Need a List of UPS for ReadyNAS Ultra 4 Plus unit

4.2.20 (http://www.readynas.com/RAIDiator_x86_4_2_20_Notes) is the latest version of RAIDiator. I would recommend updating to it.

Most APC UPS units with USB ports are compatible with the ReadyNAS.

Got a ReadyNAS Ultra 4 here (not a Plus model), I'm using a BackUPS ES700uk (1st Gen) and it works well. Need to allow network PC's to monitor the NAS using WinNUT to get them to shut down too, but it all works well.

I found this list. I can't tell you if it's current or not: http://www.readynas.com/?page_id=92.

One thing that seems missing from discussions about compatible UPS's is whether or not ReadyNAS Ultras have active PFC power supplies and whether or not compatible UPS's output pure sine wave signals to properly feed PFC power supplies.

This thread seems to hint at it: http://www.readynas.com/forum/viewtopic.php?f=88&t=48761&p=279403&hilit=sinus#p279403 ("sinus" = "sine")

Another individual created a ReadyNAS compatibility list on Amazon, but makes no mention of PFC consideration: http://www.amazon.com/UPS-for-NETGEAR-ReadyNAS/lm/RRYNRRGBHAMM5/ref=cm_srch_res_rpli_alt_1

Is there a consensus yet? Feeding PFC power supplies with "approximated sine wave" backup power can either result in the power supply shutting down to protect itself (negating the whole purpose of having a UPS) or can result in damage to the PFC power supply.

According to APC their current Back-ups models include firmware tweaks to make their stepped fake sinewave work with many PFC PSU. Still some users claim to have issues. I have not heard that the Ultra 4 has a PFC PSU.

BTW i have used APC Backups ES550 with a few ultras and new Pro's and have yet to hear of issues.

If you are concerned get a Smartups.

claykin wrote:
If you are concerned get a Smartups.

I'm going to give the Cyberpower CP850PFCLCD a try. Unfortunately, the lowest pure sine wave PFC-friendly UPS's on the market today are in the 700-800W range, which is overkill for just a ReadyNAS Ultra 4 Plus. At $120 from Amazon, the CP850PFCLCD is $60 more than a 200-300W APC UPS. $60 extra is easy peace of mind for me when protecting a $1000 NAS-and-4-harddisk combo. Plus, I'll have plenty of reserve power for future added networking equipment.

I have a PFC power supply in my custom built desktop PC. I chose to buy the Cyberpower CP1500PFCLCD for the same reason and it has worked marvelously.

I hope the industry provides a little more information on this issue going forward.

Have you checked to see the battery runtime you get with that Cyberpower PFC UPS? From my limited experience with them, the batt runtime was poor. Also note that even though Cyberpower represents them as pure sine wave, they are not pure sine wave by the definition. Cyberpower applied their marketing "magic".

I'm very impressed with the CP1500PFCLCD that runs my custom Intel Core i7, 2 large monitors, modem, router, and NAS (currently). At full load (around 800W), I get about 20 minutes runtime. I'm moving the NAS to a new location in the house, which is why I hunted for a new UPS. I hope the new one performs as well.

I'm all ears if you've got some sources that talk about Cyberpower's "pure sine wave" claim. Never can be too informed.

Best not to put full load on a UPS. Putting more than about 80% load on a UPS leads to the battery draining quickly which is not good for the life of the battery in the UPS.

mdgm wrote:
Best not to put full load on a UPS.

Sorry. Got my numbers wrong. Full load of all the equipment I mentioned above is about 400W...about half of the CP1500PFCLCD's rated 900W.

Thanks all for reply.

Bob K-

Can it be used the two USB ports to connect the PC and ReadyNAS?