In reply to a post by thomaswarne01:

Opinions on Network Equipment and UPS Backup for the appliances
When installing network equipment is it user requirements, best practice or common practice to instigate the use of a UPS to cope with short term power outage eg 1-20mins,
I know their are many variables to this subject such as power outage frequencies or reliability of power but personally I have UPS on my Router, Switch and POE AP but I feel that if I recommend to family to invest in a UPS it is just another device to go wrong.
Any thoughts?

Whether a UPS is really needed is dependant on the type of kit being protected, the likelihood and potential duration of supply faults and the users needs during a power outage/supply fault. Basically if it stops working what are the consequences and will an unexpected power out result in damage to the equipment itself, property or person.

I have certain equipment that has an absolute need for supply backup. Some of these are IT/network related and some are not. For example my NAS array which also hosts a DVR app for security camera recording is quite important and doesn't like being switched off without a proper shutdown sequence, as the data is cached and striped as its written. There are also data scrubbing routines which get quite upset if you just yank the plug out, so to speak.

A non-network/IT example are the double pumps for the below ground drains for our surface water and foul water, which could be catastrophic if there was no power supply during a period of sustained rainfall.

A "standby" type UPS will usually be more than sufficient for home/light business use. An "online" (double-conversion) UPS is technically better, but usually not worth the added investment - for home use. There is quite a big difference technically, between the types and that is reflected in the cost of the units.

Thomaswarne01

First question to ask is, how often do they have a power cut?

Some areas get these regularly ( more than once a year) some areas never seem to see one. ( Less than one every 5 years).

If the first it may be best to recommend if the 2nd don't bother. In the gap between the two the question is does it matter?

If all the end devices are portable it doesn't. ( Laptops / Phone etc)

If they are mains powered it may matter. (CCTV / security devices / sensors) then the router will also need UPS.to keep them all working.

I've had a UPS on the routers (modem) for a couple of years now.

Reason, being rural, we tended to get power cuts every so often (improving picture though with the upgrades to the network over the years). They don't tend to last long but the UPS stops the routers from disconnecting.

At a stroke it seems to have cured the chance that we get reduced download speeds when it does reconnect - due to DLM thinking its a dodgy line. Strange to say, before the UPS was connected I use to see about 72Mb/s as a norm. Now 78Mb is standard for my line.

Whether one needs one, only the user can answer. I do find it very handy that I can still use my laptop, smartphone as if nothing as happened. Indeed its usually the alarm on the UPS going off that is the tell tale of a power cut occuring. Otherwise life simply carries on as normal for the equipment connecting through it.

From my experience of trying to protect a modem, router and a mail server (low power PC) good luck in getting 20 minutes protection. I have about ten minutes before the mail server decides to shut down. It's still useful since we do get the occasional glitch but 20 minutes will be difficult unless you pay a lot.

From what I understand the problem is today's efficient equipment. It has a horrible power factor and by the time the power has been converted from 12v DC to 240 AC then back to DC most has been lost. It's a shame UPS manufacturers don't provide versions with USB or 12V outputs so that the whole 240v AC stage can be skipped.

Edited by Andrue (Sun 03-Jan-21 15:00:22)

It all depends on what you want and need. I have two UPS's for my gear. One is in my attic with my networking equipment and I'm powering my 4G modem and my FTTC modem via POE. I'm also powering my security cameras via POE and a couple of wifi access points. I can get 2-3hours from this UPS.

I have another UPS in the office powering the server, a couple of PIs and a WiFi AP. This too will give me a couple of hours of run time.

Where I live we have quite a few power cuts throughout the year and the annoying thing is when the power goes down the mobile phone network goes down too so our mobiles wont work. The UPS's provide more of an emergency cover for phones too.

The day after I ordered my UPS's we had 4 x 5min power outages. The day after the outages the UPS's arrived
They've had some use since I got them though which is both annoying and good at the same time.

