Whether you are a specialist or not, and if you decide to change the wiring in your house, even if in the “box - switch - light bulb” section, you should know the elementary rules of the PUE (full transcript - “Rules for electrical installations”, that is, a set of standards applicable to any electrical installations and power networks). It is from here that you can get information about whether zero or phase goes to the switch.
Which wire powers the light switch?
Despite the fact that in some apartments you may find that the switch comes to "zero", this is by no means normal. Because any switch must break the phase. If the zero or phase on the switch is reversed, most likely, some unfortunate craftsman has already “poked around” in the wiring of this apartment, or initially the neutral wire was not powered according to the standard.
What colors should the wires have in the electrical wiring of the apartment
Anyonethe conductor purchased for the installation of electrical wiring must contain a core with a blue (blue) braid. It is it that is recommended to be used on the network as a neutral wire. If the apartment has a third wire - direct grounding, it is recommended to run a yellow-green wire on it. All other wires (it can be white, brown, black, etc.) are used as phase carriers. So to the question whether the switch breaks the phase or zero, the answer will be unequivocal - the phase, and this wire will not be blue (blue) and not green.
If the wires are mixed up in your apartment, it means that not professionals were engaged in the installation of electrical wiring in it and, most likely, it has already undergone repairs.
Essence of electricity
Let's try to explain the work of electricity in the most accessible words. Even from the lessons of physics, we know that the very essence of electricity is such that the phase always tends to discharge to zero. It is between the carrier of electricity and the grounding stream that various devices are included in the circuit. Then discharge occurs in them, forcing them to work.
In particular, this is how a filament or diode circuit works in a lighting lamp. A filament or a diode circuit has its own resistance, which is balanced so that the lamps, when the network closes through them, do not burn out, but begin to glow. And in fact, it doesn’t matter which wire is suitable for the switch - zero or phase, if zero is supplied to the lamp itself from one contact, and phase from the other, it will work anyway. On theThe performance of the device will not be affected in any way. This is for security purposes only.
Why "phase" and not "zero"?
We have come close to answering the question of whether zero or phase goes to the switch and why. The switch opens the section of the network in which the light bulb works. And it interrupts in simple switches only one of the wires that is passed through it. The second wire remains powered directly to the lamp. If in your case zero is passed through the switch, then a phase is connected directly to the chandelier, which means that even with a simple replacement of the light bulb, the device can shock you.
If the switch opens the phase, then zero goes directly to the chandelier from the box. This means that if the switch is in the open (off) state, the phase is no longer supplied to the device, since it is interrupted by the switch itself, and replacing the lamp will be safe.
Proper installation of the switch with the replacement of wires going to it and to the chandelier
When we figured out the question of which wire - “phase” or “zero” should come to the switch in order to comply with the PUE standards, let's figure out what the correct diagram of the home electrical network section will look like, which will determine the normal operation of the electrical appliance. Again, let's explain everything in simple words (for safety reasons, all work related to the installation or repair of electrical wiring must be carried out with the central machine turned off in the main switchboard).
- For correct wiringfrom the nearest junction box, we should have two gates - one to the switch, one to the chandelier.
- How to connect a "phase - zero" switch, that is, an ordinary switch? We take a piece of two-wire wire. We pass it through the side hole of the box, going to the gate to the switch. We also pass the cable through the side opening of the switch box.
- We feed one core to the left terminal of the switch, the other to the right. In the box, one of the cores is fed to the phase wire. One remains free for now.
- What did we get? Now the current comes to the switch and in the closed position of the switch returns back to the box. It remains to mount the network for the lighting fixture.
- Let's say our chandelier is designed for one lamp. Then a regular two-core cable will do. We pass it through the side hole of the box leading to the chandelier, close it in a gate and connect it to the chandelier terminals.
- In the box, we connect the two-core cable going to the chandelier as follows: we feed one core to the returning free core - the phase from the switch, the other is powered to the main zero in the box.
The scheme is assembled. Now, knowing which wire goes to the switch, "zero" or "phase", you have made a section of the network that ensures the operation of the lighting device is completely safe.
In conclusion, some nuances
In our article, we focused on a simple network that does not provide for a third wire - grounding. We also started from the fact that we have a simple chandelier,designed for 1 lampholder. Therefore, our switch is simple - single-key.
In the case of grounding, you will never mix it up. You just have to use a three- or more-core cable and always power the yellow-green core to ground, that is, to the terminal going to the device case.
And in the case of multi-key switches, you will have to throw two or more wires (depending on how many keys are in the switch) out of the box onto the switch. The same should be done with the power supply of the chandelier. No matter how many phases come from the switch to the chandelier, there will always be one zero in it, its terminal will be highlighted separately. You can also navigate through the wires. Zero in instruments will always be blue (light blue).
