Below are the questions asked during the live event, along with their respective answers.
Q: Is there a rule of thumb on which component of the filter works better on which frequency? For example, I have a filter that will not work on the lower frequency. Which component should I increase on the filter (more X caps more inductor, more y caps)?
A: Usually we see differential mode components work more on the lower frequencies. This is the differential mode inductance (leakage inductance) of the common mode choke and the X-caps. Adding big X-caps might help in the lower frequency.
Q: Which model of filter do you use with ELEKTRA software DEMO?
A: I am using different filter types. At the moment we are using the FN3288-10-44-C34-R65. Later on, we will use the FN3288-16-44-C17-R65 and FN3287-10-44-C28-R65.
Q: Do we need this filter to pass the EMC conducted emission test? Or should it be included in our design in input of power supply or motor drive ?
A: Usually a filter is always needed if you want to connect your device to the grid. The best placement for the filter is always as close as possible to the noise source. Sometimes this is not possible and a filter could also be used directly at the entry point of a machine, so-called sum filters.
Q: How is the filter attenuation influenced by different source impedance (e.g. generators)?
A: The filter attenuation is influenced by the impedance of the grid and the load. The filter itself is based on creating impedance mismatch and uncouple the grid from the load. Since we cannot judge from far how the filter will work it is needed to take measurements in the system.
Q: What happens if the Cy caps fail?
A: If Cy fails (not further described why it fails) the used capacitor type is a safety EMI capacitor which fails safely, which means the capacitor type used is Y2 (usually) which fails as open and will only reduce the performance of the filter without safety issues.