why aggregate is placed all around substation ground.
- 9 Answers
- 12762 Views
- I also Faced
- E-Mail Answers
Answer Posted / brandon
A thin layer of aggregate above a low-resistance substrate
(or embedded ground grid if the substrate is a
high-resistance material) provides a high resistance between
the bottom of a human's feet and the substrate. This will
lower the upward current through the body considerably in
the event of a L-G fault compared to the equipment bonds
(assuming equipment is properly bonded to the substation
ground). However, since the aggregate is thin relative to
the ground plane, it does not impede the shape of the
equipotential voltage field of the substation and thus
reduces the step potential by keeping a consistant voltage
grading.
Aggregate is not for lightening as lightening protection is
provided through overhead shield conductors bonded to the
ground grid or substrate.
If oil-filled equipment fails and and a fire is started, the
aggregate also has a quenching effect by distributing the
oil within the void spaces and creating small pockets
instead of a large surface of oil.
See IEEE 80 for the complete explanation.
| Is This Answer Correct ? | 1 Yes | 0 No |
Post New Answer View All Answers
in indoor type circuit breakers why only the corner breaker trips specially during cold season. What is the reason.
How can you calculate the size of the down conductor cable for the lightning protection system. Is 70mm2 cable can replace 95mm 2 bare copper cable when the copper tape size is 25Wx3 thk mm.
What is expention fastener (Fan)
what is method for testing CT
why we need to us lenz's law for synchornous motor
How short circuit MVA(Fault MVA) in a power system calculated for calculating number of earth plates ?
what is the usage of microcontroller in the panel board?
what is the use of permanent magnet generator in exciter
what is the diference between the 4pole & 6pole DC Motors & what is advantage 6pole over the 4pole ?
is it necessary to earth the rmu before cutting off the transformer winding?if yes why?
Atwhat condition reverse power relay will act?
What will be the fault current of any system when its generation is 10% of BASE generation( FUll Load )?Will is 10% or the same as full base calculation?
prove that power consumed in 3 phase delta system is 3 times as compared to 3 phase star system
The electrical energy required to raise the tempreture of a given amount water is 200 kwh. If the heat losses are 20%, the energy required is?
The SFC of an engine is 0.25 kg/kW hr. when the fuel used has a calorific value of 36000 kJ/kg. the thermal efficiency of the engine is
