Use a multimeter to check whether the filter is good or bad
If there is an internal circuit break in the filter, the inverter will stop working, because the filter is usually connected in series to the power supply of the inverter.
If the filter fails, it may cause interference to the equipment around the inverter, which may cause the elevator to work abnormally, or the equipment around it to not work properly, resulting in noise, abnormal movement, etc. In serious cases, Will cause damage to these sensitive electromechanical equipment
The difference between active filters and passive filters:
1. Active filters are electronic, while passive filters are mechanical;
2. The active filter detects a certain harmonic order and then cancels it. The passive filter forms a certain harmonic channel through the cooperation of the reactor and the capacitor to absorb the harmonics;
3. Use passive filters because of capacitors.
For the surface acoustic filter, its two input pins 1 and 2, its two output pins 3 and 4, and the input and output pins are insulated (as shown in the figure), and they are all insulated from the shielding pin 5. Therefore, when measuring the resistance between two using the R×1 k Ω range of a multimeter, it should be ∞. If there is a resistance of hundreds or thousands of ohms, it indicates that the performance of the surface acoustic filter has deteriorated. If the resistance is very small, it indicates that the surface acoustic filter has broken down.
