UPS for home use, which one?

[Karel]

Hi everybody,

I want to buy myself a UPS to deal with the power surges here. It needs to be an active one that protects also against very short voltage fluctuations (brownouts).
A backup time of 5 minutes will be enough. Linux support is a pre. Any recommendations?

I'm thinking about something like this:

https://www.cyberpowersystems.com/product/ups/pfc-sinewave/cp1350pfclcd/

Thanks,
Karel

[Wuerstchenhund]

Hi everybody,

I want to buy myself a UPS to deal with the power surges here. It needs to be an active one that protects also against very short voltage fluctuations (brownouts).
A backup time of 5 minutes will be enough. Linux support is a pre. Any recommendations?

I'm thinking about something like this:

https://www.cyberpowersystems.com/product/ups/pfc-sinewave/cp1350pfclcd/

How bad is your power line? Because Line-Interactive may or may not be the right UPS.

There are essentially three categories of battery-powered UPSes:

- Standby: the simplest form. If the power drops below a certain level then they switch to battery mode.
- Line-Interactive: like Standby, but also monitors input voltage variations and can compensate for certain under- and overvoltage conditions (i.e. brownouts) as well as power factor.
- Active (usually called  'online'): uses a constant AC-DC-AC conversion where the batteries remain connected to the inverter, which means it doesn't have to switch between battery and mains supply. Unlike the other two types, the active UPS provides truly uninterrupted power, and can compensate for a wide range of line issues.

The disadvantage of the online UPS is its power draw as the constant AC-DC-AC conversion causes some loss of power (and heat, which is normally removed by a fan, so there's usually also some noise).

While I wouldn't recommend a Standby UPS for a computer, a Line-Interactive is usually fine if the power grid is generally reliable (and computer PSUs can easily deal with the short switchover event). If your local power line is poor however I'd recommend to get an online UPS.

As to brands, I'd normally look at Tripp-Lite, Eaton Powerware, Liebert/Emerson, Xtreme. Wouldn't recommend APC as we had lots of problems with them over the years. But that is mostly for professional use.

If it's for home use then there might well be other brands which would do fine, and the one in the link appears decent.

[Karel]

Thanks Wuerstchenhund.

It's for home use and compared with the country I origin from, the powergrid here is pretty bad.
Sometimes it's ok for more than a month. Sometimes we have a surge once a week.
The surge can be relatively long, up to a minute or very short, less than half a second.

And you are right, the continuous conversion wastes energy but makes it easier to provide a stable voltage and waveform.

[KaneTW]

I have an Eaton 9PX 1500i. It's an online UPS, although I run it in energy-saving mode most of the time (the network grid is fairly stable here).

Stock fans are rather loud for a quiet home office environment, but I replaced them with Noctua fans. Personally, I'd go for the quietest, lowest RPM fan you can find. The heat load isn't particularly big.

[Mechatrommer]

you can buy any UPS that you think the brand is legit and the price is within reasonable figure etc but dont make mistake like i did, i have 3x ~500VA UPS in the store waiting to serve the right device for them after i pulled them out from my PCs. i thought 500VA can deal with my 450W PCs, wrong. i thought the first one is bad brand or bad design, then i bought the second different (better) brand, behaved the same, during power blackout, they are not 100% protecting my work. then i bought the 4th unit, now i beefed up to 1000VA, works charming until now, its just a matter of replacing expired batteries, this is unavoidable maintainance that we have to take care, SLA battery can die in just a matter of 2-3 years. as for how long it can protect your work in blackout it depends on how big the SLA battery is. i modded the earlier unit to take car's battery, but since the bottleneck is in the 500VA circuitry, then it didnt make any different at protecting from surges, but car battery could last maybe 15-30 minutes. i never have a need to mod my 1000VA since it has 2 batteries inside so i have plenty of time to do last minute editing and save my work before getting along with the blackout. ymmv.

[Halcyon]

Honestly, just pick up a second-hand line interactive APC, Eaton/Powerware etc... (sometimes rebadged as Dell, IBM and so on). Throw some new batteries in and you'll be on your way.

Even the APC Back-UPS series are perfectly fine for most residential use cases and are inexpensive.

