Wiring Condition Testing Technique
Initial inspection after purchase
If you just bought a house or an apartment, the first thing you need to check the condition of the wiring, because even the slightest malfunction may subsequently lead to electric shock or fire. In the new and old houses, the revision technology will be different, so we will separately look at both methods. Immediately draw your attention to the fact that before checking the wiring, it is necessary to disconnect the electricity in the shield. It is strictly forbidden to work under voltage, especially to inexperienced electricians!
New building
After installation, it is most often necessary to check the wiring in a new building after installation, before major repairs - wall decoration and furniture placement. The importance of this event is that if you do not inspect the cable line from the very beginning, in the future it will be much more difficult to check the wiring under a stretch ceiling or behind plasterboard sheets.
First of all, you must calculate the total power of the electrical appliances that you will use, based on which calculate cable cross-section by power and compare this value with the cross section of the conductor already laid in the walls. If the cross-section is insufficient, be sure to replace the electrician, however, as experience shows, such problems do not arise in new buildings.
The next step is to check the condition of the hidden electrical wiring. The insulation must not be damaged, and all wire connections must be made using terminal blocks or other connectors (for example, PPE caps), but not by twisting. Twisting is prohibited; see the list of permitted connection methods in chapter 2.1. PUE p. 2.1.21. Also important determine cable cross-section and check the ratings of the sockets. Copper conductors with a cross section of at least 2.5 mm must go to the outlet group2, the rating of the circuit breaker of the outlet groups must not exceed the rated current of the outlets, usually it is 16A.
If all of the above requirements are met, the last thing left to do is check the wiring in the apartment for load.In other words, you yourself need to check the correct assembly of the switchboard. When you connect all the equipment and turn on all the lights in the rooms, the machines should not work. If knocks circuit breaker, then the wiring is not able to withstand the load from the connected electrical appliances, as a result of which it will be necessary to replace the machines, division of wiring into groups etc. If the machines in the shield did not turn off after turning on the load, then the home wiring is correct. It does not hurt to additionally check the reliability of the connection of the machines in the shield, as well as the verification of the ratings with the load that comes to them.
Old housing
It is more difficult to check the condition of the electrical wiring in an old house or apartment, especially if you just bought a house and have no idea how the electrical wiring in the rooms is done. So, the audit of the power grid must be performed according to the following procedure:
- Find all junction boxes by room. Opening the cover, you can understand what cable is used for the hidden wiring of electrics: aluminum or copper, as well as what section of wires. You should also immediately check the condition of the insulation - if the wiring is old, even the slightest bend in the cable will cause the insulating layer to begin to crumble or crack. Such wiring must be unconditionally changed. Will be correct insulation resistance test with a megger (so to speak on breakdown and leakage of current). Its resistance should be at least 0.5 megohms. But not everyone has such a device, so you can "for decency" measure resistance even with a multimeter, although it can hardly be called a normal test. If the insulation resistance is poor, leaks will occur, and an RCD may trip if you upgrade the electrical panel. It is equally important to immediately inspect all wire connections - there should be no damage and twists, especially aluminum with copper. If necessary, you must immediately connect the wires with terminal blocks instead of twists. About, how to find a junction box in the wall the apartment building, we described in detail in the corresponding article.
- Check outlets and light switches. In sockets, it is necessary to inspect the integrity of the wires, insulation, and also determine the rating for which they are designed. If a three-wire wiring is connected to the sockets, it is necessary to determine where the phase is, where is zero and where is the ground. To do this, you need a multimeter or an indicator screwdriver, and the technology itself phase and zero definitions we provided in the corresponding article. Once you determine where the ground conductor is, you mustcheck the grounding in the socket. We also talked about this in detail. Another very important point - if the outlet is installed in a metal socket, it is better to replace it with a more modern, plastic one. As for the light switches, you need to disassemble them yourself and make sure that the phase wire is breaking, and not zero. If before this grief-electrician failed to break zero, you will have to redo the connection, because this option is unsafe - even when replacing the light bulb in the chandelier, it can shock you.
- Inspect the entry shield. It should be installed modern machines, not traffic jams that were used in the distant past. Be sure to check that the wiring in the bathroom is installed RCD, which will protect against electric shock during breakdown of insulation and leakage current. At the same time, note that the installation of RCDs in two-wire wiring (TN-C system) is prohibited according to the PUE p. 1.7.80 (see Chapter 1.7) Also check the quality of all connections and the cross section of the input cable. If the cross-section is insufficient, replace the cable with a more suitable one.
- When all the most important nodes are analyzed, it remains to check the old wiring for the load, as we described above.Experience shows that in old private houses and apartments electricians can’t do without replacement, but for some time you can wait (for example, before repair), just do not turn on a lot of powerful electrical appliances at once.
It should also talk about a special device, with which you can check the correct wiring - megaohmmeter:
That's the whole technology of checking old and new home wiring. As you can see, it is not very difficult to make an audit, but it will take enough time! We draw your attention to the fact that in your home or apartment you need to check the condition of the electrical wiring about once a year. All that is required of you is to tighten the screws on the wire clamps, as well as visually see if there is any burnt insulation.
What else is important to know
Sometimes it’s not enough just to check the electrician and replace all the inappropriate wiring elements yourself. Sometimes, for example, after flooding an apartment, you need to check the network for a short circuit. For this, it is best to use a special tester - a multimeter. About, how to find a short circuit, we spoke in sufficient detail in the corresponding article.
I would also like to note separately that during the revision of the wiring, you need to pay attention to the convenience of the location of outlets and switches, because after the repair it will not be completely logical to rearrange them. It seems to be a simple moment, but many miss it.
That's all I wanted to tell you about how to check the wiring in the apartment and the house with your own hands. We hope that the provided methodology was understandable and useful for you. Do not forget to rate the article and share information with friends!
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