Telephones dead

[highspark]

Hi lads,

too cut a long story short - working on occupied commercial building, had to isolate sub-board to work and test. After isolation and re-energise phones are off. no dialling tone.

At main board there was an mcb saying server do not switch off (thought phones may be fed from this along with broadband). never touched tha-main board - just sub-board which serves the office area.

Anyhow phones have power to them but the lines are dead. on inspection there is a few BT boxes in a cupboard which look as though they control the phones. when isolated do these boxes need to be reset?

When isolated the alarms also went into a reset mode which i managed to do. Absolute nightmare as sub-board has no marking of phone lines or alarms complete joke.

I need a solution to but to the manager as its beyond my knowledge as i am not a telecoms engineer any thoughts on this?

 

[alarm man]

sounds like its possible you could have blown telephone system when testing..

 

[highspark]

Highly doubt it unless phones where ran of lighting circuit. Only done 1 i/r test and it was at 250v across live/neutral - earth. Any ideas lads?

 

[i=p/u]

Wish i had knowledge to help ya, hopefully someone will instead of laughing

 

[alarm man]

Highly doubt it unless phones where ran of lighting circuit. Only done 1 i/r test and it was at 250v across live/neutral - earth. Any ideas lads?

well if it worked before you turned up,then its something youve done..you could call bt out,about £95ph i think..could cost you more in lost business for the client if phones dont work on monday

 

[SW1970]

How unhelpful i=p/u's post was. The BT boxes you refer to could be an old style PABX, which might need a reset by an engineer although most should sort themselves out after a power failure. Can you describe these boxes, size, colour etc.

 

[SW1970]

Other thoughts are that the office phones might be run from virtual PBX software running on a PC. This means if that PC was running when you turned the power off, the application might need to be restarted for the lines to work again. This is very common in small offices that have an IT department that likes to sort everything out itself.

 

[i=p/u]

Well some people do laugh when you have wrecked something or as they say youve wrecked and it only needs reset. I wish i could actualy heelp. But im sure youl help him sw1970

 

[highspark]

well if it worked before you turned up,then its something youve done..you could call bt out,about £95ph i think..could cost you more in lost business for the client if phones dont work on monday

No you don't say? I've come on for some knowledge on telecoms systems and all you have to tell me is its something I've done! Well that's fairly obvious as the issue has only began since the installation was isolated. I've done one i/r test at 250v between live/neutral-earth. That's why I highly doubt I've blown the phones as you say. Thanks for the good advise above.

 

[alarm man]

No you don't say? I've come on for some knowledge on telecoms systems and all you have to tell me is its something I've done! Well that's fairly obvious as the issue has only began since the installation was isolated. I've done one i/r test at 250v between live/neutral-earth. That's why I highly doubt I've blown the phones as you say. Thanks for the good advise above.

you could try the telecoms forums then..

 

[highspark]

The boxs are a blue grey colour a little bigger than a shoe box there seems to be a couple

 

[alarm man]

look for something with mains going to it,should have make model on it might look similar to this

 

[SW1970]

Like this one? If not, perhaps you could upload a picture.

 

[SW1970]

Snap! Funny old world.

 

[MarkieSparkie]

Business phone systems are usually connected to two or more direct exchange lines (DELs). There are several ways this may be achieved. The most common approach is to use a private automatic branch exchange (PABX), where the incoming lines are connected to a central control unit (CCU) and then routed between a number of extensions. The extensions themselves are able to call other extensions (“internal” or “intercom” calls), and other features such as call transfer and call barring are normally available. The system may be designed only for the with special proprietary telephones known as a key telephone system (KTS). The special telephones, “keystations”, are powered, intelligent and feature rich. KTS does not allow the connection of standard phones, answer machines, fax machines or cordless phones. For this reason, CCUs are available to which standard telephone apparatus may be connected. Hybrid systems allow both types of connection, with a mixture of standard and KTS extension ports.
When a business phone system has it’s power supply interrupted for any length of time, most older CCUs and KTS lose their programming, on re-instatement of the power supply the CCU and/or KTS stations will need resetting. On older systems this is just a momentary power-down, or it may require a digital programming code to be set. Once the system is reset, it returns the system to a “clean state” and the individual user selected functions will need to re-programmed, before the system is back to it’s operational state. Or modern systems this happens automatically on boot-up, with all the user selected functions recalled from non-volatile memory.
The server supply is almost certainly dedicated to the computer network rather than the telephones system, however, the office phones might be run from virtual PABX software running on the server or a PC. This means if that server/PC was running when you turned the power off, the programme may need re-booting for the lines to work again. This is common in offices that have there own IT department.
If, it’s a dedicated system there should be a box, containing the PABX CCU and main distribution frame MDF, the exchange and distribution network for the office telephones. This box will have a power supply routed to it from the DB.
I have been on the other end of this type of problem, as I used to install/configure/maintain private telephone exchanges in a previous job. Even if outgoing calls are barred out of normal working hours, it is not allowable to ban the calling of either 999 or the alternative European emergency number (112) from any telephone.
You should contact whoever employed you to do the work, and mention the problem now, rather than waiting for the staff to turn up for work on Monday morning and find the phone system not working. There is usually a nominated staff member who is familiar with the reset procedure and programming required.