IP Codes

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IP Rating:  IP Rating First Digit Second Digit Third Digit (Optional) Solid Objects Protection Liquids Protection Mechanical impacts 0 No special protection No protection. No protection. 1 Protected against solid objects greater than 50mm in diameter ( such as large part of the body like hand) Protection against vertically falling drops of water e.g. condensation. Protects against impact of 0.225 joule (150 g weight falling from 15 cm height) 2 Protected against solid objects over 12 mm in diameter (person’s fingers) Protection against direct sprays of water up to 15° from the vertical. Protected against impact of 0.375 joule (250 g […]

How to calculate size of a cable for 11kV or 33kV line

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There are three factors affecting the size of a cable Load Length & Voltage drop Short Circuit Current of the system Now, we can consider these four points one by one and choose a cable which complies all these requirements. Load – The load of circuit is available in kW or watts. For example if you are calculating the size of cable for a 1 kW single phase pump. Load on the circuit is 1 kW. Now, calculate the current that will be running in the circuit due to 1 kW load of the pump. P=Volt X Current X Cos […]

Installation of copper Earth mat in under ground Metro Staions

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Call Us @ 9711681771 for earthing work Abstract of IEEE-80/ IS 3043 / BS 7430 for earthing The installation process of earth mats in under ground metro stations includes square grids of copper rods and parallel connected copper electrodes. Factors affecting the design of the earth mat Soil resistivity – The size and no of electrodes required in an earth mat system strictly depends upon the soil resistivity value. Soil resistivity varies from 12-300 ohms normally and for larger values we must use satellite earth mat systems. Step touch voltages – The size of one grid depends on the allowable […]

Solar Initiatives in Delhi and Haryana

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Ministry of environment and ministry of renewable energy has taken initiatives to increase the solar power generation in India. In Haryana, it is now mandatory (from September 2015) to install roof top solar plant for every building premises which is built on equal to or more than 500 sq yards. The size of the solar plant depends on the load of the entire building. i.e. 5% of the total load. (A fine of 10000 to 1000000 can be charged against failure of the same) It is being planned to install and produce 2 GW solar power in Delhi NCR region […]

Soil resistivity test for installation of Earth Mat in under ground metro station

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As most underground metro stations have a limited space/ land area, the earthing system for the auxiliary sub station or the feeder post or the signalling and telecom are inside the station box area, basically 300-1000 mm below the station base level. And for an earthing system which is very close to humans, we should consider the touch and step voltages that will come into effect during the fault. (For more details read GPR and step-touch voltages) That’s why the preferred earthing is Copper electrode grid earthing (also known as copper earth mats) For a good soil strata the soil […]