5.1 Frequency: Earth pit and grid continuity testing shall be done yearly.
5.2 Start up:
5.2.1 Open the lid of the earth pit.
5.2.2 Disconnect the earth electrode from the system.
5.2.3 Clean the contact surface of the earth electrode with emery paper.
5.2.4 Follow the SOP for electrical safety as per applicability.
5.2.5 Wipe out the contact with clean cotton waste.
5.2.6 Ensure that there is no dust, oil, grease etc., on the contact surface.
5.3 Checking of Earthing resistance:
5.3.1 Take the earth pit tester and set the selector switch on 10 ohm position.
5.3.2 Take three test cords and connect one end of each cord to the earth pit tester terminals E1, P2 and E2.
5.3.3 Short terminals E1 and P1 of the earth tester.
5.3.4 Connect other end of the cord E1 to earth electrode under test.
5.3.5 Connect other end of the cord P2 to the test rod driven minimum 0.6 meter deep in ground and at a distance of 3 meter from earth electrode.
5.3.6 Connect other end of the cord E2 to the test rod driven minimum 0.6 meter in the ground and at a distance of 3 meter from the test rod P2. All three electrodes should be in a straight line. The distance between test rod E2 and earth electrode is 6 meter.
5.3.7 Press the button of the earth tester for few seconds and note the values indicated on the earth test meter.
5.3.8 If the value displayed is 1ohm or minimum then the earthing pit is in good condition.
5.3.9 If the value displayed on the earth tester is more than 1 ohm add salt and water to the earth pit to improve the earth resistance.
5.3.10 Check again and continue the above process till you achieve the desired value.
5.4 Checking for grid continuity:
5.4.1 Connect all the disconnected earth strips to the earth electrode
5.4.2 Repeat the steps from 5.3.1 to 5.3.10.
5.5 Steps after completing the test:
5.5.1 Check the condition of the nuts and bolts of the earth electrode. Replace if required.
5.5.2 Tighten all nuts and bolts and reconnect the electrode to the system.
5.5.3 Apply anti-corrosive paint, wax or grease and then close the lid of the earth pit.
5.5.4 Change the dates on the lid of the earth pits satisfactory
5.5.5 Record the details in the given Annexure-I.