This article will show you the type of cable and the cable distances required for installing a a 2Voice 2 wire system with 1 main entrance and up to 32 blocks with 2 entrances per block. There are two options here with a maximum distance from main panel to furthest power supply of 200M (Option 1) or 800M (Option 2).
IMPORTANT NOTE: If installing this type of system you should consider using the 2Voice IPerCom gateway. In this solution a 2 wire IP gateway can be installed making the entrance panels IP allowing for a more flexible installation whilst keeping a simple to install 2 wire riser. Block panels can be 2 wire or IP.
Below you can download the schematic drawing.