How to troubleshoot when the high-frequency quenching equipment finds a fault?
1. Fault phenomenon The high-frequency quenching equipment is running normally, but a sharp beep-beep can be heard from time to time, and the DC voltmeter slightly oscillates. Use an oscilloscope to observe the voltage waveform at both ends of the inverter bridge. It can be seen that the period of the inverter is short, one cycle fails or a short period of indeterminate period fails, and the parallel resonant inverter circuit fails for a short time, but the self-recovery period is short, and the failure is generally the inverter control. Part of it is disturbed by the rectifier pulse, and the aperiodic short-term failure is generally caused by the poor insulation between the turns of the intermediate frequency transformer.
2. Fault phenomenon After the high-frequency quenching equipment has been running normally for a period of time, the equipment has abnormal sound, and the meter reading shakes and the equipment is unstable. Abnormal noise occurs after the equipment has been working for a period of time. The work is unstable, mainly because the thermal characteristics of the electrical components of the equipment are not good. The electrical parts of the equipment can be divided into two parts: weak current and strong current, and the control part can be detected separately to prevent damage. When the main circuit power device is not connected to the main power switch, only the power supply of the control part is turned on. After the control part works for a period of time, use an oscilloscope to detect the trigger pulse of the control board to see whether the trigger pulse is normal.
On the premise of confirming that there is no problem in the control part, turn on the equipment, and after the abnormal phenomenon occurs, observe the voltage drop waveform of each thyristor with an oscilloscope, and find out the thyristor with poor thermal characteristics; if the voltage drop waveform of the thyristor is All are normal. At this time, we should pay attention to whether there are problems with other electrical components, and pay special attention to circuit breakers, capacitors, reactors, copper bar contacts and main transformers.