Changzhou Lima Automation Co

Series/ Determine the location of the fault point through the display of Mitsubishi inverter.
Overcurrent, this may be the most common fault in the frequency converter. We first need to eliminate faults caused by parameter problems.
For example, current limitation and too short acceleration time may lead to overcurrent. Then we must determine whether there is a problem with the current detection circuit.
For example, we sometimes see the current display on the panel when the motor is not connected. Where does the current come from? At this time, it is necessary to test its three Hall sensors. In order to determine which phase sensor is damaged, we can turn on the machine every time when removing a phase sensor to see if there is a current display. After this test, the fault can basically be eliminated.
For overvoltage, we must first eliminate the fault caused by parameter problems. For example, the deceleration time is too short, and overvoltage due to regenerative load, etc. Then we can see if there is a problem with the input side voltage. Finally, we can see if there is a fault in the voltage detection circuit. The voltage sampling of the general voltage detection circuit points are all the voltages of the intermediate DC circuit. Let's take it as an example. After it is sampled by the DC circuit (the left and right DC), it is stepped down through a resistor with a larger resistance and then isolated by an optocoupler. When the voltage exceeds a certain value, it displays overvoltage (this machine uses a digital tube display). You can check whether the resistor has oxidized value, whether there is a short circuit in the optocoupler, etc.
Under voltage. We can first check whether there is a problem with the input side voltage, and then look at the voltage detection circuit. Fault judgment is the same as overvoltage.
Rapid fuse failure. Most of the frequency converters currently launched have a fast-fuse fault detection function. (Especially high-power frequency converters) Take
frequency converters as an example. It mainly samples and detects the voltage at the front and back of the fast fuse. When the fast fuse is damaged, there will inevitably be no voltage at one end of the fast fuse. At this time, the isolation optocoupler will act and an alarm will occur. Replacing the quick fuse should solve the problem. In particular, it should be noted that it is necessary to determine whether there is a problem with the main circuit before replacing the fast fuse.
Overheating is mainly caused by poor internal heat dissipation of the inverter. We can check the cooling fans and ventilation channels.
Short circuit fault. We can check whether there is a short circuit inside the inverter. Let's take Mitsubishi as an example. If we check the internal circuit, there may not necessarily be a short circuit. At this time, we can check that the power module may be faulty. If the drive circuit is normal, replacing the power module should be able to repair the machine.