BT Wiring Question

[CEC]

I have a customer who owns two adjacent holiday cottages, each with their own distinct phone number. They have a BT master socket in each. BT provided a single 8 core cable to one of the cottages and ran a seperate cable between the incoming master socket and the master in the other cottage. The incoming master socket is connected to two wires, one orange and one white and six wires are unused. This cottage works just fine.

The second cottage used to work but the owner says that BT, for reasons unknown, disconnected it while installing ADSL in the first cottage. Now the cable running from the incoming master socket to the second cottage's master socket is not connected to anything at all. The owner has had BT out to have a look to see what's wrong. BT said all their cabling was fine, charged £120, and left the customer in exactly the same position as before. Customer not happy.

I've tested voltages across all combinations of the incoming wires and only the orange and white have a voltage (49v DC). All the others appear to be dead. I've also tested voltage across the orange and white when the incoming cottage number is called, it remains at 49vdc and the telephone rings normally. When the second cottage number is dialled the orange and white start fluctuating from 49vdc to a whole range of voltages, both DC and AC.

So from this I deduce, perhaps incorrectly, that both telephone numbers are served by the single pair of orange and white. Is this correct? If it is correct, where and which colours should I attach to this incoming master socket to spur off to the second master socket?

This is a picture of the incoming master socket. The bottom right cable is the incoming BT cable. You can see the orange and white wires running to the faceplate. The blue/white, white/blue, and orange/white wires runing up to the right-hand cable at the top of the box are to an extension in this cottage. The left hand cable is the run to the second cottage's master socket. None of these are connected to anything in this box.

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• CEC
• 19 Nov 2009
• 1

This is a picture of the faceplate of the incoming master socket.

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• CEC
• 19 Nov 2009
• 1

Any help would be most welcome.

 

[Lectrician]

If there is nothing at the master NTE socket, it is a BT problem and down to them to sort - I would chase for a refund and revisit.

The black cable coming up the wall is likely to have all three lines in it (assuming you are correct that all 3 buildings had a seperate number, and the master sockets in those buildings all come back to this socket int he photo). One pair will carry one line. The orange/white is carrying the line in the photo. The other pairs may be carrying the other lines, and would usually be jointed with jellies behind the socket onto the cables to the other buildings.

I would chase BT.

 

[Paul_C]

Are you certain there isn't a separate drop wire somewhere providing service to the phone in cottage #1?

Did you try disconnecting the extension wiring by pulling the faceplate on the NTE in your photo to see if that phone stopped ringing? And which line are you on if you plug directly into that NTE? (Check by calling the numbers or just plugging into the NTE test jack and dialing 17070.)

 

[CEC]

Are you certain there isn't a separate drop wire somewhere providing service to the phone in cottage #1?

Absolutely certain. I've traced it from the pole to the house and through the wall to inside.

Did you try disconnecting the extension wiring by pulling the faceplate on the NTE in your photo to see if that phone stopped ringing?

Yes. Phone stopped ringing and BT Home Hub lost BB connection.

And which line are you on if you plug directly into that NTE? (Check by calling the numbers or just plugging into the NTE test jack and dialing 17070.)

The number for cottage #1.

Thanks for your help so far.

 

[Paul_C]

So pair 1 in the incoming cable must be the line for cottage #1 which has had ADSL provided on it then. The only problem there is your description of the voltages measured:

I've also tested voltage across the orange and white when the incoming cottage number is called, it remains at 49vdc and the telephone rings normally. When the second cottage number is dialled the orange and white start fluctuating from 49vdc to a whole range of voltages, both DC and AC.

Measuring across the line when an incoming call arrives, you should normally see first a polarity reversal of the DC, then the AC ringing voltage superimposed on that (when the call is either answered or abandoned, the DC polarity will return to normal). If you're using a digital meter it won't be able to keep up with the ringing bursts, hence the fluctuating readings.

