[SOLVED] Does Power supply run through the UPS

daspal

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Oct 25, 2016
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Suppose my computer draws 900W at full load, and I have a 850 watts UPS. I know if there is a blackout, and I am at full load, my computer will shut down.
What I want to know is this:
When there is NO blackout and I am at full load, can my computer actually draw 900 W or is it like the power supply can only draw upto the UPS specification?
Like If I have a 1000W power supply and 850 watt UPS connected to my computer, can It never draw more than 850 watts?
I mean does the power supply get power only from the UPS, not from the wall?
 
Solution
A PSU will only draw the power demanded of it.
You can use a killawatt device to measure exactly how much you are really drawing at max load.
A PC with a RTX2080ti, for example might run well on 600w.

Then, if you do exceed the capability of the UPS, connect some components directly to the wall. A monitor, for example.

TJ Hooker

Titan
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I think it would depend on the UPS and how it's configured. Some (offline/standby type) just pass the AC straight through until there's a failure, so I imagine those would allow you to draw more power than the UPS is rated for (although wire gauges could still be a factor I suppose). But even then, it may have overpower protections that are active even when the UPS is in standby, potentially shutting off the power. The other types of UPSs I believe would be more strict on power limits.

Why? What would be the point of buying a UPS that you know is underpowered in the first place?
 
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A PSU will only draw the power demanded of it.
You can use a killawatt device to measure exactly how much you are really drawing at max load.
A PC with a RTX2080ti, for example might run well on 600w.

Then, if you do exceed the capability of the UPS, connect some components directly to the wall. A monitor, for example.
 
  • Like
Reactions: TJ Hooker
Solution