Detection and debugging method of new 3T induction melting furnace
New 3T induction melting furnace main circuit detection
1 Under the normal condition of the rectification part of the intermediate frequency power supply, connect the inverter and the intermediate frequency load. If it cannot start normally, check the inverter main circuit wiring first. If it is normal, but still can't start, you should check the inverter control board; the copyright of the website is: If all is normal, but it can not be turned on normally, there is a problem with the IF power load. The load circuit should be tested on a unit-by-cell basis. The inverter includes 4 fast thyristors and 4 pulse transformers, and the detection method of the main circuit is the same as that of the rectification part.
2) Inverter control and trigger circuit detection of new 3T induction melting furnace
Connect the oscilloscope to the output of the intermediate frequency power supply (check to confirm that the reactor, cable, capacitor, and furnace body are normal), press the inverter switch, and carefully observe whether the IF voltmeter is swinging up a bit, and the oscilloscope has an instantaneous AC sinusoidal current. It means that the inverter meets the oscillation condition, indicating that the angle before the lead is wrong, and the voltage and current angles need to be adjusted. If the adjustment cannot be started regardless of the sample, the component on the pre-pulse pulse, the current transformer, the IF voltage signal transformer, and the potentiometer on the current and voltage board should be detected.
Check if the IF signal transformer is open or shorted. Connect the oscilloscope to both ends of the coil of the IF signal transformer to see if there is an instantaneous start pulse. If not, the IF signal transformer is faulty. In the case of power failure, use the multimeter ohm gear to further check the IF signal transformer. If the resistance of the IF signal transformer is infinite, the circuit is open; if the resistance is zero, it is short circuit, and the IF signal transformer is replaced.
Check whether the current transformer is open or shorted. Connect the oscilloscope to both ends of the current transformer coil to see if there is an instantaneous start pulse. If there is no instantaneous start pulse, you can judge the current transformer is faulty. In the event of a power outage, the current transformer is further inspected with a multimeter ohm gear. If the resistance of the secondary coil of the current transformer is infinite, it is open: if the resistance is zero, it is short circuit, and the current transformer is replaced.
The new 3T induction melting furnace IF signal transformer, current transformer is normal, all. Then check if the sampling capacitor is normal. If the sampling capacitor is normal, check if the potentiometer on the current voltage board is normal. Connect the oscilloscope to both ends of the magnetic plate potentiometer and check for an instantaneous start pulse. ‘Recheck the inverter KK trigger coil is normal. Connect the oscilloscope to the primary end of the inverter thyristor KK trigger coil. If the inverter pulse is not started instantaneously, the fault is triggering the coil. In the case of power failure, use the multimeter ohm gear to further check the trigger coil. If the resistance across the trigger coil is infinite, it is open; if the resistance is zero, it is short circuit and replace the trigger coil.