To protect the equipment from excess current

To maintain the line current constant

To maintain the supply voltage constant

To increase the life of the equipments

earth terminal

phase terminal

neutral terminal

live terminal

for over current

for high voltage

for leakage current

for low voltage

Red

Green

Black

Blue

To prevent a damage to the Insulation of wires

To prevent a damage to the wires

For safe current flow

To pass the leakage current to the earth