Question Inrush current - What is considered 'low'? (Seasonic Prime Snow Silent 650w Platinum)

Jan 4, 2020
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Long time lurker here, finally decided to register and post something :)

I'm considering buying the Seasonic Prime Snow Silent 650w Titanium for a new rig (black and white theme in a P400A case), and i've been trying to find reviews for it. So far, no real luck, but apparently it's almost identical to the 'normal', non-Snow Silent unit, for which i can find a review here:

https://www.tomshardware.com/reviews/seasonic-prime-titanium-650w-psu,4690-4.html

It specifically states that the inrush current on 230V is a bit high (i'm in Western Europe so this would apply to my situation), so i got a bit worried about the unit.

However, when trying to read up on inrush current i can't really find an 'ELI5' explanation for what it actually affects. From what i can tell, a too high inrush current can trip the circuit breaker for that power circuit in the house, and doesn't affect the PSU itself.

So, that would be worrying, obviously, so i wonder - Was the 62A on 230V too high to risk it?

I went on viewing a lot of other reviews on the site, trying to get a bearing on what's considered 'normal' on 230V, but it seems to be a bit inconsistent. Pretty much all other units with an inrush current of 60A or lower are considered 'normal'.

I then came across the Corsair AX850 review on the site:

https://www.tomshardware.com/reviews/corsair-ax850-psu,5986-2.html

This review lists an inrush current of almost 64A as 'normal', and now i am utterly confused.

What should i use as a benchmark? When is the inrush current too high? When is it normal? What exact considerations should i make in this specific case? Or does the Seasonic review only list the inrush current as 'high for a unit of that quality'? A poster called turkey3_scratch says that the inrush current is fine, but without further qualifying that statement.

I've been looking at various forums, websites, reviews for the better part of the day and i'm no closer to understanding this specific issue than i was when i saw the review... :p

As an addendum: I've been trying to find the exact figures (inrush current specifically that is) for a Seasonic X-560 or a Cooler Master Real Power 620M (the PSU's in my current PC's) for comparison, which ran absolutely fine for years, though i can't seem to find any hard data on that specific property of those PSU's. If anyone can point me to the figures for them i can put them in the correct frame of reference :)
 
Jan 4, 2020
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I don't actually know for sure. I only know that the electricity box has a 3x25A connection (it's closed off otherwise), and i can say that i've had two pc's, 5 monitors, some smaller peripherals and occasionally a laptop on a single group for 5+ years without any issue whatsoever.
 

Mezoxin

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Nov 3, 2019
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inrush current is needed to charge the 2 hold-up caps in your psu this current lasts for a handful of ms , this only happens when you connect the psu to the power source , my guess you would be fine , my psu inrush is 72A@220v and my circuit breaker is 32A and it doesn’t trip
 
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Reactions: Khrome
Jan 4, 2020
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I am 90% sure i'll be fine too, it's just the wording of the reviews which makes me worry, and the conflicting messages about the issue from others with very little information otherwise. If i could somehow find out what the inrush currents are of my current psu's i'd at least know what to expect from the numbers i'm seeing in the reviews in the correct perspective :)

Still, it's a bit of a difficult topic and strange thing to measure in reviews without really explaining it beyond the dry technical description - Maybe adding in a blurb about how this pertains to the circuit breaker rating would be rather helpful, like "with 60A inrush you'd be fine with 25A circuit breakers" (as it would have to be in this case) or something like that.

That said, i did take another peek at my box and while i have 3 main groups with 25A breakers, apparently the actual power lines are connected to 4 groups with 10A breakers. I can switch them all out though, maybe i should look for some replacements.

EDIT: Found something:

https://www.quora.com/If-my-power-s...nally-on-6-amps-how-do-you-select-the-breaker

If i've checked my circuit breakers properly i think i should be safe with the Seasonic unit :)
 
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Mezoxin

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Nov 3, 2019
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10A can be a problem , try out the psu , if it triggers the CB , then get a technician to check you wirings and see if he can put a higher rated one

the review mentioned it was high according to the psu nominal capacity and the size of the caps , the bigger the psu the higher capacity caps and higher inrush that’s why in the 850w review he said it was normal for cap of this size
 
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Reactions: Khrome
Jan 4, 2020
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Might help to specify that my power box uses fuses which i can switch out myself (language barrier here - Was struggling to find the correct English terms). If i understand it correctly they are more tolerant to short, high loads such as these.

Still, i'll check to have them replaced with 16A or 25A fuses i can get from the DIY shop close to me if the PSU ends up tripping them. I'll have to double check but those should be ok to be used.