Does a UPS actually protect hardware?

[Deanoff]

I did as much research into UPS units as I thought I needed in order to understand all of the top level jargon, but the fundamental issue of whether the appliances plugged in will be physically protected hangs over the entire industry (for domestic use).

For example, a CyberPower UPS unit claims that it employs "Surge Protection & Filtering" with a surge "suppression" of 405 Joules. However, lighting will strike power lines with many hundreds of thousands of Joules, so how can such a UPS be of any genuine use?

ref: https://www.cyberpower.com/uk/en/product/sku/CP1500EPFCLCD

My reckoning was that the lightning strike would be sufficiently suppressed at the power station level before it reached my home's power lines, but I just don't know, there are many variables. Just how realistic can domestic computing hardware be protected when plugged into utility supply? (through a UPS)


Another thing: there is apparently no such thing as a perfect sinusoidal wave, both "clean" and "dirty" power suffer from spikes; noise, and ripple voltages, but with the way DC powered microelectronic devices are designed today they do not suffer from these fluctuations as UPS manufacturers would have us believe, such claims are then a gimmick?

The one thing I need are solid numbers, not claims, but the actual irrefutable numbers. I am not smart enough to do that, I need help from people that are, to put this issue to rest.

Thanks.

 

[BonzaiDuck]

I've lost more than one modem or computer (either way) to electrical spikes coming through a surge protector. After a very bad storm in 1993 Virginia, I always put a UPS between my PC and the wall. I couldn't tell you "solid numbers" for serious electrical spikes.

All I can say is that my (various) UPS's have got me through lightning storms with no damage to a UPS and the systems. They've protected my systems from brown-outs and blackouts. Ah! you say -- how would that protect my system?

Losing power to a system can do the same thing that a BSOD can do. You can eventually have a corrupted hard disk with OS by not shutting down Windows normally.

A good UPS like an APC has communications software and a USB connection to the system. When the UPS switches to battery for a blackout lasting more than a minute, it can have a scheduled shutdown occur within minutes. When the power comes back on, you only need to restart the systems -- perhaps after switching the batteries back on -- if you shut them off yourself or they turn off as part of the scheduled tasks.

 

[UsandThem]

Like BonzaiDuck already mentioned about storms, we had our power knocked out for a day after hurricane Matthew. We were on the outskirts of the full storm, but it provided enough wind to down some trees and branches here. So when when a branch knocked down a power line somewhere in our town, the lights flickered and dipped down, then went back to full power. It did this 3-4 times before the power totally went off. I was on my computer at the time this happened, and if it wasn't on a UPS I would have: 1. Lost what I was working on. 2. My computer (router, modem, etc) would have been hit with four power dips/surges within seconds\ which could have corrupted my OS (depending on write-crash buffer setting, etc.) or damaged something.

And this wasn't the first time this has happened. Living in NC with all the trees, I have this same thing happen with storms 4-5 times a year. I do know that from over the many years on here, there have been many people who weren't using a UPS when a storm/brownout/surge hit their computer, and lost their entire computer or components (most common are PSU, motherboard, hard drive, or video card).

As far as hard numbers go, you can only go off of what the UPS companies claim. You are right about one thing though. If you have a lightning strike hit your equipment full-on, no UPS or surge protector will likely stop it all. However, they all offer warranties for such a thing (how well they honor them, who knows). While some lower-end UPS system feature a low joule rating like the one you linked to, many models have a much higher rating like the CP1500PFCLCD which as a joule rating of 1,030.

Lastly, there is a fluctuation in the power coming into most residences. Usually it is small and not an issue. However, brownouts and dips can be low enough where your PC will shut itself down if not on a UPS, and over time it can not be good for electronics.

 

[Red Squirrel]

Improper shutdowns are very hard on computers, so UPSes do help in that respect. Downside of most consumer UPSes is that they are standby, so they actually run directly off commercial AC then switch to inverter only when they detect a fault. This delay can potentially be seen by the computer. But it's still better than nothing. If you're lucky, whatever UPS you get will also have a delay before it switches back to commercial AC when power comes back. This will ensure the computer does not see the initial surge of the power coming back. So you don't want your electronics seeing that.

 

[imported_ats]

In general, most consumer UPS offer power surge protection that's a fraction of a good high quality surge protector. You tend to have to go well into the biz/rack mount UPS before you get to a decent level of surge protection. Outside of server room UPS/PCS, it is best to think of a UPS as just a power interruption or brownout protection device. I would still run high quality surge protectors.

 

[mnewsham]

UPS's aren't surge protectors.

