Instruction Manual
Pulsar Plus Controller Family
Issue 7 December 2011 102
Tri-Color LVD Status
Condition Red Green Amber
ID not configured Flashing
Alarm Inputs
─ Open String
─
FAJ alarms
X
Fault Alarms
─ Board Fault
─ Contactor FAIL
X
Lamp Test operation activated
(10 second operation)
Red 3 seconds On, Green 3 seconds On,
Amber 3 seconds On, All off for 1 second
Alarm Inputs: The NE872A has been designed to allow it to be referenced to either VBus(-) or Vbus(+) so it
can be used in both positive and negative grounded systems. All alarm or control inputs are either alarmed
on an open or a closure to VBus(-) or provide its own signal return as described below:
• Remote LVD Open: The NE872 has the ability to accept a dry contact closure that will allow an
external controller to force open the LVD independently from the system controller. The
contactor will remain disconnected as long as the input is asserted. Upon de-asserting the input
contactor closure, the NE872 will return the LVD to the a state dictated by the controller.
• Fuse Alarm Major: A contact closure to the non-grounded “Battery” side of the DC bus (-
48V/±24V) applied to this respective input, by default, produces an “Fuse Alarm Major” alarm by
the controller.
• Open String: A contact closure to the non-grounded “Battery” side of the DC bus (-48V/±24V)
applied to this respective input, by default, produces an “Open String” alarm by the controller.
External Shunt Monitoring Input: The NE872 has the ability to monitor a single shunt mounted in the
grounded or non-grounded side of the DC bus in a ±24V or -48V power system. The shunt must have a 50mV
rating. Its current rating as well as its assignment to load or battery is configured at the controller. Three
leads are used to monitor the shunt: Shunt+, Shunt-, and Shuntref. Shunt+ is the most positive side of the
shunt input voltage as defined during a battery discharge. Shunt- is the most negative side of the shunt input
voltage as defined during a battery discharge. Shuntref is the reference lead which must be attached to the
DC side of the bus in which the shunt resides to properly reference the circuitry.
Contactor Management: Controls and monitors one load or battery contactor. The contactor is of the
magnetic latching type equipped with an auxiliary switch for status. The board is designed to drive both 24V
and 48V rated contactors.
Reverse Battery Protection: The NE872A will prevent the closure of the battery contactor when it senses
batteries have been connected in reverse polarity. A Major alarm “Reversed Battery” is generated by the
system controller.
Note: when a battery disconnect breaker is used to take battery strings off-line for servicing, care must be
taken to ensure battery connections are correct at the disconnect switch.
Autonomous Backup LVD Function: The NE872 monitors the system bus voltage to provide a backup for the
Low Voltage Disconnect (LVD) function. In the event of a loss of communication between the NE872A due to
a failed or removed controller, communication cable disconnect, etc. the configured disconnect and
reconnect values assigned to a particular LVD function at the controller are used along with the boards