Thyristor is the heart of induction furnace, and its correct use is very important to the operation of the equipment. It is normal for a device to damage three or five thyristors a year. If it often burns the silicon, the furnace stops and affects the production, it will cause alarm. The working current of thyristor ranges from several hundred to several thousand amperes, and the voltage is usually one or two thousand volts. Good main control board protection and good water cooling conditions are necessary
Overload Characteristics of thyristor: the damage of 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, the silicon is definitely damaged under overpressure. Considering the surge voltage, manufacturers often choose silicon components according to 3-4 times of the working voltage when manufacturing equipment, When the rated working voltage of intermediate frequency cabinet is 750V, two 1400v silicon elements are selected to work in series, which is equivalent to 2800v voltage
The correct installation pressure of thyristor: 150-200kg / cm2. When the equipment leaves the factory, it is usually pressed by hydraulic press. Manual use of ordinary wrench can not reach this value with the maximum force, so when manual installation and pressing, there is no need to worry about the silicon will be crushed; if the pressure is loose, it will burn silicon due to poor heat dissipation
Thyristor radiator structure: water cooling cavity + multi copper column support. If the circulating water is too hard, it will scale in the water cavity, causing poor heat dissipation; if the water cavity enters leaves and other debris, it will also cause poor water flow
The factory test temperature of silicon controlled rectifier is 100 ℃ (junction temperature). Generally, the normal operation of the electric cabinet can be ensured when the circulating water temperature of the electric cabinet is kept below 40 ℃. The handheld infrared thermometer is very useful. The 350 ℃ thermometer is only a few hundred yuan, which is not too expensive. It can be used to measure the temperature of the silicon controlled rectifier and the radiator of the working power supply, so as to find the abnormal points in time and deal with the faults
The surface of the radiator must match the dimension of the component surface to prevent the device from being damaged due to pressure deviation and deflection. The surface of the radiator must be flat and smooth. It is suggested that the surface roughness of the radiator surface should be less than or equal to 1.6? M, and the surface flatness should be less than or equal to 30? M. during installation, the component surface and the radiator surface should be clean, clean, and free of oil and other dirt
During the installation process, the pressure is required to be applied through the center line of the element, so that the pressure is evenly distributed in the whole contact area. When the user manually installs, it is recommended to use a torque wrench to alternately and evenly apply force to all fastening nuts, and the pressure should meet the specified requirements
When reusing the water-cooled radiator, special attention should be paid to check whether the surface of the radiator is smooth and smooth, whether there is scale and blockage in the water chamber, especially whether the surface of the radiator is sunken. In case of the above situation, it should be replaced
Yiphee Electric Furnace Co.,Ltd specializes in producing induction smelting furnace.Tel(WhatsApp):+86-13450756789, yiphee@yiphee.cn