Substation : grounding resistance
Substation : grounding resistance
(OP)
Hi,
I've been trying to find any standard on the net (IEC, NEM, etc) about the maximum (or minimum) value of grounding resistance for a substation.
I appriciate any help.
Thank you.
I've been trying to find any standard on the net (IEC, NEM, etc) about the maximum (or minimum) value of grounding resistance for a substation.
I appriciate any help.
Thank you.






RE: Substation : grounding resistance
RE: Substation : grounding resistance
Some utilities impose their own limits on grounding resistance. If you have communication lines coming into the station, ground resistance may have to be limited to keep the ground potential rise (GPR) within the limits of the communication line interface.
RE: Substation : grounding resistance
RE: Substation : grounding resistance
A good grounding system provides a low resistance to remote earth in order to minimize the GPR. For most
transmission and other large substations, the ground resistance is usually about 1 Ohm or less. In smaller distribution
substations, the usually acceptable range is from 1 Ohm to 5 Ohm, depending on the local conditions.
RE: Substation : grounding resistance
Less than 0.5 Ohm for substations (transmission and distribution), less than 10 Ohm for individual groundings (like earthing rod for OHTL towers for example).
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It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant
RE: Substation : grounding resistance
If you like to know a bit more you should try link
http://www.tlc-direct.co.uk/Book/3.4.2.htm
and of course legendary site (I suggest reading all posts) considering what you should not do when doing human ohm resistance test:
htt