DIY telephone wiring (Ireland)

[Adrian Brentnall]

HI Folks
We're getting a 'real' telephone/broadband line installed in our shop in
West Cork, Ireland.

I'm used to the UK / BT situation - where the telephone provider would
normally provide a master socket.

Seems things are a little different over here - man I spoke to @ Eircom
(telephone provider) said 'You have three lines going into the property'
and claims to have re-enabled one of them for us.

Checking in the property, we do indeed have a 6-core cable coming in -
and it terminates in a junction box, but not one with a phone socket.
Eircom man said 'you'll have to wire it up to a socket - we don't do that'.

So - couple of questions.

a) To identify the 'live' pair - I guess I just look for a pair of wires
with 50v across them ? True ??

b) I'll need to install probably 25ft of cable from the junction box to
a phone socket. I have 'stock' of 6-way, solid core 'alarm' cable, as
well as some 4-core stranded cable. I've seen mention of twisted pairs
being used in 'proper' phone cable. Do I need to find some of that - or
will either of the above cables suit instead?

Thanks
Adrian

[Graham.]

On Sat, 02 Feb 2013 21:34:53 +0000, Adrian Brentnall
<adr...@inspired-glass.com> wrote:

>HI Folks
>We're getting a 'real' telephone/broadband line installed in our shop in
>West Cork, Ireland.
>
>I'm used to the UK / BT situation - where the telephone provider would
>normally provide a master socket.
>
>Seems things are a little different over here - man I spoke to @ Eircom
>(telephone provider) said 'You have three lines going into the property'
>and claims to have re-enabled one of them for us.
>
>Checking in the property, we do indeed have a 6-core cable coming in -
>and it terminates in a junction box, but not one with a phone socket.
>Eircom man said 'you'll have to wire it up to a socket - we don't do that'.
>
>So - couple of questions.
>
>a) To identify the 'live' pair - I guess I just look for a pair of wires
>with 50v across them ? True ??

True

>b) I'll need to install probably 25ft of cable from the junction box to
>a phone socket. I have 'stock' of 6-way, solid core 'alarm' cable, as
>well as some 4-core stranded cable. I've seen mention of twisted pairs
>being used in 'proper' phone cable. Do I need to find some of that - or
>will either of the above cables suit instead?
>
>Thanks
>Adrian

Use proper twisted pair telephone cable, it's widely available. Solid
core CAT5 network cable is also suitable.
Twisted pairs help with immunity to interference originating
externally.
Google "common mode rejection".

[Frank Erskine]

On Sat, 02 Feb 2013 21:34:53 +0000, Adrian Brentnall
<adr...@inspired-glass.com> wrote:

>HI Folks
>We're getting a 'real' telephone/broadband line installed in our shop in
>West Cork, Ireland.
>
>I'm used to the UK / BT situation - where the telephone provider would
>normally provide a master socket.
>
>Seems things are a little different over here - man I spoke to @ Eircom
>(telephone provider) said 'You have three lines going into the property'
>and claims to have re-enabled one of them for us.
>
>Checking in the property, we do indeed have a 6-core cable coming in -
>and it terminates in a junction box, but not one with a phone socket.
>Eircom man said 'you'll have to wire it up to a socket - we don't do that'.
>
>So - couple of questions.
>
>a) To identify the 'live' pair - I guess I just look for a pair of wires
>with 50v across them ? True ??

The easiest way of doing that is to connect the +ve of your meter to a
nearby earth, then probe with the -ve to find the "B" wire. Connect up
the B wire to your meter, then probe the rest of the wires to find the
"A" wire.
You should find that the pair is lightly twisted together, and there
may be some commonality in the colours, e.g. white/blue and
blue/white, IYSWIM.

>
>b) I'll need to install probably 25ft of cable from the junction box to
>a phone socket. I have 'stock' of 6-way, solid core 'alarm' cable, as
>well as some 4-core stranded cable. I've seen mention of twisted pairs
>being used in 'proper' phone cable. Do I need to find some of that - or
>will either of the above cables suit instead?

