UPS Configuration

Thanks. In Australia both the copper network and the domestic fibre network have a separate power supply so I assumed that the cable had its own supply with adequate backup and would not be affected by a local power fault. My Googling failed to find any details of how the Telstra (Australian) cable is powered. Does anybody know?

Reply to
Gordon Levi
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I have a Raspberry Pi in a colocation center, and for several years the cost was zero and now it is quite low.

But I know how "services" work, and it is not as described above. Those people work on a very tight cost budget and within that there is absolutely zero room to solve problems. When it works, fine, but when it stops working you are out of luck. Not much different from running things at home, except that you don't have the possibility of solving it yourself.

Reply to
Rob

There are services and services. I've recently changed ISPs - something that was painless since, as I previously said, the master website copies are kept locally and are ISP-agnostic since they don't depend on anything apart from basic Apache capabilities. In addition I use a separate domain host, so swapping over web and email redirection from one ISP to another was straight forward.

The new ISP has a good reputation for service, has been around for quite some time and is considerably more responsive and helpful than the previous one.

I thought about local web hosting but decided to use an external web host because that avoids both the need to drill http or https holes in my firewall and the additional hardening that would be needed if I did that, along with failover etc.

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martin@   | Martin Gregorie 
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Reply to
Martin Gregorie

In my part of the UK (Harlow) the fibre network is one of the oldest in the country (it was originally put in by NTL) and connects to fairly local streetside boxes, becoming copper from there to the house. Openreach fibre/'superfast networking' seems to follow the same pattern. I think these boxes use local mains power, so they'd also drop out if the power cut is external to my house.

If you have copper to the house rather than fibre, I'd expect you to have the same arrangement and so your broadband would have the same dependency on the local mains supply.

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martin@   | Martin Gregorie 
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Reply to
Martin Gregorie

Indeed. It behoves one to rysnc ones online server with some home based spinning rust from time to time, in case they lose the bloody lot

But when all is said and done I have had more uptime on the hosted VPS than at home with power cuts and broadband loss.

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Reply to
The Natural Philosopher

You could ring technical support and ask? If they are like my ISP tech support first line calls go through the call centre jockeys and their scripts "have you turned it on/off, restart windows etc. etc." so I don't expect them to know or tell.

You'd need to talk to the installers/tech people and they are normally well isolated from customers.

Reply to
mm0fmf

But if you see their van parked by a street box ...

Reply to
Rob Morley

Yes, that's why I thought that a contributor to comp.sys.raspberry-pi was probably a better source than my ISP but I will try a more local news group.

Reply to
Gordon Levi

Our broadband is on copper but remains active when the local power goes. Two reasons: 1) It's ADSL2 (up to 8 Mbps) and sourced from the exchange which has BFO battery backup and autostart genset. 2) The exchange is not on the same 11 kV distribution from the 33 kV primary substation as us.

Our line does go through a fibre enabled cabinet but at the exchange.

3.5 km of line is wonderful leveler of all these fancy modulation schemes... If we switched the broadband would die some time after power loss down in town, the cabinet has it's own, specially installed, mains feed. They didn't export the maintained 48 v DC from the exchange just across the road to the cabinet.

Prehaps ADSL does have something going for it, rather have FTTP though.

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Cheers 
Dave.
Reply to
Dave Liquorice

Must be quite a low output to manage the normal "10 mins, full chat" specification of most small UPS's. IIRC the 2 x 12 V, 7 AHr, batteries in my UPS can only manage 10 mins or so at the full 700 VA. If I'm quick to shut down my (greedy) PC and monitor it'll keep the essential modem (itegral switch) and VOIP/DECT phones up for the best part of 6 hours. The server auto shutdowns 2 mins after the power goes out.

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Cheers 
Dave.
Reply to
Dave Liquorice

The UPS thinks it can sustain the load it sees (i.e. my house server), which averages around 30w (125 mA at 240v), for 55 mins. The continuous load factor is 9% of the UPS capacity.

Yes, its not huge - 700 VA isn't a lot of capacity. As I think I said, what I bought was its ability to tell the computer it supports when power goes off and comes back on rather than sheer capacity. What it was always intended to do was to tell the computer when power is lost or restored so the UPS monitoring process on the computer can say "OK, power was lost x minutes ago and hasn't come back, so shutdown NOW" to the kernel.

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martin@   | Martin Gregorie 
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Reply to
Martin Gregorie

A conversation in the pub tonight showed my guess to be wrong. Apparently the Openreach fibre includes the copper needed to power the fibre termination cabinets from the central site. Therefore, UK broadband will die if a power cut last long enough to exhaust the exchange's backup batteries, generators, etc. and a more local cut will only affect the stuff inside your house.

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martin@   | Martin Gregorie 
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Reply to
Martin Gregorie

Not around here, a lot of the delay in getting the fibre cabinets up and running was due to delays in getting mains to them. ENW are not the quickest but also getting the required way leaves for those supplies.

AIUI the fibres are direct connections from each cabinet to Hexham,

40 km away. They do go via the exchange but only through a patch panel to make maintenance and use/access to the dark fibres in the cables a bit easier.
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Cheers 
Dave.
Reply to
Dave Liquorice

That 7AHr capacity is at the 20 hr rate. i.e. The current can you draw for 20hrs before the cell is discharged.

That gives 20 x 0.35A = 7AHr (20hr).

If you draw more current the AHr rate is lower. I'd expect the same cells to be nearer 5Ahr if you draw a large current.

If they are in parallel you have 12V and (5 + 5)AHr = 12v at 10Ahr =

120WHrs. If the UPS is rated at 700VA then you'll get

120/700 = 0.17Hrs = 10.2 minutes. +/- depending on load, temperature, battery age, phase of the moon etc.

Reply to
mm0fmf

I think it's your friend that misunderstands.

Yes, there is 48v on the individual copper pairs that are jumpered through the cabinet, but the current available in each pair is barely sufficient to power a single telephone, let alone a rack of VDSL DSLAMs.

Like Dave says it you're worried, stick with ADSL and hope the diesel at the exchange don't run out.

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Reply to
Graham.

What's the 48v for, then, if there's so little power available? A cut cable monitor, or just some PHB's bright idea?

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martin@   | Martin Gregorie 
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Reply to
Martin Gregorie

It's there to power the carbon granule microphone on the telephone. Backwards compatability is a great thing.

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Steve O'Hara-Smith                          |   Directable Mirror Arrays 
C:>WIN                                      | A better way to focus the sun 
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Reply to
Ahem A Rivet's Shot

The curbside VDSL cabinets commonly used now to distribute broadband in areas where no FTTH has been deployed yet are powered from the local mains supply and have only local batteries as a backup. I don't know how long such a cabinet can run off the batteries. (I have seen pictures of mishaps that indicate that there is substantial energy in those batteries, but that is a different topic)

I have such a connection as well. 100/20 Mbit/s VDSL from a cabinet around the corner here, with fiber to the central office. It is so close that it likely is on the same low voltage distribution as my own house. The telco probably does not worry about extended operation when there is no power, assuming that the clients will have no power either.

Reply to
Rob

That makes sense. Thanks for the info: I'll pass this back to educate my friend.

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martin@   | Martin Gregorie 
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Reply to
Martin Gregorie

Aye.

Series, but it makes no difference, the amount of stored energy is the same. But of course the current required at 24 V for 700 VA is half that at 12 V, a mere 30 A against 60 for 12 V...

Which is about what it can do.

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Cheers 
Dave.
Reply to
Dave Liquorice

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