PRIVATE AUTOMATIC TELEPHONE EXCHANGES
CAPACITY 50 LINES
Each telephone is connected to the unit by means of a twin conductor, suitable instruments being the ST1500, ST1600, ST2500, ST2600, ST3500 and ST3600 ranges. Alternatively, use can be made of the loud-speaking telephone MT3101 and MT 3102.
The unit is particularly designed for systems that will not exceed 50 lines; it cannot be extended beyond that total. If the need for such extension is anticipated, the unit shown overleaf should be installed.
Mains supply up to 250 volts: two suitable 26-volt batteries are used, together
with a charging panel fitted with the necessary instruments, switches and fuses
to enable one battery to be charged through a resistance while the other is
supplying the unit.
Last revised: January 27, 2011