Is Modu+82 compatible with my APC UPS??? YES INDEED

Michael Sandstrom · Post by **Michael Sandstrom** » Fri Mar 21, 2008 12:14 am

Hello People,

I ordered an Enermax Modu82+ 425W PSU with active PFC. I am currently running an APC Back-UPS ES 725VA 450 Watt UPS.

Enermax FAQ states if your power supply has Active PFC function, you must purchase a pure sine wave type UPS.

I have been running a Seasonic SS-400 with PFC for a couple of years with no apparent problem.

I have my APC application set to shut down quickly in the event of an outage. Should I be concerned that the battery of my UPS sends a step-approximated sine wave?

yukon · Post by **yukon** » Fri Mar 21, 2008 4:42 pm

Active power correction is helpful, I'm told, in getting more battery time from a UPS. Since that UPS does not have power conditioning, aka Automatic Voltage Regulation, meaning that it isn't sending all power through the battery first, the only time it'll send an approximated sine wave is if the power goes out.

A number of companies say not to mix active PF with square sine-wave UPS. I'm using a cheap PSU with it, and it's causing a problem. I'm hoping it's because of the PSU quality.

I've been told by an electrical engineer that it won't cause a problem, and that pure sine wave UPS are either just closer approximations of a sine wave, or far more expensive.

I'm interested in what SCPR thinks though. Is active power factor correction compatible with approximations of sinewave power from a UPS?

Michael Sandstrom · Post by **Michael Sandstrom** » Fri Mar 21, 2008 8:40 pm

Since I originally posted I have been researching this issue and the answer remains uncertain. Some people have suggested testing the battery's functionality by unplugging the UPS while the computer is running. If the PC runs off the battery then all is well. Other people have said to only use a Smart UPS.

I tend to think that running off the battery for a short time should not cause a problem if the UPS is sufficiently powerful relative to the current demanded. Right now if I run the Seasonic SS-400 off the battery I do notice a slight buzzing noise which seems to come from the UPS.

frostedflakes · Post by **frostedflakes** » Fri Mar 21, 2008 9:39 pm

yukon, what problems are you having?

For what it's worth, I've been running active PFC power supplies on my 350VA square-wave UPS for a few years and there haven't been any apparent side effects.

Could anybody explain why you aren't supposed to feed simulated sine-waves into active PFC power supplies? I guess I've never really looked into this, but I should probably read up on why this isn't good.

Michael Sandstrom · Post by **Michael Sandstrom** » Fri Mar 21, 2008 9:50 pm

Additional research on my original question led me to SPCR forum posts by member Oleg Artamonov of Xbit Labs and Moscow State University, Skobeltsyn Institute of Nuclear Physics. Check his posts out. He seems authoritative.

frostedflakes · Post by **frostedflakes** » Sat Mar 22, 2008 10:28 am

Thanks for the suggestion, I'll check it out. Oleg always seemed like a pretty smart guy, so I'm sure he knows what he's talking about.

merlin · Post by **merlin** » Sat Mar 22, 2008 11:36 am

Personally I've been really tempted to switch from my current square wave ups to a sine wave smartups. Sadly that's an expensive upgrade...I wish the prices dropped like cpus do.

Michael Sandstrom · Post by **Michael Sandstrom** » Sat Mar 22, 2008 12:51 pm

I was just looking at an APC Smart-UPS 750. Noise specs for that unit were listed as 55db at one meter. I plan to continue using a fanless simulated sine wave UPS and hope that everything works out. Based on everything I have read, I don't anticipate a problem.

Michael Sandstrom · Post by **Michael Sandstrom** » Mon Mar 24, 2008 12:25 pm

I received my new 425 watt Modu82+ a few minutes ago. I was extremely concerned about compatibility with my step approximated sine wave UPS because of the FAQ on the Enermax site.

The Modu82+ manual states "This power supply is compatible with simulated and pure sine wave UPS." It is great to have a definitive and positive answer. Tonight I install the new PSU in my Solo.

dv8ed · Post by **dv8ed** » Tue Mar 25, 2008 7:35 pm

i have the corsair hx520 power supply what is that compatible with?