In reply to a post by Andrue:

From my experience of trying to protect a modem, router and a mail server (low power PC) good luck in getting 20 minutes protection. I have about ten minutes before the mail server decides to shut down. It's still useful since we do get the occasional glitch but 20 minutes will be difficult unless you pay a lot.

From what I understand the problem is today's efficient equipment. It has a horrible power factor and by the time the power has been converted from 12v DC to 240 AC then back to DC most has been lost. It's a shame UPS manufacturers don't provide versions with USB or 12V outputs so that the whole 240v AC stage can be skipped.

I presume you're just using relatively cheap APC or similar standby units that have (non-expandable) built-in batteries. In this case you're better off tripling or quadruplling the rated VA of the UPS based on the total device VA load. Typically such UPS are only rated to hold their full load to enable a safe shutdown, i.e. around 10 minutes or so.

If you overspec and get a self-contained larger VA rated device, then it will have correspondingly larger Ah batteries to run longer, on a lower than rated load.

Personally I wouldn't bother with anything less than 1000 to 1500VA to hold up a (small) server, router, modem etc. but only because I expect a self run time of around 50 minutes.

But as we anything in life your mileage may vary

Obviously more serious commercial UPS units get around this problem by having external expandable battery units. These can typically be daisy chained, as its not the VA rating but the Ah capacity of the battery bank which determines how long the UPS will stand up in an outage.

I have mainly asked just to see what people's responses are regarding various purpose's and uses and the only real benefit/s are coming back as modems, Internet routers, switches and access points which make sense on the basis of maintaining the connectivity in a short duration power outage, so modem staying in sync/not dropping etc and internet not dropping for home working etc..
Pc's are also another consideration but runtime, ups capacity and shutdown communication are also factors needing to be considered, however when laptops are involved I am not normally concerned

In an office with thin clients at the desk's running from a server I have got only the server on a APC 700va/390w ups (no backup for thin clients) and then the onsite pbx telephone exchange, router and ethernet switch on a separate 500va/300w apc ups, all of which provides upto 20mins of backup (timed) which is ample for a minor outage, The thin clients boot up and re-connect to the users active session, unless server had to shut down then it all re-loads from scratch which can take up to 15 mins!

One large UPS is going to be more efficient than lots of smaller scattered units and that is where a centralised computing model, like thin clients work great.

If the thin clients actually needed to keep working during the outage could, one theoretically could use the network itself and have centralised UPS supporting thin clients with PoE++ (802.3bt) at up to 60 watts per client. Most laptops could easily cope with that, so should be possible for thin clients.

It could be a heck of a load through the structured cabling though!

I have just bought this: https://www.amazon.co.uk/dp/B075QZQSS1/ref=cm_sw_em_... for my router. That eliminates the wastage of plugging in 240V to convert back down to 12V DC.

The modem is already FTTP (an old-ish install) that has battery back-up and the last power cut it was quite frustrating that the internet was working but couldn’t access it.

(I did toy with the idea during that last power cut of just plugging in a laptop to the modem and then sharing the WiFi, but as I appear to have ended up with just Macbooks, they don’t come with an Ethernet port and I didn’t have an adapter to hand)

Not sure I think it is worthwhile. For a computer, where files may be open and get corrupted by a sudden power failure, an UPS makes a lot of sense, to allow for an orderly shutdown. Similarly for something like a Raspberry Pi, because they don't handle power failures well.

For something like a modem/router I really don't see the need. If the power goes off, they will generally just sit there until it comes back on, and then carry on where they left off.

Of course, the added complexity of a UPS is as likely to cause an outage as to prevent it. Especially if it is one of the execrable APC ones.

Our trusty old Leibert UPS just soldiers on, Every few years it beeps to tell you it needs new batteries, but even changing them doesn't require power off. Just unclip the front, slide the old batteries out and the new ones in. Neat, cheap and easy.

More of a problem is surge protection. About half of our power cuts seem to be followed by a voltage surge on (or before) power resumption. Over time, I've added more surge protection, but it still kills stuff from time to time.