Register for the iXsystems Community to get an ad-free experience and exclusive discounts in our eBay Store.

Large Rackmount UPS Recommendations

Status
Not open for further replies.

GPSpiderMKII

Junior Member
Joined
Dec 26, 2016
Messages
19
Hey everyone, hopefully this will be my last plea for help before finally finishing my FreeNAS build. My rack finally came in (bought the one recommended by @BigDave in my other thread - thanks again!) and the server is installed in it, though I need an UPS system to power it and keep the investment safe.

Having looked around some of the previous threads on this site requesting help with UPS systems, I came upon the CyberPower OL1500RTXL2U, thought I started second guessing myself when I was reading about NUT compatibility and some UPS systems not playing too nicely with FreeNAS. Then I started looking at the APC SMT1500RM2U but haven't been sold on that unit either.

My FreeNAS system is pretty large (a 4U SC846 SuperMicro Chassis that has a 1280W PSU with a secondary for failover) and will host 24 HDDs. I'm thinking I need a larger UPS system because my current one will supply battery power, but not without a break in service during a power outage, so it's not really serving its purpose and it's supposedly rated to around 900W. I'd like the UPS system to be rack-mountable, have the ability to install additional rack-mountable battery packs, be pure sine wave, and be able to replace the battery packs when they eventually die (if that is possible for a pure sine wave system - I haven't found one yet), and be compatible with NUT and FreeNAS so that in the event of a power outage I can shut the system down gracefully after a given amount of time.

If anyone needs any more information to help identify a proper system just let me know, and as always, thanks for any help you can provide!
 

danb35

Wizened Sage
Joined
Aug 16, 2011
Messages
11,946
Mine (see my sig) works well, and with the 9631 network card it came with makes it trivially easy to interface with FreeNAS (and any other system running nut). And you can expand it with extra battery packs for more runtime if desired.
 

Ericloewe

Not-very-passive-but-aggressive
Moderator
Joined
Feb 15, 2014
Messages
17,019
Any recent rackmount APC unit should be fine.
 

jlentz3

Member
Joined
Feb 6, 2017
Messages
26
I use multiple smt1500rm2u ups at work. They are pretty damn solid.

I’ve got a couple of cyberpower at work as well without issues. I bought a cyber power for my home server since it’s.


Sent from my iPhone using Tapatalk
 

Stux

Wizened Sage
Joined
Jun 2, 2016
Messages
4,163
I’ve got a 5000VAC APC unit, and would submit it’s too big for your use case ;)

It requires a hard line!

So go with something smaller ;)

You will probably never need more than a 1000W, but I’m not sure if the 1400/1500VAC units will deliver that

So, probably go for something in the 2000 VAC range.
 

danb35

Wizened Sage
Joined
Aug 16, 2011
Messages
11,946
You will probably never need more than a 1000W, but I’m not sure if the 1400/1500VAC units will deliver that
The problem with pretty much all UPSs is that they're rated by peak power output, not by watt-hour capacity. So one model of 1500VA unit could power a 500-watt load for 2 minutes, another model for 10 minutes. If you dig enough on APC's web site, you can find load vs. runtime charts; I'm not sure if other manufacturers provide that data.

Edit: And my system (with 21 disks installed) draws around 300 watts most of the time, FWIW. I'd be surprised if OP's system draws (or will draw) more.
 

GPSpiderMKII

Junior Member
Joined
Dec 26, 2016
Messages
19
And my system (with 21 disks installed) draws around 300 watts most of the time, FWIW. I'd be surprised if OP's system draws (or will draw) more.
I've estimated that at full capacity I should be drawing somewhere around 400W (I have a dual processor board). My main concern is making sure there's enough overhead on the UPS that during a power outage the failover will happen without a break in service. I'm assuming that in a pure sine wave system this isn't as much as an issue since the system runs off the battery the whole time.

I appreciate everyone's responses so far; it's looking like so far that APC is the preferred brand.
 

danb35

Wizened Sage
Joined
Aug 16, 2011
Messages
11,946
I'm assuming that in a pure sine wave system this isn't as much as an issue since the system runs off the battery the whole time.
That's not what pure sine wave means, and there will be a momentary interruption in power. It should not affect the attached equipment, though; a decent power supply (which your Supermicro chassis should certainly have) can easily handle the few milliseconds of switching time.
 

GPSpiderMKII

Junior Member
Joined
Dec 26, 2016
Messages
19
That's not what pure sine wave means, and there will be a momentary interruption in power. It should not affect the attached equipment, though; a decent power supply (which your Supermicro chassis should certainly have) can easily handle the few milliseconds of switching time.
Ah, maybe I misread one of the products. In addition to cleaning up the signal and producing a pure sine wave, I was under the impression that this is done by utilizing the battery power internal to the UPS through an inverter and the AC voltage is only used to charge the batteries. That way, in the event of a power outage there doesn't appear to be a loss in service because it is running off the battery power already and they just lose the ability to continuously charge. I'm guessing that was just specific to that model now.

@danb35 , you're saying that it's primarily the power supply that determines if it can handle the switch over in a power outage and not necessarily the overall wattage output of the UPS?
 