If you want actual surge protection, get a real surge protector and run your UPS on that.

 

[Torn Mind]

Typical surge protectors use metal oxide varistors to "protect" against voltage spikes. There is the let-through voltage, or basically how high a voltage can be before the MOV activates and shunts to ground some current. MOVs degrade as when subjected to such spikes to the point the form a short and the circuit fails completely. To get joules, you need to multiply voltage, amperage, and time.

UPS protects data, first and foremost. Nothing like system corruption or lost work to ruin a day. UPS units do come with surge protection only outlets as well. Hence, there are some components dedicated to surge protection, probably some MOVs(metal oxide varistors) to suppress random spikes in AC voltage.

Standby UPS allows the attached device to be subjected to mains power. If there is a surge suppression component, it is like just some MOVs and it is really light duty.

An online/ double conversion UPS might do a better, because AC is converted to DC to charge up a battery, and then DC current flows out of the battery through and out an inverter and to whatever electrical appliance is attached to it. Should lightning strike it, perhaps that stuff gets toasted first. What actually happens though, won't be known unless lightning actually strikes a such a building.

The way PSUs are "protected" from line noise and spikes is through caps or MOVs on the primary side of the unit, before power reaches the rectification and step down transformers. Those are your X capacitors, Y capacitors, and MOVs. I doubt this is anything overly modern. I might need to tear one down myself, but I suspect even AT and XT PSUs in the had some or all of those things. There is no magic sauce for protection; everything is based on physics. Newness or oldness is not based on physics. The plumb bob is old, but it works for finding what is truly vertical.

Ripple typically refers the "waviness" of DC current after it has been rectified.

Lightning, like any electrical current, travels the path of least resistance. If it strikes a tree, it's not going to a power station. It got the tree. It could be a few thousand feet away, and then travel through the phone and kill someone(actually happens). No, a UPS or PSU alone will likely be unable to shunt the power sufficiently and something will probably die. But a UPS or PSU will still work within the actual spec of the MOVs and how they are placed in a circuit.

So, in short. yes, surge supression components in UPS DO work up to their rated spec and according to how they are wired(wiring MOVs in parallel increase their joule rating). They will not protect against a lightning strike; you'll need a whole house protector for that. Lightning will take whatever path, so not only the electrical path must be protected, but other paths like phone, cable, etc.


http://www.christidis.info/index.php/blog/33-teardown-and-operation-of-an-mge-nova-avr-600
Down in the teardown, there is a pic of two MOVs where the mains power cord is attached.

Sorry if I'm meandering a bit.

 

[Rubycon]

UPS is designed to provide power when utility mains is interrupted. Filtering can be used but that is not the primary goal. Lightning strikes to overhead utility lines will cause reclosers to open and your UPS to engage. A spike will often travel down to the service entrance on customer premise and flash over to ground/neutral. This is where the 6.6kV rating comes from. If the service entrance is not earthed per local codes then dangerous things can happen. If the building itself gets struck and there aren't safeguards in place to "path" it to earth, nasty sideflashes can cause extensive electrical and physical (house burns down!) damages.

If your power isn't clean, you want a line conditioner. You can do both with a ferroresonant UPS, for example. Such protection isn't cheap, however.

 

[Elixer]

UPS's aren't surge protectors.

If you want actual surge protection, get a real surge protector and run your UPS on that.

I don't think this should be done, IIRC it can cause the UPS monitoring issues, depending on what kind of surge protector it is.
In fact, most all home UPS systems already have surge protection circuitry built in, and a direct hit with a lightning strike would fry everything anyway, no little surge protector is going to stop it.

 

[Red Squirrel]

Best bet is an isolated dual conversion UPS but you'll pay a lot of money for that. Or what Ruby said. you'll pay even more money for that. Basically you have power coming in to rectifiers, then inverters. There is a battery bank in between. If lightning hits, technically the rectifiers will take the brunt of it. At worse will fry, but everything after *should* be ok, but lightning can do weird stuff. It also depends where it hits. We had one hit the GPS antenna of one of our buildings, you can have all the UPS/surge protection in the world but if you get a direct hit like that it will bypass all the protection. There's only so much you can do in that case such as have proper grounded lightening rods, but even then it might arc over to something else too.

 

[MongGrel]

If lightning hits anything directly it gonna to take damage.

 

[mnewsham]

I don't think this should be done, IIRC it can cause the UPS monitoring issues, depending on what kind of surge protector it is.
In fact, most all home UPS systems already have surge protection circuitry built in, and a direct hit with a lightning strike would fry everything anyway, no little surge protector is going to stop it.

