# Uninterruptible Power Supply



## davidedric (Jun 29, 2020)

As a matter of interest, do you have a UPS for your computer system?
I don't, and power outages are relatively rare, but I wonder if I should.  I don't know how likely is corruption after a power outage
My aim would be a managed and unattended power down.
I don't use my system professionally, but it would be awfully inconvenient to lose it!


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## Linwood Ferguson (Jun 29, 2020)

Yes.  They are relatively inexpensive, and all it needs to do is prevent one unexpected crash that corrupts something and your time NOT spent cleaning up is paid back.   I also have one on my network closet where the cable modem and house's main switch is.  

You do need to plan on replacing the batteries every 4-5 years.  Test occasionally -- shut down the computer and plug in a couple hundred watts load (like light bulbs if you still have any) and see if it will run 5-10 minutes.

Now that said, I think the risk of corruption from power outages is small.  Not sure how small, maybe 1 in 10.  Probably not 1 in 100, probably not 1 in 2.  Somewhere in the middle.  Higher if it occurs while you are doing things than if just sitting.   I tend to be paranoid, so if it is 1 in 10, it will happen to me the time when it can do the most damage and when I do not have time to clean up.  That's why I consider them relatively cheap insurance.   But I would place the priority well below things like good security and backups.


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## Victoria Bampton (Jun 29, 2020)

You bet! I just have an inexpensive APC one, works nicely. I only need it to last long enough to safely shut the computer down.


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## Linwood Ferguson (Jun 29, 2020)

Victoria Bampton said:


> last long enough to safely shut the computer down.


Oh... speaking of which, the software for most UPS's is pretty unsophisticated.  You generally will need a separate UPS for each computer if you want it to shut down.  Some are more sophisticated, but most look like they were written by 3rd graders. 

While I'm thinking this through, it is worth noting why I put a UPS on my network closet - SO much software now is cloud/network related, that getting a good clean software shutdown (at least a quick on) often requires an internet connection.  So I make sure the internet stays up longer than the computers.   Often a computer UPS will keep your network stuff up for 30-60 minutes (low power).  This also might let you make a few phone calls if you use VoIP phones, send a few emails like "won't be joining the zoom call today", etc.


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## Johan Elzenga (Jun 29, 2020)

A laptop has a built-in UPS...


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## Linwood Ferguson (Jun 29, 2020)

Johan Elzenga said:


> A laptop has a built-in UPS...


I realize intellectually that many people use a laptop for photo post processing, but it still just never seems possible to me.  However your point is well taken.   Beware externally powered external hard disks though!


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## Johan Elzenga (Jun 29, 2020)

Ferguson said:


> I realize intellectually that many people use a laptop for photo post processing, but it still just never seems possible to me.  However your point is well taken.   Beware externally powered external hard disks though!


There are very powerful laptops these days. The main drawback might be the screen, but you can use an external screen. That screen will turn off when the power is interrupted, but that does not corrupt anything. Use bus powered external drives and you're safe.


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## Johan Elzenga (Jun 29, 2020)

BTW, I use a Mac Mini as my main computer, but I do not use a UPS. Power outs are very rare here, so it simply isn't worth it as long as you make regular backups. In 40 years of using computers I've never had a power-related disk problem (knock on wood). The new Apple AFPS disk format also protects against corruption, if I'm not mistaken.


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## clee01l (Jun 29, 2020)

My first U-verse came with an APS. I moved after Harvey and the Xfinity modem had a small battery backup . I moved again and was able to get U-verse over fiber. This time AT&T did not supply an APS box. These are essential if you have VOIP. 

I’ve been in this townhouse for a little over a year and had only 2-3 power failures none have resulted in data loss. 

I don’t shutdown LrC because it gets images sync’d from the Adobe cloud if I am in the field. Maybe an APS is a good investment in providing time for a quiet shutdown if there is another Harvey and an extended power outage. 