Sensitivity and min/max voltages can be adjusted through software on most models to suit your requirements. If you have sensitive equipment, go for a line interactive APC Smart-UPS or similar model.

If you find your power to be particularly bad, maybe go for a larger unit that can support longer run-times in between battery charges.

[Wuerstchenhund]

Honestly, just pick up a second-hand line interactive APC, Eaton/Powerware etc... (sometimes rebadged as Dell, IBM and so on). Throw some new batteries in and you'll be on your way.

Even the APC Back-UPS series are perfectly fine for most residential use cases and are inexpensive.

Sensitivity and min/max voltages can be adjusted through software on most models to suit your requirements. If you have sensitive equipment, go for a line interactive APC Smart-UPS or similar model.

If you find your power to be particularly bad, maybe go for a larger unit that can support longer run-times in between battery charges.

Good suggestion, however I would recommend to avoid APC. We had lots of issues with them over the years, a lot more than with our Powerwares (which are a lot more reliable) and Sola/Hevi Duty units (which are built like tanks, not a single defect even on very old units).

For a 2nd hand unit, I'd rather look for that Eaton/Powerware or Best Power (which later became part of Powerware).

Some of these units have also been sold under the HP brand.

[KaneTW]

Yeah, I would avoid APC. I've had some units fail silently (self-test passes, battery is ok, doesn't provide emergency power).

[Mechatrommer]

right, my 3rd 500VA unit is APC the 1st and 2nd is Contronetix, and now in use is KOSS, i believe local brand.

[tkamiya]

I strictly use APC's commerical models.  I have a few from 1KVA to 3KVA rack mount models.  While they are quite costly new, used ones are very cheap on eBay and all I had to do was to replace batteries.  I had only one that had relay problems, but I was able to repair it quite easily.  Fault was obvious in visual inspection.  Oh, yeah, I had one that was DOA.  Seller game me my money back and said not to bother returning it.

I do not like consumer version of APC.  Their specs are often over-rated.  As a result, after a while and few up and down cycles, batteries swell up and get stuck in the chamber. 

[edpalmer42]

Another nice feature that you'll often find in a higher-end UPS is some form of 'battery care' option.  Each brand is different, but typically they might reduce the battery charge voltage or even disconnect the charger when the batteries are fully charged.  This can significantly extend the life of the batteries.

So, a used, online (also called dual-conversion) UPS with 'battery care' would be a really nice score.  A network management card would be icing on the cake!   

[chriva]

We don't really know how much your computer draws during full load nor what its nominal power draw is so it's hard to say what would be a good device for you

Here's my setup:
A APC 500VA unit that has been slightly modified to mitigate some of its known flaws (Way too low a resistance in one of the divider nets and some other stuff I didn't like. Went down from 28-30 to 6-8 Watts idle draw. Drawback is that it takes two days to fully charge the battery but I rarely have black/brownouts).

Can't remember the exact model number right now since I'm not at home but it does have rudimentary line compensation (like -+20 VAC or something). configurable brownout trigger etc.

Mine would probably only last two minutes on full blast so it's set to throttle back everything as soon as the "on battery" signal is received and then enter hibernation (store everything to disk).


Last note:
I can definitely vouch for a second hand one. You have to replace the batteries regularly anyhow so it's not worth the cost of a new one if you don't use it for your business.

[fordem]

What is critical is the type of load - since you list linux support as a prereq then I assume some sort of a computer load.

Switch mode PC power supplies are tolerant of a wide range of voltage fluctuations and the more recent units will accommodate an input voltage from 100~240 without user intervention - I'm reading this off of the power supply for a six your old Lenovo/IBM.  By design, switch mode power supplies do not draw power from the line continuously, the input is essentially a rectifier followed by a storage capacitor and current is drawn from the line only on the peak of the AC wave form and only when the rectified voltage is higher than that stored in the capacitor, making them quite tolerant to "millisecond" outages of the type seen when a line interactive UPS transfers from line to battery.

