Mitigation of Transferred Potential
Mitigation of Transferred Potential
(OP)
Hello members,
It is an industry practice to separate two ground rods by 2 times the rod length
so that one is not influenced by the other. Similarly, to mitigate the transfer of GPR
as a transferred potential from SUB A to SUB B, instead of sharing a single ground grid for
both subs, is it acceptable to install two individual ground grids for SUB A & B separated by
minimum of 100m so that one grid is not influenced by the other?
Is there any any code or standard recommendation
It is an industry practice to separate two ground rods by 2 times the rod length
so that one is not influenced by the other. Similarly, to mitigate the transfer of GPR
as a transferred potential from SUB A to SUB B, instead of sharing a single ground grid for
both subs, is it acceptable to install two individual ground grids for SUB A & B separated by
minimum of 100m so that one grid is not influenced by the other?
Is there any any code or standard recommendation
RE: Mitigation of Transferred Potential
I'm not aware of a guide/standard that is direct to your question, however we can consider the measurement process for the Fall of potential in IEEE Std 81. Essentially your grids can be 3-6x the maximum grid dimension(s) away from so that they do not conductively couple.
With substation grounding systems there may be shield wires or neutrals that metallically connect grid A and B so this isolation may not be possible.
RE: Mitigation of Transferred Potential
RE: Mitigation of Transferred Potential
Since you wish to segregate based on the transferred potential via the earth itself, to achieve what you want, you must consider all connections to earth and possible parallel paths. The recommendation by @DBL-E is good, however you need to be considering using software modelling if you need a truly reliable answer.