Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Weaver]

[We have talked about this before at least once, some years back, so would appreciate a brief up-to-date recap.]

Would appreciate tips for a UPS for a Firebrick (low power, supposedly but runs quite hot imho as fanless), two switches, four modems, and three PoE WAPs. Would have to simply guess what that currently consumption is.

But I would just like to maximise the runtime on a budget of £100 - £200. Ideally long enough to get the generator running.

[jelv]

If you don't know what the consumption is why not buy something like this first?

I think you might be surprised at little you need and will find a UPS for well under your budget. When you have a power cut, before going out to start the generator (before you know how long a power cut will last), my first reaction would be to unplug the WAPs or switches not actually needed at that moment to maximise the run time.

[johnson]

Seconded, bought one just like it for £8 on ebay recently. Hours of fun to be had finding out how much power things about the house use... my personal favourite, or rather most shocking at least, was our ageing 32" LCD TV, 95W! 95W and its routinely on all day for no reason.

Had some fun the other day seeing how much I could reduce the consumption of an old first gen i5 PC by undervolting and underclocking, went from a little over 100W at idle to 40W, not bad but have sandybridge systems that reliably sit at 20W idle without reducing the performance to nothing.

[Weaver]

@jelv only essential core kit is on that ups. Other things like PCs had their own separate UPS and a shutdown interface which talked to the o/s and shut processes down, shut the o/s down cleanly or did a suspend-to-disk, writing the entire RAM and saving state, presumably all register files of each core arranged to be spilled out onto the stacks so it gets saved anyway?

I really would like a long run time because if it is night, bad weather, need to go out to shed where the generator lives. That has to go because Janet's hands are really bad and she is not strong enough to start it since we stupidly bought a pull-start one 13 years ago. So the generator needs to be replaced with a modern push-button one and they are miles cheaper now somehow.

The run time with the current APC unit is really crap, just a few minutes. Could be because the battery is dead because I bet it is 12 yrs old.

[Weaver]

An excellent tip about the plug-meter, thanks! I had no idea.

If anyone sees any reliable big bang-for-the buck units then I would be glad of further tips.

Actually, apart from possible mains droops or spikes or brownouts, but I wouldn't know about those anyway, as I do not have logging thereof, we do not get short power cuts. So it is always generator on, except that now my poor wife always tries to make up some lame excuse that we do not need to bother with electricity, to cover up the fact that she can't start the generator. Bless her and big kiss in her direction, wish her hands were better. So we really need an appropriate generator now, it is all about time-to-get-generator-started too.

[jelv]

If you have never replaced the batteries in a 12 year old APC unit I'd guarantee that they are knackered!

I'd suggest replacing the battery(s) first.

[Weaver]

understood, I had no idea about longevity

Any solid recommendations then folks?

[lloyd]

If you have never replaced the batteries in a 12 year old APC unit I'd guarantee that they are knackered!

I'd suggest replacing the battery(s) first.

I'd stop using it immediately, unless you've got the right PPE to deal with a leaking battery.

[jelv]

What model is the existing UPS?

[petef]

This is slightly off topic but I asked a while ago if broadband would still work in a power cut. There is little point in getting a UPS for your modem if it has nothing to talk to.

The perceived wisdom was that the cabinets would be good for about 4 hours on their battery backup.

[Deathstar]

This is slightly off topic but I asked a while ago if broadband would still work in a power cut. There is little point in getting a UPS for your modem if it has nothing to talk to.

The perceived wisdom was that the cabinets would be good for about 4 hours on their battery backup.

Though a good UPS will act as a great filter, and can regulate the incoming AC.

[Weaver]

@jelv - will have to check.

Re dslam - in the past the dsl has remained up all day prob because we are in completely different system coming off a substation. An outage may well be a problem confined entirely to the village, or because of very local maintenance or a problem with weather or lightning on the high moorland run of the electricity line to Heasta from civilisation.

Power cuts are very infrequent, unless hurricane with 130mph winds.

[j0hn]

The perceived wisdom was that the cabinets would be good for about 4 hours on their battery backup.

My understanding is it is entirely dependant on how populated the DSLAM is.

I believe it to be in the 8-10 hour range though.

More likely a domestic UPS will die before the local FTTC cabinet does.

[jelv]

Around 2:40 this addresses the FTTC cabinet battery issue.

[youtube]https://www.youtube.com/watch?v=TBMoR1NMwVg[/youtube]

[sevenlayermuddle]

Be careful using a power meter to determine requirements, as appuratus may be smart enough to reduce power when it is not required, whereas your UPS would probably want to be able to handle the worst case scenario.

My TP-link switch, for example, senses whether ethernet connections are active and, if not, puts individual interfaces into low power mode.

Also, I think UPS generally have VA ratings as well as Watt ratings, you need one that satisfies both the wattage and the VA.  Some plug-in power meters can measure both Watts and VA, but others may not.