How much power(w) UPS must be for PSU( input 220V/10A)? If UPS rated power is smaller then PC drain power before power loss, will the UPS shut down or what will happen?
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Watts is a multiple of Amperage and Volts. So what’s the question? You effectively have a 1450 Watts power supply. – Ramhound Jan 04 '24 at 21:53
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Power factor can account for some of the input / output differences. – John Jan 04 '24 at 22:01
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Power Factor can also cause losses and so you need the UPS ability to handle that. – John Jan 04 '24 at 22:13
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" will the UPS shut down or what will happen?" The UPS will shutdown, if you have the manufacturers software installed and a cable linking them the UPS will cause the PC to shutdown normally at a preset percentage of battery remaining. In addition to the actual power draw we need to know the runtime you want. Even a small 10w load for 100 years would require 10's of thousands in batteries. – cybernard Jan 05 '24 at 16:24
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Typically I like to provide 50 to 100% more power in a UPS to provide for surge loads and other variability in power supplies.
I have a 750 Watt true UPS for machines with hard drives and less efficiency when I set if up. Now with SSDs and better efficiency it is somewhat over specified but works well.
For the above for the 240 volt line 1450 Watts, you should specify a 2500 to 3000 Watt UPS. This also allows you to add another device.
For that size of UPS get a True UPS (pure Sine Wave, runs off battery all the time, and the AC side keeps the battery charged).
John
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There can be variability in loads so I like 2X to provide latitude for the variability. 1.5X is normally enough as well so you can consider a 2,300 Watt UPS and that will likely work fine. The higher capacity allows you to add another device. – John Jan 04 '24 at 21:56
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Input of PSU is 220V/10A, does that mean PSU can drain 2200w from UPS? Is that reason why you use 100% more power or what is your math behind that? – user707264 Jan 04 '24 at 21:57
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I used the Output watts to determine size. Power Factor may account for some of the differences. – John Jan 04 '24 at 21:59
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"This also allows you to add another device."I am sure I will use only this device, so can I buy 1.2x(20%) more power UPS? – user707264 Jan 04 '24 at 22:17 -
I would use 1.5x as the future is not always known. 20% can cut it fine. Th rating of a UPS is not that exact. – John Jan 04 '24 at 22:25
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"Th rating of a UPS is not that exact" - You have it backwards. UPS specifications tend to be reasonably accurate, and can be tested/verified. It's the (variable) power requirement on the load side that has be be guess-timated that confuses people. Using a PSU maximum is so crude, yet that's the advice you tout. – sawdust Jan 05 '24 at 05:15
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I should have said "sizing of UPS is not exact" That is what I meant. Remember as well that a UPS has to run the load for some time to either span the outage or allow for an orderly shut down. – John Jan 05 '24 at 12:59
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How much power(w) UPS must be for this PSU, my voltage is 220V?
Be careful, because you (and responders) are comparing apples to oranges to pears.
Your "1500 Watt" PSU claims that it can deliver (output) up to 1450W while it draws (consumes) 10 Amps of current from the 220V line. Since its power factor is not given/known, the actual wattage (i.e. power) consumed (nor the efficiency of this PSU) cannot be stated with any certainty.
You are probably not running your PC at full blast and the PSU is not stressed to deliver anything close to 1450W. You neglect to provide any details of this PC, but the odds are that you have over-specified the PSU. See this answer for the downside of having a large-capacity PSU.
If you're concerned about not over-specifying a UPS for your PC, then actually measuring the power consumed by your PC while you are performing various tasks could be worthwhile. A power meter, such as a Kill-a-Watt, can report the instantaneous current, VA, and Watts consumed while your PC is at idle or running a stress test.
Input from PSU is 220V/10A, does that mean PSU can drain 2200W from the UPS?
No. 2200VA perhaps, but even that is unlikely.
This 2200VA represents the maximum apparent power that this PSU could draw when under full load. Do you regularly use this PC to cause anything even close to a full load, e.g. perform bitcoin mining or really intensive gaming? Otherwise this PSU probably consumes about 50-100VA at idle, and likely less than half of that 2200VA for most tasks.
But the power consumed in Watts is unknown because the power factor of this PSU is not stated.
For AC electricity, power in Watts is not just voltage multiplied by current.
For AC electricity, power in Watts is voltage multiplied by current multiplied by the power factor. The power factor of the circuit is related to its reactance (i.e. inductance & capacitance) as an electrical load.
The power factor is not the same as efficiency (i.e. the ratio of power out to power in). For more on AC electricity see this answer.
sawdust
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If the UPS is a True UPS, it is usually comfortable for rated and lower than rated loads. My own UPS now runs lighter loads – John Jan 05 '24 at 01:33
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@user628075 - How much power does this PC actually use? What else are you going to plug in? A monitor? If you don't care if you over spec & over spend, and/or want an extended up-time, then use the PSU maximum (which is a lot of power). Note that 1450W is more than a small electric space heater! BTW a UPS is not a one-time expense. It will need new batteries in 4 years. – sawdust Jan 05 '24 at 05:30
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The only practical way to measure PC load is with a Wattmeter. I can do that here – John Jan 05 '24 at 12:17
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I don't think you can do that. I don't even know if manufacturers have loading tools. – John Jan 05 '24 at 21:22