# How to detect Line (Hot) and Neutral Reversed with the electronic circuit?

#### Nanda Kumar 1

Joined Aug 25, 2016
40
Hi every one ,
I want detect the line and neutral reverse with any electronic circuit .Is there any circuit like that ?

#### Sensacell

Joined Jun 19, 2012
2,985
For a test? or part of an automated detection circuit?

Measure between earth ground and the wire in question, the neutral should measure almost zero with respect to ground.
The hot will measure full line voltage with respect to ground.

The tricky part is having a ground!

#### Nanda Kumar 1

Joined Aug 25, 2016
40
For a test? or part of an automated detection circuit?

Measure between earth ground and the wire in question, the neutral should measure almost zero with respect to ground.
The hot will measure full line voltage with respect to ground.

The tricky part is having a ground!
I want for an automated detection circuit.

#### crutschow

Joined Mar 14, 2008
29,492
If you have a typical mains circuit with a safety ground then it's a simple matter to measure between the voltage between the hot wire and safety ground, and the neutral and safety ground.
The first measurement should give the line voltage and the second should give zero volts.

#### Nanda Kumar 1

Joined Aug 25, 2016
40
If you have a typical mains circuit with a safety ground then it's a simple matter to measure between the voltage between the hot wire and safety ground, and the neutral and safety ground.
The first measurement should give the line voltage and the second should give zero volts.
thank you for your reply @crutschow . But i want circuit where if line and neutral gets reversed it will break the circuit.

#### BillB3857

Joined Feb 28, 2009
2,560
They make plug-in testers that will give a visual indication of proper relationships between Hot, Neutral and Safety Ground. Use one of those and monitor the light pattern with photo sensors. The output of the photo sensors could then be used to determine proper connections with a small microprocessor.

#### #12

Joined Nov 30, 2010
18,223
This is one way to break the circuit. Connect this circuit and the circuit breaker will break the circuit if the power line and neutral are reversed.

#### Attachments

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Joined Jul 18, 2013
24,995
Or a detect relay coil across the neutral and earth conductor.
Max.

#12

#### crutschow

Joined Mar 14, 2008
29,492
thank you for your reply @crutschow . But i want circuit where if line and neutral gets reversed it will break the circuit.
If you had said that at the beginning it would have saved a lot of unnecessary posts.

#### Dodgydave

Joined Jun 22, 2012
10,241
A simple half wave diode and capacitor with a relay between Neutral and earth will detect if Phase and Neutral is reversed, or just an AC relay.