Re: Pure Sine Wave UPSes EPILOGUE
- From: "RnR" <rnrtexas@xxxxxxxxx>
- Date: Wed, 14 Apr 2010 10:12:50 -0500
On Wed, 14 Apr 2010 09:49:39 -0400, Daddy <daddy@xxxxxxxxxxxxxxx>
Ben Myers wrote:
On 4/13/2010 6:37 PM, Daddy wrote:
I had to give myself a basic education on alternating current, output
waveforms and active PFC power supplies just to be able to ask this
It all started because I heard that new Dell PCs need a new kind of
UPS (uninterruptible power supply.)
It's a fact: To comply with regulations, Dell now includes something
called an active-PFC power supply with their PCs. I also understand
that users and power companies benefit from PFC, as does the
The problem is, active PFC power supplies supposedly need current with
a pure sine wave output - and a Dell technical rep told me that all
new Dell computers need this - but virtually all UPSes for home use
have a stepped approximation of a sine wave.
Has anybody priced a UPS with pure sine wave output? Those buggers are
On the other hand, according to APC: Starting in mid-2008, all APC
Back-UPS (home and small office) products were revised to better
handle load requirements for PFC devices...allowing the majority of
Back-UPS being manufactured now to handle most (not all) PFC loads
within their wattage range much better than older units. Their output
is still step-approximated, however, and APC still finds the
occasional PFC device that they have trouble with.
Here's where I throw up my hands. Do I really need to pay an
arm-and-a-leg for a pure sine UPS, or is most any properly sized UPS
I know you're all sitting on pins and needles over this...
You may recall that I 'tested' my UPS to see if it could power my
system, and the result of the test was that my system completely lost
power. I have now discovered the reason why my system lost power: I am a
(That's a 'dolt' for those unfamiliar with the lingo.)
I performed the test by pressing the Off button on my UPS...which
powered off the UPS. Duh! The correct thing to do was to pull the plug
(of the UPS) out of the wall socket.
Tonight I pulled the plug...and my system kept on working, without
interruption. So there. No fancy, expensive, sine wave UPS for me.
My UPS *is* somewhat under-powered for my system, by almost any
calculation. I'll just wait for a good sale.
FWIW, Staples had a good solid decently rated APC UPS on sale a few
weeks ago, and my son bought one to overcome the old and substandard
electrical wiring where he lives. CDW had APCs on sale a few weeks ago,
and I bought an APC Back-UPS 1250 for a little over 100 bucks. Made my
life easier, because our local National Grid electric company has very
frequent electrical hiccups, and my old UPS was worn out. I no longer
suffer from spontaneous reboots. Of my computer. My brain still
Keep checking the sales, schlep on over to a sale, and buy a
good-quality name brand UPS.
How on earth a company like Dell can tell everyone that a UPS must
provide A/C with a pure sine wave is beyond me. Or, to put it more
succinctly, it is a large load of bullshit... Ben Myers
I'm not wild about UPSes by APC, because every APC unit I've ever owned
- 4 in all - eventually starts to 'buzz' intermittently. Then I have to
go underneath my desk and smack the thing once or twice to get the
buzzing to stop.
When I asked APC about this, they said "Oh, that's normal." I guess that
makes my Tripp-Lite APC abnormal.
Tom: A shlemiel spills coffee on a shlimazel. That's the difference.
Thanks Daddy for clearing up whether the newer Dells need this type
UPS. I don't know a lot about UPSs so this subject kept my interest.
I guess I know a little more about them now thanks to you and others.
Appreciate the info. .
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- From: Daddy
- Re: Pure Sine Wave UPSes EPILOGUE
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