Why We Use Stone in Outdoor Electrical Substation?

Electrical Earthing System, Electrical Substation No Comments

Ok, you don’t need to be an Electrical Engineer to ask yourself that, Why They Use Stone in Outdoor Electrical Substation? But if you are an Electrical Engineer then you may need to answer this type of question to anyone.

Did I get one question like this from my top management that, Why We Will Use 2-2.5 inch size Stone and Why Not 0.5-1 inch Stone? In this post, I will discuss “Why We Use Stone in Outdoor Electrical Substation?”

Explanation – Why We Use Stone in Outdoor Electrical Substation?

First of all, we use stone in our electrical substation for reducing the Ground Potential Rise (GPR) and in electrical engineering, it also called Earth Potential Rise (EPR) and it occurs when a large current flows to earth through earth grid impedance.

Stone increase the resistance of soil, for this reason, step potential, and the touch potential limit decrease. When people are working in substations stone reduces the possibility of electric shock during work.

Generally when we design an electrical substation that time step potential and touch potential is one of our first priorities. Because there is no compromise with safety. If there is any small glitch then the percentage of electrical shock will increase and we really don’t want that to happen with us.

Step Potential: The amount of potential present between a two or four-legged animal is called step potential. If there is imbalance potential on substation areas and if we stand that place then between our two legs we will have a potential difference and this is the real step potential.

Step Potential and Touch Potential

Touch Potential: When a person stands on the ground and touches a machine then the potential between his hand and leg called touch potential.

Now there are some others and different benefits that we can get by using stone in an electrical substation.

By using stone in substation grass and weed does not grow, so it remains nice and clean for perfect visual observation from outside.
Stone reduces the potential movement of wild animals like snakes, frogs, rats, etc. For this reason, it decreases the risk of short circuits when the substation is operational.
Rainwater can drop fast so that it does make any mud inside the substation.
If there is any oil fall from power transformers or circuit breakers then oil does not stay there if the substation ground is covered by stone. But it also creates some problems. If you can’t see any oil under the transformer when there is an oil leakage then you may think everything is alright. So check the transformer oil reserve tank indicator during the physical inspection.
If we compare with concrete casting using stone in the substation is cheap and remains clean.
Stone can carry much higher capacity weight.

Now if you find this post useful then please share it with your friends. Your support is very important to us. If you want you can join us and share your knowledge with others. Thanks!