Powering Requirements - Meridian Nortel 1 Option 11C Technical Reference Manual

Note: A 500 Hz buzz signal is provided for incoming call notification
while the receiver is off-hook.

Powering requirements

Both the M2009 telephone and M2018 telephone are loop powered. Loop
power uses +15 V and -15 V sources, and assumes 3500 feet maximum loop
length of 24 AWG wire and a minimum of 13.5 V at the telephone terminals.
The Handsfree unit, which is integrated in the Meridian M2112, requires an
auxiliary power supply. Power can be obtained from either a QUT1 25 V AC
closet power supply or a local plug-in transformer (AO273077) over a
separate pair of wires.
If the power supply fails, Handsfree will not operate, but all other features
will continue to function, provided the power failure does not affect the
system. The loop-powered functions of all Meridian digital telephones
remain operational only if the system is equipped with a backup battery.
Additional power is obtained over a separate pair of wires. Maximum
Handsfree current is 110 mA with a minimum of 16 V AC to be present at the
telephone terminal. The following rules apply:
• For the QUT1 closet power supply:
— The power supply loop for the Handsfree unit should follow the
same rules as the loop powering requirements, i.e. the maximum
allowable loop length and wire gauge are 3500 ft. of 24 AWG wire.
— Each M2112 Handsfree must be powered by one tap of one winding,
however, it is permissible to connect two (2) 12.5 V AC windings in
series to provide 25 V AC power for Handsfree.
• For the local plug-in transformer:
— A single winding transformer equipped with a 3 m (10 ft.) cord of 22
AWG two-conductor stranded and twisted wire with a modular
duplex adapter (NE-267QA) at the end is required.
— The following minimum specifications have to be met by this
transformer:
– No load output voltage:21 V AC max.
– Voltage at rated current:16 V AC ±10%
– Rated load current:375 mA
Meridian Digital Telephones
Option 11C and 11C Mini
Page 267 of 544
Technical Reference Guide