The need to measure electricity arises not only among employees of the relevant profile, but also among ordinary people. In this case, electrical clamps become indispensable, which are distinguished by their convenience and ease of use.
Varieties
This tool allows you to measure almost all electrical parameters, such as voltage or current. At the same time, the operation of the network does not change in the process, and it does not break. Devices are divided into several types depending on the measured values:
- ampervoltmeter;
- wattmeter;
- ammeter;
- phase meter;
- ohmmeter.
The most popular clamp meters are needed to determine the alternating current in the conductor. They take into account the physical processes of the current transformer, which has two windings. The first is a bus with measured parameters, and the second is connected to a special magnetic core.
What are clamp meters used for
Bthey are primarily used to calculate network load. In a single-phase version, work is carried out in the following sequence: measurements are taken on the incoming conductor, the obtained parameters are multiplied by the mains voltage and the cosine of the interphase angle (in the absence of a reactive load, it is equal to one).
Also, with the help of such a tool, you can determine the power of electrical equipment or household appliances. The result is calculated according to the formula, which should take into account the value of the current in a certain section of the circuit.
In addition, current clamps are suitable for checking electrical metering devices, in particular, to determine the correctness of their functioning. So you can find out if there are any discrepancies in the meter readings and actual energy consumption.
Design
The main elements of the tool is the working part that makes measurements, winding and magnetic circuit. The latter is a handle, between it and the working element there is a winding that acts as insulation. All units have this design, regardless of the specifics of work and the measured voltage. It is worth noting that in one-handed tools there is no handle, its function is performed by an insulating connection.
Electrical measuring and insulating tools are divided into two types depending on what the electrical clamps are intended for, that is, on the power of the network. Two-handed devices are suitable for work with voltage up to 10 kV, while the limit of one-handedis 1 kV. The first option provides measurement without disconnecting the mains, while the indicators must comply with the established standards: the length of the handles must be more than 13 cm, and the insulating piece must be at least 38 cm. Equipment used for low-power networks does not have such requirements.
Terms of Use
First you need to open the tool and take one cable with it, which can have any phase. After closing, the parameters of the determined value are displayed on the screen. If you need to take measurements in a place with difficult access, you can use a special button designed to fix readings. That is, the values will be displayed on the screen even after disconnecting from the conductor. Use is possible on installations of any kind, both closed and open. Outdoor measurements should only be taken when the weather conditions are suitable and there is no precipitation.
Work with electrical clamps is carried out only when equipped with special dielectric gloves. Also, the person involved in the measurement must be on a surface that has insulating functions. The tool is subject to a systematic check in case of intensive use, it is based on a high level of voltage and is produced every two years. When buying a device for working at home, you need to pay attention to the presence of a manufacturer's check, which is indicated on a special stamp. Despite the fact thatelectrical pliers are available to everyone, you must be careful when using this tool and follow the established rules. It is desirable that measurements be made by two people - one is engaged in the removal of parameters, and the other reads and writes the total values.
How to choose
Quality materials used for manufacturing is the main selection parameter. There are many cheap Chinese-made tools on the market today, but they are usually made of low quality rubber and plastic and have a characteristic pungent odor.
The cost of such products is small, as well as the service life. At the same time, if you need digital electrical meters for domestic use, you should not choose devices with an extensive list of functions and possibilities of use, since most of them will remain unclaimed, and their price is quite high. The best option would be a device that measures voltage, resistance and current strength.
Preparation for use
Works can be carried out in current-carrying elements with or without insulation. Electrical pliers must be carefully inspected for defects before use, after which the handle and insulating element must be wiped with a clean, dry cloth. Also, during the inspection, you need to pay attention to the joints of the parts of the magnetic circuit: they should not have traces of corrosion and contamination, and the insulating part should haveuniform coverage without visible damage. It should be noted that rust particles on the magnetic circuit will reduce the fit of its elements, as a result, the measurement results will be incorrect. As mentioned earlier, dielectric gloves are an essential addition to the tool.
What you need to know
In the process of measurement, electrical measuring clamps must be kept on outstretched or bent arms, while they should not touch grounded and current-carrying cables. This is necessary to ensure safety and prevent accidental contact of the operator's hands with live parts.
Special materials are used for the manufacture of the insulating part and the handle. The working part can have a metal base or be made of insulating material. If steel was used for the manufacture of sponges, then pads must be fixed on them to prevent damage to the fuse holder during manipulation.
Changing fuses without removing the voltage is carried out in safety glasses. Before use, the pliers are inspected to check their serviceability and the integrity of the varnish coating of the insulating parts.
Features
Clamp meter prices may vary depending on workmanship, features and designs. On average, such a tool will cost between 3000-4000 rubles.
From the side of the handles on the insulating elementthere is a limiter in the form of a stop or ring, the diameter of which is 10-15 mm larger than the size of the handle. The working part must have an ergonomic shape that provides a tight grip on the electrical protective equipment and the fuse holder. The size of the pliers is determined by the convenience of use.
