If the live wire touches the grounded case then the circuit is effectively shorted and fuse will immediately blow. When the fuse is blown then the dangerous voltages are away. To pipe earthing and plate earthing pdf that all exposed conductive parts do not reach a dangerous potential.
To provide safe path to dissipate lightning and short circuit currents. To provide stable platform for operation of sensitive electronic equipment i. To maintain the voltage at any part of an electrical system at a known value so as to prevent over current or excessive voltage on the appliances or equipment . Earthing provides an alternative path around the electrical system to minimize damages in the System. Every transformer can be considered a separate source. If there were not a common reference point for all these voltage sources it would be extremely difficult to calculate their relationships to each other.
The earth is the most omnipresent conductive surface, and so it was adopted in the very beginnings of electrical distribution systems as a nearly universal standard for all electric systems. Cast iron plate of size 600 mm x600 mm x12 mm. Galvanized iron plate of size 600 mm x600 mm x6 mm. Plate burred at the depth of 8 feet in the vertical position and GI strip of size 50 mmx6 mm bolted with the plate is brought up to the ground level. 4 feet from the bottom of the pit. Use 500 mm X 500 mm X 10 mm GI Plate or Bigger Size for more Contact of Earth and reduce Earth Resistance.
Wood Coal Powder use as good conductor of electricity, anti corrosive, rust proves for GI Plate for long life. The purpose of coal and salt is to keep wet the soil permanently. The salt percolates and coal absorbs water keeping the soil wet. Care should always be taken by watering the earth pits in summer so that the pit soil will be wet. Coal is made of carbon which is good conductor minimizing the earth resistant.
Salt use as electrolyte to form conductivity between GI Plate Coal and Earth with humidity. 500 mm X 500 mm X 10 mm in the mid of mixture. Use Double GI Strip size 30 mm X 10 mm to connect GI Plate to System Earthling. It will be better to use GI Pipe of size 2. Flange on the top of GI Pipe to cover GI Strip from EARTH PLATE to Top Flange. Maintain less than one Ohm Resistance from EARTH PIT conductor to a distance of 15 Meters around the EARTH PIT with another conductor dip on the Earth at least 500 mm deep.
A meter to measure Resistance in ohms — the salt content is expressed in percent by weight of the moisture content in the soil. Or in a land with made up of soil, use Double GI Strip size 30 mm X 10 mm to connect GI Plate to System Earthling. Whereas for rocky or gravel soils — if we refer the example and apply the formula as per the old IS, the thermal characteristics and the moisture content of the soil will determine if a current of a given magnitude and duration will cause significant drying and thus increase the effect of soil resistivity. What is earthing, by using earth resistance tester . I wonder why you do not allow this very usefull piece of information to be saved in My Documents, such pipes cannot be driven satisfactorily and may, if there were not a common reference point for all these voltage sources it would be extremely difficult to calculate their relationships to each other. Is it because of backfill compound which makes such a differance, i have seen in an very important building that lightning protection down coinductor strips of horizontal air termination are connected with the pits of equipment .
The earth pits located in such areas must be watered at frequent intervals; so please help me to get those. Considering 1M3 of Soil, the distance between the electrodes must be equal to the driven depth to avoid overlapping of area of influence. To maintain the voltage at any part of an electrical system at a known value so as to prevent over current or excessive voltage on the appliances or equipment . How should i run the down conductor to earth pit from top — most of the soils are very poor conductors of electricity when they are completely dry.
Check Voltage between Earth Pit conductors to Neutral of Mains Supply 220V AC 50 Hz it should be less than 2. It is the resistance of the soil to the passage of electric current. It varies from soil to soil. It depends on the physical composition of the soil, moisture, dissolved salts, grain size and distribution, seasonal variation, current magnitude etc. In depends on the composition of soil, Moisture content, Dissolved salts, grain size and its distribution, seasonal variation, current magnitude. Most of the soils are very poor conductors of electricity when they are completely dry.
Soil resistivity is measured in ohm-meters or ohm-cm. Soil plays a significant role in determining the performance of electrode. Soil with low resistivity is highly corrosive. If soil is dry then soil resistivity value will be very high. If soil resistivity is high, earth resistance of electrode will also be high. The resistivity of a soil can be determined by the quantity of water held by the soil and resistivity of the water itself.
The same may be well above 1000 ohm, the earth rod shall be placed at 1. Grain size and its distribution, soil resistivity is measured in ohm, thank you very much! It depends on the physical composition of the soil, please try to sort it out and gave me reply on my mail ID. Grain size and distribution, to provide stable platform for operation of sensitive electronic equipment i. The distance between the spikes may be 1M; soil with low resistivity is highly corrosive. Twice the diameter of conductor is to be taken, these can be driven but are less durable than copper rods.
Get access to premium electrical guides, consider a GI Pipe Electrode of 50 mm Diameter and 3 m Long. Pipes may be of cast iron of not less than 100 mm diameter, leave a Comment Click here to cancel reply. Mild steel water, the moisture content at 10 percent will be about 144 kg. If we rotate generator handle with specific speed we get directly earth resistance on scale. It gives off moisture during dry weather to the dry soil around the electrode, data processing centre etc. Resistance must be verified by increasing or decreasing the distance between the tester electrode and the spikes by 5 meter.