The use of pyrometers in power plants

In the process of performing preventive work in electrical equipment, in accordance with the current rules and instructions, the quality of bolted and contact connections is constantly monitored. The need for this management is explained by the fact that in places with poor electrical contacts, the so-called Transient resistance and significant overheating occurs in such places.

The permissible heating of contact connections and wires is determined by the rules.

Several methods are used to find hotspots.

1. Visual inspection of connections and contacts. Cleaning of contacts and tightening of bolted and screw connections, tightening of stud nuts (see — Visual inspection in electricity).

2. Determining the temperature by feeling the joints after removing the voltage (dangerous, takes time to discharge the circuits, extremely labor intensive)

3. Sticker "temperature signs" - stickers with a composition applied to them, which changes color when exposed to temperatures above a certain threshold. These brands allow you to control the temperature.There are two types: they restore their color after cooling and change color irreversibly when overheated.

4. In practice, and this is allowed by the rules, the following method is used to determine the temperatures of live elements under voltage: a piece of paraffin, usually a candle, is inserted into the holder of an insulating rod, and with this piece the electrician touches the contacts and joints of the busbars . Since the melting point of paraffin is from 63 to 70 ° C, the fact of wax melting on the contact joint indicates heating that is close to or exceeds the dangerous limit. There is no need to talk about the dangers of this method of measurement. It is necessary to open the bars of the protective fence, remove or tighten the blocking contacts, etc.

5. Use of infrared diagnostic methods - manual non-contact pyrometers and thermal imaging equipment.

However, checking the temperature of the live busbars and the contacts of the switching devices is a rather dangerous procedure.

For measuring the temperature of elements of electrical equipment, connections, sockets, etc. it is recommended to use a non-contact infrared thermometer (pyrometer).

The temperature of many elements of electrical equipment provides relatively accurate and complete information about the condition of these elements and their operation. So if we compare the temperature of the connections of busbars with current or wires at different points, then when the same current flows in areas with poor electrical contacts, due to the high resistance of the transition, the heating of these areas will be greater, and the temperature will become an indicator of the quality of the connection and a signal to carry out repair work.At the same time, in order to identify defective areas, there is no need to turn off the equipment and identify these areas by feeling with hands or to carry out continuous tightening of all threaded connections without exception. A non-contact handheld infrared pyrometer without touching live, rotating or moving parts of the equipment allows you to almost immediately assess the condition of the equipment, identify potentially dangerous areas and quickly make the right decision.

For work in industrial conditions, depending on the nature of the tasks to be solved, the range of measured temperatures and distances to the object, you can choose the models of pyrometers manufactured by Raytek that most fully meet the requirements of a potential user of non-contact pyrometers.

Despite the fact that the most modern achievements of high technology are used in non-contact pyrometers, the use of such pyrometers is available to personnel of any qualification. It is enough to point the pyrometer at the surface of the object whose temperature is to be measured, press the trigger and read the value of the measured temperature from the display. A laser, built into many models, shows either the point in the vicinity of which the temperature is measured, or in some models the multi-beam laser outlines the area where the temperature is measured with bright dots. This is especially useful when the subject has a limited size or low lighting in the measurement area.

Raytek non-contact pyrometers are ideally suited for harsh industrial environments.Ergonomic shape, robust housing, ease of use and great capabilities make devices of this class indispensable for solving the problems of competent operation of equipment and prevention of production accidents.