how to calculate no. of earthing pits and their diamensions?
no. of lightning arrester rods which are required to
protect a building of 35 mtr and we calculate?
Answer Posted / william lobo
The number of earthing pits depends on the soil resistance.
We may require earth resistance of 1ohm or 3 ohms at the
most. To get this we will have to install at least 2 pits
and as per parallel formula i.e. 1/r1+1/r2+1/r3= 1/R. We
have to keep on increasing the number of earth pits till we
get the required value for R=1 or 3 as per requirement.
| Is This Answer Correct ? | 14 Yes | 6 No |
Post New Answer View All Answers
What is the difference in calculating size of AC cables compared to calculating size of DC Cables? Usually DC Cables are larger than AC Cables although they have the same ampacity. Why is it?
I want to know all basics of electrical engineering
what is inter connected dc generator?
How much dc volt applied in cathodic protection system?
what will happen if there is a voltage leakage or current leakage in an electrical train
A power transformer 4MVA/11KV/0.415Kv has been out of use in 12years. what maintenance actions/test need to be carried out before energizing.
When calculating the speed of a rotor required for a particular frequency of synchronous generator we use the equation 60f/p Is this p is the number of pole pairs of rotor & do we consider the number of pole pairs in the stator is 1?
do we use links in a dc circuit?if so what s its use in it?
what is circuit breaker in transfomer and where it used
where are the circulat the diesel in DG parts name with pictue
could you measure current in parallel?
How will you justify IR value and Charging voltage of any motor,transformer and Cables.......???? . . . . . . . . Plz tell me any body Baljeet Singh, engineer_89@refiff.com
How does a tertiary winding filter harmonic(espcially 3rd one) from entering into load system?
what is the defination of Cable database? What are the points are considered while preparing cable database? Is there any sample available for cable database?
A car's starter motor draws a current of 100 A at 12,0 V when starting the engine. The mechanical power required to turn the engine is 960 W. At what rate is energy from the battery converted to non-mechanical forms of energy?