You are going to connect a new switch, and there is not a single sensor at hand that can indicate which of the wires is live. In this case, you need to know how to determine the phase and zero without indicators.

Content

  • 1 What is phase and zero
  • 2 What is necessary to determine the working and empty core
  • 3 How to determine without devices
    • 3.1 By marking the wires in color
    • 3.2 We make a control bulb
    • 3.3 We use potatoes
    • 3.4 Video: Determining Polarity Without Instruments
    • 3.5 Using water

What is phase and zero

outlet test

Phase detection will be required if, when connecting a new outlet, it turns out that you do not know which of the wires at the output is phase and which is zero

Phase - conductor through which voltage is transmitted to the consumer.

Zero is an empty phase. Returns current: creates a continuous electrical network when connecting devices, and also aligns the phase voltage.

Earth is a voltage-free wire in a three-core cable. Performs a protective function: removes static, parasitic currents.

What is necessary to determine the working and empty core

Many devices require polarity for normal operation:

  • thermostat;
  • controller in the gas boiler system;
  • laboratory measuring equipment;
  • other.

If you connect these devices without strict adherence to the rules of the location of the wires, no one will give a guarantee of service life and the quality of their work.

How to determine without devices

There are some simple and most accessible ways.

By marking the wires in color

wire color marking

The color coding of the wires is precisely intended so that it would be possible without devices to find out which of the wires is neutral and which is phase

The first and most reliable way to independently determine where the phase and zero without a tester is to inspect the insulation color of each conductor:

  • zero - blue / blue;
  • the earth is yellow green;
  • phase - any other color from black to white, except for the above.

In older homes, wiring can be done with a single-color wire. In this case, we recommend to mark the findings of the wiring using heat shrink tubes.

We make a control bulb

indicator light

This option is the most dangerous and can cause electric shock.

For this method, you need to find an incandescent lamp with a cartridge and two pieces of stranded wire about 50 cm long:

  1. Connect the conductors in the cartridge connectors.
  2. We clean the heating pipe to the metal.
  3. We fasten one wire to the pipe, and with the second we “probe” the wires of interest to us.

As soon as the wire touches the phase, the light will come on.

We use potatoes

It will take:

  • 1 MΩ resistor;
  • 1 potato;
  • 2 wires 50 cm long

One end of the first conductor is connected to the pipe, the second is inserted into the cut potatoes. Another conductor is also inserted at one end into the potato, and with the other we “probe” the wires.

We are waiting for 5-10 minutes.

phase detection using potatoes

This is a fairly effective way to determine the phase and zero without devices.

Phase - a small dark spot appears. Zero - there is no reaction.

phase detection on potato slices

In this case, the determination should occur with a short delay in contact with the cut of the potato

Video: Determining Polarity Without Instruments

Using water

To determine the polarity of the contacts by a similar method, lower two wires into a container with water. If bubbles form around one, this is a minus. Consequently, the second vein is a plus.

phase detection using water

This method is also dangerous. When using it, you must take precautions.

Applying the tools at hand to determine the conductors under tension, you must be extremely careful. If security measures are not followed, you can get an electric shock.