But you say you just read steady battery on the line when calling cottage #1's number and (presumably) ringing voltage when dialing cottage #2's number, which is puzzling. Is there a possibility that you accidentally had the two numbers mixed up when you did that test?

If there is/was a second line and that external drop wire is the only cable to the building, then the second number should be on one of the pairs in that cable, most likely pair 2. For reference:

Pair 1 = Orange / White
Pair 2 = Red / Slate
Pair 3 = Blue / Brown
Pair 4 = Green / Black

By the way:

So from this I deduce, perhaps incorrectly, that both telephone numbers are served by the single pair of orange and white. Is this correct?

There are systems which allow a single pair of wires back to the exchange to be shared by two subscribers (or two different lines to the same subscriber), but they are separated before they reach the point of being connected to the NTE. And those systems aren't compatible with ADSL anyway.

 

[CEC]

Measuring across the line when an incoming call arrives, you should normally see first a polarity reversal of the DC, then the AC ringing voltage superimposed on that (when the call is either answered or abandoned, the DC polarity will return to normal). If you're using a digital meter it won't be able to keep up with the ringing bursts, hence the fluctuating readings.

I was using a digital meter.

But you say you just read steady battery on the line when calling cottage #1's number and (presumably) ringing voltage when dialing cottage #2's number, which is puzzling. Is there a possibility that you accidentally had the two numbers mixed up when you did that test?

I don't think so but I'll redo the test.

If there is/was a second line and that external drop wire is the only cable to the building, then the second number should be on one of the pairs in that cable, most likely pair 2. For reference:

Pair 1 = Orange / White
Pair 2 = Red / Slate
Pair 3 = Blue / Brown
Pair 4 = Green / Black

I thought I'd checked every combination of the other wires and got no voltage. Now you've given the the specific pairings I can recheck with more knowledge.

Thanks so much for your help with this, it's helping me understand a great deal more.

 

[simonpolly]

The incoming cable is called cad55,it has 4 pairs and is used where the end user has more the 2 lines(normally),
Just a thought you mentioned that the line went off after they installed adsl broadband,adsl does not need installing which leads me to think that the two cottages may have been on a DACS,basically two lines are fed into a basic digital system in the exchange THEY THEN SHARE A PAIR OF WIRES UPTO THE DACS AT THE END USER after the dacs they then have their own pair of wires.You can not have adsl over a line which is on a dacs,so if you ordered adsl broadband and you were on a dacs a engineer would come out and de dacs the line that broadband was going on,the engineer would need to find a pair of wires from somewhere ? this could mean diverting a pair of wires from somewhere else or using a spare pair on the d.p(if there were spares you would not be on a dacs) or disconnecting line two and doing a bunk because he could not get a spare pair there or did not realsise there was a second line on the dacs

 

[Atilla]

.......so if you ordered adsl broadband and you were on a dacs a engineer would come out and de dacs the line that broadband was going on,the engineer would need to find a pair of wires from somewhere ? this could mean diverting a pair of wires from somewhere else or using a spare pair on the d.p(if there were spares you would not be on a dacs) or disconnecting line two and doing a bunk because he could not get a spare pair there or did not realsise there was a second line on the dacs

they won`t "de-DACS" you simply because you want BB provision they would just refuse the order, the only way to get off a DAC`s is to order REDCARE or another BT product thats not compatable with DAC`s, hope you get an engineer who cares and that the reason DACS`s was used in the first place no longer exists.

 

[Paul_C]

or did not realsise there was a second line on the dacs

I see that as a possibility, but then I would have to wonder why the second pair was disconnected behind the NTE in the first cottage.

If the second cottage had a working line before the change, then one of the pairs in the drop wire must have been connected through to that second NTE. I'm just wondering if the engineer had somehow gotten a mixed up order and thought that the line to the second cottage was to be discontinued?

they won`t "de-DACS" you simply because you want BB provision

Sure they will, if there now happens to be a spare pair available to the property, or the situation which originally required DACS has now changed to the point that a pair can be freed up by moving two other subscribers onto DACS.