Just about any line interactive unit with sufficient capacity to support the required load will do what you need - avoid the cheap battery backup units - so if, for example, you're looking at APC, you want to go for a SmartUPS and not a BackUPS.  If you're looking at Eaton, you don't want anything where the model number starts with a 3, you want a 5 at the very least - 3XXX is basic battery backup, 5XXX is line interactive, 9XXX is reverse transfer or true online.

Do you require true online - in my opinion it's a nice to have - for certain types of sensitive comms equipment it's a must - for general purpose computing, it's not required.

I've used TrippLite, APC, Best Power (now owned by Eaton), Exide Electronics (now owned by Eaton) and Liebert Emerson - as long as we're discussing the smaller "desk side" units (up to say 3kVA) -  they're pretty much all the same in terms of quality & functionality - so look at the features and pick one that you like and can afford.  I've owned all of the above at some point, and currently have five APC units of different vintages - personally I prefer units with network management, so that means I need to look at the higher priced units.

Do I have a preference for APC units - NO - I'm happy to use whatever I can get, and only one of the units I have was purchased new, the other four were all free and just needed batteries.

Linux support - this is where I'm going to get rapped on the knuckles - make sure the unit you choose has a comms interface and then after that you're on your own - download nut (network ups tools), learn how it works and how to configure it.  Open source has both advantages & disadvantages and it's "open-ness" is what leads to the challenges in finding support and finding devices that work well with whatever flavor of the month you're running.  Have I used it - yes - amongst other things I have a raspberry pi, running nut, powered via PoE, that shuts itself down when the APC tells it there's an outage via the ethernet interface - the pi is about 150' or so from the UPS that powers it.  I've also used Eaton's LANSafe with SCO Unix (now that was a PITA to setup).  If you're looking for plug'n'play functionality, then you're using the wrong OS.

[tkamiya]

Oh, you bring up a good point.  Capacity.

Most UPS are rated by VA.  We typically think of WATTS.  They are not the same thing.  I really don't want to go into details but I usually try to keep load 1/3 of ratings.  At most 1/2.  In my modest lab, I have total of 10KVA worth of UPS all loafing around.  It does wonders on reliability. 

Please - avoid the temptation of buying small under-the-desk type UPS and hook up a large battery.  DC/AC inverters inside these small UPS are not meant to be operated beyond 10 minutes or so.  Most rack units are made robust and many of them have fan with temperature control.  How-to do this type of conversions are numerous on YouTube and Blogs.  They are fire hazard.

[Karel]

Thanks for all the replies.
I should have mentioned in my first post, that I need it for home use, not in a lab.
I have no other choice than to put it under my desk.

At work we do have a dieselgenerator backup but that one takes approx. 30 seconds to startup.
To deal with that I'll need something more "professional" but for now I'm looking for something
for home use.

[tkamiya]

APC's 1500VA version works well in home/office environment. 

Back-UPS Pro1500 is what I have.  One lasted 8 years with few battery changes.  I still have 2 of them here, not in lab but in office.

[madires]

If you buy an APC make sure it has a SmartSlot and get also the AP9620 "Legacy Communications Card" (around 60 bucks) for the communication with NUT (Network UPS Tools). The newer Modbus based protocol is a trade secret, therefore not supported by NUT. I'd suggest to avoid APC for that reason.

Edit: I mean the Microlink protocol.

[fragile]

I just talked to my uncle Joe, just now, because he is a tech at Vertivco, which makes Liebert UPSs. Liebert is the industry standard. The make 750VA to 1000KVA units. He got me a 1500KVA for my bedroom. I think my Dad he got a 3000KVA.

SO, I guess if you want protection from 'utility' power unevenness, line interactive are bad.. He said you want ''double inversion' UPS, because nothing can get through it! It changes the input power to DC, and then back to AC. He got mine on eBay, with a extra battery box, for 250$. Shipping was ok, bc it had no batteries in it.
'
So, I says, what should I tell this guy? He sent me a email, so I'm sort a readi g it right now. There's a lot  of small libert systems on eBay.


OK, I HOPEE you get one you like! His company uses yausa batteries, or  exide, or enersys.

[BradC]

If you buy an APC make sure it has a SmartSlot and get also the AP9620 "Legacy Communications Card" (around 60 bucks) for the communication with NUT (Network UPS Tools). The newer Modbus based protocol is a trade secret, therefore not supported by NUT. I'd suggest to avoid APC for that reason.

