PROTECTIVE RELAY MAINTENANCE

DESCRIPTION

Solid-state technology is a logical evolution of protective relays. While electromechanical relays are usually single phase, single function, solid-state relays may be multi-phase, single function. Solid-state relays are less affected by vibration, humidity and other environmental factors. Because of fewer moving parts, they require less maintenance and are less likely to fail at critical times. They are common in nuclear or critical applications where NERC or 1E classifications are a concern. At the same time, they are sensitive to voltage spikes and require additional test precautions. Proper testing and maintenance of solid-state relays ensures the integrity of the protection scheme, prevents nuisance tripping, and minimizes damage to equipment and interruptions to the power system when faults do occur.

WHO SHOULD ATTEND
This hands-on course is intended for electricians, technicians and engineers responsible for testing and maintenance of solid-state protective relays.

LEARNING OBJECTIVES

• Describe the operating principles of solid-state relays
• Perform test and calibration on overcurrent, voltage, current differential, synch check, directional overcurrent, directional power, and motor protection relays
• Interpret internal and external wiring diagrams for solid-state relays
• Explain the various applications for solid-state relays
• Identify solid-state relay elements
• Interpret AC and DC relay schemes
• Perform as found/left tests and calibrate relays with the following functions (ANSI device numbers): Sync Check (25); Under voltage (27); Directional Power (32); Instantaneous Overcurrent (50); Time Overcurrent (51); Overvoltage (59); Directional Overcurrent (67); [Transformer] Differential (87T)
• Targets and Indicators
• Explain the application of these relay functions
• Utilize a relay test set to perform direct injection testing and interpret results

REQUIREMENTS
The student should have basic knowledge of AC/DC electricity. In addition, students must bring a scientific calculator. Technicians that successfully complete this course will be certified to maintain solid-state relays. This certification is valid for 3 years from the date of issue.

INSTRUCTOR

HASAN SURYA, Drs.Ir.MT. & Team