Arc Flash Basics and Hazard Planning Program Author: Velimir Lackovic This course gives an overview of arc flash hazards and explains the different causes, nature, findings, directions and processes related with arc flash hazards. An electric arc or an arcing fault is a flashover of electric current through air in electrical devices from one exposed…
Arc Flash Calculation Methods Author: Velimir Lackovic This course provides an overview of arc flash hazard computations as specified by IEEE and NFPA. Students are encouraged to consult the standards for additional details. It is suitable for engineers with a desire to understand procedures for completing arc flash studies. The course covers arc flash calculation…
Limiting Arc Flash Exposure Author: Velimir Lackovic Arc flash incidents may happen despite precautions taken to avert them. Arc flash incidents can be minimized by use of adequate equipment, proper preventive care, planning and coordination of operation, as well as skill improvement and real experience. Also crucial is the mental and physical circumstances of the…
Introduction to Protective Device Coordination Analysis Author: Velimir Lackovic The objective of a protection scheme in a power system is to minimize hazards to personnel and equipment while allowing the least disruption of power service. Coordination studies are required to select or verify the clearing characteristics of devices such as fuses, circuit breakers, and relays…
Introduction to Motor Starting Analysis Author: Velimir Lackovic The starting current of most AC motors is several times normal full load current. Both synchronous and induction motors can draw five to ten times full load current when starting them across the line. Motor-starting torque varies directly as the square of the applied voltage. If the…
Harmonic Analysis Basics Author: Velimir Lackovic A harmonic-producing load can affect other loads if significant voltage distortion is caused. The voltage distortion caused by the harmonic-producing load is a function of both the system impedance and the amount of harmonic current injected. If the system impedance is low, the voltage distortion is usually negligible in…