Michael Sandstrom · Post by **Michael Sandstrom** » Tue Mar 25, 2008 7:46 pm

Hello dv8ed,

The moderator on the Corsair forum who is RAMguy or something similar has posted that Corsair units have no problems with simulated sine waves.

dv8ed · Post by **dv8ed** » Tue Mar 25, 2008 7:57 pm

Hi Michael,

Thank you for your info... i've been doing some research. yeah you're right. my pc hd dvr uses about 110 watts. i need to make sure it lasts for at least one hour of recording so i'll probably go for the APC BR1500LCD

Bursk · Post by **Bursk** » Thu Apr 17, 2008 3:17 pm

I wonder if anyone can give me some help with this issue. I have to be honest and say that I haven't a clue what this simulated/pure sine waves issue is all about, but I'm in the market for a UPS so am concerned about it from reading this thread (which I found via a search).

I'm currently using a Seasonic S12 Energy+ 550 PSU, and have been considering the APC BACK-UPS RS 800VA 230V - http://www.apc.com/resource/include/tec ... tryCode=gb

Can anyone tell me if this sine wave issue is something I need to be concerned about?

Also, the 'audible noise at 1 meter from surface of unit' is 45.00 dBA for this UPS. Is that loud? The loudest things I've currently got in my PC are Papst 4412 FGL fans. If that APC UPS is loud, is there anything I can do to make it quieter?

Michael Sandstrom · Post by **Michael Sandstrom** » Thu Apr 17, 2008 5:06 pm

Hello Bursk,

I have seen no reports of Seasonic power supplies having problems with simulated sine wave UPS units. Before I got my Modu82+ I was running a Seasonic SS-400 with an APC Back UPS 750va. Knowledgeable power supply reviewers such as Paul Johnson and JonnyGuru also say or imply that Seasonics are OK with simulated sine waves

Conversely, the FAQ on APC's web site say to only use active PFC power supplies with pure sine wave UPS units. There are some active PFC units that may have compatibility issues--For example, Enermax previously specified only pure sine waves on its older lines of active PFC units.

It sounds like the UPS you are considering is quite loud. The unit must have a fan. I can easily get by with my fanless unit. You might consider checking your system to see how much power it draws when fully loaded. Folks here ofter use power meters such as the Seasonic Power Angel or the Kill-A-Watt meter. An easier alternative would to to visit the Extreme Power Supply Calculator site and input your specs. People who have tested with both power meters and the EPSC site have found the site reliable. You may find that a fanless UPS unit will suffice.

Bursk · Post by **Bursk** » Fri Apr 18, 2008 5:09 am

Thanks Michael!

I found another topic on this forum which talks about UPS noise:

viewtopic.php?t=45834

Fortunately, the APC BACK-UPS RS 800VA I'm considering is listed as being a quiet UPS, provided it's not too close to you. I assume that the fan only comes on when the UPS is powering the PC. I'll ring APC shortly to confirm this.

That UPS really is the most suitable for my requirements, which is why I'd have been very disappointed if it had been too loud for me. Like many on here, I've built my PC so that it's quiet, and I'm not prepared to ruin that via a UPS.

Anyway, I'll edit this post once I've spoken to APC. Thanks again for putting my mind at ease regarding that sine wave issue.

Edit: Yup, APC confirmed that the fan only runs when the PC is being powered by the UPS i.e. in the event of a power failure.

Michael Sandstrom · Post by **Michael Sandstrom** » Fri Apr 18, 2008 10:24 am

Hello Bursk,

I did not know that the fan only kicked in when you are on battery. I looked at the UPS thread you linked to. Are you located in Europe?

Bursk · Post by **Bursk** » Sat Apr 19, 2008 7:51 am

UK, mate.

Poodle · Post by **Poodle** » Sun Apr 20, 2008 4:38 pm

I have a APC RS 1500 I think it's called. The fan only kicks in when on battery otherwise 0db no noise from it at all of any kind.
But on battery the fan kicks in ofcourse and my Corsair and also a Seasonic M12 makes a really loud clicking buzz. But both of them are bad sounding anyway with softer clicking sound when on normal power. The corsair is really loud. BUT the computer runs fine no hickup or anything like that when on battery. My two psus are faulty no doubt (same when connected to directly to wall outlet). Will rma when I can be bothered.

Will try the new Enermax when I can get my hands on one. Never again seasonic based stuff for me.

I really doubt the APC is to blame as it has a feel of old school quality to it (and as the PSUs are just as noisy when just connected to wall outlet). The APC comes with a long and impressive QC check list signed with ballpen by an APC tech. That's a quality check!

I will report back when on an Enermax psu..

Is Modu+82 compatible with my APC UPS??? YES INDEED

Is Modu+82 compatible with my APC UPS??? YES INDEED

Re: Is Modu+82 compatible with my APC UPS???