Retrofit Legacy Transformer Protection With Smaller SEL-487E Chassis Options
The proven SEL-487E Transformer Protection Relay provides modern protection and automation capabilities in new space-efficient form factors, including a 3U chassis.
The new smaller form factors of the SEL-487E Transformer Protection Relay simplify retrofits in control houses where space is limited. Reduce installation effort with flexible analog input options tailored to your application.
The SEL-487E differential protection algorithms reduce fault-clearing time without compromising sensitivity—and comprehensive monitoring features improve system awareness and reduce maintenance costs.
Choose chassis options from 3U to 9U to match your transformer protection applications.
Proven Protection Performance
The adaptive differential element responds to most internal faults in less than 1.5 cycles. The SEL-487E also detects turn‑to‑turn faults affecting as little as 2 percent of the winding and operates securely during energization and low second-harmonic inrush conditions.
Flexible Field Implementation
Select from 9, 18, or 21 CT inputs using a combination of 5 A and 1 A nominal values in the SEL-487E to match existing CT connections. The SEL-487E accommodates CT ratio mismatch up to 35:1 and accepts the delta connections commonly used by legacy CTs.
Streamlined
Deployment
Protection and control processing executes 8 times per cycle for responsive logic execution during testing and commissioning. A built-in web server and support for IEC 61850 Edition 2.1, DNP3, File Transfer Protocol (FTP), and Telnet streamline system integration. The integrated commissioning assistant helps reduce setup errors by flagging incorrect field wiring and CT issues.