You will need
  • - flat screwdriver;
  • - a cartridge with a bulb and two wires;
  • - voltmeter.
Check out the colors of the wires. Modern cables designed for wiring, laid three copper conductors of various colors. Identify the ground wire is yellow with a strip of green. The neutral wire is usually blue and the phase – black–brown.
If the wires without color marking (also happens that the electrician during the installation messed up the wires), take flat screwdriver. Disconnect all voltage – unplug all the home or apartment. Bare, that is, lightly smooth the ends have a check of wires.
Connect voltage. Take a screwdriver over the dielectric handle. Tap the screwdriver end of each wire. If the indicator comes on, it means you touched the wire "phase". The other two, respectively, zero and earth.
Take the bulb to which is connected the two wires. One of them attach phase, which is already defined. Second alternately attach to transactions. Lit light bulb – wire zero, and the other respectively, land. But it happens that the bulb lights up and when you touch the ground wire.
Use the voltmeter. Between the grounding wire and zero wire is no voltage, the voltmeter needle will not budge. But in a pair of phase-earth voltage and is lower than the voltage in the pair of wires phase-zero.