BT Versatility - Manual (Page 37)

BT Versatility
Installation and maintenance Manual
36
Options Module MDF Connections
The options module is equipped with a stereo jack for an ‘external Music on hold’ input. Krone IDC
connectors are provided for the Central Bell and the External extension.
The Central bell and the external extension are cabled with extension cabling. They are connected with a
single pair a,b.
Central Bell
The Central Bell is cabled by running a cable pair from the central bell IDC on the Options Module to a
master line jack unit. Bells/tone callers can then be connected to the line jack unit or hard-wired to LJU
terminals 3 and 5.
External Extension
This port is designed to operate “long line “ extensions up to a distance of 2 kilometres away from the
main unit and is approved for connection of 2-wire external extensions using PTO network cabling.
Cable limitations
• 2-wire external extension = 2 kilometres maximum cabling distance or
3 dB at 1600 Hz.
• The cable route should not be exposed to high voltage surges, such as lightning.
Note: These figures assume the use of 0.5mm 2 diameter telephone wiring.
All Extensions should connect into standard line jack units. Extension cabling
should not be exposed to high voltage surges, (for example, surges induced by
lightning or neighbouring high current-carrying cables). If this is a possibility
external protection of the Main Equipment and Extensions using ‘earthed line
surge protectors’ is essential.