- 1. The most basic methods for detecting flush-mounted wiring
- 2. Overview of the most commonly used search devices
- 3. Methods that do not work
- 4. Fans of electrical engineering: making a search device with your own hands
Sometimes such an elementary action as, for example, wall mountingshelves or paintings can be a real problem. This is due to the fact that the performer is simply not known, and whether there is an electrical cable in this place. This situation may arise if you purchased a new home, and the previous owners did not bother to provide you with a plan for electrifying the premises. And in the presence of a layout plan, one should not rely on the decency of the people who performed it, because, in order to save, electricians often neglect the established norms. For our own safety, we strongly do not recommend hoping for good luck. In this article, we will tell how to find the hidden wiring in the wall with or without using special devices.
1. The most basic ways to detect hidden wiring
Wizards who neglect the measures associated with finding the exact location of electrical cables may face some very unpleasant consequences . Starting from damage of the cable itself, which will lead to a short circuit and, accordingly, failure of the object that was powered from this cable itself, up to electric shock. It is necessary to perform the search without fail if you need to:
- install a new outlet or switch;
- perform other installation work related to the drilling of the wall;
- partially replace electrical cable;
- eliminate various problems with the electrician( open circuit or short circuit);
- in redevelopment of the premises associated with making new openings;
- when re-planning the wiring diagram itself.
Only if you are planning an complete replacement of wiring, you do not need to know the location of the cables. When overhauling the old wires, you can simply pull out of the wall. This is not hard to do, since only a small layer of putty hides them. And if the new wiring will be held on the ceiling, which is very much in demand recently, the old wires can be left in place.
Consider the the simplest ways to detect hidden wiring :
- Visual inspection. This method is quite good. Especially if you plan to change the wallpaper. After all, he means their complete removal from the wall. You need to get to the plaster. Therefore, the base layer also needs to be soaked and removed. Now you just need to carefully examine the walls. Flush mounting is done by laying the wires in shallow grooves, which are then simply covered with a layer of plaster. It is not always possible to do it perfectly. Often in these places there will be small bulges, or vice versa, small depressions. It is these places that need to be discovered. To be 100% sure, run your hand across the wall at the intended location. You definitely feel these nuances. Now you need to bare the wire, that is, to rid it of the masking layer of the solution. To do this, use a small hammer. Knock gently along the entire length of the groove and the putty will crack.
- Using the old radio. This simple method is described in many sources, because it really works. You will need a receiver that needs to be tuned clearly at 100 kHz. The room should be complete silence. Turn on the receiver to lean as close as possible to the wall, but not to scratch it on the surface, and hold along until a characteristic cod or increase in the noise level. If there is a retractable antenna, you must drive it on the wall with its tip. This signal will alert you to the presence of a wire. The only condition, under which this method will work, is the presence of voltage in the desired wire. The closer you get to the strobe, the more the crack will increase. This method cannot boast with particular accuracy. But you can easily define a corridor in the range of ± 10 cm. Often this is quite enough to not get a nail into the wire.
- Using Indicator Screwdriver. This thing is definitely the majority of the owners. This device is cheap and easy to use. Indicator screwdriver works on the principle of response to the electromagnetic field, which emits an electrical cable. It has three degrees of sensitivity - “O”, that is, the definition of the supply phase, “L”, that is, contactless detection of the presence of electrical wiring with a small degree of sensitivity and “H”, which means contactless determination of the presence of electrical wiring with a high degree of sensitivity. Indicator screwdriver is equipped with a light indicator. When you find a hidden wire, a small diode on its end will light up. Using the device is very simple. You need to touch the tip of the screwdriver and just drive it along the wall. To disadvantages, associated with the use of this method, can be attributed to a large error and a small depth of action. If the cable is hidden under a layer of plaster more than 2 cm thick, the indicator screwdriver will not help you. And the width of the channel in which the cable is supposed to pass will lie in the range of ± 10-20 cm.
- Using an hearing aid. A very unusual way, for the realization of which the old-style hearing aids are ideal, for example, brand AK-1.With it, you can quite accurately determine where the wire passes. This device has a “phone” mode, which helps people with hearing disabilities to carry out telephone conversations without obstacles. To detect hidden wiring, it is necessary to transfer the device to this mode. Now he will perceive only electromagnetic oscillations. It remains only to bring the sensor to the place where in your opinion should pass the cable and listen carefully. When you find yourself in the right place you will hear the characteristic noises.
According to established standards, , all wires from the junction box must be laid vertically or horizontally and have angles of rotation equal to 90 degrees. Laying the cable diagonally is strictly prohibited. Perhaps this knowledge will simplify your searches a little. If you see a socket or a switch, then it is logical to begin the search for the cable leading to it, directly above this point or to the side of it, if we are talking about parallel connection.
2. Overview of the most commonly used search devices
Not always "popular" methods, given their large error, give the desired result. In this case, you have to resort to using special devices. Before we consider the most popular of them, it is necessary to understand the principle of the and their actions. There are three types of searchers:
- Electrostatic - the principle of their action is based on capturing the electromagnetic field, which emits a current, passing through an electric cable. Devices based on this principle, one of the most simple and affordable. They are most common among professional electricians, and among home craftsmen. Their accuracy is quite high. An electrostatic device can only be used on the condition that the walls are completely dry and not damp, and there are no foreign metallic inclusions in them. First of all, we are talking about fixtures, which are often found in the rebuilt panel houses.
- Electromagnetic devices are based on the same principle of operation as electrostatic, but with one difference. The required wires must be under load of at least 1 kW.That is, before you take up the search for wires leading to a particular outlet, you must include something in it. This could be an electric kettle, a microwave or something else.
