Uninterruptible Power Supply inquiry

[bobnova]

A full range APFC will work with input from 90VAC through 264VAC. So yes, you have one hell of a voltage drop from 220VAC before a full range APFC PSU quits.
Europe and asia are said to have a fair number of 220V-only APFC units, which are a different story entirely. I haven't seen one personally, just 220V/240V-only PPFC or no-PFC.

[McSteel]

They're mostly 220V-only because of a slim Graetz bridge (usually 4A/600V) and PFC/primary transistors. Some of the PSUs don't have an undervoltage protection in the APFC stage, so the PSU will actually work below ~180V (which is the usual UVP trip point on 220V-only models). The only problem is if you're pulling more than the bridge and the APFC transistor(s) can handle under reduced voltage input - which is rare, since > 500W 220V-only models are also rare.

[Digerati]

Originally Posted by McSteel

They're mostly 220V-only because of a slim Graetz bridge (usually 4A/600V) and PFC/primary transistors.

I suspect you are right, but I also note a big reason they are mostly 220V is simply because the EU mandated it for all EU member countries. Non-PFC PSUs on the higher voltage grids were too inefficient, and often destabilizing.

since > 500W 220V-only models are also rare.

Ummm, huh? You lost me there. Were you referring to non-universal input power supplies? A quick search of UK and European parts sites finds lots of PSUs bigger than 500W. The PSU power rating is determined by it's output voltage - not power consumed at the wall and the ATX Form Factor standard is the same the world around with 3.3VDC, 5VDC, and 12VDC outputs.

Nevertheless, I highly doubt a computer running in a 230VAC environment will be of much use if the voltage drops to those low levels, unless the monitors, and all the network equipment are on UPS too.

Originally Posted by Beto Garcia

I checked the APC Back-UPS XS 1500 and it’s very similar to the APC BR1500G BACK-UPS Pro 1500. Can anyone tell me the differences and / or pro-cons between the two? Is its operation silent?

I think XS is the designation for the previous version as the specs are virtually identical otherwise (my XS is 3 years old). The one big difference I see is the total recharge time is twice as fast with the newer version but that is not really an issue, unless you have multiple, back to back extended power outages that prevent a full recharge after each power restoral. You can operate your computer just fine while the batteries are charging - you will just have less runtime should you lose power while still charging.

They are totally silent when all is good. However, when you lose power, many UPS will start yelling (beeping) at you. Some UPS let you silence the alarm - some irritatingly don't. Some UPS also have internal cooling fans that sadly, over the years, can develop noisy bearings.

[Beto Garcia]

Hello folks!


Alright then, lets wrap up this topic by briefing some of the provided information:

• Simulated vs. pure sine wave: The Corsair AX1200 is a very good power supply and it would not care about what kind of AC would receive.
• UPS with AVR will help shape (regulate) the sine wave into something more easily used by the devices plugged into it. They help with undervoltage and overvoltage events.
• The best protection from power anomalies comes when the UPS or protector is plugged into a properly wired and grounded wall outlet.
• So, you can buy a good UPS with a quick cut-over that provides a "stepped approximation to a sinewave" for your computer system with no worries.

I’ve decided to purchase the better UPS taking into consideration all of your valuable comments and advices.

Thank you all for your participation and kind help on this topic.


Best regards,

[Digerati]

The Corsair AX1200 is a very good power supply and it would not care about what kind of AC would receive

Sure it cares - very much. But a quality PSU is likely to be more tolerant than $20 no-name generic.

BTW - a 1200W PSU? That is likely WAY OVERKILL - unless you are running 2 (or 3) MONSTER graphics cards, several hard drives, and many gobs of RAM. It's your money, but for that money, you can get a decent 750W supply AND a "good" UPS with AVR and still have plenty of wiggle room with that 750W.