Nortel DMS-100 Series Maintenance Manual page 33

50A rectifier assembly. This assembly contains one NT5C10BA shelf and two
NT5C06CA modular switched mode rectifiers. The rectifiers power the OPM
equipment and fans and charge the batteries. Voltage is adjustable from -44V
to -56V. The voltage is normally adjusted to -52V for Yuasa A037761 and
Eagle-Picher A0386201 batteries. A current limit of a maximum of 25A is
available.
Batteries
The OPM batteries consist of a maximum of eight strings of Yuasa A037761.
The batteries also consist of a maximum of six strings of Eagle-Picher
A0386201 batteries. Each battery string consists of 24 cells, four six-packs.
These battery strings connect to the OPM load or charge bus through the two
BCCs in the BCU. The BCC 0 and BCC 1 each control a maximum of four
battery strings as follows:
BCC
0
1
The BCU controls the BCC cards and the associated battery strings. The
battery strings move in pairs from bus-to-bus. The battery string pairs are as
follows:
Battery Strings
0 and 4
1 and 5
2 and 6
3 and 7
Note 1: Battery strings 3 and 7 are not equipped when Eagle-Picher
A0386201 batteries are used.
Note 2: For major retrofits of Yuasa batteries, Northern Telecom
recommends that you convert to Eagle-Picher batteries. Eagle-Picher
batteries have an extended life expectancy.
Battery string pairs can connect to the load bus or charge bus open-circuit.
Moves from the load to charge bus or charge to load bus must occur through
the open-circuit state. Power and environmental system (PES) software
enforces this condition. Battery string pairs normally connect to the load bus.
A minimum of one battery string pair remains on the load bus at all times to
prevent a loss-of-service.
DMS-100 Family OPM Maintenance Manual ISN07 (TDM)/SN07 (DMS) and up
OPM maintenance summary 1-17
Battery Strings
0 1 2 3
4 5 6 7
Battery String Pair
0
1
2
3 (Yuasa only)