The density of electronic components used in modern electronic devices has been becoming higher and higher, which will cause thermal coupling between components through conduction, radiation and convection. Therefore, thermal effect has become one of the most important factors affecting the failure rate of electronic components. For some circuits, reliability is almost entirely dependent on the thermal environment. The data shows that for every 10 °C increase in ambient temperature, component life is reduced by approximately 1/2. This is the famous "10 °C rule." We analyzed the test report of a 24-portswitch industrialpoewith fan cooling, we also analyzed the test results of no fan switch and fan switch at ambient temperature of 30, 40, 50.
It can be seen that the impact of temperature on industrial network products is very large. If they are cooled by fans like civilian switches, it can effectively reduce the temperature inside the machine and extend the MTBF of the device, but the life of the fan itself is very limited (2.28 years) (data given by SANYO FAN DATA SHEET). The switch industrial poe
equipment of the subway integrated monitoring system is often operated all the year round, and the operating environment is often harsh. Sand, insects and moisture will directly affect the operation of the fan. The active heat dissipation switch is designed to dissipate heat mainly by the fan. Once the fan fails and is not replaced in time, the "10 °C rule" will work: for every 10 °C increase in the ambient temperature, the component life will be reduced by 1/2. The internal heat accumulation of industrial POE switches will cause the performance of switches to drop quickly until the switches crash. Therefore, the design of the heat dissipation system of industrial switches is particularly important.