Question Why is there a 'static-y spark' noise/arcing noise when I slowly switch off my PSU while still connected to the UPS?

Trez_YTR

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Dec 14, 2013
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I only noticed this happened today for the first time. Maybe cuz today I switched it off slowly whereas previously I did it quickly. Every time I switched it on then off the same thing happened all the time.

What causes that static/sparking sound? It's very brief but audible. When I do it fast though (as in, I switch it to the off immediately) there's no sound.

Is this also something that I should be worried about?


Additionally - what's the proper procedure for when you should actually switch the PSU off? If I shut down my PC and leave it connected to the UPS, can I turn off and turn on the UPS without having to switch the PSU off? I'm worried that when I do switch it on, there might be a sudden rush of current or charge and it might fry the power supply.
 
I only noticed this happened today for the first time. Maybe cuz today I switched it off slowly whereas previously I did it quickly. Every time I switched it on then off the same thing happened all the time.

What causes that static/sparking sound? It's very brief but audible. When I do it fast though (as in, I switch it to the off immediately) there's no sound.

Is this also something that I should be worried about?


Additionally - what's the proper procedure for when you should actually switch the PSU off? If I shut down my PC and leave it connected to the UPS, can I turn off and turn on the UPS without having to switch the PSU off? I'm worried that when I do switch it on, there might be a sudden rush of current or charge and it might fry the power supply.
Vic40's comment is dead on, except if you'd rater save the power than the parts (to each his own) - which is, I guess, a matter of priorities : switching off your computer for the night doesn't bring so much wear to your PSU that you need to concern yourself with it is my experience.
As for the sparky sound, it often happens when 2 conductive elements under a current are in close proximity (when the contacts the switch connects are getting further away) : it can cause an electric arc, which is noisy. In such a case, it's not overly dangerous as it lasts only a short time, and it actually occurs when you switch off rapidly too - i's just lost in the noise the switch's spring is making.
Of course, the less it happens the better chance your switch won't get damaged, but considering the kind of switch we're talking about, your PSU's capacitors will blow before the switch becomes inoperable.
Back to the matter of wear on electronic components when powered off and on, my experience is that, provided you leave your system on long enough for it to cool down slowly after some intensive use (gaming, rendering etc.) instead of shutting it down abruptly causes much more of a difference in the components' life span than there is between leaving it on all the time and switching it off for the night.
Now, if you want to leave it on 24/7, think about contributing some CPU/GPU time to Folding@Home.