UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Telephony and Telecomms

Notices

Vintage Telephony and Telecomms Vintage Telephones, Telephony and Telecomms Equipment

Closed Thread
 
Thread Tools
Old 11th Jul 2020, 8:04 pm   #1
hannahs radios
Hexode
 
Join Date: Jan 2012
Location: Weymouth, Dorset, UK.
Posts: 422
Default BT street equipment cabinets

Can any one tell me if the green BT cabinets for conventional phone lines, the sort that have been around for years not the new digital ones, have any power supply's built into them? The reason I ask is because I saw inside the one at the top of my road the other day, and noticed some fairly thick looking green/yellow wiring connected to the metal doors and sides of the cabinet. That's why I'm asking.
hannahs radios is offline  
Old 11th Jul 2020, 9:04 pm   #2
Jonster
Heptode
 
Join Date: Apr 2008
Location: Eastbourne, East Sussex, UK.
Posts: 671
Default Re: BT street equipment cabinets

If it's thick green/yellow wiring that would be earth bonding to keep all the parts of the cabinet at the same potential for safety.
Jonster is offline  
Old 12th Jul 2020, 7:20 pm   #3
Graham G3ZVT
Dekatron
 
Graham G3ZVT's Avatar
 
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,675
Default Re: BT street equipment cabinets

Quote:
Originally Posted by Jonster View Post
If it's thick green/yellow wiring that would be earth bonding to keep all the parts of the cabinet at the same potential for safety.
Those who work on line-plant must be mindful that dangerous voltages could unexpectedly be introduced via faulty customer premises equipment.
__________________
--
Graham.
G3ZVT
Graham G3ZVT is offline  
Old 12th Jul 2020, 7:34 pm   #4
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,798
Default Re: BT street equipment cabinets

Also there is the possibility of high voltage surges induced by lightning in overhead sections of line. Normal ye olde worlde telephone cabinets just had -48v from the exchange battery via hundreds of ohms on each exchange line.

Phone equipment in the home/office used to be tightly controlled especially with respect to anything using mains.

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is online now  
Old 12th Jul 2020, 11:30 pm   #5
hannahs radios
Hexode
 
Join Date: Jan 2012
Location: Weymouth, Dorset, UK.
Posts: 422
Default Re: BT street equipment cabinets

It makes sense now why they would need to have the cabinets properly earth bonded next time they are working in it il try to have a better look. Radio wrangler why is it -48 volts? Is this the 55 volts from the battery minus the volt drop of the wiring?
hannahs radios is offline  
Old 13th Jul 2020, 6:50 am   #6
bobsterkent
Hexode
 
bobsterkent's Avatar
 
Join Date: Apr 2006
Location: Medway towns, Kent, UK.
Posts: 271
Default Re: BT street equipment cabinets

One of the first 'powered' cabinets came with the wifi installations for the 'open cities' project. I was the lead test manager for that and had to spec up the use of mains powered equipment. (including 24 hour noise tests). The other normal powered equipment is the fibre and DSLAM cabinets, which have to be close (spec was originally under 5m away) to the original cabinets which only carry normal phone voltages.
__________________
"Oh yes I love television, all those wiggly lines"!
bobsterkent is offline  
Old 13th Jul 2020, 11:09 am   #7
hannahs radios
Hexode
 
Join Date: Jan 2012
Location: Weymouth, Dorset, UK.
Posts: 422
Default Re: BT street equipment cabinets

Thanks bobster that really answers my original question thanks. So far all but one of the new fibre cabinets I've seen are only a very short distance from the original cabinets as you say within 5 yards/metres however a newly installed one just up the road from here is out on its own although it's linked back to one at the top of my road in fact before they started work someone had written the words PARENT POWER on the pavement just in front of it so I guess the new box is fed from this possibly to avoid having to pay yet another power connection charge
hannahs radios is offline  
Old 13th Jul 2020, 1:27 pm   #8
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,951
Default Re: BT street equipment cabinets

One thing I've always wondered about the 'powered' street-cabinets is - how is the electricity they use charged-for? Is there a meter inside the box? Or is there some generally-accepted-power-consumption figure that's been neasured for an 'average' box and this is simply multiplied by the number-of-boxes?

I watched the installation of the nearest one to me [it's fed from the same underground 3-phase supply which then goes up onto overhead-wires to feed my house] but never got to see its insides.
G6Tanuki is offline  
Old 13th Jul 2020, 1:47 pm   #9
Dennis M
Pentode
 
Join Date: Jun 2020
Location: Bude, Cornwall, UK.
Posts: 180
Default Re: BT street equipment cabinets

I think they charge for power the same way as they do for street lights, they don’t have individual meters either.

A fixed charge based on calculated usage of power, it would cost too much to fit individual meters.
Dennis M is offline  
Old 13th Jul 2020, 3:44 pm   #10
Dave Moll
Dekatron
 
Dave Moll's Avatar
 
Join Date: Feb 2005
Location: West Cumbria (CA13), UK
Posts: 6,118
Default Re: BT street equipment cabinets

Quote:
Originally Posted by Dennis M View Post
A fixed charge based on calculated usage of power, it would cost too much to fit individual meters.
Not only that, but it would require a meter reader to go round and read them all - unless they were "smart" meters.
__________________
Mending is better than Ending (cf Brave New World by Aldous Huxley)
Dave Moll is online now  
Old 13th Jul 2020, 9:02 pm   #11
Tim
Dekatron
 
Tim's Avatar
 
Join Date: Jan 2003
Location: Bradford on Avon, Wiltshire, UK.
Posts: 3,301
Default Re: BT street equipment cabinets

The nearby ADSL fibre DSLAM is mains powered and there are tie cables carrying customer’s lines in and out. There have been a few ( rare) instances of cabinet shells being live so they should all be bonded. Engineers are supposed to test for “ liveness” with one of those voltage detectors before starting work.
__________________
"Nothing is as dangerous as being too modern;one is apt to grow old fashioned quite suddenly."
Tim is offline  
Old 14th Jul 2020, 6:58 am   #12
bobsterkent
Hexode
 
bobsterkent's Avatar
 
Join Date: Apr 2006
Location: Medway towns, Kent, UK.
Posts: 271
Default Re: BT street equipment cabinets

yes we are charged for power based on what the power consumption is. An earlier installation in Cardiff I worked on put mobile phone masts inside lamp posts and we had to notify which ones and how many to pay the council who paid the additional costs. Some of them have now been working in Cardiff for nearly 20 years. We were the first to combine both 2G and 3G and 4 operators all within one installation providing a mesh across the city.
__________________
"Oh yes I love television, all those wiggly lines"!
bobsterkent is offline  
Old 16th Jul 2020, 3:19 pm   #13
Welsh Anorak
Dekatron
 
Welsh Anorak's Avatar
 
Join Date: Apr 2005
Location: North Wales, UK.
Posts: 6,882
Default Re: BT street equipment cabinets

The telephone kiosk opposite (now gone) had a small fluorescent light in it that was on permanently and fed by an unmetered supply from our house across the road.
We used to own and maintain a TV distribution system for a village and our supply was unmetered and based on an assumed constant usage.
__________________
Glyn
www.gdelectronics.wales
Welsh Anorak is offline  
Old 16th Jul 2020, 4:01 pm   #14
Sparks
Heptode
 
Join Date: Oct 2006
Location: Leeds, West Yorkshire, UK.
Posts: 593
Default Re: BT street equipment cabinets

I'm intrigued by the TV aspect, Glyn. Was your system anything like a small Rediffusion network ?
Sparks is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 10:00 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.