GE B90 Instruction Manual page 35

2 PRODUCT DESCRIPTION
The main protection functions of the B90 are provided on a per-phase basis. The AC signals of a given phase, both cur-
rents and voltages, are connected and processed by a single IED. These IEDs provide for all the protection and monitoring
functions that require the AC information. Also these IEDs provide for certain input/output capability (up to a maximum of 48
inputs or 18 outputs per IED).
The simplest B90 configuration for non-re-configurable busbars without Breaker Fail protection consists of three B90 IEDs.
The Breaker Fail and Isolator Monitoring function for dynamic bus replica require a separate IED, and thus a four-IED B90
architecture. These are shown in the figure below.
In any B90 configuration, the IEDs are capable of exchanging digital states (FlexLogic™ operands) in a fast and reliable
way over a dedicated B90 fiber connection. The B90 communication capability allows the user to distribute input and output
contacts freely in various IEDs. Also, the communications facilitates Breaker Fail and Isolator Monitoring.
If more input/output capabilities are required, a fifth B90 IED can be included into the B90 communications ring as shown
below.
The EnerVista UR Setup software is used to control the B90 IEDs. Each IED is configured and accessed individually. Func-
tionality is provided to perform certain operations on all the B90 IED simultaneously.
Three-IED Architecture
for simple busbars
phase A currents and voltages I/O Contacts
phase B currents and voltages I/O Contacts
phase C currents and voltages I/O Contacts
836756A1.CDR
Figure 2–2: THREE-, FOUR-, AND FIVE-IED B90 ARCHITECTURE
GE Multilin
Four-IED Architecture
with Breaker Failure
phase A currents and voltages I/O Contacts
phase B currents and voltages I/O Contacts
phase C currents and voltages I/O Contacts
I/O Contacts
B90 Low Impedance Bus Differential System
2.1 INTRODUCTION
Five-IED Architecture
for extra I/Os
phase A currents and voltages I/O Contacts
phase B currents and voltages I/O Contacts
phase C currents and voltages I/O Contacts
I/O Contacts
I/O Contacts
2
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