Reducing Step and Touch potential 1

[ks100]

Hi All,

I'm looking for cost effective ways to reduce step and touch potential at a brownfield site.
Adding a higher resistivity top layer (i.e. blue metal) or asphalting is not an option, so I would like to consider limiting the incoming fault current instead on the LV line.

The application of an isolation transformer has been raised, but chatting with the a supplier, I doubt it would work. Agree/disagree?
Alternatively, I was looking at a current limiter.

Thoughts?

 

[cuky2000]

Reducing the clearing time is also an effective way addressing the safety issue for grounding application.

 

[jghrist]

If you have a ground wire with the source, you need to determine how much of the ground fault return current flows through the earth and how much through the ground wire. In most low voltage sources, practically all of the return current flows through the ground wire. Only the portion that flows through the earth contributes to touch- and step-voltages.