GPSpiderMKII

Junior Member
Joined
Dec 26, 2016
Messages
19
Last edited:

danb35

Wizened Sage
Joined
Aug 16, 2011
Messages
11,946
you're saying that it's primarily the power supply that determines if it can handle the switch over in a power outage and not necessarily the overall wattage output of the UPS?
The wattage output of the UPS isn't a significant factor. The rest of the UPS can be, of course--how long it takes it to detect power failure, and to switch to battery, is obviously going to be a factor. But in practice, any decent UPS should be able to switch over a load within its rated capacity quickly enough that any decent power supply should tolerate it without an issue.

The model you mention looks like a good pick. Also consider used units--you might need to replace batteries, but that's easy enough to do.
 

Stux

Wizened Sage
Joined
Jun 2, 2016
Messages
4,163
In addition to cleaning up the signal and producing a pure sine wave, I was under the impression that this is done by utilizing the battery power internal to the UPS through an inverter and the AC voltage is only used to charge the batteries
I believe the term used to describe that behaviour is an "online" UPS.

The Pure sine wave stuff is about the quality of the generated AC, and is a good thing, the other important thing is the switching delay. Online UPSes have no switching delay, but pretty much any good UPSs will be fine because ATX power supplies have a specified amount of runtime with no power attached... and that's about 20ms? I forget. But I suspect the switching time on the APC Smart UPS is measured in microseconds.

http://www.formfactors.org/developer/specs/atx12v psdg2.01.pdf
Voltage Hold-up Time
The power supply should maintain output regulation per Section 3.2.1 despite a loss of input power at the low-end nominal range—115 VAC / 47 Hz or 230 VAC / 47 Hz—at maximum continuous output load as applicable for a minimum of 17 ms
17ms minimum. There ya go. So as long as the UPS will switch in a few ms, all is fine with the world.

Checking the specs for a random Smart UPSs they don't mention the transfer time, but if you check there BackUPSs pro line, they have a "stepped approximation to sine wave", which is no good for running motors... and they mention a 4ms transfer time...

Since APC don't list the trasnfer time on their SmartUPS range, I suspect its essentially zero, as its probably got enough capacitors to ensure a clean switch-over... This is also how it can probably test a faulty battery without failing if the battery is non-existent...

Also, the UPSs are Line Interactive. This means the UPS is capable of boosting/correctling for under/over voltage in the mains... without using battery... which I think is a good thing. I know my UPSs triggers this mode in summer when everyone else turns on all their air cons and the line voltage drops. It also means brown outs won't necessarily trigger power failures.

So, first thing you need to know is the MAXIMUM power spike, your UPS *must* be sized greater than this, otherwise it will cut out when you hit peak, say during boot/spinup. A 1000VA APC is good for 800W, so I suspect 80% of the VA rating is probably a good ball park.

And magically, 1250W PSU / 80% = 1550VA, so even a 1500VA unit should be plenty... power wise...


Then you just step up the VA ratings until you get a runtime with your typical draw that you are happy with. Remembering that some of the UPSes allow you to extend runtime with additional batteries too.

The VA rating is basically dependant on how beefy the transformers and power circuitry in the UPS is, where as the runtime is dependant on how big and how many batteries it has. And bigger UPSes tend to have bigger and more batteries.
 
Last edited:

Stux

Wizened Sage
Joined
Jun 2, 2016
Messages
4,163
Also consider used units--you might need to replace batteries, but that's easy enough to do.
I've had very good luck with used APC units. Bought half a dozen or so. They're built like tanks...

Budget for a new battery, but wait for the UPS to tell you the battery has failed before getting new batteries.

Also, you can buy battery refurbishment kits off ebay etc, and reuse the wiring harness that comes with the UPS. Much cheaper than buying APC batteries, and also, often better quality that the OEM batteries!

And don't stock pile batteries, they fail in storage ;)
 

danb35

Wizened Sage
Joined
Aug 16, 2011
Messages
11,946
And bigger UPSes tend to have bigger and more batteries.
True. There's no reason that needs to be the case, but it almost always is. And that's why I have a 3 kVA UPS for an 800-watt load.
 

trentk10

Member
Joined
Jan 7, 2017
Messages
67
I have a used from ebay Eaton 9130 UPS 1000VA 900W 120V 2U Rack Mount PW9130L1000R-XL2U. I thought I got a reasonable price @ $270. Also, it looks like I can pick up and extented batter module (adds another 1000VA) for less than $300 off of ebay as well. FreeNAS recognized it easily.

This is for a home set up.
 

Arwen

Neophyte Sage
Joined
May 17, 2014
Messages
1,312
I have a used from ebay Eaton 9130 UPS 1000VA 900W 120V 2U Rack Mount PW9130L1000R-XL2U. I thought I got a reasonable price @ $270. Also, it looks like I can pick up and extented batter module (adds another 1000VA) for less than $300 off of ebay as well. FreeNAS recognized it easily.

This is for a home set up.
I'd guess the extended battery adds run time, not power. The 1000VA figure for the external battery pack probably means it's designed to work with 1000VA UPS.

I've seen advertisements for external battery packs that have twice as much batteries as the UPS built in batteries. Same sized package, (2U), but the external battery pack does not have any electronics. So, that would tripple the run time, (aka off-A.C. time), but do nothing for the maximum amount of power the UPS can supply at once.

This is mostly for people reading the thread, for information, not for the poster I quoted who likely understands this already.
 
Status
Not open for further replies.
Top