between the power supply system(s) and the power consuming telecommunications and datacom (ICT) equipment; this
point is called interface "A" as defined in clause 4.
The purpose of the present document is to use a power supply system with the same characteristics for all
telecommunications and datacom (ICT) equipment defined in the area of application:
- to facilitate inter working of different (types of) load units;
- to facilitate the standardization of telecommunications and datacom (ICT) equipment;
- to facilitate the installation, operation and maintenance in the same network of telecommunications and
datacom (ICT) equipment and systems from different origins.
The present document aims at providing electrical compatibility between the power supply equipment and the power
consuming telecommunications and datacom (ICT) equipment, and also between different system blocks connected to
the same power supply.
The requirements are defined for:
- the output of the power supply equipment or power supply installation of telecommunications centres
providing power at the interface "A";
- the power supply input of any type of telecommunications and datacom (ICT) equipment installed at
telecommunication centres that are connected to interface "A" powered by DC;
- any type of telecommunications and datacom (ICT) equipment, installed in access networks and
customers' premises, the DC interface "A" of which is also used by equipment requiring a supply to the present
- any type of telecommunication and datacom (ICT) equipment powered by DC, used in the fixed and mobile
networks installed in different locations as building, shelter, street cabinet.
Disturbances on the power supply interface "A" relating to the continuous wave phenomena below 20 kHz are covered
within the present document.
The present document does not cover safety requirements, they are covered by relevant safety standards.
The present document does not cover EMC requirements, they are covered by relevant EMC standards.
NOTE 1: The present document is applicable only to -48 VDC power supply interfaces. However, during a
transitional period, other DC voltages may be used in existing installations. Annex B gives guidance on
working in conjunction with existing -60 VDC supply systems.
NOTE 2: The DC voltage at interface "A" may be derived from the AC primary supply. The DC supply may
incorporate a backup battery