Testing ground resistance of interconnected ground grid
Testing ground resistance of interconnected ground grid
(OP)
Hi,
We have been ask to test the ground grid of an existing petrochemical plant.
The plant have 2 exterior substations, and a lot of interior substation.
The exterior substations are interconnected with a lot of thing, like building, and it's nearly impossible to isolate their ground grid. Also, there's a railroad close to the substations that will probably affect the result.
We read that in this situation, the touch potential measurement is a good solution. See the last section of the document:
h ttp://www. dranetz-bm i.com/pdf/ groundprin ciples.pdf
So, we would like to do this test for the 2 exteriors substations, and do a continuity test of the ground conductor for all the interior substations.
Is there any other and better option that we can do. The client doesn't really have an idea of what he want to be tested, it's more like a demand of his insurance company for safety. We would like to do the best we can to insure personal safety, without exorbiting cost.
Thanks for your help
We have been ask to test the ground grid of an existing petrochemical plant.
The plant have 2 exterior substations, and a lot of interior substation.
The exterior substations are interconnected with a lot of thing, like building, and it's nearly impossible to isolate their ground grid. Also, there's a railroad close to the substations that will probably affect the result.
We read that in this situation, the touch potential measurement is a good solution. See the last section of the document:
h
So, we would like to do this test for the 2 exteriors substations, and do a continuity test of the ground conductor for all the interior substations.
Is there any other and better option that we can do. The client doesn't really have an idea of what he want to be tested, it's more like a demand of his insurance company for safety. We would like to do the best we can to insure personal safety, without exorbiting cost.
Thanks for your help






RE: Testing ground resistance of interconnected ground grid
STEP AND TOUCH POTENTIAL TESTS ON LARGE SYSTEMS.
If I were you I would measure the ground resistance at major locations and ignore the interconnection whose contribution is small.This would indicate any problem areas. IEEE 665 does not recommend connecting the switchyard grid to a power plant grid if more than 200 m apart.This standard although for power plants, has some good guidlines, including rail roads tracks.