66kV sub transmission line - earth potential rise
66kV sub transmission line - earth potential rise
(OP)
Hi All,
I am in a situation where a the distributor's 66kV line reticulates overhead through what is proposed to be my client's property.
The utility needs a 30m easement under the line. My client plans to install some underground piping (metal) under the lines in the easement. Ignoring the fact that, obviously, they are not allowed to build in the easement, what potential do you see for earth potential rise problems? Obviously I am talking about the case where the 66kV may drop to the ground.
The protection won't operate for around 5 or 6 seconds. Additionally there are many control systems and earth-sheathed cables on the site.
I don't have a good understanding of the possible problems with earth potential rise in a situation like this and I would be greatful for a description.
thanks.
I am in a situation where a the distributor's 66kV line reticulates overhead through what is proposed to be my client's property.
The utility needs a 30m easement under the line. My client plans to install some underground piping (metal) under the lines in the easement. Ignoring the fact that, obviously, they are not allowed to build in the easement, what potential do you see for earth potential rise problems? Obviously I am talking about the case where the 66kV may drop to the ground.
The protection won't operate for around 5 or 6 seconds. Additionally there are many control systems and earth-sheathed cables on the site.
I don't have a good understanding of the possible problems with earth potential rise in a situation like this and I would be greatful for a description.
thanks.






RE: 66kV sub transmission line - earth potential rise
The protection clearing time you've given is also extraordinarily slow for 66kV.
Regards
Marmite
RE: 66kV sub transmission line - earth potential rise
Any dangers locally from earth potential rise will be insignificant compared to the danger of the live 66 kV line on the ground.
RE: 66kV sub transmission line - earth potential rise
Yes well apparently the line is quite far from the substation and the protection is "not very good"
Anyway, surely every site that is near a power line would be subject to EPR problems should a power line fall to the ground. I have to say I don't understand the EPR problem at all - could someone help me out?