SEL-587 Current Differential Relay

Products for Protection, Monitoring, Control, Automation, and Metering

SEL-587

Current Differential Relay

Provide inexpensive differential protection for two-winding transformers or other two-terminal apparatus.

Two-Winding Current Differential Protection
Sensitive current differential protection with programmable single- or dual-slope percentage restraint, supervised by the second- and fifth-harmonic elements for secure differential protection on two-winding apparatus. Choose from common or independent harmonic blocking or restraint. Unrestrained differential elements provide fast operation for high-magnitude internal faults. Automatic calculations of relay tap settings simplify application.
Individual Winding Overcurrent Protection
Individual winding phase, residual, and negative-sequence overcurrent elements, including instantaneous, definite-time, and inverse time-overcurrent elements for comprehensive overcurrent protection.
Protection and Control Logic
SELOGIC^® control equations with SELOGIC variables and timers facilitate traditional or advanced protection schemes.
Monitoring and Reporting
Oscillographic event reports (up to ten 15-cycle reports) and metering functions eliminate or reduce external recorder and metering requirements.
Serial Data Communications
Use the serial port for communications with ASCII terminals, local HMI, SCADA, or DCS systems. As an ordering option, select an EIA-232 or EIA-485 serial port. Through settings, select and configure the port for SEL ASCII and interleaved SEL Fast binary messages, or Modbus^® RTU Slave protocol.
ACSELERATOR^® QuickSet™ Software
Develop relay settings off-line, program SELOGIC control equations, and analyze post-fault event reports.

Panel-mount or rack-mount hardware package.
Connectorized^® packaging for quick connect/disconnect includes high-current interrupting output contacts.
EIA-232 or EIA-485 serial communications - either port includes a demodulated IRIG-B time-code input.
Bracket with mounting hole for FT-1 switch (switch not included) to mount one 500 series relay in a 19-inch rack.
Conformal Coating—Protect equipment from harsh environments and airborne contaminants such as hydrogen sulfide, chlorine, salt, and moisture.
Learn more about conformal coating.

Protect any two-winding power transformer.
Protect reactors, generators, large motors, and other two-terminal power apparatus.
Apply with any combination of delta- or wye-connected CT secondary circuits.
Use built-in winding overcurrent elements for backup protection.
Detect ground faults through delta-wye transformer banks, or provide sensitive phase-to-phase protection, independent of load current, with negative-sequence overcurrent element.
Use low-side overcurrent elements for backup distribution bus or feeder protection.
Use SEL-5010 Relay Assistant Software to manage your relay settings.

SEL provides options to help you efficiently and safely commission and test these relays.
	When access to the back of panels and cabinets is allowed, use a Connectorized^® version of this relay for fast installation and testing.
	Improve safety, save time, and reduce costs with SEL-4600 Series Test Blocks and Plugs. Use the SEL recommended standard block and plug configurations for SEL-587 relays.

Budgetary Retail, Quantity 1: $2,080
Fully Optioned Price: $2,422
(Prices displayed are for planning purposes and are subject to change. Contact your SEL sales representative today for a quote on configurations and quantities to meet your needs.)

APP 87 - SEL-387 and SEL-587 Percentage Restrained Differential Relays

"We have applied SEL-587 transformer differential relays for over five years on our clients' systems. We are especially impressed with the relay's ability to confirm proper wiring and settings after it has been commissioned and load is initially placed on it. In many cases, the SEL-587 Relay, through its easy-to-use front panel display, was able to demonstrate that a wiring error had occurred, which could then be fixed easily, instead of showing up later as misoperation.

The relay displays metered quantities on the front panel LCD screen, comprising phase current magnitude and phase angle, operate current, and restraint current. By making a few simple checks (which don't require sophisticated test equipment), it can easily be confirmed that the wiring is correct.

We are very pleased with the SEL-587, and we specify it whenever the project calls for a transformer differential relay."

Blair A. Metsger, PE
DGR Engineers
Rock Rapids, IA