How to detect the Electrolytic capacitor of the frequency converter?
When measuring with a multimeter, the appropriate range of the multimeter should be selected for electrolytic capacitors of different capacities. According to experience, under normal circumstances, electrolytic capacitors below 47μF can be measured with R×1K file, and electrolytic capacitors larger than 47μF can be measured with R×100 files.
The red meter of the multimeter is connected to the negative pole of the capacitor and the black lead to the positive pole. At the moment of contact, the pointer of the multimeter is deflected to the right by a large margin, and then gradually rotated to the left until it stops at a certain position (back to the infinite position). The resistance at this time is the positive leakage resistance of the Electrolytic Capacitor. The larger the value, the smaller the leakage current and the better the capacitor performance. Then, swap the red and black pens and the multimeter pointer will repeat the above swing. However, the resistance measured at this time is the reversed-phase leakage resistance of the electrolytic capacitor, and this value is slightly smaller than the positive-drain resistance. That is, the reverse leakage current is larger than the forward leakage current. Practical experience shows that the leakage resistance of electrolytic capacitors should generally be more than several hundred kilohms, otherwise it will not work properly.
In the test, if there is no charging in the positive and negative phases, ie, the hands are not moving, it means that the capacity of the capacitor disappears or the internal short circuit occurs; if the measured resistance is small or zero, the capacitor has a large leakage or breakdown breakdown. Can not be used again.
On-road testing: Testing of electrolytic capacitors on roads should only check for serious leakage or breakdown faults, and the accuracy of minor leakage or low-capacity electrolytic capacitor testing is poor. In the road test, the influence of other components on the test should also be taken into account. Otherwise, the value read out will be inaccurate and will affect normal judgment. The electrolytic capacitor can also use a capacitance meter to detect the capacitance between the two ends to determine the quality of the electrolytic capacitor.
