selprotopy is intended to be used as a protocol binding suite for the SEL Protocol suite which includes SEL Fast Meter, SEL Fast Message, and SEL Fast Operate; each of which are proprietary protocols designed by Schweitzer Engineering Laboratories for use primarily with protective. selprotopy is intended to be used as a protocol binding suite for the SEL Protocol suite which includes SEL Fast Meter, SEL Fast Message, and SEL Fast Operate; each of which are proprietary protocols designed by Schweitzer Engineering Laboratories for use primarily with protective. The SEL-751 is the right solution for industrial and utility feeder protection, with conventional/low-energy analog (LEA) current and voltage input support, flexible I/O options, easy mounting, and fast settings. The SEL-751 provides complete protection for radial and looped distribution circuits. Schweitzer En gineering Laboratories, Inc. r eserves all rights and benefits afforded under federal and international copyright and patent laws in its products, including without limitation software, firmware, and documentation. Protect lines and equipment with an extensive range of protection elements, including:. Schweitzer Engineering Laboratories (SEL) produces a wide range of relays for protection, automation, and control in power systems. Protect any transmission line using a combination of five zones of phase- and ground-distance and directional overcurrent elements.
