Could someone please explain the key issues in the VDE 565-2 standard relative to inductor performance. "Radio interference suppression devices; radio interference chokes up to 16A & protective wire chokes 16 up to 36A"
I am in the process of selecting inductors as the first stage of an AC power filter to protect against surge. Picture an inductor in series in both hot and neutral followed by X and Y caps, followed by common mode choke etc. In addition up front there may be a MOV line to line - I was hoping to avoid this but so far it doesn't look promising. This filter needs to withstand the overvoltage conditions of at least installation class 2 and perhaps as high as class 4 as per IEC 1000-4-5. This would be 2KV normal mode and 4KV common mode (1.2 by 50 uSec.). In the USA market I have found numerous suppliers of safety X and Y caps with the VDE 565-1 but next to nothing on VDE 565-2 rated inductors. I tried Siemens but from the response they do not have much call for these parts. It appears that the USA suppliers such as ACT, Coil Craft etc. don't get requests for this standard either. Why is this? Would this rating/recognition be required to gain overall product VDE or TUV approval? Without any standard guidance (so far) I have considered the following issues in selecting an inductor: Current ratting - steady state Saturation current - under surge condition Inductance Impedance versus frequency plots Voltage withstand Joule rating (temperature, Safety issues) I have started to model with Pspice the circuit and the intended exposure to gain some insight into the expected exposures to the inductor. It appears with the low frequency nature of surge that one would need a rather high inductor value to be effective. In competitive designs I have seen series inductors ranging from 200 uH to 6 mH! I realize that an AC front end has to deal with many different immunity and emission issues. If you can shed some light on where to start in this analysis or what relevance VDE 565-2 lends to the picture it would be much appreciated. Regards Chris Wells Sr Des. Eng Cutler Hammer well...@ch.etn.com ph# 1-(412)-494-3723
