Fault phenomenon: The equipment can be started, but the voltage rise is not high, and it is easy to generate overcurrent or overvoltage faults. At the same time, it can be observed that the phase failure fault light flashes.
Fault analysis and processing: This is similar to the above fault No. 3, but different. This is a problem with the three-phase incoming power supply.
a. The incoming contactor has a contact that is not well contacted. When the voltage is applied, the armature suction is weakened, resulting in a phase loss.
b. High-powered power supply, the incoming circuit breaker has a contact that is not well contacted.
c. The synchronous signal lines K4, K6, and K2 introduced from the No. 4, No. 6, and No. 2 rectifying thyristors have poor contact.
d. There is a bad contact at the high voltage end, and there is a phenomenon of arc discharge.
19 Fault phenomenon: The equipment can be started, but the voltage rise is not high. The reactor sound is particularly large and dull. When the voltage rises, it is unstable and there is tremor. There are overcurrent or overvoltage faults from time to time, and sometimes even the inverter tube is burned out, but it is good to disconnect the rectifier circuit of the inverter circuit.
Fault analysis and processing: Most of these faults are problems with the reactor.
a. The inductance of the reactor is larger than normal, the magnetic circuit is saturated, the freewheeling filter is not used, and the current of the AC and DC terminals cannot be separated. The number of turns of the reactor coil is larger than normal.
b. The air gap plate of the reactor is thinner than normal, and the inductance is increased. At this time, the air gap plate is thickened.
c. The coil of the reactor has water seepage and the inter-turn insulation reduces the occurrence of sparking and discharging.
20 failure phenomenon: For the new melting furnace or knotted diathermy furnace, the oven can be started at the beginning, the voltage can be raised to the maximum value, but after the oven is stopped for a period of time, it is not good to start after the shutdown, and the voltage is also increased after the rise. It is not high, sometimes it stops or overruns.
Fault analysis and processing: Most of these faults are caused by sensors.
a. For the smelting furnace that has just been knotted, since the binder will generate a large amount of water during the oven, a large amount of water droplets are accumulated between the inductors, causing the insulation between the turns to be reduced. At this time, the oven voltage should not be very high. High, increase the voltage after drying.
b. Some sensor coils are directly knotted with knotting without immersion varnish. This kind of furnace should pay more attention to the moisture content of the oven.
c. Some knotted diathermy furnaces will have tiny gaps in the knotting after a period of use. If the inductor insulation is not handled properly, a small amount of oxide scale will enter the turns of the induction coil, causing the daytime. Short circuit, easy to generate overcurrent phenomenon. It is better that the inductor coil is wrapped with mica tape and then dipped and dried, and the final knotting effect is better.
