Countermeasures Against Influencing Factors of Two-color Infrared Thermometers
Electrical equipment faults, whether caused by current effects or heating faults (conductive circuit faults), have a heating power proportional to the square of the load current value. The heating fault caused by voltage effect (insulation medium fault) has a heating power proportional to the square of the operating voltage. Therefore, the working voltage and load current of the equipment will directly affect the effectiveness of infrared detection and fault diagnosis. The increase in leakage current can cause uneven voltage in some high-voltage equipment. If there is no load running or the load is very low, it will cause the equipment to malfunction and heat up insignificantly. Even if there are more serious faults, they cannot be exposed in the form of characteristic thermal anomalies. Only when the equipment is operating at rated voltage and the load is higher, the heating and temperature rise become more severe, and the characteristic thermal anomalies of the fault point are exposed more clearly. Therefore, in order to achieve reliable detection results during infrared detection, it is necessary to ensure that the equipment operates at rated voltage and full load as much as possible. Even if continuous full load operation cannot be achieved, an operation plan should be developed so that the equipment can operate at full load for a period of time (such as 4-6 hours) before and during the detection process, allowing sufficient heating time for the faulty part of the equipment and ensuring stable temperature rise on its surface.
Due to the fact that in infrared diagnosis of electrical equipment faults, the fault diagnosis criteria are often based on the temperature rise of the equipment at rated current. Therefore, when the actual operating current during detection is less than the rated current, the temperature rise at the fault point of the equipment measured on site should be converted to the temperature rise at rated current.
