Purpose. The purpose of this guide is to provide a basic overcurrent protection philosophy for generators. Generator Overcurrent Protection. Time current curve (TCC) landmarks (figure 1) • Full load amps (FLA) - located in the upper decade. • Overload curve - located in the upper 1 or 2 decades. • Short circuit withstand capability A simple generator has two basic parts - field and winding. The field is the magnetic field and the winding is the conductor formed into a coil. Field. The field is connected to a shaft that may be turned. These are two elements necessary for electromagnetism. When the turning field is placed near the winding, all A-C GENERATOR AND MOTOR PROTECTION 177 I is the initial rms magnitude of the fundamental component of primary current. This enables us to calculate the value of (IS1 — IS2).Finally, the curves of IS1 and IS2 versus (IS1 — IS2) for each of the two CTÕs is plotted on the same graph, as in Fig. 8.For only one value of the abscissa (IS1 — IS2 Course Description. Protection of Electrical Power Systems requires an understanding of system faults and their detection, as well as their safe disconnection from the power system. This course presents a comprehensive and systematic description of the concepts and principles of operation and application of protection schemes for power generators. Inadvertent Energization Protection (27, 50, 60, 81U, 62 and 86) Protects against closing of the generator breaker while machine is not spinning / on turning gear Caused by operator error, breaker flash-over, control circuit malfunction. Two schemes illustrated: Frequency supervised overcurrent Voltage supervised overcurrent 31. this presentation reviews the established principles and the advanced aspects of the selection and application of protective relays in the overall protection system, multifunctional numerical devices application for power distribution and industrial systems, and addresses some key concerns in selecting, coordinating, setting and testing of smart … • Store fuel for the generator electrical codes. in a container that is intended for the purpose and is correctly labeled as such. Store the containers outside of living areas. • Generators should be used in well ventilated locations outside at least 5 feet (1.5 metres) away from all doors, windows, and vent openings. Measure the 5-foot The BE1-11g Generator Protection System is designed with a complete line of protection and control elements, from backup distance (21) protection to phase differential (87). Drawing, 9108551021, J Case (PDF) (145.5KB) Adapter plate for GE S2 or ABB FT-21 cutout. BE1-11, Drawing, 9108551022, J Case (DWG) (70.7KB) Basic Low Impedance A list of the protection elements that tripped included: generator system backup protection, over-excitation (volts/hertz), undervoltage, reverse power, loss-of-field, under/overfrequency and inadvertent generator energizing protection. • 51G acts as back up protection for uncleared system ground faults • 51G is too slow to protect generator for internal fault Ground Fault in Machine • Detected by the 87GD element • The Low-Z ground path is opened by a vacuum switch • Only High-Z ground path is then available This protection, usually is in the form of a regulator which compares the vacuum against atmospheric pressure, it is normally fitted to the generator set above 30 MW. The modern practice is for the regulator to unload the set via the secondar