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Lancaster power outage

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waltergmw:
Gentlefolk,

Lancaster residents might be interested to read this:-

https://b4rn.org.uk/b4rn-service/network-status/

I assume all BT ADSL services remain unaffected but does anybody know if there is a published battery duration for the different types of FTTC ?

Kind regards,
Walter

j0hn:
I can't find the relative pdf at the moment but I believe the DSLAM's have a 48v battery intended to last a minimum of 4 hours.
I'm often wrong though :-[

burakkucat:
All three types of Openreach cabinet (containing a Huawei SmartAX MA5616, a Huawei SmartAX MA5603T and an ECI Hi-FOCuS Mini-Shelf M41, respectively) contain four 12V SLA batteries, in series.

The last time we discussed the available backup time, before total discharge, I recall that the batteries were expected maintain the service for 8 hours. I believe Black Sheep mentioned that Openreach/Operate technicians were expected to attend after 4 hours of outage to perform a battery set swap. However with a wide area mains power outage, I don't think there would be sufficient technicians -- nor charged battery sets -- available to achieve that target.

WWWombat:
BT Business' status page is here: https://btbusiness.custhelp.com/app/service_status/

It shows an Infinity problem in the Lancaster area from 12:20 to 15:07, and one in Morecambe from 12:16 to 13:21.

There's a quote on TBB saying:

--- Quote from: http://forums.thinkbroadband.com/fibre/3920901-fttc-and-backup-power.html ---fully loaded 3-4 hours is expected
partially loaded stands at 6-12
with no load before fully commissioned they lasted a couple of days

--- End quote ---

As something of a sanity check, we can see how long a battery is likely to last...

The Kitz page on FTTC cabinets shows an AIO cabinet with room for a 26 amp-hour battery.

Back in 2014, Openreach applied for permission to use DSLAMs without meters. As part of this, they told us the power consumption data...
As an example, an MA5616 (ie 128 variant used in an AIO) uses 70W when empty, 160W when half full (64 ports), and 210W when full (128 ports).

At a supply voltage of 48V, that equates to currents of 1.5A, 3.3A, and 4.4A respectively.

If the diagram indicates a 48V battery of 26AH, or 4x 12V batteries each of 26AH, it would last 17 hours, 8 hours, 6 hours respectively.

The 288-port variant looks to have room for considerably bigger batteries, and the glimpse of batteries seen here are of a size that, by my guess, can handle 60-70 AmpHours each.

The 288-port 5603T starts at 100W and peaks at a 600W usage, or 2.1 Amps and 12.5 Amps respectively. Such batteries would last around 28 hours at best, 5-6 hours at worst.

I'm guessing 5-6 hours is a reasonable bet.

WWWombat:
Looking a bit further, I found some more hints about batteries...

This video of an ECI cabinet uses a stack of "Haze" batteries:
https://www.youtube.com/watch?v=G1RvCEBoiJ4

Concentrating on the Haze brand, I reckon a set of 4 of their 55Ah "front access telecom" batteries could fit into the box in a 288-port Huawei.
https://www.blueboxbatteries.co.uk/brands/haze/hzb-front-access/hzb12-55fa-battery

At a pinch, using the full depth, you might even get a bank of these Exide 86Ah batteries in there:
https://www.blueboxbatteries.co.uk/brands/exide-gnb/marathon-m-ft/m12v90f-battery

Seeing these, I could believe that a DSLAM is given lower-capacity batteries when it has fewer ports in use, but that they could be swapped out for higher capacity when the number of ports increases.

Also, for future note: A G.Fast pod would place additional demand on the batteries.

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