it requires less material
fault location and rectification is easy
installation cost is less
inspection more easy
all lamps give more than normal brightness
over loading of the phase cable
saving of cable for the customer
neutral conductor gets over heated
bigger size of wire
double the size of wire
half the size of wire
next bigger size of wire
improper earthing
high earth loop impedance
insulation failure
low earth resistance
Bureau of Indian Standards
Bureau of Institute Standards
Bureau of Indian Supply