Active Power Factor PSUs and UPS choices

Enclosures, modding, blowholes, and the power needed to run it all.

Moderators: Nemesis, SpotTheCat

Active Power Factor PSUs and UPS choices

Postposted on Tue Apr 20, 2010 6:33 pm

Everything I read says that active power factor-correcting PSUs should only be used with dual-conversion online UPSs. Looking at the prices of same, I gagged a little. What's the accumulated experience here running active PF PSUs on everyday line-interactive UPSs?
Life is hard; but it's harder if you're stupid. Big Al.
Captain Ned
Global Moderator
Gold subscriber
 
 
Posts: 20647
Joined: Wed Jan 16, 2002 7:00 pm
Location: Vermont, USA

Re: Active Power Factor PSUs and UPS choices

Postposted on Tue Apr 20, 2010 8:29 pm

Hi check out this link and you will see a reply I got from Thermaltake.

I would recommend emailing your manufacturer of choice and getting an answer from them.
FDISK /MBR
Dirge
Gerbil Jedi
 
Posts: 1554
Joined: Thu Feb 19, 2004 3:08 am
Location: New Zealand

Re: Active Power Factor PSUs and UPS choices

Postposted on Fri Jun 11, 2010 3:42 pm

I saw this rumor somewhere recently, and it makes me wonder. Knowing what little I know about power supplies (AC power->transformer->diodes->capacitors etc. :wink:), it seems peculiar, but I really don't know how active PFC circuits work so that's where I'm stumped. The link's quoted Thermaltake reply encourages me, though.

Now to find a good deal on one of the confusing multiplicity of APC 1500VA UPSes, hopefully with inexpensive batteries so I can replace my 7.5 year old 1200VA Belkin, which seems to like to eat batteries and do little else. It's actually worse during power fluctuations than not having one at all, now.
Ragnar Dan
Gerbil Elder
Silver subscriber
 
 
Posts: 5355
Joined: Sun Jan 20, 2002 7:00 pm

Re: Active Power Factor PSUs and UPS choices

Postposted on Tue Jul 20, 2010 2:10 pm

I recall reading on corsair's support forums while bugging them about a memory issue that this was basically hogwash that only used to be an issue with some server power supplies when active PFC was first being done. I believe the way it is implemented is a better design now, considering they can take anything from like 90-260V or whatever I'd imagine an imperfect wave isn't a big deal. If its a 'computer' UPS from one of the usual brands its going to be at least a decent simulated approximation of a sine wave. It won't be as efficient on battery power and it might buzz or hum but it will do its back-up power job just fine.

I have also noticed this rumor pop up a few times this year on various hardware sites.

I would advise checking with your OEM to be sure, but I ran a 750HX on a regular cyberpower ups for over an hour right after the big Feb blizzard killed my power so I could transfer my files to an external drive and finish a doc.
I didn't have any problems or hear any odd noises, granted the constant beeping from the UPS itself nearly drove me nuts.
blah blah blah signature blah blah blah
Bauxite
Gerbil Elite
 
Posts: 619
Joined: Sat Jan 28, 2006 12:10 pm
Location: electrolytic redox smelting plant

Re: Active Power Factor PSUs and UPS choices

Postposted on Tue Jul 20, 2010 2:51 pm

Bauxite wrote:If its a 'computer' UPS from one of the usual brands its going to be at least a decent simulated approximation of a sine wave.

Only for sufficiently small values of "decent"! From what I've read, the "modified sinewave" used by most UPSes still has only 3 discrete voltage levels in the waveform. Essentially, you get this:
Code: Select all
  +---+       +---+
  |   |       |   |
+-+   +-+   +-+   +-+   +-
        |   |       |   |
        +---+       +---+

Instead of a pure squarewave like this:
Code: Select all
+-----+     +-----+     +-
|     |     |     |     |
|     |     |     |     |
|     |     |     |     |
+     +-----+     +-----+
(this space intentionally left blank)
just brew it!
Administrator
Gold subscriber
 
 
Posts: 38125
Joined: Tue Aug 20, 2002 10:51 pm
Location: Somewhere, having a beer

Re: Active Power Factor PSUs and UPS choices

Postposted on Tue Aug 31, 2010 2:30 pm

I missed this thread being updated, evidently during my email transfer period.

