Types of damage

On the rising hallway

First of all, in general, consider what the electrical network of an urban multi-storey building is. The power source in this case is a transformer substation, from which wires are extended to the main switchboard of the building. The voltage in the main shield is three-phase, i.e. network of 380 V. From here, wiring groups for each apartment have already been derived.

In the apartments themselves, the network is already single-phase – 220V. If a common zero breaks when the doorway rises, it may cause failure of the home appliance. This leads to inequality – in a three-phase power circuit, phase imbalance and instead of a symmetrical load, an asymmetric load is formed, passing in a circuit with four wires.

In simple words, this can be explained as follows: from the main panel at the entrance to each individual apartment the same voltage is applied – 220V. If there is a break in the zero wire, it can happen that 300 volts go to one apartment and 170 volts to the other (as an example). The result – overvoltage and “undervoltage” will lead to failure of electrical appliances. Usually, if no damage occurs, equipment with a motor breaks down: washing machine, refrigerator, air conditioning, etc. In addition, a fire may occur, even worse.

Inside the living room

The exact opposite situation can occur when zero breaks in a 220 V single-phase network, that is, inside your apartment, a private house or in the country. In this case, the result may be an electric shock to the person. This happens because at the outlet you will have the same phase on both ends. Now we will tell you what caused the appearance of the so-called second stage.

From your input shield, the current passes through the phase wire, and since most electricity consumers are constantly connected to the network (the same chandelier), when the circuit is interrupted, the phase voltage will go to zero. Result – electric current will be present in two outlet slots. But this is not the worst thing, because the main danger is that electric shock can occur from any equipment. The reason for this is the faulty grounding system of the network in the apartment or house.

If you connect the “ground” in the distribution board to the zero bus (which cannot be done), you will immediately be shocked by touching the grounded housing of the household appliance. The consequences, as you know, can be dire.Immediately we draw your attention to the right option for protection against zero interruptions in the house – a network with grounding system TN-S:

To summarize the consequences of a zero interruption in a three-phase and single-phase network, it should be noted that: if the neutral wire is damaged in the riser, the danger spreads to household appliances, and if the working zero is damaged in the apartment itself, the threat spreads to you.

How to identify risk?

To find where the neutral wire is damaged, you can use a special tester that can accurately show where the break occurred even under the walls, as shown in the photo below (if the wires are hidden). About, how to find a wire in the wall, tell us in the corresponding article.

Another search option is a visual inspection of the entire circuit. Show all wiring connections in the switchboard.

Perhaps a zero burned out on one of the machines, which is not difficult to identify and eliminate. If the neutral wire broke while going up the stairs, it means that it is not your business and housing and communal services or a special service they will call to check the power transformer and the secondary circuit including troubleshooting.

How to protect home wiring?

To protect the home electrical network from an open circuit, special devices must be used: monitoring relays and voltage limiters. We recommend connecting these devices to an input shield to protect yourself from harmful effects.

Causes of the phenomenon

Well, the last thing I want to talk about is why there is no break in the apartment. There can be many reasons, but the most realistic, based on comments on forums and personal experience, we can distinguish:

1. Burn the neutral wire in a power surge or short circuit.
2. Poor connection lived or poor connection.
3. Mechanical damage to the line due to the elements (for example, in strong winds) or due to human negligence during repair work.
4. The wiring is old and the wires simply wear out over time.
5. Theft or malicious intent (this happens sometimes).

So we examined the types and consequences of a zero break in a three-phase and one-phase network, as well as methods of protection against this phenomenon and tips for troubleshooting. If you do proper grounding in a private house, and also protect the wires with special devices, then when the zero is cut, no diseases will occur!