It's perfectly supported by apcupsd. If the authors of NUT haven't read the very detailed and publicly available APC Modbus specification document, that really isn't APCs fault. The "APC Netlink" protocol is a trade secret, but there are very few units that support that and aren't upgradable to support Modbus also. All the new ones do it out of the box.

Personally I'm an (early, SU to SUA) APC SmartUPS fan, but I also have MGE (pre APC merger) and Liebert dual-conversion units here.

I prefer the early white APC SmartUPS (3G / SU) units because the schematics are "available" and they are all conventional through-hole and dead easy to work on. Whatever floats your boat.

An dual conversion unit is going to be noisy, as will a lot of the later line-interactive units as they have one or more fans running continuously (even if at low speed). Most of the APC BackUPS are pretty quiet as are the early SmartUPS. I'm not a fan of the BackUPS, but I have a few in service.

[madires]

Thanks for the hint! I messed up the protocols. What I actually meant is the Microlink protocol. Modbus is a later extension for some (many?) APC models.

Someone has done some reverse engineering of the Microlink protocol end of last year:
- https://sites.google.com/site/klaasdc/apc-smartups-decode
- https://github.com/klaasdc/apcups-serial-test

[themadhippy]

He got me a 1500KVA for my bedroom. I think my Dad he got a 3000KVA.

You sure about that? I once installed a 500kva ups,the switch panel alone was 6ft x 8ft and the battery bank took up a fair bit of space.One thing i learned from the commissioning engineer was dont run up your load bank on the ups output before checking how much load is already on the incoming supply.

[fordem]

I just talked to my uncle Joe, just now, because he is a tech at Vertivco, which makes Liebert UPSs. Liebert is the industry standard.

Liebert is just another one of the many brands out there - if you want to talk about industry standard - go look at market share.  Vertiv actually ranks as #10 in the top 10, with Eaton being #1 and Schneider (APC) being #3.

For the type of product being discussed here, which is single phase UPSs, APC is the market leader, however Eaton takes the lead for three phase.

https://www.marketresearchreports.com/blog/2019/08/20/world%E2%80%99s-top-10-uninterrupted-power-supply-ups-manufacturers

[Marck]

We have probably 50 APC smart units of various capacities deployed.  Over 7 years i think we have had maybe 5 failures not related to batteries. Some of these units are in fairly hostile environments with plenty of dust and heat and being supplied by generators that are shut down every 300 hrs for service. 

The biggest issue I have is the batteries expanding and having to dismantle the units to remove them. 

I have a 2000va unit at home that I am about to replace the internal batteries with a bank of 150AH SLA batteries.  It will all be moved into the bottom of my rack for space and protection from any inadvertent interactions with the battery bank. I am not sure that this is a great idea but our power is fairly reliable most of the time.  And I run at about 30 percent capacity of the unit most of the time so with any luck it will tolerate the new found run time ability if its ever called on. 

If anyone has any concerns about the upgrade I would be interested to hear your advice 

Thanks
M

[madires]

The biggest issue I have is the batteries expanding and having to dismantle the units to remove them. 

I've seen that also many times. AFAIK, APC runs the float voltage fairly high. The pre-2009 models have a hidden service menu which supports changing the that voltage. On my personal APCs I've set the float voltage a little bit lower than what the SLA's datasheet state. What annoys me the most are overpriced battery packs.

[fordem]

Whilst overcharging can cause the gelled electrolyte lead acid batteries to swell, in my experience it will require significant overcharging - I believe the problem relates to failed batteries being left in the unit, on charge, long after they have failed.

UPS batteries have, realistically speaking, a 3~5 year expected life span, and if the units are being properly managed & maintained, you should have no issues with swollen batteries - unfortunately, especially with the smaller desk side units, no one pays them any attention until they drop dead.

Regarding the extended run times - with proper cooling the challenge becomes the recharge times - does remember the APC XL series of SmartUPS - they had no internal batteries and could take anywhere from 1~10 external packs each with 4 x 18Ah gel cells?  I still have one of those and will occasionally run it for multiple hours.