Determination of Size of Earth Wire And Earth Plate for Domestic And Motor Installations

Determination of Size of Earth Wire And Earth Plate for Domestic And Motor Installations Points : determination of size of earth wire and earth plate for domestic and motor installations In case of I w voltage supply, the consumer need not provide his own earthing system, with an independent electrode as the supplier is required to provide and maintain a suitable earthed terminal in an accessible position at or near the point of commencement of supply at the consumer premises. Hence earth plate is not-required on submain distribution boads for connecting each terminal provided on submain distribution boards to the earthing terminal provided by the supplier on main distribution board.

From submain distribution boards copper no 14 SWG wire will be required to run to three-pin socket outlets and connected to their earth sleeve.

In case of motor installations consumer is to provide his own earthing system. The size of earth wire and earth plate used will depend upon the rating of the motor for which it is to be used. The conductor used for earthing purpose should not be of: cross-section less than that of 14 SWG, and greater than 64.5 mm2 from mechanical consideration. From electrical consideration the copper earth wire should not be of size lesser than current carrying conductor. GI wire may also be used as earth wire provided its conductivity is not lesser than that of copper conductor. The figures regarding size of earth wire for various capacity motors for guidance are given in Table.