Medium frequency power supply check (in broken condition)
1) Power supply: Use a multimeter to check whether the power supply and fuse are charged.
2) Rectifier: consists of 6 fast fuses, 6 thyristors (KP), 6 pulse transformers, 1 regenerating diode. Use a multimeter to check that the fast fuse is closed.
The measurement method of the thyristor is to measure the resistance with a multimeter, the resistance is set to 200Ω, the resistance between the cathode and the anode should be infinity. The resistance between the gate and cathode should be 10-50Ω.
The secondary side of the pulse transformer is connected to the thyristor and the original side is connected to the main control board. Use a multimeter to measure the resistance of the original side at about 50Ω.
The junction pressure drop is about 500mV when the diode is used for continuous flow and the meter is detected in the forward direction, but the reverse is not possible.
3) The inverter contains 4 thyristors, 4 pulse transformers. It can be tested as above.
4) Transformer: Every winding of every transformer should be through. Generally, the primary resistance is in the tens of ohms and the secondary resistance is a few ohms. It should be noted that the original side of the IF voltage transformer is connected in parallel with the load, so its resistance value is zero.
5) Capacitors. The resistance between the two sinks of each set of capacitors should be infinity. The capacitor has four cores, and generally only one core may be broken. When this core is disconnected, the capacitor is still usable and the capacity becomes three-quarters of what it was. Insulate the capacitor housing from the mounting ground, otherwise it will ground the main circuit.
6) Water-cooling cables.Water-cooled cables may break from metal fatigue after prolonged use. An oscilloscope and multimeter can be used to check for breakage.