE TAKEN WHILE WORKING 3.5 PREVENTION OF ELECTROCUTION Digging in the vicinity of overhead power cables represents a serious hazard which could even lead to death by electrocution. When working near overhead cables, always observe the minimum safety distances specified by the authorities and all relevant accident pre- vention regulations. The minimum safety distance from underground power cables is determined by the type and thickness of the protective sheathing in which the cables are laid. The following are basic precautions which must be taken to avoid risk: 1 - Wear footwear with thick rubber or leather soles.
2 - Seek assistance from someone who can stand in a suitable position and give you directions to ensure that no part of the machine makes contact with power cables. 3 - Work slowly. 4 - Learn the first aid procedures to be applied in case of electrocution. 5 - Keep the telephone numbers of the local electricity board and the nearest first aid post in a handy and easily visible place. If by any chance the machine does make contact with power cables, remain in the cab until the electricity board has been contacted and the power supply to the cables has been cut off. Warn all persons in the area to maintain a safe distance from the machine and all working equipment.
Contact the electricity board before starting work to find out the voltage carried by the lines and the minimum safety distance from them. DANGER Minimum safety distances from overhead lines vary from one country to another depending on climate and humidity. The following table provides approximate distances. 15 Voltage of cables Minimum safety distance 1.0 kV (supply lines) 5 m 6.6 kV (2-3 insulators) 5.2 m 33 kV (min. 3 insulators) 5.5 m 66 kV (min. 6 insulators) 6 m 154 kV (min. 10 insulators) 8 m 275 kV (min. 19 insulators) 10 m