Lucent Technologies Lineage
®
2000 ECS/GPS Battery Plant J85500G-2
2 - 26 Product Description
Issue 6 May 1999
Low Voltage
Battery
Disconnect/
Reconnect
(LVD/R) Feature
In unattended battery plant locations, especially those without
automatic back-up ac, 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 (see Figure 2-10).
The LVD/R Contactor is used either to connect or disconnect
Charge Bus and Battery Bus. The LVD circuit on CP5 monitors
the battery bus voltage, designated RB. When the RB 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 Charge Bus
and Battery Bus, disconnecting the batteries from the rectifiers
and the load. The user has a choice of disconnect threshold
voltages (40.5 and 42.5 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.)
The red “LVD OPEN” and yellow “LVD FAIL” LEDs are
located on the dc distribution panel as shown in Figure 2-11. The
red “LVD OPEN” LED on the CP5 Fuse Board is lit whenever
the contactor is open, during a normal disconnect or in the
unlikely event of a contactor failure. The LVD sensing circuitry
on CP5 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 yellow LED on the controller front panel
and sending Power Minor (PMN) alarms to the alarm reporting
center.
Once the contactor opens it remains open until the RB voltage
again exceeds the set threshold voltage. Voltage does not return
until ac power is restored and the rectifiers restart and deliver
