At CIKIT we just don’t intend to sell our products but to provide complete solutions to all Lightning & Earthing related issues. Our expert technical team would provide all assistance and guidance in all the processes involved in designing and installation of a perfect Lightning Protection and Earthing Systems.
Soil Resistivity Test
Soil resisitivity test is done to determine the properties of the soil at the given location, especially the electrical properties. By carrying out this test we will know how much the soil will resist the flow of electricity within. Soil resistivity has been found to be non-uniform at many sites. Resistivity measurements at site will reveal whether the soil is homogenous or non-uniform. As soil plays the most important roll in any earthing system, it is important to know its characteristics to design a perfect Earthing system. Soil resistivity test should be performed in at least eight test directions from the centre to cover the whole site.
Principle of Tests
Wenner’s four point method: In this method four electrodes are driven into the earth along a straight line at equal intervals. The four terminals Megger is the earth tester used. When using such a megger, the resistivity may be evaluated from the equation as given below:
p = 2 π s R
p = resistivity of soil in ohm meters
s = distance between successive electrodes in meters and
R = Megger reading in ohms.
Earth Resistance of an Earth Electrode
Fall of Potential Method
This is one of the most common methods employed for the measurement of earth resistance and is best suited to small systems that don’t cover a wide area. It is simple to carry out and requires a minimal amount of calculation to obtain a result. The Fall of Potential or the 3-point method, comprises the Earth Electrode to be measured and two other electrically independent test electrodes, usually labeled P (Potential) and C (Current). An alternating current (I) is passed through the outer electrode C and the voltage is measured, by means of an inner electrode P, at some intermediary point between them. The Earth Resistance is simply calculated using Ohm’s Law; Rg = V/I.
Two-Spike (Fall-of-Potential) method
Installation of an Earthing System
- Determine the size of the earth pit based on the dimensions of the Earth electrode to be installed. For instance if you are using copper bonded rod of 17mm dia, you can a augur a minimum of 4inch dia earth pit, and in case of a 76mm dia pipe, you can augur a minimum of 8inch dia earth pit.
- The depth of the earth pit would be in accordance to length of the electrode to be installed.
- Mix the Earthing Compound in water to a slurry form and put approximately 5kgs of the mixture at the bottom of the earth pit.
- Place the Earth Electrode at the centre of the earth pit.
- Fill the earth pit with the slurry Earthing Compound till the top of the earth pit.
- Water the pit adequately.
- Remove air gaps in the pit by poking with a long stick till the air bubble stops appearing.
- Water the pit for the following couple of days for the earthing compound mixture to get set with the soil around.
- Once the pit is set, construct/place a suitable chamber and cover as per the requirement.
- Complete the testing & commissioning of the Earthing System as per the procedure recommended by the standards.
View Other Products
- ESE Lightning Arrester
- Conventional Lightning Arrestors
- Single Air Terminal
- Plate Earthing
- Mat earthing
- Pipe earthing
- Rod earthing
- Bus Bar
- Earthing Conductor
- U Bolt Clamp
- Earthing Rod Clamp
- Full Threaded Coupler
- Half Threaded Coupler
- Square Tape Clamp
- DC Flat Clamp
- Test Link
- Copper Flexible connector
- Flexible Tinned Braid
- Chamber and Cover
- Cable clamp ( C type )