Functions - Ericsson CME 20 R6.1 Reference Manual

Power Supply
30.3

Functions

30.3.1 Central AC-DC Conversion
The incoming AC mains is converted by the Cabinet power system to
several DC voltages adapted to the users need.
To get the required AC power for the Cabinet, the Cabinet power
system can be connected to the following alternative AC mains:
•
Single-phase (2-wire; earthed end of phase), TN and TT power
systems
•
Single-phase (3-wire; earthed mid point), TN and TT power
systems
•
Single-phase (2-wire; impedance grounded (earthed) neutral, IT
power system
TN, TT and IT power systems according to IEC 950.
30.3.2 DC Power Distribution
The users are disconnected from the DC power in cases of low system
voltage. The users are reconnected to the DC power when the system
voltage is restored.
The units for control and supervision of the Cabinet power system are
powered independently of user disconnection.
The DC power is produced and distributed in different modes:
•
Produced from incoming power and distributed
•
Produced from backup batteries and distributed
•
No distribution
30.4 Operational Conditions
30.4.1 Operation and Maintenance
Maintenance functions related to Power Supply are described in chapter
Operation and Maintenance Terminal.
180 (306)
© Ericsson Radio Systems AB
— All Rights Reserved —
EN/LZT 123 2697 R5A
1998-08-13