Pretty sure it's the exact opposite. You don't want to plug a surge protector into a UPS, you're just fine plugging a UPS into a surge protector.

The only issue you'd run into is if you had more than just the UPS on the surge protector something that comes before the UPS could end up drawing more power than is available and the UPS would switch over to battery whenever that happens, the solution is ONLY plug the UPS into the surge protector, and everything else into the UPS. Also if you use a cheap surge protector without proper grounding you could end up screwing yourself, the solution is to get a decent $30-40 3000joule+ surge protector. I'd rather have 3000+ joules of protection from a small surge instead of the ~350 joules of protection I get from JUST my UPS.


And yes, the only thing that will protect against a direct lightning strike is a proper ground rod installation.

 

[Flapdrol1337]

If lightning strikes every long wire will have a high voltage on it because of the magnetic induction. The ethernet cable goes right into the motherboard, so I doubt a ups will help much in this case.

Lightning once hit close to here, the psu was broken and the ethernet, rest of the pc seemed fine, continued to work for years with a new psu and a network card.

 

[Elixer]

Pretty sure it's the exact opposite. You don't want to plug a surge protector into a UPS, you're just fine plugging a UPS into a surge protector.

The only issue you'd run into is if you had more than just the UPS on the surge protector something that comes before the UPS could end up drawing more power than is available and the UPS would switch over to battery whenever that happens, the solution is ONLY plug the UPS into the surge protector, and everything else into the UPS. Also if you use a cheap surge protector without proper grounding you could end up screwing yourself, the solution is to get a decent $30-40 3000joule+ surge protector. I'd rather have 3000+ joules of protection from a small surge instead of the ~350 joules of protection I get from JUST my UPS.

Did a bit of looking, and I mainly see that it is not recommend to put a surge strip before the UPS, and only one maker (APC) said that it is still not recommended to use them after the UPS (as in plugged into the UPS), but, if it is a APC surge strip, you won't lose your warranty. CyberPower & Tripp lite just say no.
Having MOVs in series seems to be a fire code violation as well, so don't dasiy-chain them either.
Also found some non-official (forum talk mainly) saying all is fine, but, I think I rather trust people that are in the power business than just random forum talk.
http://serverfault.com/questions/29288/ups-and-power-strip-interactions
https://www.tripplite.com/support/faqs/tagID/29
Lots of people quote this one...
https://blog.codinghorror.com/power-surge-protection-pcs-and-you/

The only use the UPS has for wall power is to charge its batteries. And be sure not to plug your UPS into any surge protection strip! Plug it directly into the wall. I've seen some truly bizarre PC behavior resulting from daisy-chaining UPSes or surge protection strips.

CyberPower:

Spoiler

Can I hook up a surge strip to the UPS unit?
Surge strips cannot be installed before OR after the UPS unit. Doing so will void the UPS' warranty. If you require additional units, please upgrade your UPS to a unit that has more outlets.

APC

Spoiler

Plugging a surge protector into your UPS:
The noise filtration circuitry in a Surge Protector can effectively "mask" some of the load from the UPS, causing the UPS to report a lower percentage of attached load than there actually is. This can cause a user to inadvertently overload their UPS. When the UPS switches to battery, it may be unable to support the equipment attached, causing a dropped load.

Surge protectors filter the power for surges and offer EMI/RFI filtering but do not efficiently distribute the power, meaning that some equipment may be deprived of the necessary amperage it requires to run properly causing your attached equipment (computer, monitor, etc) to shutdown or reboot. If you need to supply additional receptacles on the output of your UPS, we recommend using Power Distribution Units (PDU's). PDUs evenly distribute the amperage among the outlets, while the UPS will filter the power and provide surge protection. PDUs use and distribute the available amperage more efficiently, allowing your equipment to receive the best available power to maintain operation.


Plugging your UPS into a surge protector:
In order for your UPS to get the best power available, you should plug your UPS directly into the wall receptacle. Plugging your UPS into a surge protector may cause the UPS to go to battery often when it normally should remain online. This is because other, more powerful equipment may draw necessary voltage away from the UPS which it requires to remain online. In addition, it may compromise the ground connection which the UPS needs in order to provide adequate surge protection. All APC Back-UPS and Smart-UPS products provide proper surge suppression for power lines without the need of additional protection.

