[S.O.A.D.A.]

Hello,

I need a new UPS, and decided to go for APC, since I want quality.

Now, the simplest design is a standby UPS, and I'm not interested in that. An online UPS is too expensive for me.
I need good isolation from the mains, and I think the best compromise between my means and the quality I want would be the ferroresonant design.

So I have two questions: could you recommend me a model of ~650 watts ferroresonant APC? Couldn't get the details on their site. For some reason they do not mention the UPS topology in their product descriptions.....
And the other - just how much better, in terms of isolation and providing really uninterrupted power, is a line interactive UPS than the simple standby UPS?

Thanks,
SOADA

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Good info here:

Wikipedia: Uninterruptible Power Supply (UPS)
http://en.wikipedia....le_power_supply

[SpywareDr]

Good info here:

Wikipedia: Uninterruptible Power Supply (UPS)
http://en.wikipedia....le_power_supply

[S.O.A.D.A.]

Yeah, I've read it. But since I don't understand electronics too well, I still dunno how line-interactive UPSs work.

[Digerati]

It might be better if you tell us your budget. I personally applaud you for wanting to get an UPS. I think every computer should be on a good UPS with AVR. But today's UPS are pretty good so not sure you really need a $500 one. Just a good one. I have an APC XS 1500VA UPS with AVR and it was less than $200 that supports my i7 computer, all my network hardware, 2 22" widescreens and my PDA with no problems.

For 650W coverage, you need ~ 1083VA UPS.

Edited by Digerati, 24 August 2010 - 07:38 AM.

[S.O.A.D.A.]

Yeah, I want a good APC of about 650W.
My question: does a line-interactive UPS provide better isolation from network blackouts, brownups, spikes & other instabilities than a simple standby UPS?
I guess it's not as good as ferrous-coil, which is what I really want.
If you could recommend a ferrous-coil model from APC of ~650W that would e very helpful : )

Thanks,
SOADA

[S.O.A.D.A.]

PS: I've been using UPSs for years, it's just that my current one, after having served for over 3.5 years has finally come to the end of its road.
And now I want something of better quality. My limit is $200, though the prices in my country (Israel) are probably different than in your's.

[Digerati]

My question: does a line-interactive UPS provide better isolation from network blackouts, brownups, spikes & other instabilities than a simple standby UPS?

I guess that depends on how you, or rather the maker defines "simple". I would not put a "simple" UPS on my computers. To me, a simple UPS is a simple "backup power" device in the event of a full power outage. Something I might use for lighting, or... well I can't think of anything else - maybe a small TV to keep track of weather updates (I live in Tornado Alley, USA).

Note I said above, "a good UPS with AVR". With a good UPS with AVR, it is the AVR - automatic voltage regulation that is the key feature of the UPS. Unlike a surge and spike protector, it does not simply "clamp" or chop off the tops of the sinewaves during high voltage anomalies (surges and spikes), it regulates, or attenuates the voltage back to within normal limits presenting the supported equipment with a fairly decent (stepped approximation sinewave) voltage. And note a surge and spike protector does absolutely nothing for low voltage anomalies (sags, dips and brownouts or extended sags - note that is brownout, not brownup) by using the batteries to boost the voltage, and the AVR to shape it as needed. Providing backup power in the event of a full power outage is only the icing on the cake for a UPS with AVR.

Now, like PSUs, there are cheap ones and good ones and I would never trust my expensive high speed digital electronics, and more importantly, my data, to a cheap power supply. So the same goes with a UPS.

Now, the ATX Form Factor PSU Design Guide, paragraph 3.2.9 says an ATX power supply should be able to hold full power for 16ms after loss of power. A "good" UPS should be able to switch to batteries in 10ms or less.

I've been using UPSs for years, it's just that my current one, after having served for over 3.5 years has finally come to the end of its road.

Oh? The downside to all UPS is the batteries, typically sealed lead acid (SLA) batteries only last for, and must be replaced about 3 years - hopefully before you discover they can no longer hold a load. Are you sure the UPS is bad and not just the batteries?

Edited by Digerati, 24 August 2010 - 12:42 PM.

[S.O.A.D.A.]

The battery is bad for sure, the UPS itself - I suspect. I think it caused my computer to shut down when there was no interruption in network voltage.

I understand what you are saying about AVR. But which UPS designs contain AVR? How can I tell?

[Digerati]

But which UPS designs contain AVR? How can I tell?

AVR is the the common term. So if the UPS has AVR, it will say AVR, or automatic voltage regulation.

[SpywareDr]

APC's Back-UPS "RS" and "LS" series have AVR. For example:

APC.com > Back-UPS® RS (500VA - 1500VA)
http://www.apc.com/p...index.cfm?id=23

A distinguishing feature of the Back-UPS RS is automatic voltage regulation (AVR).

They range from 420 Watts/700 VA to 865 Watts/1500 VA for between $129.99 and $249.99.