During repair work, it is necessary to determine where the electric cable lies in the wall, so as not to get an electric shock when drilling or damage the wiring, which may still be useful. This will help the device to search for hidden wiring. You can buy it in a store or assemble it yourself - this will require minimal knowledge of electrical engineering.
How to choose a hidden wiring detector
The wiring detector has different characteristics. The main indicator is the scanning depth. Since the cable is rarely laid deep, the optimal indicator is 5 - 6 cm.
What else is the device capable of doing:
- identify empty spaces in the walls;
- respond to wire damage;
- identify materials other than metal.
The signal or indication when finding the wiring can be color or sound. At the same time, the device shows how deep the cable is. There are devices with two different indications, confirming each other.
The most convenient is a wiring detector with a liquid crystal display, but it will cost more. If you buy the device for the first time, it is better to take more expensive. Some masters get used to simpler indications, therefore they are well guided by them.
When buying, it is recommended to test the detector and ask the seller to help understand the features of the work. They mainly test the depth of the cable.
Wiring and metal detectors - purpose and types
In panel and brick houses, power cables are laid by the method of gating and plastering the walls before finishing. For replanning, arranging doors in a new place, when demolishing partitions, there is a risk of damage to the installation, after which it will need to be completely replaced. Before starting work, it is advisable to conduct a search where exactly the cable is located in the wall in order to get around it when drilling and dismantling the walls.
It happens that with the shrinkage of new buildings, the walls crack, and the electrical communications laid in it are damaged. In order not to completely break the walls, you can buy a device that is able to detect damage in the circuit and start working in the place where it is needed.
Even simple actions - drilling holes for a shelf or a lamp, installing an outlet - require a preliminary check to see if there is a cable nearby that could be damaged by a drill, in addition to receive an electric shock.
The wiring detector in the wall also checks the correct connection of the electricity meters, determines the phase wire, ungrounded electrical appliances, the condition of the fuses.
There are several types of devices:
- Responsive to static electricity. There are many functions in such detectors, although most of them may not be useful. Their minus is that a cable disconnected from the power supply will not be detected.
- Devices of electromagnetic action. Accurate devices but do not detect a cable with a load of less than 1 kilowatt.
- Metal detectors. In addition to wiring, they are able to find nails and other metal objects in the walls. It can both interfere and help in the work - it depends on the goal.A de-energized wire, inaccessible to the first two types, the metal detector will quickly find.
Combined metal detectors have more functions, so they cost more. With their help, you can detect non-ferrous metals or very deeply embedded wiring. Cheap appliances are usually designed for any one action.
Detector Features
Each device for detecting hidden electrical wiring has its pros and cons. For example, electrostatic are able to determine the location of wires that are energized, even if no current is passed through them. Also respond to breaks in the chain. The minus of the device is its sensitivity to electrical devices - routers, microwaves, a computer and even a mobile phone. Walls that are wet for any reason also interfere with the operation of the device.
The electromagnetic indicators of the wiring are very accurate, to a millimeter they determine its location in the wall, but they do not catch the low-power cables that are equipped with lighting fixtures - lamps or chandeliers. You cannot use cheap devices in this case, you have to buy an expensive detector, for example, Bosch, which is the best of its kind.
Metal detectors are often used to clarify the data from other devices, for example, electromagnetic type, if the signal is weak due to insufficient electrical load.
Distinguish between professional and household appliances. A professional hidden wiring detector with many features and high accuracy cable location costs around 500 - 600 dollars. Such a device has several simultaneous indications - color, sound, graphic.
In appearance, flat detectors are also distinguished in the form of a cylinder. The second ones are usually cheap, but they are suitable for determining extremely shallow embedded wiring. If the owner knows at what depth the cable was laid during the last repair, a cylinder detector is enough. If the apartment is new and there is no information about the electrical part, it is better to get a more functional appliance.
How to check the hidden wiring warning light
Check the device in the store. At small points, sellers may interfere with testing, citing the lack of working electrical devices. This means that the detector may be of poor quality.
The verification procedure consists of several stages:
- Turn on the device and bring it to any visible wiring.
- Try to catch a signal from the same cable, but at a distance specified by the manufacturer.
- Turn off the device that consumes electricity and try to detect it without voltage. This is necessary if the seller does not know all the functions of the detector.
- Cover the device with any object so that the detector detects it through an obstacle.
If all parameters correspond to those described in the instructions, the detector can be purchased.
Hidden Wiring Search Procedure
Before using the wiring detector, it must be configured (calibrated). The description and sequence of actions is indicated in the attached instructions. After adjustment, the device is brought to the place where the cable is definitely located. If the device signals with sound or light, you can begin to work.
A common way to lay the cable can help - vertically and horizontally. Most likely, the wire will go up from the outlet, and most masters lay the wires horizontally at a distance of 15 cm from the floor or ceiling.
