SEL551 Relay Instruction Manual Date Code The relay contains devices sensitive to Electrostatic Discharge (ESD). When working on Schweitzer Engineering Laboratories, Inc. SEL751A Data Sheet SEL751A Feeder Protection Relay Major Features and Benefits The SEL751A Feeder Protection Relay provides an excep 3 GENERAL DESCRIPTION The SEL251 DISTRIBUTION RELAY protects, controls, and monitors distribution feeders. It offers important new and unique features, like userprogrammable SEL OGIC control equations, negativesequence overcurrent elements, and selectable setting groups.
SEL421 Relay Protection and Automation System Instruction Manual Applications Handbook PM NB The SEL4515 Protection, Automation, and Bay Control System integrates bay control for breakers and disconnect switches with full automation and protection in one device. The SEL451 is the ideal relay for use in pilotbased tripping schemes. Enhanced M. IRRORED. B. ITS. Instruction Manual SEL5870, 1 Relay Current Differential Relay Overcurrent Relay Instruction Manual PM NB The SEL451 Protection, Automation, and Bay Control System is a complete standalone system.
The SEL451 has the speed, power, and flexibility to combine complete substation bay control with highspeed breaker protection in one economical system. The SEL751 Feeder Protection Relay provides a comprehensive combination of protection, faultlocating features, monitoring, control, and communication in an industrial package. Standard Protection Features. SEL421 Relay Protection and Automation System Instruction Manual Reference Manual PM NB Access basic SEL451 information on a standard Ethernet network with the instructions in this manual will void the manufacture's warranty and may pose means an instruction must be followed.
Figure 6: SEL551 Relay Provides Overcurrent Protection for a Distribution Bus (Includes Fast Bus Trip Scheme) The fast bus trip scheme is often referred to as a reverseinterlocking or zoneinterlocking scheme. For dedicated breaker failure protection, the SEL551 Relay is connected similar to Figure 6, with