The wave you describe, jbi!, looks like it would be sitting at 0 volts for a significant period, which doesn't look too great for producing power efficiently.

I've decided to quit dawdling and just bought a replacement for my dead Belkin UPS. APC updated their 1500VA unit recently, and though I haven't seen any reviews of it, it was cheaper than using APC's trade-in program (who charges enough for shipping and taxes to make the deal worse compared to sites offering free shipping). I got it from a site I've never used before, CompSource, so hopefully I won't get screwed over. Here's a link to their APC BR1500G page, BTW, for any interested.

Edit: One thing I don't love about the UPS is the battery replacement costs. But hopefully it will require them infrequently enough to make it even out in the end.
Ragnar Dan
Gerbil Elder
Silver subscriber
 
 
Posts: 5355
Joined: Sun Jan 20, 2002 7:00 pm

Re: Active Power Factor PSUs and UPS choices

Postposted on Tue Aug 31, 2010 2:42 pm

Ragnar Dan wrote:The wave you describe, jbi!, looks like it would be sitting at 0 volts for a significant period, which doesn't look too great for producing power efficiently.

Since we're talking about AC here, it is dv/dt (the change in voltage over time) that transmits the power, not the absolute voltage level. You are correct that there is some inherent inefficiency though. The large amount of higher-order harmonics produced by the steps in the waveform will likely not be utilized as efficiently, and that translates into wasted energy.
(this space intentionally left blank)
just brew it!
Administrator
Gold subscriber
 
 
Posts: 38125
Joined: Tue Aug 20, 2002 10:51 pm
Location: Somewhere, having a beer

Re: Active Power Factor PSUs and UPS choices

Postposted on Tue Aug 31, 2010 2:45 pm

Ragnar Dan wrote:Edit: One thing I don't love about the UPS is the battery replacement costs. But hopefully it will require them infrequently enough to make it even out in the end.

Note that when that time comes, it pays to get good branded batteries. The ultra-cheap ones from eBay work fine for awhile, but they go bad earlier, and when they go bad, they won't even hold a charge for a few seconds. The UPS will go from online to dead almost instantly.

That doesn't mean you need to get APC batteries, as over-priced as they are. For example, I got Tripp-Lite branded batteries during my last replacement. They're good quality, with a decent warranty, but significantly less expensive than APC-branded batteries.
Buub
Maximum Gerbil
Silver subscriber
 
 
Posts: 4214
Joined: Sat Nov 09, 2002 11:59 pm
Location: Seattle, WA

Re: Active Power Factor PSUs and UPS choices

Postposted on Tue Aug 31, 2010 2:55 pm

jbi!: I thought sitting at 0 volts for an extended period in the wave you approximated was the more problematic thing, though I know it's not an actual 'scope picture or anything.

Buub: Yeah, now that I'm moving to APC I will have more replacement options than I had for my Belkin. The Belkin only had 1 site I could find replacements at for the last 3-4 years, and they were ~$35. Hmm, now that I'm looking at APC's site, I could've sworn they had batteries for the thing for something like $80+. But now they're claiming:


Step 1: Select Your Model > Step 2: Results

--------------------------------------------------------------------------------
APC Model #: BR1500G
Modify


Results
This model may not have user-replaceable batteries, or the batteries may not be released at this time. Check the product specifications online, or call technical support for more information.

You can upgrade your UPS to a newer model at a substantial discount by participating in our Trade-UPS program.

For more information, please click here.


Click here to view the product technical specifications.


Click here to contact APC technical support.


If you think you have received this message in error, please contact APC's webmaster.



Maybe I'm thinking of their earlier, white plastic model. They'd better have batteries for this thing or I'm sending it back. In fact, I think I'm going to cancel my order until I get this cleared up.
Ragnar Dan
Gerbil Elder
Silver subscriber
 
 
Posts: 5355
Joined: Sun Jan 20, 2002 7:00 pm

Re: Active Power Factor PSUs and UPS choices

Postposted on Mon Nov 01, 2010 11:26 pm

I thought I'd update this thread with the information I've learned.

