One of the first factors to consider is the power handling capability of the device. Simply reading the data book does not guarantee accurate comparison data. Engineers must understand how the product performance data listed in the manual is tested and determined. Currently, organizations such as UL, IEC, CSA and DIN do not have uniform standards in determining the power and performance specifications of terminal products. Users need to understand the differences between UL and IEC specifications. Terminals manufactured in Europe are subject to the IEC standard, while products manufactured in the U. S. adopt the UL standard. The difference between the two standards is very large. Engineers who do not know the product specifications will risk considerable risk because the selected devices may not meet the required power levels, or the specifications of the devices are well beyond the design requirements. In Europe, the current rating of a device is determined by monitoring the temperature of the metal conductor when the current increases. When the temperature of the metal pin is 45 degrees higher than the ambient temperature, the measuring staff will use the current as the rated current value (or maximum current value) of the device. The other item in the IEC specification is to allow current value, which is 80% of the maximum current. In contrast, the UL standard will make the metal conductor temperature higher than the ambient temperature by 30 degrees centigrade, and the current value of 90% will be the current nominal value of the device. Thus, the temperature of the metal conductor part is a very important factor in all applications. This is even more important for industrial equipment. Because industrial equipment usually needs to work at temperatures up to 80 degrees celsius. If the temperature of the terminal is 30 degrees or 45 degrees higher than the temperature, the temperature of the terminal will be over 100 degrees centigrade. According to the nominal value type and insulation material adopted by the selected device, the product must work at a current lower than the rated value so as to ensure that they can work reliably in the desired temperature range. Sometimes, materials suitable for compact packaging devices may not be well suited for thermal dissipation, so the current used by such terminals must be much lower than the rated value.
