2. The main circuit structures of Siemens AC drives are similar
3. The drive of Shenyang machine tool is the core of the power part, and more than 70% of its failures are power part failures. First, check whether the intermediate DC voltage is normal. If it is not normal, check the rectifier or filter circuit. If it is rectified by a thyristor, there may be a fault in the trigger control circuit. This can be detected with the help of an oscilloscope. If the intermediate DC voltage is normal, you can check the inverter power part. In the early products, most of the devices were Darlington power modules with freewheeling tubes. The multimeter makes a preliminary judgment like measuring a transistor. Further, it can be judged by a transistor characteristic grapher. If each power module is normal, further check whether the signal sent to the base of each module is normal.
4. You can add power to each channel separately. In the absence of an enable signal, the base voltage of each base should be the corresponding negative reverse bias voltage, so that the power module is in a cut-off state. If a certain channel is found to have no reverse bias voltage or If the voltage deviation is large, it can be determined that there is a problem with the path.
5. For further inspection, the inverter control device (pre-amplification link) of Shenyang machine tool should be overhauled, and the failure rate of this part is relatively high. One is the fault caused by this part itself; the other is that if the inverter power part is damaged, most of the pre-amplifier parts are also damaged, which is the key to repairing the driver.
6. The preamplifier part of Shenyang machine tool consists of 6 identical circuits. It is easy to find the optocoupler and the output terminal of the preamplifier, add the required source, and measure the voltage at the output terminal, which should be all negative values (the B terminal is measured based on the E terminal), generally about -5v , If a certain circuit cannot generate a negative bias voltage, the power module will be damaged as soon as the drive circuit is turned on, and the fault will be further expanded. Then add an artificial positive signal to the optocoupler to make the optocoupler turn on. At this time, the output voltage should be positive, generally about 8v. At this time, if you can clearly see the presence or absence of the optocoupler input signal, If the voltage at the output varies between positive and negative, the channel is already normal. Use this method to test the 6-way preamplifier channels respectively. If the Shenyang machine tool test is normal, it can be basically determined that the control loop is normal. However, if it is found that a certain circuit is different from the basic normal circuit, it is certain that the circuit is faulty, and the comparison method (measurement of resistance or voltage) can be used to compare it with the normal circuit point by point, and finally find the damaged components and replace them. until the test result is the same as the normal path.
Note: It must be added here that the positive and negative bias voltages in Shenyang machine tools are different due to the different designs of various drivers. The test should be based on the same positive and negative bias voltages of each channel.
At Be-cu.com,we use advanced equipment to offer you Unparalleled precision for producing metal and plastic machining parts
- We combine the latest Cnc milling and turning processes with proprietary technology to deliver high quality, on-demand parts.
- Our team of engineers and machinists program the equipment to optimize cutting time, surface finish, and final tolerance to meet your design specifications
- We specialize in cnc precision machining, single part prototyping, short to medium production runs, manufacture parts on time, every time, so you can stay ahead of schedule
- CNC machining can create very similar parts to series parts. It is often more efficient and faster than other rapid prototyping technologies for the manufacture of a quantity of prototypes between 1 and 10 parts . We also recommend CNC machining for parts with large sizes (greater than 600 mm).