If there's no way to free up a pair for DSL service, then there's no way to free up a pair for Redcare, ISDN or any other DACS-incompatible services either.

I've heard of some ISP's which refuse to take a DSL order any further when their database reports back "Incompatible services on line," but that's down to them not caring enough to get the changes made and pay for them, not BT/OpenReach.

 

[Lectrician]

BT used to drag their heels with broadband provision on DACS lines, but these days they have a duty to the providers to sort it, in some cases requiring extra line plant.

Some ISP's do not want the hastle or cost of getting Openreach to de-DACS a line, and so refuse the order, but going to a different ISP usually sorts the issue.

The only time recently when BT caused some issues on a site I was working on hapened to be a large dairy farm with large offices. They had 4 PSTN lines on a telephone system, these all fed from two DACS units over an old 2 pair cable which ran a mile or so 'ploughed' into the fields.

When they requested ADSL the initial connection was refused and quote issued......some £60k! To install a new cable from the main road up over the hills following a different route on land BT could install on without wayleaves and the like.

Satallite broadband is now installed and working

 

[Atilla]

If there's no way to free up a pair for DSL service, then there's no way to free up a pair for Redcare, ISDN or any other DACS-incompatible services either.

thats not what i said now, was it ...............

I've heard of some ISP's which refuse to take a DSL order any further when their database reports back "Incompatible services on line," but that's down to them not caring enough to get the changes made and pay for them, not BT/OpenReach.

instead of swallowing your line managers drivel listen to someone who actually requests this stuff - BT/OPENREACH will not de`DAC no matter who the ISP asking for it is.

 

[Atilla]

BT used to drag their heels with broadband provision on DACS lines, but these days they have a duty to the providers to sort it, in some cases requiring extra line plant.

no they dont

Some ISP's do not want the hastle or cost of getting Openreach to de-DACS a line, and so refuse the order, but going to a different ISP usually sorts the issue.

no it doesnt.

 

[simonpolly]

.......so if you ordered adsl broadband and you were on a dacs a engineer would come out and de dacs the line that broadband was going on,the engineer would need to find a pair of wires from somewhere ? this could mean diverting a pair of wires from somewhere else or using a spare pair on the d.p(if there were spares you would not be on a dacs) or disconnecting line two and doing a bunk because he could not get a spare pair there or did not realsise there was a second line on the dacs

they won`t "de-DACS" you simply because you want BB provision they would just refuse the order, the only way to get off a DAC`s is to order REDCARE or another BT product thats not compatable with DAC`s, hope you get an engineer who cares and that the reason DACS`s was used in the first place no longer exists.

I wish you had informed me of this before,could have saved me loads of time and hassle on the hundreds of jobs i have done diverting pairs and re arranging dacs so that eu who have ordered adsl but are on a dacs can have the service they have requested.

 

[Atilla]

.......so if you ordered adsl broadband and you were on a dacs a engineer would come out and de dacs the line that broadband was going on,the engineer would need to find a pair of wires from somewhere ? this could mean diverting a pair of wires from somewhere else or using a spare pair on the d.p(if there were spares you would not be on a dacs) or disconnecting line two and doing a bunk because he could not get a spare pair there or did not realsise there was a second line on the dacs

they won`t "de-DACS" you simply because you want BB provision they would just refuse the order, the only way to get off a DAC`s is to order REDCARE or another BT product thats not compatable with DAC`s, hope you get an engineer who cares and that the reason DACS`s was used in the first place no longer exists.

I wish you had informed me of this before,could have saved me loads of time and hassle on the hundreds of jobs i have done diverting pairs and re arranging dacs so that eu who have ordered adsl but are on a dacs can have the service they have requested.

of course you have dear.

 

[simonpolly]

Yes i have many times HAVE YOU ? you just think you know everything,
Ok clever dick if you disconnect the b1 in the exchange what happens to the b2 ?
And explain this mar 1 .9.02.07