The need to measure electricity arises not only among workers of the corresponding profile, but also among ordinary people. In this case, the electric meter becomes indispensable, characterized by its 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 network does not change in the process, and its break does not occur. Devices are divided into several types depending on the measured values:
- ampervoltmeter;
- wattmeter;
- ammeter;
- phase meter;
- ohmmeter.
The most popular clamp meters required to determine the alternating current in the conductor. They take into account the physical processes of a current transformer, which has two windings. The first is a bus with measured parameters, and the second has a connection to a special magnetic circuit.
What are the electrical clamps intended for?
They are primarily used to calculate network load. In the single-phase version, the work is performed in the following sequence: measurements are made on the incoming conductor, the obtained parameters are multiplied by the voltage in the network and the cosine of the phase angle (in the absence of reactive load, it is equal to unity).
Also, using a similar tool, you can determine the power of electrical equipment or a household device. The result is calculated by the formula, which should take into account the current value at a certain section of the circuit.
In addition, clamp meters are suitable for checking electrical metering devices, in particular, for ascertaining the correctness of their functioning. So you can find out if there are any discrepancies in the meter readings and the actual energy consumption.
Design
The main elements of the tool is the working part, making measurements, winding and magnetic circuit. The latter is a handle, between it and the working element is a winding that acts as insulation. All units have this design, regardless of the specifics of operation and the measured voltage. It should be noted that in one-handed tools the handle is absent, its functions are performed by an insulating connection.
Electrical and insulating tools are divided into two types, depending on what the electrical meter is designed for, that is, the power of the network. Two-handed devices are suitable for voltages up to 10 kV, while the limit of one-handed devices is 1 kV. The first option provides measurement without opening the mains, and the indicators must comply with the established standards: the length of the handles must be more than 13 cm, and the insulating part must be at least 38 cm.No similar requirements are applied to equipment used for low-power networks.
Terms of use
First you need to open the tool and take them one cable, which can have any phase. After closing, the parameters of the determined value are displayed on the screen. If you need to make measurements in a place with complicated access, you can use the special button designed to record 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 carried out under suitable weather conditions and no precipitation.
Work with electrical clamps is carried out only when equipped with special dielectric gloves. Also, the person involved in the measurement, you must be on a surface with insulating functions. The tool is subject to systematic testing in case of intensive use, it is based on a high voltage level and is produced every two years. When buying a device for work at home, you need to pay attention to the presence of a check by the manufacturer, which is indicated on a special stamp. Despite the fact that the ticks are available to everyone, it is necessary to exercise caution when using this tool and follow the established rules. It is advisable that measurements be made by two people - one is engaged in taking parameters, and the other reads and writes the final values.
How to choose
Quality materials used for manufacturing - this is the main parameter of choice. There are many budget-made Chinese-made tools on the market today, but they are usually made of low quality rubber and plastic and have a distinctive pungent odor.
The cost of such products is small, as well as the service life. At the same time, if you need digital electrical measuring pincers 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 the price for them is quite high. The best option would be a device that measures the voltage, resistance and current.
Preparation for use
Work can be carried out in current-carrying elements both with insulation and without it. Before use, the electrical pliers must be carefully inspected for malfunctions, 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 dirt, and the insulating part should have a uniform coating without visible damage. It is worth noting that rust particles on the magnetic circuit will reduce the contact density of its elements, as a result, the measurement results will be incorrect. As indicated earlier, dielectric gloves are an essential complement to the tool .
What you need to know
During the measurement, the electrical clamp must be held on outstretched or bent arms, while they should not touch grounded and live cables. This is necessary to ensure safety and to prevent accidental contact of the operator’s hands with live parts.
Special materials are used to make the insulating part and the handle. The working part can have a metal base or can be made of insulating material. If steel was used for the manufacture of sponges, overlays should be fixed on them to prevent damage to the fuse holder during manipulation.
Change fuses without removing the voltage is carried out in goggles. Before use, the mites are inspected to check their serviceability and integrity of the varnish coating of the insulating parts.
Features
On pincers, the electrical measuring price may vary depending on the quality of workmanship, available functions and design. On average, such an instrument will cost in the amount of 3000-4000 rubles.
On the side of the handles on the insulating element there 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, providing tight compression of electrical protective equipment and the fuse holder. The size of the ticks is determined by the ease of use.