GE Multilin 350 - Page 9

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350 Feeder Protection System
Distribution Feeder Protection
Logic Elements
The 350 relay has sixteen Logic Elements
available for the user to build simple
logic using the state of any programmed
contact, virtual, remote input or the output
operand of a protection or control element.
The logic provides for assigning up to three
triggering inputs in an “AND/OR” gate for
the logic element operation and up to
three blocking inputs in an “AND/OR” gate
for defining the block signal. Pickup and
dropout timers are available for delaying
the logic element operation and reset
respectively.
Virtual Inputs
Virtual inputs allow communication devices
the ability to write digital commands to
the 350 relay. These commands could be
open/close the breaker, changing setting
groups, or blocking protection elements.
Multiple Settings Group
Two separate settings groups are stored in
nonvolatile memory, with only one group
active at a given time. Switching between
setting groups 1 and 2 can be done by
means of a setting, a communication
command or contact input activation.
The two settings groups allow users to store
seasonal settings- such as for summer and
winter or alternate profiles such as settings
during maintenance operations.
Monitoring & Diagnostics
Event Recording
Events consist of a broad range of change
of state occurrences, including pickups,
trips, contact operations, alarms and self
test status. The 350 relay stores up to
256 events time tagged to the nearest
millisecond. This provides the information
required to determine sequence of
events which facilitates diagnosis of relay
operation. Event types are individually
maskable in order to avoid the generation
of undesired events, and includes the
metered values at the moment of the
event.
Oscillography/ Transient Fault
Recorder
The 350 captures current and voltage
waveforms and digital channels at 32
samples per cycle. Multiple records can
be stored in the relay at any given time
with a maximum length of 192 cycles
Oscillography is triggered either by internal
signals or an external contact.
Trip/Close Coil Monitoring
The 350 can be used to monitor the
integrity of both the breaker trip and closing
coils and circuits. The supervision inputs
monitor both the battery voltage level,
while the outputs monitor the continuity of
the trip and/or closing circuits, by applying
a small current through the circuits.
Basic Metering
Metered values include:
• Current:Ia,Ib,Ic,In,Ig,Isg
• Phase-to-phaseandphase-to-ground
voltages for bus and line: Van, Vbn, Vcn,
Vab, Vbc, Vca
• Activepower(3-Phase)
• Reactivepower(3-Phase)
• Frequency
Advanced Device Health
Diagnostics
The 350 performs comprehensive device
health diagnostic tests during startup
and continuously at runtime to test
its own major functions and critical
hardware. These diagnostic tests monitor
for conditions that could impact system
reliability. Device status is communicated
via SCADA communications and the front
panel display. This continuous monitoring
and early detection of possible issues helps
improve system availability by employing
predictive maintenance.
IRIG-B
IRIG-B is a standard time code format
that allows time stamping of events
to be synchronized among connected
devices within 1 millisecond. An IRIG-B
input is provided in the 350 to allow time
synchronization using a GPS clock over a
wide area. The 350 IRIG-B supports both
AM and DC time synchronization with
an auto detect feature that removes the
requirement for manual selection.
Power System Troubleshooting
Analyze power system disturbances with transient fault recorder and event records