Been away from unRaid for far too long (man - it's been a tough year!) but finally getting back to putting my unRaid box back on the network.

 

One thing I was in the process of sorting out at the tail-end of last year was a UPS. Now, after some heavy reading, I've revealed mention of "Active Power Factor Correction", "step approximated sine waves".....I understand enough of the science to know I need to slow down and make sure I make the right selection.

 

I was going to purchase APC Back UPS RS Pro 900VA 540W 230V, which seemed more than ample for the server I'm running (details in my signature when I create it!) - in particular using a Corsair CMPSU-450HX - 450w (discontinued it seems, but this shopping link may suffice. Also this testing report may be useful).

 

So, do I have to worry about this sine wave....stuff? I don't need my box to run on batteries for long - just enough time to perform a safe shutdown. But I don't really know where to ask about this (could I use some other brand with unRaid to have the same effect), so I figured I'd start on the unRaid forums and go from there.

 

MTIA

Are you 110 or 220 (UPS you link is 220)?

 

Sine wave has little to do with our application.  It is more important for DC only devices, not AC devices that then convert to DC like our computer power supplies.  DC pumps for example will have major issues if feed a incorrect wave.  The short answer is, if it has a "power supply" or "AC adapter", the wave type will likely not matter much at all.

Unfortunately, there are some PFC power supplies which will not work with some step function UPS's.  (I also understand that the designers of the PFC PS have addressed this issue in later designs.)  When I was looking for a UPS, I came across the same type of warnings and 'horror stories'.  However, I could not find a list of which PS worked with which UPS.  (APC has a page on their webiste where they basically say, 'use our true sine wave UPS with any PFC PS".  Of course, the true sine wave UPS are at least double the cost of the step function UPS.)

 

What I did was this.  I purchased an APC Back-UPS BX1000G UPS from Amazon.com and tested it out with my server IMMEDIATELY.  (Be sure to stop the array FIRST!!!!)  It worked and has successfully handed several power outages in the six months it has been installed. 

 

If it had not worked, I would have gotten an RMA from Amazon.com by contacting their customer service to return it because it did not work.  In that phone call, I would have politely requested a prepaid UPS label.  (I personally have never been refused but I am a frequent customer of Amazon.com.)

 

 

Thanks for the responses both. It will be a 230v UPS (over in the UK)

 

I'm a little wary that I'll hit a snag with this, but I've read the info on testing a UPS via the wiki/forum and I should be able to tell quite quickly if the UPS will auto-shutdown the way I want it to. If there's other thoughts out there I'd welcome hearing them.

 

As an aside, is that a reasonable UPS to go for? I don't anticipate going over 8-10 drives and as long as I'm using 1TB+ drives all should be well. The calculations I did when I build my box suggested 12 drives would be fine for the PSU....at which point I would be looking for a larger box to hold everything in!