The search should be conducted on a dry surface with the wiring turned on, otherwise the errors in the determination will be large.
When a Bosch professional detector is operating, when a hidden wire is detected, the indicator light turns red, and the graphic moving labels located on the LCD screen converge to the center, accurately indicating its location. Based on the readings of the sensor, you can make a mark with a pencil.
DIY indicator
An amateur device can be made by yourself, having at hand several options for circuits and improvised materials - aluminum tape or copper wire as an antenna, a frame from a colored marker or a small lamp for the case. The circuits use resistors or field effect transistors.
A more accurate device that responds only to a frequency of 50 Hz can be made using a microcontroller. This type of alarm will only work if it finds the wiring and the magnetic field formed above it. The LED lamp can be used as an indicator, and a piezo emitter that starts to crackle is also suitable.
It is possible to assemble a professional-level wiring detector at home, but this requires serious knowledge in the field of electrical engineering and time.
How to make a do-it-yourself wiring detection device
To make a home contactless wiring identifier, you will need:
- 3 bipolar transistors of the brand NPN, C945 - can be taken from an unnecessary board;
- red LED;
- resistance resistor 1kOm;
- 0.5 mm insulated copper wire;
- Connector with crown battery.
Build Order:
- Cut off 30 cm of copper wire, wrap on a toothpick - this will be the antenna.
- Connect all the elements by soldering, starting from the copper antenna: transistors to each other, a resistor, to the transistors an LED, to the resistor the first tap from the connector, the second tap to the transistor.
- When the circuit is ready, the crown battery is taken and connected to the connector.
You can test a non-contact voltage detector by connecting any electrical device to the network, for example, a hairdryer or a drill. If you bring the copper antenna of the detector connected to the battery to the wire, the LED will light up. The farther from the wire, the weaker the lamp will be.
As the test test shows, an amateur device is enough to detect a wiring that is not deeply lying in the wall.
When testing or verification is complete, disconnect the circuit from the battery.
How to replace the wiring tracking indicator
There are many other ways in which to determine the place where the wire is laid. The simplest is visual. If you know how electricians lay the cable, you can predict in advance where it is. The most likely location is horizontally on the floor and ceiling at a distance of 10 - 15 cm. Vertical wires go up from all sockets and switches.
The principle of operation of the detector is similar to the operation of a radio receiver. With it, you can detect both the wiring itself and its gaps. The difference will be heard by sound. To do this, turn on the radio and tune it to the transmission wave. Further lead close to the wall on which the wiring is supposedly located. A receiver light will come on above it.
Magnetic waves from a live cable can be detected using the smartphone app. Special sensors will pick up the signal and send it to the monitor.
If there is an old radio with a microphone, it can also be used for searching, but there may be errors of up to 15 cm, so it’s better to use several methods at once to narrow the search radius. A microphone usually pops when approaching a wire. Hearing aids or multimeters work in a similar way.
Functional features of signaling devices
Most alarm models are available in combination. They are very likely to determine the location of the cable, as well as metal objects, as well as wood and plastic. The main goal is achieved - the device confirms the presence of voltage cable and its depth, as well as the location line up to a millimeter.
The main functions that are inherent in high-quality combined models include:
- Devices are capable of operating at temperatures from minus 10 to plus 50 degrees.
- Determine the polarity in DC circuits from 6 to 36 V.
- Capture magnetic radiation with a power of more than 0.5 MW per cm.
- Contactless models detect AC voltages from 70 to 600 V.
- Home appliances are able to detect metal objects and cable located at a depth of 2 to 6 cm.
- Determine the integrity of the resistance in the area from 0 to 50 mOhm.
- They transmit information to the screen or in the form of sound, light indicators. In high-quality models, there are several types of displays.
- Almost all detectors are powered by finger batteries.
A manufacturing defect or fake of a well-known brand of devices may not correspond to the description, for example, a comparative analysis of the original Bosch brand device and the Chinese expensive M120 device, which was positioned as a complete analogue of the German brand, was carried out. As a result of testing, significant shortcomings were revealed - the Chinese analogue could not cope with the search in the electromagnetic search mode, although it proved to be good in the metal detector mode.
Which device is better - imported or domestic
To decide on the choice of signaling device, you need to know the nuances: each country produces devices designed for wiring and the rules for its installation on the territory of its state. There is a risk that imported equipment will not provide reliable information.
It is possible to order a batch of equipment that will be made specifically for the Russian cable and its features. In this case, it would be better to ask the store whether the device is suitable for our electric networks or whether it is better to buy a domestic one. Not a good option is to buy the device abroad. In this case, it will definitely prove unsuitable for use, but it will not work to return it.
The quality of Russian electrical appliances is quite high, so they are often used by professional electricians. There are cheaper devices - for domestic needs, which also work well, but require preliminary settings.
