I did some sums on the safe clearance distance for powerlines in my local area of Eyre Peninsula, SA.
A high number of the powerlines on Eyre Peninsula are attached to the older, shorter 9m poles. (many SWER lines, 19000v)
With areas on Eyre Peninsula getting into temperatures of 45-48 degrees or more at times, the powerlines droop in this extreme heat.
Currently, ETSA do not attend to this type of powerline unless it is drooping below 5.5m in height.
The illustration above is a calculation of our Header height, including tyres, aerials etc.
It shows clearly that we can easily exceed the safe clearance distance, especially in summer when the lines droop in the heat.
I guess the main thing to do is be aware of this scenario, especially when:
- Extending your auger to unload
- Travelling under powerlines with a full box
- Parking the machine to get out
- And when purchasing new machinery
It is surprising how close we actually come to this electricity risk.
Safe Clearance Distances as per the Electricity Regulations
2012:
Voltage
|
Clearance
distance in all directions (in metres)
|
Under 11 000 volts
|
0.6
|
19 000 volts (SWER)
|
0.9
|
33 000 volts
|
0.9
|
66 000 volts
|
1.4
|
132 000 volts
|
2.4
|
275 000 volts
|
3.2
|
330 000 volts
|
4.6
|
500 000 volts
|
5.5
|