How to reduce the probability of SCR burning out(1)
Silicon controlled rectifier is the heart of the medium frequency power supply of the medium frequency furnace. Its correct use is crucial to the operation of the equipment. It is normal to occasionally damage a few thyristors during the use of the medium frequency furnace. If silicon is burned frequently, it will cause vigilance. Silicon controlled rectifier has a working current of several thousand amperes and a voltage of 1,000 to 2,000 volts. Good main control board protection and good water cooling conditions are necessary.
Overload characteristics of thyristor: Damage to thyristor is called breakdown. Under normal water cooling conditions, the current overload capacity can reach more than 110%. No voltage overload capacity, that is to say, silicon is definitely damaged under overvoltage. Considering the surge voltage, manufacturers often choose silicon components according to 3-4 times of the working voltage when manufacturing equipment. For example, when the rated working voltage of the intermediate frequency cabinet is 1750V, two silicon components with a withstand voltage of 2500V are selected to work in series, which is equivalent to a withstand voltage value of 5000V V.