Sent from my iPad using Tapatalk


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## Linwood Ferguson (Jun 29, 2020)

clee01l said:


> I don’t shutdown LrC because it gets images sync’d from the Adobe cloud if I am in the field.





Johan Elzenga said:


> The new Apple AFPS disk format also protects against corruption, if I'm not mistaken.


Disk corruption is getting better handled by file systems over time, but that doesn't mean you cannot get file corruption, especially if something is running and updating files when the computer turns off.  Lightroom is a great example, because it often just sits there in background doing "stuff".   Maybe it's doing "stuff" only 5% of the time, maybe it's 1%, who knows -- but if your unexpected shutdown hits while it is updating the catalog, you may have a perfectly fine disk, but a corrupted catalog. 

It's a good reason to close lightroom, if you have no good reason for it to be open (Cletus has a good reason).


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## PhilBurton (Jun 29, 2020)

Any recommendations for good  brands or models for a UPS?


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## PhilBurton (Jun 29, 2020)

Ferguson said:


> Disk corruption is getting better handled by file systems over time, but that doesn't mean you cannot get file corruption, especially if something is running and updating files when the computer turns off.  Lightroom is a great example, because it often just sits there in background doing "stuff".   Maybe it's doing "stuff" only 5% of the time, maybe it's 1%, who knows -- but if your unexpected shutdown hits while it is updating the catalog, you may have a perfectly fine disk, but a corrupted catalog.
> 
> It's a good reason to close lightroom, if you have no good reason for it to be open (Cletus has a good reason).


I always shut down Lightroom if I step away from my system, because unless I'm wrong, you cannot force a catalog backup while Lightroom is active.


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## Johan Elzenga (Jun 29, 2020)

PhilBurton said:


> I always shut down Lightroom if I step away from my system, because unless I'm wrong, you cannot force a catalog backup while Lightroom is active.


Correct. I also shut down Lightroom if I'm not using it. My computer too.


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## Linwood Ferguson (Jun 29, 2020)

PhilBurton said:


> Any recommendations for good  brands or models for a UPS?


I suspect it varies by country and the OP is in the UK, but I have found for home use CyberPower seems to represent a decent blend of value and quality.  APC is probably the best known but I think a bit over priced . But take all that with a grain of salt as I do not pay that much attention and never bought small ones in my I.T. days. 

Look for sales.   

Don't buy used (well, at least not unless you want to replace the batteries which is often the most expensive part). 

I guess while we are on that subject there are many kinds.  Most home units  are variations of surge suppression and filtering layered over a failover during outages.  In other words, it is primarily utility voltage that normally flows to your device until the power goes off, then it switches.  

There are a few, quite expensive usually, which are often termed "double conversion".  These convert line voltage into battery voltage, and then all the time convert battery voltage back to line voltage.  This "recreation" of line voltage provides more effective filtering of any irregularities in line voltage.  This is almost completely pointless for home units, and you are unlikely to find them.  But it may be useful for people with really bad quality utility power.

There are also, separately,  variations of the output often called "pure sinewave" or similar terms containing "sine".  The cheaper UPS's recreate line voltage from battery by simple circuitry which produces square-ish waves, and not clean smooth sinewave output like a generator (or utility pole) provide.  For the vast majority of "stuff" you might put on a UPS, including computers, this does not matter.  You might think computers need "clean" power, but not so much - their own power supplies clips these rough edges.  Where you might want sinewave UPS's are audio (if you must have your tunes playing during an outage), and oddly enough motors.   AC Electric motors often do not do well with UPS's, so if you have some kind of medical device, or maybe even need a blender to work, test it first (some types work better than others with non-sinewave UPS's). 

Generally speaking sinewave UPS's cost quite a bit more and may be pushed on you by electronics stores, but are not needed for computers.  They do no harm, they just cost more.


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## clee01l (Jun 29, 2020)

Ferguson said:


> It’s a good reason to close lightroom, if you have no good reason for it to be open (Cletus has a good reason).


