by May 1, 1999 0 comments

UPS manufacturers are entering the market by the
dozens. That’s good for variety, but it can be bad news for quality, as we keep
finding out. The average quality of UPSs this year has declined from last year, so you
need to be careful when selecting a UPS. Even UPSs that we’ve tested and
awarded high points. Here’s why.

Caveat-VA ratings may lie: But first, how we
designed our tests. For starters we did pre-tests to measure how much power
a PC actually consumes. We took a Pentium II/350 with a 4 GB hard disk, 64 MB SDRAM,
Creative AWE64 Value sound card, Intel 82557 Network card, 15″ Samtron color monitor,
a 56 kbps external modem, and a basic HP DeskJet color inkjet printer.

We booted up the PC, and noted that on an average, the PC with its entire load actually
consumed only about 85 Watts. This is about 150 VA–quite modest. We checked multiple
PCs several times to get a valid and correct average.

We thus concluded that a 400VA UPS should easily handle two such PCs.

The reality was somewhat different. Several of the “400 VA” UPS units failed
to sustain this load! They displayed an overload, or tripped the moment they were switched
to battery. And that includes a few rated at 500VA!

So be wary of VA ratings: they may not tell the truth.

Are there fewer batteries in there? If
you’re planning to buy a specific model covered in this shootout, ensure that you get
exactly the same model, with the same number of batteries. That is why we have
given the number of batteries and its rating for each UPS in the tables. Therefore, check
the number of internal batteries, and the price quoted in our tables, before talking to
any vendor. You may need to open the UPS for this; else at least try to get the vendor to
certify the number of batteries.

Voltage regulation This is an area of grave
concern. You expect your UPS to protect your PC from voltage variations, right? Several of
the models that we reviewed did not do this. They did not even trip on over-voltage. The
output voltage to the PC kept increasing with the mains voltage. Some even went beyond
300V! This could damage your PC.

While you can’t verify everything about a UPS, don’t simply believe a vendor
claim for the spec. At least, run it on a load a bit higher than what you plan to use, and
simple things like cold-start the load (start the PC when the UPS is on battery). And be
alert. About the price, the number of batteries, the rating.

So when you buy a UPS, and find discrepancies in any of these, bring it to our notice,
and we’ll take it up with the vendor — quickly, and publicly.

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