AC and DC voltage ratings on pushbutton switches

[eecook]

Hi All,

I was looking for a simulated roller lever type switch on Digikey and noticed that there is a huge difference between the AC and DC ratings for each part. I am wondering why that could be?
Digikey results page: https://tinyurl.com/y52fknbl

The only things that come to mind are:
  1. Tracking.
  2. Finite probability of low voltage switching with an AC waveform.

But neither 1 nor 2 could explain it. Tracking is related to the RMS voltage, doesn't matter if it's AC or DC. Regarding the finite probability, the average switching voltage will be the voltage of a rectified sine wave which is very similar to it's RMS value.

Any clue?

[ataradov]

This is the similar to relays. Connecting and disconnecting AC current is easier, since it naturally goes to 0 very often, so there is no arcing, or arc gets extinguished fast.