2.3.7 Electrical hazards in tree worker rescue
This section of the manual discusses the risks associated with undertaking a rescue in the vicinity of live electrical conductors .
It is critical to note that if the casualty or the tree they are in has become energised , or if there is no way to conduct the rescue without becoming too close to the conductors , the rescue cannot proceed until the conductors have been dropped or isolated . Vegetation can be highly conductive , so any vegetation in contact or close proximity to conductors may be extremely hazardous .
The purpose of this section of the manual is solely to discuss the risks associated with rescuing an injured tree worker who is outside of the Safe Approach Distance of conductors but who has injured themselves whilst performing tree work .
• If there is any possibility of live conductors on a rescue site , the conductors must be dropped or isolated before the rescue proceeds .
• If unsure regarding the proximity of conductors , contact the network authority whilst travelling to the incident and arrange for immediate isolation of the conductors .
Overview of utility tree work
A significant proportion of tree pruning and removal is conducted for vegetation management around conductors . Vegetation management is undertaken to ensure that trees , branches , and foliage do not contact , or come too close to , live conductors .
Vegetation does not have to touch the electrical conductors for damage to occur . An arc flash occurs when electrical current flows through an air gap between two conductors or between conductors and a pathway to earth . The arc reaches extremely high temperatures ; vegetation near the arc , or that has electrical current passing through it , will catch fire . In addition , there may be a pressure wave , flying debris and hearing damage .
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