Avoid alarm cable. Since the wires aren't (normally) twisted into
pairs you're much more likely to suffer interference, especially with
a longish run as you describe.

Proper telephone cable is dirt cheap.

HTH -

--
Frank Erskine

[Bob Eager]

On Sat, 02 Feb 2013 22:39:06 +0000, Frank Erskine wrote:

>>b) I'll need to install probably 25ft of cable from the junction box to
>>a phone socket. I have 'stock' of 6-way, solid core 'alarm' cable, as
>>well as some 4-core stranded cable. I've seen mention of twisted pairs
>>being used in 'proper' phone cable. Do I need to find some of that - or
>>will either of the above cables suit instead?
>
> Avoid alarm cable. Since the wires aren't (normally) twisted into pairs
> you're much more likely to suffer interference, especially with a
> longish run as you describe.
>
> Proper telephone cable is dirt cheap.

Just to add; don't attempt to use the stranded cabel, as it won't work
properly in punch-down blocks (e.g. the phone socket).



--
Use the BIG mirror service in the UK: http://www.mirrorservice.org
My posts (including this one) are my copyright and if @diy_forums on
Twitter wish to tweet them they can pay me £30 a post
*lightning surge protection* - a w_tom conductor

[John Rumm]

On 02/02/2013 21:34, Adrian Brentnall wrote:
> HI Folks
> We're getting a 'real' telephone/broadband line installed in our shop in
> West Cork, Ireland.
>
> I'm used to the UK / BT situation - where the telephone provider would
> normally provide a master socket.
>
> Seems things are a little different over here - man I spoke to @ Eircom
> (telephone provider) said 'You have three lines going into the property'
> and claims to have re-enabled one of them for us.
>
> Checking in the property, we do indeed have a 6-core cable coming in -
> and it terminates in a junction box, but not one with a phone socket.
> Eircom man said 'you'll have to wire it up to a socket - we don't do that'.
>
> So - couple of questions.
>
> a) To identify the 'live' pair - I guess I just look for a pair of wires
> with 50v across them ? True ??

I would expect so... if in doubt wire a phone across em and listen ;-)

> b) I'll need to install probably 25ft of cable from the junction box to
> a phone socket. I have 'stock' of 6-way, solid core 'alarm' cable, as
> well as some 4-core stranded cable. I've seen mention of twisted pairs
> being used in 'proper' phone cable. Do I need to find some of that - or
> will either of the above cables suit instead?

Assuming you are fitting a UK style master socket, then you will need a
solid core twisted pair really. Your alarm cable might do, but then
again the proper stuff (CW1308) is cheap and usually easy to get (CPC
have it)

--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/

[Mike Tomlinson]

En el art�culo <an5f3u...@mid.individual.net>, Adrian Brentnall
<adr...@inspired-glass.com> escribi�:

>b) I'll need to install probably 25ft of cable from the junction box to
>a phone socket. I have 'stock' of 6-way, solid core 'alarm' cable, as
>well as some 4-core stranded cable. I've seen mention of twisted pairs
>being used in 'proper' phone cable. Do I need to find some of that

Yes. You can use Cat 5 network patch cable as an alternative.

> - or
>will either of the above cables suit instead?

They'll work, but it's a bad idea.

--
(\_/)
(='.'=)
(")_(")

[Graham.]

On Sun, 3 Feb 2013 01:24:30 +0000, Mike Tomlinson <mi...@jasper.org.uk>
wrote:

If you specify "patch" CAT5 you will probably get stranded cable,
which, as John has pointed out is not ideal in Krone type connectors.

Mind you, it's not as bad as trying to crimp conventional RJ45 plugs
onto solid cable as I often see people trying and failing to do.

[Dave Liquorice]

On Sun, 03 Feb 2013 02:03:20 +0000, Graham. wrote:

> Mind you, it's not as bad as trying to crimp conventional RJ45 plugs
> onto solid cable as I often see people trying and failing to do.

