Voltage indicators are portable devices used to establish the presence or absence of voltage on all kinds of current-carrying parts of mechanisms and apparatus, as well as elements of the electrical network.
Carrying out such checks is a vital measure, since when working on disconnected conductive elements, as well as when looking for damage at installations connected to the electrical network, and taking measures to monitor the he alth of various power supply elements, there is a certain probability of people falling under voltage. In turn, voltage indicators are a means that can guarantee the safety of the he alth and life of people working in repair and maintenance services.
However, it should be borne in mind that such devices can only establish the presence of voltage, but cannot measure and show its magnitude. Traditionally, voltage indicators are equipped with a light signal, which provides information about the presence of the desired value on the current-carrying parts. Howeverwith this simple but very effective device, one can judge not only whether voltage is present on any one current-carrying part, but also to say that there is no phase-to-phase voltage that can occur between two or more current-carrying elements.
Modern voltage indicators can be divided into two groups. The first includes devices for indicating the absence of the desired parameter in networks and installations up to 1000 volts. The second includes all other protective equipment that are designed to work with electrical installations over 1 kV.
Let's consider each of them in more detail.
Low voltage indicator - a device widely used both in industrial and domestic conditions. Among modern means of protection up to 1 kV, single-pole and two-pole devices are distinguished. Their fundamental difference lies in the principle of operation: two-pole ones can show the presence of voltage between two current-carrying elements of an electrical installation, while single-pole ones need contact with any one conductive part. It should also be noted that the first of these devices can be used in both AC and DC networks, while the latter can only be used to determine the presence of alternating current. In case of contact with a live DC network, the single-pole voltage indicator will give a false result. The presented pointers are recommended to be used for checking secondary voltage circuits, meters,fuses, switches and other elements of the electrical network.
The high voltage indicator is used for similar purposes in networks over 1 kV. These devices have a structure similar to protective equipment up to 1 kV and include working, insulating and signal parts. According to the rules of use, dielectric gloves must be used when working with such indicators.
