For easy Identification

To Avoid transfer of heat from power cable to control cable

To avoid leakage

To avoid short circuit

Open circuit

Short circuit

Earth fault

Earth leakage

10 M Ohm

100 M Ohm

10 k Ohm

1 M Ohm

Open circuit

Earth leakage

High value series resistance fault

Short circuit

Protect from short circuit

Protect from over current

Protect from open circuit

Protect from earth leakage