Page 101
© Copyright 2021 ABB. All rights reserved.
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. 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 internal measurement capability to control the LVD. These disconnect and reconnect
threshold values are sent from the controller to each respective QS871A upon establishing initial
communication.
8-Position Jumper: 8-position jumper arrangement that uniquely identifies up to eight NE872 remote
distribution monitor and control modules. Placing no jumper, ID position 0, is an invalid configuration.
The Pulsar Edge can address up to eight unique NE872s. Note: factory ordered systems are generally
pre- configured and will have the jumpers appropriately set. Jumpers are arranged as shown.
ID1
ID2
ID3
ID4
J12
ID5
ID6
ID7
ID8
J11
Figure 23 NE872A ID Jumper Settings
To Next Page
Loading...
Need help?
General
