SOLUTION

In the case of household wiring or installation, a 14 SWG hard-drawn bare copper conductor is used as earth wire. For power installations, the size of the earth wire depends upon the rating of the motors installed. The conductor used for earthing purposes should not be of cross-section less than 14 SWG and greater than 64.52 sq. mm from mechanical considerations. From electrical considerations, the copper earth wire should not be of size less than half of the largest current-carrying conductor.