How to define earth wire

How to define earth wire

Helps to prevent the fire or electric shock in life grounding of electric contour which equips all electrical household appliances. It is necessary to know how to define earth wire, on case if it is necessary to deal with connection of any device.

It is required to you

  • - indicator screw-driver;
  • - boss with bulb and two wires;
  • - voltmeter.


1. Check colors of wires. The modern cables intended for wiring are laid by three copper veins of various color. Define earth wire − it is yellow with strip of green color. Zero conductor, as a rule, blue, and phase – black-brown color.

2. If wires without color marking (also it happens that the electrician at installation has mixed wires), take the indicator screw-driver. Disconnect all tension – deenergize completely the house or the apartment. Bare, that is slightly smooth out tips at the checked wires.

3. Give tension. Take the screw-driver for the dielectric handle. Concern the end of the screw-driver of each wire. The indicator has lit up – means, you have concerned wire "phase". Other two, respectively, zero and earth.

4. Take bulb to which two wires are connected. Fasten one of them to phase which is already defined. In turn attach the second to conductings. The bulb – wire zero, another, respectively, the earth has lit up. But it happens so that the bulb lights up also at contact of earth wire.

5. Use the voltmeter. Between earth wire and zero conductor tension is absent, the arrow of the voltmeter will not move a little. And here in couple the phase earth tension is also it less, than voltage is couple of wires phase zero.

Author: «MirrorInfo» Dream Team