few minor setting changes are all that is required to apply this relay to a com-
munication-based scheme.
Remote-end-just-opened logic provides accelerated clearing of certain fault types
without communications equipment.
Internal negative-sequence ground directional polarization provides sensitive, secure
ground overcurrent element polarization without additional external inputs or
connections.
An event reporting feature is included. The relay stores eleven cycles of fault data
including voltages, currents, status of relay elements, inputs, and outputs. The time
tagged event reports also include fault type and location data.
The relay calculates fault location using a method which compensates for fault
resistance, load flow, and remote infeed. The accurate fault location may be used to
quickly sectionalize and restore a faulted system.
Backup Relaying
Where adequate high-speed primary protection already exists, the SEL-221F relay can be
applied as backup protection. Its programmability and remote-access capabilities allow
remote adjustment of relay settings to meet virtually any contingency. Its application also
offers the benefits of event reporting and fault locating.
Replacement of Outdated Protective Relays
The relay is an ideal replacement for aging or obsolete electromechanical relays. Compact
size and simple field wiring make replacing electromechanical relays with this relay especially
convenient in crowded substations. Both horizontal and vertical mounting configurations are
available. The required panel cutout is equivalent to that of a single electromechanical
distance relay, eliminating panel cutting where relays already exist.
Event reporting and fault locating features economically provide valuable engineering and
operating information, eliminating the need for event recorders and oscillographs in most
applications. A negligible instrument transformer burden makes the relay an attractive
alternative for overburdened current and potential transformers.
Other Applications
The SEL-221F relay is cost-effective in applications requiring fault locating, temporary
installations, bus-tie breaker relaying (where frequent setting changes may be required), and
remote control and monitoring.
5-2
Applications
SEL-221F, -1 Instruction Manual
Date Code 920508
Summary of Contents for SEL-221F
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Page 69: ...Date Code 920508 Specifications SEL 221F 1 Instruction Manual 2 44 ...
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Page 110: ...Example Event Report 2 4 12 Event Reporting SEL 221F 1 Instruction Manual Date Code 930830 ...
Page 158: ...SETTINGS SHEET FOR SEL 221F RELAY PAGE 2 OF 6 DATE Date Code 921110 ...
Page 160: ...SETTINGS SHEET PAGE 4 OF 6 FOR SEL 221F RELAY DATE Date Code 930601 ...
Page 161: ...SETTINGS SHEET PAGE 5 OF 6 FOR SEL 221F RELAY DATE Date Code 961208 ...
Page 229: ...SEL 200 Series Relay Main Board Troubleshooting Test Points and Jumper Locations ...