Maintaining EPP and Warranty:
Plugging any non-APC surge protector, power strip, or extension cord into the output of an APC brand UPS could void your Equipment Protection Policy (EPP). However, the standard 3 year product warranty is maintained. If, after taking into consideration this knowledge base document, you choose to use an APC brand surge protector in conjunction with your APC brand UPS, your warranty and Equipment Protection Policy will be maintained.

 

[Deanoff]

Thank you all for your informative replies!

To be clear I would like to protect a desktop PC, this unlike a laptop will not have it's own battery supply and the initial reason as to why I was interested in one. I am fairly certain of the software impacts of intermittent, and complete loss of, power, it's the hardware side I need to better understand.

I live in London in the UK and so we don't get hurricanes and the like, thunder only on occasion and our power lines are more often than not not buried underground. So the likelihood of receiving the majority of the millions of Joules that a single bolt of lightning on a transformer that fed our house (and I'm in rented accommodation, so complete house surge protection is not an option for me) would be slim, but fatal, unless I were to unplug my electronics before the strike.

Aside from the physical connection that my desktop computer has to the outside world drawing power from the utility wall outlet, it also has a physical connection to two external HDDs, attached via USB ports, these themselves are utility powered and so they would need to be protected also. Another would be a pair of wireless headphones, of which the base station is powered from the wall utility outlet and once again connected to my desktop PC via usb port, those too being a route for the electricity to wreak havoc. Other than that I wirelessly receive my internet connection and that is from a router outside of my room.


UsandThem: Thanks for the heads up on the CP1500PFCLCD, I am shocked that a lesser model can absorb more than double the Joules of the more expensive PR1500ELCD model!

Red Squirrel: A double conversion - three phase (online) UPS should not draw directly from the utility supply as with the single conversion - line-interactive and standby (offline) topologies, isolating microelectronic equipment from the supply. However, in terms of cost and noise, I favour a line-interactive UPS as it will run silently (this is to run in my room) relying on a open transition transfer switch to prevent backfeed as you mentioned. But it will need to switch from utility power and the transfer time for CyberPower's PR1500ELCD is 4ms, which should be quick enough, but I don't have data on that.

imported_ats: This was my original thinking, only after reading all of the marketing spiel did I consider services I didn't realise that I needed. But, it has been an educational experience learning about them. As I mentioned to Red Squirrel just before, the transfer time of 4ms should be enough for an external HDD, but I read in Wikipedia of hardware functions operating in the hundreds of milliseconds, such is the pressure on the technology to keep up everything is so fragile now, but I'm unsure of the effect on SSDs.

I will reply to the rest of you later, it's 5am, I need to work tomorrow..

 

[Deanoff]

Torn Mind: "To get joules, you need to multiply voltage, amperage, and time", true, but that is still a very subjective measurement. While a surge can be dampened, a MOV will wear away over time, I'd rather have an AVR regular the sinusoidal wave than have them chip away at my surge protector, which may even stop functioning without my knowledge and allow them through anyway!

You're right about lightning, side flashes are a frightening thought, but that would be an unlikely event in a two story building and there wouldn't be much left of it anyway as it would likely be on fire. The best option is an offsite backup I think, something disconnected and decoupled in that case. UPS units are, as you say, for protecting data, first and foremost.


Rubycon: I was looking into transfer switching noticing that a zero time ferroresonant option wouldn't be necessary, or useful for computing equipment as a break is needed to prevent problematic power travelling to devices. I'm beginning to see filtering less as an imperative than before, but am still looking into how it affects tradition mechanical HDDs before I migrate over to SSDs, especially as there is no clean power, it too has wild spikes and noise relative of their own. But I'm afraid the line-conditioning option isn't for me as it makes too much noise an I need something to run silent (until needed), not all of the time.


mnewsham & Elixer: I was set on the idea that a UPS should be separated from the utility wall power by a surge protector, it appears as though the two confuse each other. The closest description I've got that approaches the arbitrary 405 Joules rating goes some way to demystify the choice of number: telecommunications companies provides for copper phone lines, protectors for these lines typically activate at around 400V and can carry about 10A of current to ground - if a typical lightning strike might last 1/10 second, that equates to about 400J of energy. But I still wonder how they arrived at that number and what other, more likely, dangers would reach within that threshold?

 

[ronbo613]

I live in a remote area and the power goes out all the time. Maybe for just a minute or two, sometimes for a day or two, but it happens quite a bit. Abrupt power outages cause lost data and damaged electronics. How do I know that? Because I used to run my computer without a UPS, only a surge strip and damaged some components. A modest UPS will prevent this. Will it stop lightning strike damage? Of course not. If lightning strikes your house, you'll be lucky if your house doesn't burn down.