UPS issue with Active PFC PSU's

JVM · Post by **JVM** » Mon Sep 28, 2009 9:27 am

I was going to buy a UPS backup for my system and discovered an issue with Active PFC and UPS backup devices not using a pure sine wave. I called both Cyberpower and APC to verify what I read, and was told by both I need a pure sine wave UPS. The models with true sine wave are both heavy and expensive.

What brought me to call both APC and Cyberpower was what I read on a review of Cyberpower on amazon.com about someone having a problem. Here is an excerpt from that review with full reply by Cyberpower:

Emailed Cyberpower about this and they did get right back to me with this response,

"The power supply in the XPS 435T has good and bad attributes. The good news is the power supply is extremely energy efficient and uses a PFC power supply design. The bad news is that PFC power supply designs will not accept the type of power supplied by a traditional UPS. In order to support the XPS 435T with a UPS you need a UPS that supplies power with a true sine wave form. Any of our Smart Application Series UPS would work"

Considering I read many reviews about different non-true sine wave UPS backup devices, I am amazed I found just one issue as above.

Klusu · Post by **Klusu** » Mon Sep 28, 2009 11:40 am

They just want more money from you. And you have no choice.
Good active PFC should accept any power.

tima · Post by **tima** » Mon Sep 28, 2009 1:43 pm

While researching a new system, I recently became aware of this myself, and to my horror, I discovered I had been using a plain old APC XS1500 for the last three years with my NeoPower 550 HE, which I confirmed on Antec's site is Active PFC. It's worked fine all this time. Nevertheless, I was in the market for a new UPS, and last week I ordered the pure sine wave CyberPower PP1500SWT2 from Amazon.com. Unfortunately, it is incompatible with the AFCI breakers in my bedrooms and home office (converted bedroom). Simply turning the PP1500SWT2 on trips the breakers every time. It works on other circuits in my house that aren't protected by these finicky AFCI things, but I need it for my home office, so it's a showstopper. My multiple APC Back-UPS units are fine with AFCI, but I don't know about the Smart-UPS, which is APC's pure sine wave line. Major props to Amazon.com for free shipping both ways for the PP1500SWT2, including pick-up. I was not looking forward to toting that heavy thing to the UPS store!

JVM · Post by **JVM** » Mon Sep 28, 2009 2:58 pm

I just ordered the CyberPower Intelligent LCD Series GreenPower UPS CP1500AVRLCD 1500VA 900W. http://www.newegg.com/Product/Product.a ... 6842102048

I called Enermax, I have the MODU+82 625W, and the tech guy said my PSU is compatible with simulated sine wave. At first I doubted him, but he directed me to the manual and it states the PSU is compatible with both simulated and pure sine wave. He assured me there wouldn't be any issues because of my PSU, so I went and ordered the simulated sine wave UPS and will find out soon enough, should be here either tomorrow or Wednesday.

The tech from Enermax did say their older PSU model Infinity was Active PFC and it was not compatible with simulated sine wave.

colm · Post by **colm** » Mon Sep 28, 2009 10:50 pm

wow. I am glad to have found this, I forgot all about the ups. I have had some weird things happening, unlikely squeals with power out etc.
I upgraded to active pfc not all that long ago. The UPS cost is ridiculous, my old back ups es 500va was over 100 dollars, has a thicker cord than a new one, and ran my old 17 inch crt with my 3400 mhz and two hard drives with 3gb of ram...a new back ups es 500va will not even come close. Its like they changed the guts and kept the name.How do I sell that on craigslist in my poverty state? Better off keeping it for nothing.

anyway, if you are uptight about ups and cost for the upgrade

APC SC620 620VA Smart-UPS

seems to be a roundabout average for normal pc. understands active pfc. Right now there is 38 used at 100 dollars, and amazon has free shipping. I will go for that one.

Post by **CA_Steve** » Tue Sep 29, 2009 7:02 am

My APC ES 750 works just fine with my Corsair PSU. There's a bit of PSU noise when the UPS has a powerline noise/voltage event trigger it active, but that's it. I don't think the simulated sine wave will hurt the PSU.

Buying a used UPS: it's the replacement battery costs that add up. APC battery life is warrantied for (I think) 3 years. Look into the cost (and shipping) of the batteries before you buy.

JVM · Post by **JVM** » Tue Sep 29, 2009 5:28 pm

Update: I received the CyberPower unit shown in my first post above, model number CP1500AVRLCD and no issues so far with my PSU or anything. The unit is silent in normal operation and I am very pleased.

Michael Sandstrom · Post by **Michael Sandstrom** » Tue Sep 29, 2009 6:06 pm

My APC ES750 also works quietly and flawlessly with the Enermax Modu82+ 425W PSU. Based on previous experience there are no problems with Seasonic units.

colm · Post by **colm** » Tue Sep 29, 2009 6:25 pm

CA_Steve wrote:My APC ES 750 works just fine with my Corsair PSU. There's a bit of PSU noise when the UPS has a powerline noise/voltage event trigger it active, but that's it. I don't think the simulated sine wave will hurt the PSU.

Buying a used UPS: it's the replacement battery costs that add up. APC battery life is warrantied for (I think) 3 years. Look into the cost (and shipping) of the batteries before you buy.

That was a good call. I just checked on my replacement battery, and found one at 300mah better. an interesting note I forgot was I recorded a lightning storm this past summer, and have on video the computer sustaining a direct hit to my house. The ups did what it was supposed to. and audible alarm. From there, as I cannot sustain on battery anymore, I realized I bought the ups SIX years ago. brand new, and that it does NOT have a apc battery it has a "CSB".

so, I hunted down that very place and found the bigger and better one as a direct replacement. I am beyond guessing from reviews read, that apc replacements do not get to the 2 year mark, nevermind six!

the amps/watts and time are still plenty for me, and several minutes to shutdown to save data...and the replacement battery is even bigger.
bonus.
I do not get this simulated sine wave and real sine wave stuff, I have no problems on active pfc with my old ups. I did learn the new version of my model looks dainty, I mean by the cord. the cord on mine is huge guage. It probably goes with theat double numbering scam with the dual 12v rails in psus today...somehow...