I’m never more than 24 hours away from a Lightroom backup catalog. I do shut Lightroom periodically to create a backup and I reboot my OS once in a while to clear detritus out of memory. 

I expect disk drives to fail I have two system backups running at all times. And my timeMachine backup alternates between a local disk and my timeCapsule. 


Sent from my iPad using Tapatalk


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## Conrad Chavez (Jun 30, 2020)

I have used an APC UPS for many years. Protection during a power outage is actually my _minor_ reason for owning it; we don’t have blackouts often.
The major reason is for stable, clean power for all of the electronics.

Although drives can be corrupted by a power outage, other devices including computer power supplies are also vulnerable to damage from unstable power (link is a PDF file). Significant over- or under-voltages can degrade circuitry and shorten the life of components. Although everybody knows about a UPS keeping power going during a power cut, for me it’s just as important that a UPS feeds electricity to connected devices at a voltage, frequency, etc. that are always consistent, even when mains power is erratic, something we normally don’t notice. Noise filtering can also benefit some devices (“Data corruption is one of the most common results of noise.” — from PDF linked earlier.)  I know this is anecdotal, but I like to think that the reason my 2006 Mac Pro still runs perfectly today is that it’s been on a UPS its entire life, isolated from electrical issues and always given stable power.

I do use a laptop most of the time now, so yes, it has a built-in battery backup. But on my desk, the laptop is connected to storage and backup drives, a film scanner, displays, the hub that connects then all to the laptop, and many other devices I would like to keep going for as many years as possible. I don’t want those electronics continually exposed to potentially damaging power fluctuations, so anything I want protected is on the UPS. The cheaper/more easily replaceable devices are on ordinary surge protectors.

In the living room, I used to have a problem where if the refrigerator motor came on, the TV would slightly glitch and audio cut out for a very brief moment. Going by what I had seen in the studio, I finally put the living room gear on a Tripp Lite UPS. It isolates all devices on it and regulates the power enough that the TV is now stable, no more problems. I also have an old Mac mini as an HTPC/server in the living room media cabinet; another consequence of the UPS is that Mac has been spectacularly stable, now approaching 140 days continuous uptime, just sleeping when not in use.


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## Paul_DS256 (Jun 30, 2020)

I use a UPS but this was driven by frequent quick power flickers at home.  Just long enough to cause a computer or router to crash. So I put a small UPS on both my computer, monitor and network. This was to support working from home but likely would not have run my systems for more than 15 minutes during a true power failure.

If you have stable power, all you may need is a surge protector. Investigate these because they are not created equal and as others have said, small UPS's are cheap.


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## Martin Owen (Jul 7, 2020)

Here in NW Florida we do have frequent power blips and outages caused by lightening, tropical storms etc.  We have a whole house generator, but that requires power to be out for few seconds before starting up.  I have UPS packs on both my iMac and my wife’s PC.  I did find that Windows machines need a different type of UPS than the Mac. Don’t ask now why - I can’t remember, but it’s worth checking out.  I think that only applies to more recent versions of Windows.  I also have a UPS on the equipment stack for the main TV - which also powers the PVR box, Apple TV etc.  That keeps everything online until the generator kicks in.  The same with my wife’s PC. That UPS also powers the modem, wireless router and a couple of other hubs, again until the generator starts.  All our units are CyberPower and work well.  Yes, they do need new batteries every couple of years, but it’s a small price to pay for keeping everything running.


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## davidedric (Jul 11, 2020)

Thanks for the feedback.  In the end, I bought an APC UPS and installed it today.  At least it tidies the cables up!

Now I have to screw up courage and turn the mains power off, to see what happens


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## Linwood Ferguson (Jul 11, 2020)

davidedric said:


> Now I have to screw up courage and turn the mains power off, to see what happens


Just plug in the monitors or a 100W light bulb or something, leave the computer off the first time.

