Lucent Technologies ECS Minicell Battery Plant H569-420
2 - 10 Product Description
Issue 5 February 1997
amperes. The shunt millivolt signal is sent, via the CP5 Fuse
Board, to the controller where it is translated to amperes and
displayed on the digital meter.
Low Voltage
Battery
Disconnect/
Reconnect
(LVD/R) Feature
In unattended battery plant locations, especially those without
automatic ac backup, batteries could be completely discharged
during an ac power outage. The ECS Battery Plant may be
equipped with an optional automatic battery disconnect to
prevent costly battery damage due to unforeseen deep discharge.
This disconnect is designed to isolate batteries from the load
when the plant voltage reaches the lowest usable battery voltage.
The disconnect level is below the operating range of most load
equipment, in which case service to the load would already have
been lost. The disconnect does not separate the load circuits from
the rectifiers, thus enabling the rectifiers to begin powering the
load as soon as ac power is restored.
The LVD/R option consists of the LVD/R contactor, circuitry on
the CP5 Fuse Board and associated wiring. As shown in Figures
2-2 and 2-3, the LVD/R Contactor is used either to connect or
disconnect Battery Bus 1 and Battery Bus 2.
When the battery voltage drops below a preset level, a
comparator circuit on the CP5 Fuse Board senses the low voltage
condition and removes power to the contactor. This opens the
connection between Battery Buses 1 and 2, disconnecting the
batteries from the rectifiers and the load. The user has a choice
of disconnect threshold voltages (20.25 or 21.25 volts).
When the contactor is open and the rectifiers are not delivering
power, the controller is unpowered as well. In this state, the
controller displays and LEDs are extinguished and various
alarms are issued to the alarm reporting center. (See the
Lineage
®
2000 Controller manual for further details.)
Red “LVD OPEN” and yellow “LVD FAIL” LEDs are located
on the dc distribution panel. The red “LVD OPEN” LED is lit
whenever the contactor is open, during a normal disconnect or in
the unlikely event of a contactor failure. Once the contactor
opens it remains open until the battery voltage exceeds the set
threshold voltage. The LVD sensing circuitry is redundant. A
failure of either voltage detector circuit lights the yellow “LVD
FAIL” LED, but the contactor will stay closed. A Fuse Alarm
Minor (MNF) is issued when a LVD circuit fails, lighting a
