Earthing And D.c. Supply Checks - Ericsson EDA 2530 Commissioning Instructions

4.4

Earthing And D.C. Supply Checks

These tests are classified as SAFETY TESTS.
There are different variants of Power Supply Connection Unit available, depending
on the type of subrack and the customer requirements.
SUBRACK
DESCRIPTION
S20 Flexible Connections
The EDA 2530 Power Supply Connection Unit (151-2975/53 incorporates two 5 pin
D-Type connectors. Each connector allows for connecting two –50 volt and two
earth cables to provide the duplicated power supply to each 5 pin D-Type connector.
The EDA 2530 cabinet will be supplied by two –50 volt power feeds, each protected
by an external circuit breaker rating or fuse of 32 Amps. The two Earth cables will
be connected to the EDA 2530 Earth bar.
Record the external circuit breaker or fuse rating on the Equipment Checks Test
Record.
In the United Kingdom (UK) the main –50v supply (Supply 1) is connected to two
Single-Pole 16 Amp Miniature Circuit Breakers (MCB 1 and MCB 2) fitted on the
circuit breaker panel at the top of the EDA 2530 cabinet. These two 16 Amp MCB's
are connected to Socket Vb1 on the Power Supply Connection Unit (151-2975/53) in
slot 22. The main –50v supply (Supply 2) is connected to two Single-Pole 16 Amp
Miniature Circuit Breakers (MCB 3 and MCB 4). These two 16 Amp MCB's are
connected to Socket Vb2 on the Power Supply Connection Unit (151-2975/53) in
slot 22. Other countries may have different types of Isolators or Circuit Breakers
depending on local requirements and regulations.
Check the circuit breakers or fuses in the customer's distribution equipment are
switched OFF or open. Check the EDA 2530 cabinet circuit breakers are switched
OFF. Disconnect the 5 pin D-Type connectors from Socket Vb1 and Socket Vb2 on
the Power Supply Connection Unit in slot 22.
Measurement: Check there is a connection between the EDA 2530 cabinet and
the earth bar. Check the resistance is less than 1 ohm, measured between
cabinet metalwork and an adjacent point on the earth bar.
measured value in the Test Record.
At the customer's DC distribution equipment switch ON the isolators or circuit
breakers, or insert the fuses, for the feeds to the EDA 2530 Cabinet. If the DC
distribution is from an EF80 or similar distribution, insert the two 32 Amp fuses.
Check the supplies at the cabinets are of the correct polarity and lie in the range -
48 V ±20% (-38.4v to -57.6v). Record the measured value on the Main Power
Supply Voltage Check Test Record.
1/153 22-FGC 101 0239/2 Uen Rev J 2010-04-01
EDA 2530 Commissioning Procedure for Cable and Wireless Access
SUBRACK CODE
133-1555/03
© Ericsson AB 2010
Commercial in confidence
Power Supply - Right
151-2975/53 (Slot 22)
Record the
44 (200)