Invitro Drive Repair Procedure
I. Cold test: It is normal to measure whether the main circuit is normal when the power is off. The rectifier module of the main circuit, the snubber resistor, the DC reactor, the filter capacitor, and the inverter module are damaged.
1. Detecting the rectifier circuit: Find the + and - terminals of the English Witten inverter DC bus (no terminal below CHE2.2KW), and hit the digital multimeter to the diode test file. The black pen is connected to the + end, and the red pen is sequentially hit R, S, T. At this moment, the multimeter should show the normal diode conduction voltage drop, generally between 0.3~0.5V, the big machine is slightly lower, the three phase appears The value should be similar, that is, the three phases should be balanced. If one phase or several phases are too small, the phase rectifier bridge is short-circuited. If it is too large, the phase is now broken open; then the red meter is connected to the end. The black test pen hits the three phases of R, S, and T in sequence, and judges whether it is good or bad by the same basis. If the upper bridge is open to three phases, the pressure drop of the three-phase pipe of the lower bridge is symmetrical, and it can be judged that the snubber resistor or the DC reactor may burn out.
2. Inverter module circuit detection: The same is to put the digital multimeter to the diode test file, the red test pen is connected to the end, the black test pen is connected to U, V, W, and the normal multimeter appears. Generally, it should be between 0.3~0.6V, the big machine should be slightly lower, and the three phases should be balanced. If the value is too small, the internal circuit of the phase module is now short-circuit damaged. Connect the + end, the red test pen is connected to U, V, W in sequence, and judge the good or bad according to the same method as described above.
Second, the hot state test: the so-called hot test is to check the inverter main circuit is normal, the power-on test of the inverter, pay attention to the following points before power-on:
1. Before power-on, confirm that the power input voltage is consistent with the inverter voltage level. If the 380V voltage is connected to the inverter of 220V voltage level, there will be a bomber accident (explosive electrolytic capacitor, varistor, Rectifier module, etc.).
2. Check whether the sockets of the inverter are correctly connected. If the connection is abnormal or loose, the inverter may be faulty. If the drive cable is not inserted or misplaced, the module may be damaged. This part of the line
teaches you the switching power supply maintenance skills
3. Check the DC bus voltage (about 530V) after power-on to see if it is normal, if there is any problem, if there is a problem Initially identify the cause of the problem and make corresponding maintenance treatment. If there is no problem, check the fault record and running time, then carry out the no-load operation, check whether the output voltage is normal, whether the three-phase output is balanced, and the parameters of the no-load operation test are normal. The load test can be carried out. The main indicators of the test are three-phase output voltage, whether the output current is normal, whether the three phases are balanced, whether the overload can be normal, and so on.