I checked APC's site again for the BR1500G UPS to see if anything had changed. The PDF document on the model added info on the replacement battery cartridge, but they still don't sell it. I decided to query them on the situation, and their reply from "Devendra" in somewhat imperfect English was:

I am afraid to say that the replacement battery for this unit is not released to purchase, because this is brand new unit and this unit will carry 3 years of warranty from the data of purchase(this warranty will include even the battery). So APC will take care of this unit and battery for 3 years. This battery will be released after one year.

The main reason for not releasing this battery is, customer cannot stores any battery for more than 6 months, because storing battery for long time will loose the battery life and even may lead to damage in battery body.

I also learned that the model is available at Wal Mart, so even though it will be an extra ~$24, I'll likely get it there, and soon, because it means inexpensive returns and likely less trouble. Though, it will likely mean waits because I think my nearest store won't carry it unless I have it sent there. But I've been waiting far too long and have already had enough trouble because I'm nearly at the maximum 15 amps my outlet can provide and the window A/C I have in the room sometimes crashes the circuit breaker, which is... unpleasant, to say the least.
Ragnar Dan
Gerbil Elder
Silver subscriber
 
 
Posts: 5355
Joined: Sun Jan 20, 2002 7:00 pm

Re: Active Power Factor PSUs and UPS choices

Postposted on Tue Nov 02, 2010 2:37 am

If you know the physical dimensions and electrical specs of the battery you can probably find a replacement online without too much trouble. I wouldn't worry too much about that aspect...
(this space intentionally left blank)
just brew it!
Administrator
Gold subscriber
 
 
Posts: 38125
Joined: Tue Aug 20, 2002 10:51 pm
Location: Somewhere, having a beer

Re: Active Power Factor PSUs and UPS choices

Postposted on Tue Nov 02, 2010 8:31 pm

Well my preference would be for the store I got it from to have a unit available for exchange if the battery goes dead before its 3 year life expectancy, though it looks like Wal Mart seems to only have a 1 year warranty listed on their site. Hopefully more information about the battery's terminals and amp rating will be available at some point and then I'll be able to decide about where to buy replacement batteries, certainly. I'm concerned about the sales volume at various outlets, since that makes a difference in how long the batteries are sitting. And of course if these are some screwy new kind of battery type, then it will be more expensive to replace.
Ragnar Dan
Gerbil Elder
Silver subscriber
 
 
Posts: 5355
Joined: Sun Jan 20, 2002 7:00 pm

Re: Active Power Factor PSUs and UPS choices

Postposted on Tue Nov 02, 2010 8:49 pm

I've used APC's warranty RMA process before.

I've also purchased replacement batteries for my APC UPSes from BatteryWholesale (even the ones that supposedly were not user serviceable). The batteries in the newer UPS models are really easy to swap out.
JustAnEngineer
Gerbil God
Gold subscriber
 
 
Posts: 15602
Joined: Sat Jan 26, 2002 7:00 pm
Location: The Heart of Dixie

Re: Active Power Factor PSUs and UPS choices

Postposted on Wed Nov 03, 2010 8:34 pm

Dirge wrote:Hi check out this link and you will see a reply I got from Thermaltake.

I would recommend emailing your manufacturer of choice and getting an answer from them.


Getting back to the OP, I have updated the thread I linked to in regard to Active PFC power supplies. I am not trying to split this thread, I just wish to keep all my research on this matter in one place.
FDISK /MBR
Dirge
Gerbil Jedi
 
Posts: 1554
Joined: Thu Feb 19, 2004 3:08 am
Location: New Zealand

Re: Active Power Factor PSUs and UPS choices

Postposted on Tue Nov 09, 2010 2:15 am

Captain Ned wrote:Everything I read says that active power factor-correcting PSUs should only be used with dual-conversion online UPSs. Looking at the prices of same, I gagged a little. What's the accumulated experience here running active PF PSUs on everyday line-interactive UPSs?


Hey Captain,


The UPS that you need to use with Active PFC power supplies is a line interactive model. Double conversion is absolutely unnecessary.
LazyBubba
Gerbil In Training
 
Posts: 4
Joined: Tue Nov 09, 2010 2:13 am


Return to Cases and Power Supplies

Who is online

Users browsing this forum: Bing [Bot] and 1 guest