Phase Neutral Earth Fault Indicator Circuit

Last Updated on March 16, 2024

This Circuit helps you to find Open Earth, Phase or Neutral reverse in the Power source. By using simple components like Resistors and LEDs, we can create this circuit.

Circuit Diagram

Construction and Working

Four Red color LEDs are used here, and Resistors are 56KΩ / 1W. LED1 is connected between Phase and Earth through Resistor.( Here you can connect LED in any Polarity).

LED2 is connected between phase and Neutral. LED3 is connected between Earth and Neutral.

These three LEDs will show the condition of AC power supply.

LED Indication

ONONOFFPhase Neutral Earth Wired Correctly
OFFONONWrong Polarity of Phase/Neutral
ONONONOpen Earth or Neutral
ONBlown fuse

LED 4 connected parallel to the fuse and it glows when fuse blown and appliance being connected the power source.

Some spike and surge protector use MOV (Metal Oxide Varistor) along with this kind of circuit to protect appliance from high voltage and surge current.

Leave a Reply

Your email address will not be published. Required fields are marked *