Our company controls the temperature of the thermal protector by the method of full inspection and sorting. According to the requirements of GB13232-91 (idt IEC34-11-3) "General Rules for Mounted Thermal Protectors for Rotating Electrical Machines", we use the hot air drying furnace method for detection.

Our testing equipment is two computer-controlled automatic temperature detection boxes, with a temperature field uniformity of +/- 0.5 ℃ in the working chamber; The fluctuation of temperature field is +/- 0.6 ℃.

After we put the products into a temperature detection box, the entire production process is automatically monitored by a computer, and the heating rate of the temperature box is maintained at 0.5K/min. After the detection is completed, all the results are printed out by the computer, and then the temperatures are sorted. When the sorting is completed, it will be reported to the quality department for random inspection. The products can only be delivered after passing the random inspection.

The national and IEC have strict measurement standards for temperature measurement of thermal protectors. It should be noted that different detection methods have certain measurement errors. Even for the measurements conducted with the same measurement method and the same testing furnace, there are systematic errors in the data due to the influence of temperature field uniformity and fluctuation. The magnitude of the error is influenced by the difference between the two measurement methods and measurement systems. Therefore, we need to have a detailed understanding and communication with users, confirm the systematic errors of equipment, and unify testing methods, so as to reduce misunderstandings in products acceptance due to errors caused by systems and measurements.