Why stones are used in electrical substation instead of sand or grass?

Reasons for using Stones is used in Electrical Switchyard & Transformer Yard: Stones in the substation is provided to reduce the step potential and touch potential when operators work on switch yard. So Stones/Gravel is provided to protect from fire when oil spillage takes place.

Why do we put gravel in substation?

Step and Touch Potential; Step Potential – It is the potential developed between the two feet on the ground of a man or animal when short circuit occurs. That is why substations uses gravel/stones to reduce the step potential and touch potential when operators work on switchyard.

Why stones are used in electrical substation?

Pebbles and stones are more shock resistant as compared to grass and sand therefore, it will reduce the vibration in the transformer (caused by Magnetostriction in core) and special cases like earthquakes etc. Stone and gravels increase the resistance of soil which leads to reduce the limit of touch and step potential.

What is earthing used for?

Earthing is used to protect you from an electric shock. It does this by providing a path (a protective conductor) for a fault current to flow to earth. It also causes the protective device (either a circuit-breaker or fuse) to switch off the electric current to the circuit that has the fault.

Which is used in substation?

The Substations are mainly used to convert AC (alternating current) to DC (direct current). Some types of substations are tiny in size with an inbuilt transformer as well as related switches. Other types of substations are very huge with different types of transformers, equipment, circuit breakers, and switches.

Which of the following instrument transformer is used in substations?

Current transformers
The current transformer presents a negligible load to the primary circuit. Current transformers are the current-sensing units of the power system and are used at generating stations, electrical substations, and in industrial and commercial electric power distribution.

What type of transformer is used in substation?

Substation transformers are most often offered with one of 3 different fluids: Mineral oil or silicone transformer oil. Primary voltages of a substation transformer usually ranges from 2.4 kV to 69 kV in 225 through 20,000 kVA sizes, but 600 volt through 35 kV secondary voltage ratings are also available.

Why are special stones used in electrical substations instead of sand?

Stones are used instead of sand or grass in Electrical substations (Switch yards) because of following reasons: 1. During Short circuit, Step and Touch potential increase. Step potential : It is the potential developed between the two feet on the ground of a man or animal when short circuit occurs.

Why stones is used in Electrical switchyard & transformer yard?

Reasons for using Stones is used in Electrical Switchyard & Transformer Yard: Stones in the substation is provided to reduce the step potential and touch potential when operators work on switch yard. Step and touch potential occurs due to the short circuit current flows on the conductor.

Why is the potential in a switchyard substation always high?

In switch-yard substation potential is always high. And in condition of any fault or short circuits the potential increase abruptly. Touch potential and step potential area also increase. {Step potential : It is the potential developed between the two feet on the ground of a man or animal when short circuit occurs.

What are the advantages of using stone in construction?

Stone increase 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.