BT cable install

Author
Discussion

Too Late

Original Poster:

5,092 posts

234 months

Saturday 31st January 2015
quotequote all
So I have just drilled the external BT cables into the house.

Is this correct re the wiring?
This often has Orange, White, Green and Black wires. Usually (but not always) Orange and White are the active pair and go to connections 2 and 5.

So
Orange = 2
White = 5
Green =
Black =

But what do they corrolate to the internal colour wiring?
Internal BT have 4 wires with different cables.

Thanks
N

Edited by Too Late on Saturday 31st January 15:35

Salesy

850 posts

128 months

Saturday 31st January 2015
quotequote all
If you have the active line coming in then you will either have 2 and 5 or A and B connections.

All other points are wired as 2 and 5. Don't use 3 anymore as this can cause interference on lines that use broadband, Number 3 was used when we had real "RING RING" phones.


Sheepshanks

32,530 posts

118 months

Saturday 31st January 2015
quotequote all
Salesy said:
Number 3 was used when we had real "RING RING" phones.
..and if you need that for an old phone you can use an ADSL filter between the phone and socket to generate the ring.

Wiring details are all here. http://www.wppltd.demon.co.uk/WPP/Wiring/UK_teleph... . As pointed out above, 3 isn't generally connected now, and 4 was only ever connected for neatness.

It's easier to follow in the future if you do it right, but it doesn't actually matter - incoming 2 & 5 can be either way around and internally as long as the same colour wire is used to link each terminal it'll be fine.

Scuffers

20,887 posts

273 months

Saturday 31st January 2015
quotequote all
Sheepshanks said:
It's easier to follow in the future if you do it right, but it doesn't actually matter - incoming 2 & 5 can be either way around and internally as long as the same colour wire is used to link each terminal it'll be fine.
Err..

It is polarity dependant, yes, the phone won't care, but your adsl modem will, yes it still works, but not as well.


Sheepshanks

32,530 posts

118 months

Saturday 31st January 2015
quotequote all
Scuffers said:
... but your adsl modem will, yes it still works, but not as well.
Evidence?

I've always understood it didn't matter, and, bearing in mind how much effort goes into getting decent broadband performance, you'd think Googling this would produce a lot of hits if it was an issue. Yet it doesn't.

Scuffers

20,887 posts

273 months

Saturday 31st January 2015
quotequote all
Put a meter across the line, it hase a + and -.

In telephony terms, observing polarity is important, and becomes moreso with ADSL, its about noise and cross-talk.

Usually, this will show up as frame alignment issues, the line will sync, but will struggle to maintain stable sync.

From the users POV, line will run in fits and starts, like you have contested connection, most people then blame traffic on their isp's network.

catfood12

1,410 posts

141 months

Saturday 31st January 2015
quotequote all
I always understood the B was for battery and should be at -55V compared to the A. New BT line just installed, the B is at +55VDC, and broadband performance isn't as good as I'd expect. Speedtest.net says 19Mbit/sec, however HTTPS performance is poor, and SSL VPNs keep dropping out. I was blaming Plusnet for caching stuff and having congested links out to the exchanges, but now I'm not quite as sure...

I'm going to swap them round and will report !

Too Late

Original Poster:

5,092 posts

234 months

Sunday 1st February 2015
quotequote all
I am still confused. Sorry chaps. What numbers do I punch down for the green and black cables?

External bt
Orange = 2
White = 5
Green =
Black =

Internal.. Is the correct?
2 = Blue with White Bands
5 = White with Blue Bands


So orange is punched down to 2 and white is 5.. That's correct isn't.
What do I do with green and black.

Thanks

N


Edited by Too Late on Sunday 1st February 21:38

Scuffers

20,887 posts

273 months

Sunday 1st February 2015
quotequote all
That's good, do not connect anything else, its only2 wires.

VEX

5,256 posts

245 months

Sunday 1st February 2015
quotequote all
And keep the same blue white / blue to number pairings throughout the house.

Went to a house once and the Stoopid installer a had managed to mix and match his 2's and 5's all the way through the house. Caused all sorts of ringing problems!

V.

Westy Pre-Lit

5,087 posts

202 months

Monday 2nd February 2015
quotequote all
Too Late said:
What do I do with green and black.

Edited by Too Late on Sunday 1st February 21:38
Not sure of the incoming colours for BT but the other 2 cores will be used if you have a second line installed.

Too Late

Original Poster:

5,092 posts

234 months

Monday 2nd February 2015
quotequote all
Thanks everyone!