How to find wiring in the wall yourself: choosing a detector

Recommendation points

• Locating electrical wiring with an indicator screwdriver
• Semi-professional wiring detection technique
• Detector Black&Decker BDS300
• Metal detector Zircon TriScanner PRO SL
• Universal detector Skil 0550 AA
• Digital detector Bosch PDO Multi

The article raises the issue of using various devices to determine communications hidden in the wall, such as electrical wiring, water pipes, elements of plasterboard frames, reinforcement of concrete blocks, voids, wooden elements.

Sometimes it is extremely necessary to find out where the hidden electrical wiring runs, to find the places where hidden water pipes, metal frames, cavities in concrete, steel reinforcement and many other “surprises” are hidden under a layer of plaster.

Electric shock is the most dangerous thing that can happen to an employee, so let’s start the analysis with highly specialized devices that minimize this dangerous factor..

Locating electrical wiring with an indicator screwdriver

The minimum tool any home owner should have is a hidden wiring indicator. This is the simplest and cheapest tool based on the principle of trapping the electromagnetic field emitted by electrical wiring..

Indicator screwdriver with hidden wiring detection

This device, like similar ones, has three degrees of sensitivity:

1. “О” – determination of the phase in the supply network.
2. “L” – contactless detection of the presence of electrical wiring with low sensitivity.
3. “N” – contactless detection of the presence of electrical wiring with increased sensitivity.

Screwdriver indicator operating mode switch

The quality of determining the presence of wiring for this device is fully consistent with its cost. It is possible to determine that the wiring is hidden in the wall, but at the same time, even at minimum sensitivity, it will show a zone 10–20 cm wide that is prohibited for work (the indication is performed by a green LED with an additional sound signal, its intensity will be maximum in the place of the immediate, according to the electrical circuit indicator, approaching the wiring).

A small useful bonus of this indicator is the ability to use it to check the continuity of a circuit. The device uses the human body as a “wire”, for this we put our finger on the upper contact panel, with the other hand we take one end of the conductive part of the wire, and we bring the “nose” of the indicator to the second bare point of the wire. If the circuit is not broken, then in the “O” mode the red indication lamp will light up, but the accuracy of detecting the break is poor. The device cannot find shielded or de-energized wires.

Additional contact for “dialing”

The indicator is powered by two batteries hidden in the handle next to the “buzzer”.

Indicator power

It is important to keep the indicator in the “O” state and with the screwdriver tip closed, as in the indication mode the batteries run out very quickly.

Semi-professional wiring detection technique

Semi-professional detectors are next in class and quality for detecting wiring..

These devices are mostly universal and can determine the composition of the wall in front of them, find cavities in it, live electrical wiring, non-ferrous and ferrous metals. The principle of operation of these devices is based on generating a magnetic field and capturing its changes when passing through various media (steel, cast iron, iron – they increase the electromagnetic field, aluminum and copper – reduce it, the magnetic permeability of solid concrete is higher than that of hollow concrete, etc.). ). These devices, analyzing the results obtained, can quite accurately determine what is in front of them..

The main advantage over the indicator screwdriver is the higher accuracy of object detection, thanks to the auto-calibration of the sensing element. At the same time, the ability to find reinforcing fittings and cavities in the wall allows you to avoid breakdown of water pipes and damage to drills when they hit a steel surface.

We strongly recommend that, to identify the features of the operation of each device, before direct use, test them on a wall in which the position of electrical wiring, metal, wood and other inclusions is already known.

Detector Black&Decker BDS300

Quite a simple model, in which the indication is completely made on LEDs. A hard switch of operating modes allows you to quickly reconfigure the device to search for metal or wood. When the device is “confident” in finding the desired element, a sound signal is issued. The indication of the presence of electrical wiring is placed on a separate LED, and a convenient button for forced calibration of the sensor allows you to change the sensitivity and reduce the error in object detection to a minimum. The device scans in only one direction, to accurately determine the location of the structural element, you must rotate the device ninety degrees and repeat the scan.

Metal detector Zircon TriScanner PRO SL

The device has three basic functions:

1. Detection of metal structures.
2. Detection of timber frames.
3. Deep scan.

When the object is detected with confidence, the LED that highlights the conditional direction turns on, while the object itself is located exactly under the crosshair marked on the body. Detection of live electrical wiring is carried out constantly, regardless of the selected scan mode.

Universal detector Skil 0550 AA

An advanced model with a built-in liquid crystal indicator. The device can search for wood, various types of metals, while detecting live electrical wiring, it issues an audible warning signal, duplicated by a red LED. The Focus button is used to more accurately determine the location of the found object. Location can be marked through a through hole in the center of the detection circuit.

Digital detector Bosch PDO Multi

A budget model that has all the capabilities of more expensive Bosch devices. It quite accurately determines the various materials inside the walls, identifies the presence of electrical wiring at potential. The location of the expected location of the found elements or refined using the Zoom function can be marked through the sensor target.

Summary table of the capabilities of the devices in question:

Sensor	Indicator screwdriver	Black&Decker BDS300	Zircon TriScanner PRO SL	Skil 0550 AA	Bosch PDO Multi
Detectable items	Live wires	Live wires, ferrous metals, non-ferrous metals, wood	Live wires, ferrous metals, non-ferrous metals, wood	Live wires, ferrous metals, non-ferrous metals, wood	Live wires, ferrous metals, non-ferrous metals, wood
Ability to determine the depth of the object	not	Yes	not	Yes	not
Declared metal detection depth	not	50 mm	38 mm	60 mm	60 mm
Declared depth of detection for non-ferrous metals	not	50 mm	76 mm	80 mm	80 mm
Wood detection depth declared	not	19 mm	19 mm	20 mm	20 mm
Price, rub.	150	1250	1950	2400	4000

The use of universal measuring instruments that scan the internal structure of the wall makes it possible to minimize the possibility of accidental electric shock, keep the instrument intact, and easily rebuild the premises. The only drawback of all considered devices is their versatility. They easily cope with the search for elements in a homogeneous structure, but they can give erroneous information at the junction of more than two dissimilar objects. It is necessary to “adapt” to the work of each of the scanners in order to correctly interpret the signals issued by the device.