- Metal Detectors - differ from previous devices in that they themselves are emitters of an electromagnetic field. When the metal that is in the middle of the cable falls into the range of the magnetic field created by the device, it will cause it to change. It is on these resistances that the metal detector reacts. The advantage of this type of devices is that the load on the wires is not mandatory. And an obvious lack of will be that the metal detector will react not only to metal in the middle of the electrical cable, but also to all sorts of pieces of wire in the wall, old nails and fittings. Therefore, purchasing such a device, it is better to buy a more professional model that allows you to determine the type of metal found. Such a function will greatly simplify the search.
There are also devices with combined principle of operation. The area of their application, as well as their accuracy, is much higher. With their help, it is possible not only to identify the location of the wiring, but also to determine the place of the breakage or grounding, to detect the phase conductor. Such a device will become indispensable if working with electrical wiring is your specialty.
Now let us consider in more detail the individual models of the model of the search devices:
- The device "Search" is based on the electrostatic principle of operation. It is equipped with 4 modes of different sensitivity, with which you can determine the location of the cable, which lies at a depth of up to 7 cm. Light and sound indication is used as a signaling device. This device is very easy to use and has a number of additional functions. To search for wiring, you must select the appropriate mode, in this case the fourth, and simply drive the device along the wall. For home use, “Search” is very good and has an affordable price. But for professional work, it will not work.
- Another popular model of domestic production is a device called "Woodpecker". It can be used by both home craftsmen and specialists. It is both a tester and a signaling device. With it, you can detect the electrical cable under the layer of plaster up to 8 cm inclusive. The device can monitor the operation of fuses, search for phase cables, check the phase of the electricity meter, look for electrical problems. Its principle of operation is based on the electrostatics of an alternating field. When the antenna of the device approaches the wire, the electrodynamic force begins to work and the equipment reproduces the signal.
- Tester CEM LA-1014 is a proven and high-precision instrument. With it, it is possible to detect even de-energized wires under a layer of plaster. A characteristic feature of this device is that it is able to find faulty and damaged cable sections that have melts, short circuits or openings. The disadvantage of the tester is its response to other metal objects that may be in the wall.
- One of the amateur devices based on the combined principle of operation is called MAG-2. The device combines electrostatic and electromagnetic principles. It has two modes of operation that allow the cable to be detected, with or without a load. When the cable is found, the device will notify about it with the help of light and sound indication.
- Signaling devices of the Chinese manufacturers of the MS series. For example, the device MS-58M, which belongs to the category of tester-probe, can easily detect both electrical wires and other metal objects. Given this, it is necessary to be extremely attentive when working with this device and learn by ear to distinguish the signals that it gives. For example, a signal arriving when a conventional screw is detected in a wall will be different from a signal from a power cable. It is just necessary to get used to the device. An interesting fact is that he will not be able to detect an object that is wrapped in aluminum foil. It serves as a screen that prevents the detection of metallic particles.
Using any of the above devices, you quickly and accurately cope with the task.
3. Methods that do not work
We considered effective ways to detect hidden wiring with the help of both professional devices and available tools. Now let's look at a couple of ways that, despite repeated mention on the Internet, are not worth your time to implement them:
- Search for wires using the compass. Despite the fact that most craftsmen recommend this method, you should understand its principle of operation. It is based on the fact that at home you have to create a load of such strength that the compass needle, approaching the cable, reacts to it, and also points in the right direction. In fact, you simply cannot create a magnetic induction of such a force that the compass reacts to it. And given the considerable layer of plaster, this is a disastrous thing.
- Search for wires using an magnet. There is an opinion that if you tie a single-charged magnet on a string and leisurely drive it along the wall, then in the place where the electromagnetic cable is laid, the magnet, like a pendulum, will begin to oscillate. By marking these fluctuations with dots, it is possible to outline a corridor within which the cable will pass. Perhaps, but it is very doubtful that this method will work in brick houses. In the same panel homes, or when trying to detect the power wires on the ceiling, this method is absolutely useless.
- Smartphone, as a device for finding hidden wiring. For smartphones based on Android or Mac OS in the app store you can find many programs that are designed to cope with the search. The most popular is an application called “Metall Detector”, however, there are many of its analogues. Inside the phone there is a built-in magnetic sensor, which, together with this application, turns the smartphone into a metal detector. First, the device will respond absolutely to any kind of metal that is in the wall. And secondly, you should not take this idea more seriously than an ordinary toy. Moreover, you should not rely on such a dubious method as the main one before starting any work.
4. Fans of electrical engineering: making a search device with their own hands
Those who are at least a little versed in electrical engineering can independently make a small device from elementary parts. To make you you need:
- Plastic box;
- Aluminum adhesive tape;
- Light Bulb;
The box should not be too large. A plastic box from a conventional light bulb will do. On one of its sides, you need to stick a small piece of aluminum tape. It is needed as an antenna. Install batteries 4-5 watts. Make a hole on one of the faces and mount a light bulb there. Now you need to install a hypersensitive transistor and attach the batteries and the antenna to the tape. Wire can be used as an antenna. When all parts take their place inside the box, close the lid. Drive the resulting device antenna on the wall. When you touch the cable location, the light will come on.
Another simple device can be assembled from:
Paying attention to the fact that this device is one of the elementary for understanding people, its accuracy will be appropriate. It is necessary to assemble the chain according to the diagram below. Ohmmeter is better to use the arrow type. For convenience, you can enclose all the components in a small box. The speaker will fit from the old landline phone. The device will respond to the presence of wires in the wall with appropriate noises.