how much minimum voltage a PSU can take?

from how much minimum voltage does a PSU work, for example my corsair 450, label mentions 220v to 240v, but i believe it can even run at lower voltage around 200 or something, also would a UPS boost voltage for pc or just switches off when voltage goes low

7 Answers

Relevance
  • Steven
    Lv 7
    2 months ago

    There exist international standards which responsible makers design and test for. The unbrella document is

    IEC61326 which refers to more detailed standards IEC61004-11 etc.

    https://www.iecee.org/dyn/www/f?p=106:49:0::::FSP_...

    How successfully your power supply meets these standards, we can guess from the manufacturers published specifications, but the actual performance is something you have to test yourself.

    Some power supplies continue to function as low as 40VAC however this may not be a good thing since it means the PS has to draw a large current, leading to failure and exaggerating the cause of the low line voltage. Modern "universal" power supplies have to operate as low as 90VAC input, ie 10% below to 10% above the rated 100VAC-240VAC range.

  • 2 months ago

    The Specifications for a Power Supply Unit are stated in the manufacturers data sheet. They say that the output will meet all of the stated specs when the input also meets all of its specs.

    If the input does not meet its specs then the output is not guaranteed to meet its specs. If the unit doesn't meed its specs they will repair or replace it. Some may actually operate outside the input spec but it is doubtful. One may appear supply the proper output voltage but when examined closely it has excessive noise or voltage sag or overheats.

    Most specs are very specific and involved in subtle ways. Operating outside the spec may shorten the lifetime of the unit.

  • Bob
    Lv 7
    2 months ago

    The voltages stated on the PSU are the recognized range in which the unit will operate correctly. It may work on lower voltages but this may be unstable. Similar units may not work on such low voltages, it's very much a case of the tolerance in the components.

  • 2 months ago

    I don't know about that specific supply. For the past 20 years, the power supplies we put into our computers had an input voltage range of 100 - 250 VAC. This was so that the same model could be sold both in all countries. Earlier supplies had an actual physical switch on the supply, or a relay that automatically switched from high voltage to low if needed.

    A UPS of the type someone would use at home does not boost or otherwise regulate the voltage. It passes through the line voltage directly, and in the event that the line voltage cuts out, the UPS will supply its own AC output.

  • What do you think of the answers? You can sign in to give your opinion on the answer.
  • Dixon
    Lv 7
    2 months ago

    What they give you on the label or data sheet are the guaranteed working levels. So it may well work beyond the ranges given but they are not prepared to guarantee it - and so you can guess they will have built in a degree of margin just to be safe.

  • Anonymous
    2 months ago

    Some can go to 110 v. I think it will not be good, but worse is more v than the pc can bear.

  • Anonymous
    2 months ago

    Power Supply Voltage Tolerances (ATX v2.2)

    PSU Tolerance Table

    Voltage Rail Tolerance Minimum Voltage Maximum Voltage

    +3.3VDC ± 5% +3.135 VDC +3.465 VDC

    +5VDC ± 5% +4.750 VDC +5.250 VDC

    +5VSB ± 5% +4.750 VDC +5.250 VDC

    -5VDC (if used) ± 10% -4.500 VDC -5.500 VDC

    +12VDC ± 5% +11.400 VDC +12.600 VDC

    -12VDC ± 10% -10.800 VDC - 13.200 VDC

    • 2 months agoReport

      I tried copy pasting from the chart. If you want to see it, the link is in my sources. I apologize for the confusion.

Still have questions? Get answers by asking now.