Schweitzer Engineering Laboratories SEL-387E - Frequency Protection; Programmable Optoisolated Inputs and Output Contacts; Through-Fault Event Monitor; Model Options

1-4 Introduction and Specifications Date Code 20080110
SEL-387E Instruction Manual
Frequency Protection
The SEL-387E Relay provides six levels of under-/overfrequency elements. Each element can
operate as either an underfrequency or as an overfrequency element, depending on its pickup
setting. Should any phase voltage fall below a user-defined value, the relay disables all
frequency elements, providing security against loss-of-potential conditions. The relay tracks the
system frequency from 40.1 to 65 Hz to provide measurement of frequency excursions over a
wide range. Apply the elements readily to underfrequency load shedding and restoration control
systems.
Through-Fault Event Monitor
Through faults are a major cause of transformer damage and failure. Fault currents cause
cumulative mechanical damage by displacing transformer windings every time a fault occurs.
Thermal stress from fault currents damages insulation. The SEL-387E Relay provides a through-
fault event monitor to gather fault current level, duration, and date/time for each through fault.
The monitor performs a simple I
2
t calculation and cumulatively stores calculation results for each
phase. Use these through-fault event data to schedule proactive maintenance for transformers
and to help justify possible system enhancements to mitigate through faults.
Programmable Optoisolated Inputs and Output Contacts
The SEL-387E Relay is equipped with enhanced SEL
OGIC control equations that allow design of
a custom tripping or control scheme. SEL
OGIC control equation functions include independent
timers, tripping, closing, event report triggering, and relay output contact control.
M ODEL O PTIONS
Conventional Terminal Blocks
This model includes hardware that supports nine current inputs, three voltage inputs, six
optoisolated inputs, seven programmable output contacts, one alarm contact, three EIA-232
ports, one EIA-485 port, and IRIG-B time code. It uses terminal blocks that support #6 ring
terminals. This robust package meets or exceeds numerous industry standard type tests.
This relay is available in a 3.50" (2U) or 5.25" (3U) rack-mount package or 4.9" or 6.65"
panel-mount package. Additional optoisolated inputs and programmable output contacts are
available with the larger packages.
Plug-In Connectors (Connectorized
®
)
This model includes hardware that supports all of the features of the conventional terminal
blocks model. It differs in its use of plug-in connectors instead of terminal blocks. In addition,
it provides
• Quick connect/release hardware for rear-panel terminals.
• Level-sensitive optoisolated inputs.