But you do need to do it for real, and wait and wait and make sure it successfully shuts down the computer.

You actually should do a test (including the wait, observing) at least once a year, see how the batteries are doing.  UPS batteries have this way over time of looking like they are working, holding a charge, but not having any real capacity so almost as soon as the power goes off, the UPS power goes off.

Oh... and please take no offense but I can't tell you how often I have done this, crawling around under a desk -- make sure you plugged into the correct side.  Almost all UPS's have some pass-thru plugs that are NOT on the UPS, usually one one side, with the UPS protected plugs on the other.  In the dark, under a desk, it is VERY easy to get the wrong side, and an unpleasant surprise the next power outage.


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## davidedric (Jul 11, 2020)

Thanks!
Fortunately, the UPS is on a shelf behind the desk, so no more scrabbling in darkness.   
No offence taken.  I'm pretty sure that I have battery supported sockets where I need them (in my case the system unit and the ehd)
Just a thought.  Things are a lot more complex now,  but the advances in plug and play have made a huge difference.   The UPS just got recognised when i connected it.


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## Conrad Chavez (Jul 12, 2020)

davidedric said:


> Now I have to screw up courage and turn the mains power off, to see what happens


Instead of having to cut power to everything on that circuit, another way to test is to pull the UPS plug out of the wall. It should switch over to battery without interruption.

Excellent tip by Ferguson about paying attention to which outlets are actually backed up by the battery. That does add another wrinkle into working out what gets plugged into where, and if you have a lot of devices you do have to triage which ones get to have battery backup protection . Also remember to heed the warning in the manual (there should be one) about the types of devices to plug in; for example very high current devices like heaters (and laser printers, since they have heaters) should not be on a UPS.


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## davidedric (Jul 12, 2020)

Thanks, yes, that's what I meant!  I'm expecting a cut over to battery power, followed by a graceful shut down.
I hadn't thought about power drainage, but presumably a laser printer will only draw power when it's actually printing? 
Everything else is pretty low power.  I can't connect my router because it's at the other end of the house.  One of the very few drawbacks to fttp is that I'm limited where the fibre comes in.


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## Conrad Chavez (Jul 12, 2020)

davidedric said:


> I hadn't thought about power drainage, but presumably a laser printer will only draw power when it's actually printing?


The UPS has a wattage capacity, and something with a heating element into it will typically need hundreds of watts on its own. If it does not exceed the UPS wattage rating itself, it would leave a lot less wattage for everything that was more important that you wanted to protect, such as computers and drives.

But there is another issue and that’s the peak or spike power demand. While a laser printer can go into a power saving mode when not in use, when you turn it on it assumes you want to print something right now, so before you even print one sheet, it will draw maximum current to get those fuser rollers heated up for you right away. This high load is not something you want on your UPS, especially if it’s on battery…you want the battery to last as long as possible for the devices you wanted to protect. Similarly, appliances with motors (air conditioners, refrigerators) should not be plugged into the UPS because when they crank up, there can be a high current spike that, again, can exceed the rating of a UPS. Those types of devices should be plugged in outside the UPS, and I am pretty sure all UPS instruction sheets say that.


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## Intelli (Sep 24, 2020)

UPS sounds like it could be a great option - As Conrad said you should be selective to what critical data should be protected by using a UPS, so in this case your computer and any associated hardware.

Depending on type of UPS you choose as above has said, it should cut over to battery power giving you time to either shut down or wait for power to come back online. Other option for longer outages would be battery packs to match an amount of time, such as to get back to the office, etc. 

APC was a good choice - make sure to keep up to date with maintenance so batteries perform as expected.


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## davidedric (Sep 24, 2020)

Thanks for the advice - and welcome to the forum!


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## davidedric (Nov 19, 2020)

Yesterday we had our first (short) power cut since I installed the UPS.  Everything worked as expected, though the power loss wasn't long enough to initiate the managed power down.


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