They must be doing summat else wrong then. I've only had one RJ45 to
solid fail here and that's was because I got the plug on "upside down" so
it went 87654321 instead of 12345678. B-)

All the Olympic Broadcasting Services provided commentary positions were
connected via heavy duty screened solid Cat5 into RJ45's fitted on site.

Agree it's not recomended but it does work, just don't expect it to be as
robust in repeated flexing as a stranded.

--
Cheers
Dave.

[Andy Burns]

Dave Liquorice wrote:

> All the Olympic Broadcasting Services provided commentary positions were
> connected via heavy duty screened solid Cat5 into RJ45's fitted on site.

Presumably fitted by someone who knew the difference between solid RJ45
plugs and stranded RJ45 plugs?

[Mike Tomlinson]

En el art�culo <nyyfbegfubjuvyypb...@srv1.howhill.co.uk>,
Dave Liquorice <allsortsn...@howhill.com> escribi�:

>They must be doing summat else wrong then.

There's two different types of plug - one for stranded cable and one for
solid. If you look at the pins under a magnifying glass, the plugs for
stranded cable have a pair of small prongs that pierce the insulation.
I forget what the ones for solid cable look like.

If you use the wrong type for the cable you get a poor connection.

[The Natural Philosopher]

its worse. there are - or were - slightly different RJ45 plugs and
sockets out there.

Fortunately they all see similar now.



--
Ineptocracy

(in-ep-toc’-ra-cy) – a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

[Graham.]

I chose my words carefully and said *conventional* RJ45 meaning the
more common type with the blade in line with the conductor designed to
penetrate the insulation and conform the strands it mates with without
cutting them.

You have to be quite lucky to get a reliable connection with them on
solid core, mind you we did have a surplus of luck in the Olympics.

[Dave Liquorice]

Nope, me(*) for the venue I was at. But then it was supplied kit of bits,
drums of cable, bag of connectors... So one would assume the correct
connector was supplied.

(*) Quick google later and I now know the difference. Stranded has two
spikes in line. Solid has three spikes, the end two offset one way the
center offset the other.

I didn't look *that* closely at the connectors supplied by OBS.

All the ones I've used here on solid cable are really stranded ones but
as I say the only failure has been when I got the orientation wrong. They
are all more or less static cables though not regularly moved, unplugged,
plugged etc.

--
Cheers
Dave.

[Graham.]

On Sun, 03 Feb 2013 13:17:40 +0000, The Natural Philosopher
<t...@invalid.invalid> wrote:

>On 03/02/13 12:20, Andy Burns wrote:
>> Dave Liquorice wrote:
>>
>>> All the Olympic Broadcasting Services provided commentary positions were
>>> connected via heavy duty screened solid Cat5 into RJ45's fitted on site.
>>
>> Presumably fitted by someone who knew the difference between solid RJ45
>> plugs and stranded RJ45 plugs?
>>
>>
>>
>its worse. there are - or were - slightly different RJ45 plugs and
>sockets out there.
>
>Fortunately they all see similar now.

Probably true for branded types you pay a resalable amount for.
I have to deal with some cheap crap sometimes.

Last week I encountered some sockets that had an interference fit with
the plugs I was using. In practice it meant I found it almost
impossible to insert them by feel, and had to get into an
uncomfortable position to see what I was doing.

[Bob Eager]

On Sun, 03 Feb 2013 13:31:32 +0000, Graham. wrote:

> I chose my words carefully and said *conventional* RJ45 meaning the more
> common type with the blade in line with the conductor designed to
> penetrate the insulation and conform the strands it mates with without
> cutting them.
>
> You have to be quite lucky to get a reliable connection with them on
> solid core, mind you we did have a surplus of luck in the Olympics.

Apropos of not all that much (but given that there are a lot of ex-UKC
people here), two of our CS students spent their Year in Industry working
at the Olympics. A real plum job - they were Deputy Venue Technology
Managers at the Excel and O2 (sorry, North Greenwich!).