How to check and repair your home electrical network
We will consider in more detail the troubleshooting in the electrical network and the use of special devices for this.
Eliminating faults in the electrical network is actually not difficult, but for this you will need special devices, because you need to know whether the conductor is energized or not, whether the insulation is coping with its task of not passing the electric current.
Simple appliances for home use
An electrical probe will help you find out if there is a voltage on the contact or not. The device looks like a small screwdriver, if you touch the live contact in it, the signal LED lights up. In this case, you need to touch your finger to the metal plate on top of the case. A more complex version of such a device is equipped with a display that will indicate the magnitude of the voltage.
Another type - a non-contact probe, allows you to determine the presence of voltage without touching the conductor, but at a certain distance. Allows you to search for hidden wiring and monitor the presence of voltage on it. But this device runs on batteries.
Avometer (multimeter) is a universal electrical measuring device, necessary for household use. Allows you to measure voltage and current, both AC and DC, and in a wide range - from a few millivolts, or milliamperes to hundreds of volts or several amperes. The device also allows you to measure electrical resistance, capacitance of capacitors, network inductance, pulse duration of an electrical signal, by the type of use of a non-contact probe, it will show the induction of an electromagnetic field by increasing the voltage on the probe.
Device for checking correct connections
This device allows in express mode to check the correct connection of the sockets. It is enough to plug it into an energized socket, as 3 signal LEDs will indicate if it is connected correctly. Possible malfunctions - any of the conductors are not connected - phase, zero, ground, or they are reversed. The simplicity of the device and the accuracy of the instructions make it useful for everyone who is constantly involved in the installation of electrical networks.
How to visually determine phase, zero, and ground. What are the usual colors for electrical conductors?
- The phase is red or brown.
- Zero - black or blue.
- The ground is green or yellow.
But these colors were not necessarily performed on the tested network, because the installation was often carried out "by hand"
How to make sure the voltage is off
Before performing any work on the wiring or devices connected to it, it is necessary to turn off the voltage using an RCD, an automatic switch (unscrew the plugs).
After that, it is necessary to make sure with a probe that there is no voltage on the electrical contacts.
And only after making sure of this with the help of the device, you can start the installation work.
Checking the presence of voltage, we touch the probe one by one to all three conductors - phase, zero, ground, while pressing the metal plate on the device with our finger. If the device does not give signals, then there is no electrical voltage. You can also measure the presence of voltage with an autometer (multimeter) alternately between the pairs of conductors.
Checking the RCD
The residual current device (RCD) disconnects the voltage if insulation breakdown and current leakage occurs, both in the power grid itself and in the devices connected to it. Or if a person touches a live conductor. The operation of the device is based on comparing the current strength in the phase zero conductors. In a normal situation, it should be the same, but when there is a leakage to the ground (not only to the "earth" core, but also to the wall, the ground ...), there will be a difference in current strength and the device is triggered. There is a "Check" button on the device, when it is pressed, a short to ground occurs and a working device must disconnect the voltage. You need to make sure that the RCD is working at least once every 3 months and also every time you repair the electrical network.
How to check the integrity of a conductor, network
The conductor integrity check can be performed using an autometer. The device is switched on to measure resistance at a higher sensitivity. Now by connecting it to the ends of the tested conductor, you can find out its resistance. If the conductor is intact, then the resistance will be less than 1 ohm. And if there is a break, then the device will show some resistance value in KΩ or in MΩ.
How to find a break in hidden wiring
To find a break in the wiring that is inside the wall, it is better to use a non-contact probe. If the device is placed near live conductors, it will pick up electromagnetic interference. The probe must be held along the conductor, then the breakage point will be noticeable. In this case, you need to make sure according to the connection diagram that the voltage is not applied to the investigated conductor from the other side, which is possible in old ring-type wiring. It is somewhat more difficult to check them, since you need to make the necessary disconnections in advance.
When looking for a broken wiring, you must first investigate all the connection nodes - junction boxes, switches, sockets. A break in a solid conductor of hidden wiring is a very rare case.
Insulation integrity check
If an RCD is triggered without connected electrical appliances, then this indicates that the insulation of the cores in some place is broken. If the RCD reacts to the connection of any device or branch, then the fault is in the connected objects.
Also, heating and odors can indicate insulation failure. True, heating of the contacts occurs more often due to weakening of installation or compression.
If the socket, plug, switch is heated, then it is necessary to immediately turn off the voltage and repair the contact connections. In most cases, it is enough to tighten the bolt holding the contact plates.
To check the insulation resistance, the avometer must be connected to the pairs of conductors "Earth", "Phase", "Zero", and measure the resistance between them. On a serviceable wiring, it should be calculated as Mohm. If there is a breakdown of insulation, then the device will show KOhm or tens of Ohms. In case of short circuit - less Ohm.
The check is carried out with disconnected consumers and de-energized. When searching for faults such as "Damaged insulation" and "Leakage of current to earth", it is necessary to sequentially check individual sections of the power supply by disconnecting them in the bus boxes. After identifying the damaged area, the search is carried out visually in sockets, switches, chandeliers, boxes.
Any repairs to the home electrical network must be performed by qualified electrical personnel with an appropriate electrical safety group, who must perform work in accordance with the Safety Rules.