Breakdowns, damage to the electrical network can occur due to poor contacts in home-made “twisting”, connections in switches and sockets that have weakened over time, mechanical damage to wires due to careless handling. The gradual deterioration of the wiring is not always noticeable, but by a number of signs you can guess that not everything is in order with the power grid.
One of the indicators of a wiring malfunction is the frequent «knocking out» of the RCD. The device will work in case of any violation of the current balance, so it is important to first understand the reasons for turning off the protective device — perhaps the device, wiring, electrical appliances connected to the network are faulty. There are other, more obvious signs of a wiring malfunction: sparking, heating, melting of current-carrying parts. It may even smell distinctly of burning — be careful to prevent an emergency in time.
Modern electrical installation products (pictured — Jung equipment) use clamp-on terminals instead of screw connections
Photo: Boris Bezel/Burda Media
In case of any malfunction, first of all, turn off the mains voltage. All work is carried out only on de-energized wiring! They should be entrusted to a qualified electrician. First, the network is inspected, looking for places of potential damage (for example, areas of leaks). Then they check the wire connections in the junction boxes according to the electrical plan of the apartment or house. They also assess the condition of electrical installation products, if necessary, tighten the screw terminals in sockets and switches. Recall that the screw connections in the network must be regularly, at least once a year, inspected and put in order. Further, the specialist can measure the technical characteristics of the network. The integrity of the circuits is checked with a multimeter-megaohmmeter, the insulation resistance of the wiring is measured. In accordance with the rules for the installation of electrical installations (PUE), for power cables up to 1 kV, the insulation resistance must be at least 0.5 MΩ.
Professional repairers use multifunction multimeters to test wiring.
How to determine the location of the problematic section of the wiring? In domestic conditions, of course, this is difficult to do. A malfunction is indicated by the arbitrary operation of protection devices, so it is better to simply turn off the power to an apartment or house and wait for an electrician. But you can reduce the risk of wiring failure on your own. First, you should choose the right equipment. Faulty devices can cause many problems. Secondly, it is worth replacing the old aluminum wiring with a more modern and reliable one. Thirdly, it is imperative to install devices that detect sparks, as well as fire protection RCDs and switches with screw terminals — there is never too much safety.
Schneider Electric Protective Modular Equipment Manager
Source: Ideas for Your Home Magazine#215