Voltage tester: instruction. Which voltage tester to buy: tips

Work with existing electrical installations and cable-conductor products is associated with a risk of electric injury. The reason for this is banal - the directed motion of charged particles along a conductor can not be seen with the naked eye. Therefore, during installation, maintenance and repair of electrical equipment, a voltage tester must always be used , Capable at least just to show the presence of potential, even without measuring its effective value.

A vital necessity

The voltage tester is a portable electrical appliance designed to indicate the availability of potential on conductive sections. In electric systems, not all wires are dangerous when touched. The current beats those on which the phase is present, but the zero or ground wire is safe. True, there are reservations.

To understand what the voltage tester might need at home, the easiest way to give a series of examples. Imagine that there was a need for a grinder (Bulgarian), which was temporarily provided by a neighbor. Models are still used, the body of which is made of metal. How to check that the internal circuits are intact, and there is no voltage on the shell? To work with such a tool, without first checking it, is a very risky undertaking. Or, for example, you need to change the burned light bulb in the lamp, the glass bulb of which has fallen, and only the cap remains in the cartridge. Believe the electricians who performed the wiring, that the switch really breaks the phase wire, and not zero, and bravely unscrew the base? It is doubtful! There are a lot of similar examples. Having its own voltage tester, it is always possible to quickly check the electrical installation site. In addition, more complex models allow for the measurement of the actual value.

Basic Opportunities

To verify the fact of the availability of a potential (phase), there is no need to spend money on the purchase of an expensive device. The easiest voltage tester is an indicator screwdriver. Inside its transparent case there is a small light bulb that lights up when touched by a sting to the area under potential.

How does the tester check the voltage? On the upper side of the dielectric handle there is a special metal "penny". To check the chain section, it is necessary to touch the screwdriver with the tested conductor with a finger, and with a finger to the "pyatka". At the same time, the stinger can not be touched. If the phase is present, the light bulb inside the screwdriver will light up. The second name of such screwdrivers are probes. They are rated for voltage up to 250 V.

It is not recommended to buy the cheapest models, as in the case of a breakdown of an internal resistor or an error in the circuit, you can get an electric shock. Improved solutions do not require direct contact with the circuit. The sting of such a screwdriver should simply be carried over the conductor. Calculated for voltage up to 600 V. In addition, some models are equipped with a display showing the actual value.

There are modifications that do not require a finger touching the "pyatak". You can purchase a voltage tester without any problems. The instruction must be read to him. This will not only keep the device from damage, but also protect the person himself.

Dual screwdriver

At the same time, the above-described tool is too narrowly specialized. If it is required, for example, to perform the simplest task - phasing, then it turns out to be useless due to the presence of only one pole. In this case, it is worth paying attention to a more perfect tester - a dual low voltage indicator. Structurally it can be compared to two screwdrivers connected by a wire. The maximum permissible voltage is 1 kV. The cost is from 100 rubles.

Consider how to measure the voltage of a tester of a given class. The stall electrode of one part needs to touch the verified section of the chain, and the other to the "ground". It can be any grounded conductor, because dangerous potential through the device does not flow. If the bulb inside the case lights up, it will mean that there is tension on the site. If it is necessary to perform phasing, you need to touch one probe to one phase wire, and the other to the other. If the phase on the wires is the same, then there will be no indication. Simpler models show the fact of the presence of the phase, while sophisticated ones contain several LEDs on one of the handles, which can be used to determine the voltage value.

Indicator

The next class of similar devices are voltage indicators. The most famous models are the Ukrainian manufacturer "Contact". Their cost starts from 400 rubles. Structurally, these testers are remotely similar to twin screwdrivers, but they have more advanced capabilities. In particular, with their help it is possible to determine the presence of a phase, approximately to estimate the level of voltage by the illumination of LEDs, to check the conductor for integrity. Inside the capacitor is located, which must be pre-charged by touching the probes to 220 / 380V for 20-30 seconds.

How to find a phase wire

Consider how to test the voltage with a tester. One of the gauges of the device should touch the verified area of the electrical installation, and finger of the hand - to the electrode Ph on the body. If the corresponding LED lights up, then this conductor is live. True, there is one nuance that is very well known to people who know how to work as a voltage tester of this type. It consists in that the phase check via Ph is not always correct, since the indications can be influenced by interference from nearby conductors with current. Let's explain: there are two nearby wires, one of which is energized, and the other is de-energized. If you do not know how to work the voltage tester in detail, then when checking both conductors by touching them and the Ph electrode, it turns out that, according to the indication, they are both phase ones. However, it is not. Just in the de-energized induced EMF under the influence of an electromagnetic field. It reaches only a few tens of volts, but it is determined by the device and is not a malfunction in its operation. In such cases, if there are doubts, it is necessary to do otherwise: touch one probe to the area under test, and the other to a known grounded point. If there is a phase on the conductor, the LEDs will light up and show an approximate value of 220 V. By the way, having access to a three-phase voltage, you can check the area by touching not only the ground, but also other phase wires. That is, the actions are similar to phasing. In the event of the presence of a voltage in the section, contact with the phase of the opposite phase will result in the illumination of the LEDs by 380 V.

The peculiarity of working with the tester-pointer

The specification says that the current flowing through the circuit of the device, when testing the potential of 220 V is not more than 10 mA. That is, if one of the probes is touched to a section of the electrical installation under voltage, then an ammeter connected to another probe will show the above current value. Theoretically, this is a dangerous value (100 mA - deadly), in practice, however, hand touch is possible, however, as long as the internal circuits of the device are working.

Preparation for work with "Contact"

All solutions, in which two units are connected by a wire, are potentially dangerous. One of their disadvantages is the possibility of damaging the connecting conductor with visible shell integrity. Therefore, when checking the presence of a phase through Ph, it is recommended to use the probe of the unit on which the electrode is placed. In this case, the LED will work even if the wire is damaged. Nevertheless, before performing the measurements, it is necessary to connect the device to the network and hold it for 20 seconds - during this time the internal energy source will be charged. After that, you need to connect the probes together. If the wire is full, then the "test" LED will light up.

Universal tool

In addition to all the devices listed, there is another type - multimeters. Perhaps this is the most perfect voltage tester. How to use it, we now tell. The cost of the most affordable models starts from 300 rubles. The order of work is described in the accompanying instruction, which you need to read. If we talk about checking the voltage, then one wire must be connected to the COM connector, the other to V. Then set the switch to AC 750 mode (alternating current type, 750 V limit) and touch the probes to "ground" and the tested area.

conclusions

Thus, one can not give an unambiguous recommendation for the choice of the device. Everything depends on the range of tasks that are planned to be solved. If you have extra funds, it is best to purchase a universal multimeter.