Part 7: AC Power Distribution Systems & Standards (Overcurrent, Fuse & Circuit Breaker)

Published By Nikola Zlatanov* Complete Overcurrent Device Interest in complete overcurrent device selectivity has increased due to the addition of selectivity requirements to articles 700, 701, and 708 of the National Electrical Code (NFPA70). Many users, both commercial and industrial, use fuses and circuit breakers simultaneously. Traditional Time- Current Curve (TCC) analysis is known toContinue reading “Part 7: AC Power Distribution Systems & Standards (Overcurrent, Fuse & Circuit Breaker)”

Part 6: AC Power Distribution Systems & Standards (Power Quality)

Published By Nikola Zlatanov* Power Quality Terms Technical Overview Introduction Sensitive electronic loads deployed today by users require strict requirements for the quality of power delivered to loads. For electronic equipment, power disturbances are defined in terms of amplitude and duration by the electronic equipment operating envelope. Electronic loads may be damaged and disrupted, withContinue reading “Part 6: AC Power Distribution Systems & Standards (Power Quality)”

Part 5: AC Power Distribution Systems & Standards

Published By Nikola Zlatanov* Medium Voltage Equipment Surge Protection Considerations Transformers If the voltage withstand/BIL rating of the transformer is less than that of the switchgear feeding the transformer, surge protection is recommended at the transformer terminals, in line with established practices. In addition, consideration should be given to using surge arresters and/or surge capacitorsContinue reading “Part 5: AC Power Distribution Systems & Standards”

Part 4: AC Power Distribution Systems & Standards

Published By Nikola Zlatanov* Ground Fault Protection Article 230.95 of NEC requires ground- fault protection of equipment shall be provided for solidly grounded wye electrical services of more than 150 V to ground, but not exceeding 600 V phase-to-phase for each service disconnect rated 1000 A or more. The rating of the service disconnect shallContinue reading “Part 4: AC Power Distribution Systems & Standards”

Part 3: AC Power Distribution Systems & Standards

Published By Nikola Zlatanov* Short-Circuit Currents – General The amount of current available in a short-circuit fault is determined by the capacity of the system voltage sources and the impedances of the system, including the fault. Voltage sources include the power supply (utility or on-site generation) plus all rotating machines connected to the system atContinue reading “Part 3: AC Power Distribution Systems & Standards”

Part 2: AC Power Distribution Systems & Standards

Published By Nikola Zlatanov* Voltage Classifications ANSI and IEEE® standards define various voltage classifications for single-phase and three-phase systems. The terminology used divides voltage classes into: Low voltage Medium voltage High voltage Extra-high voltage Ultra-high voltage Table 1.1-1 presents the nominal system ese classifications. Voltages and Voltage Ranges (From IEEE Standard 141-1993) BIL—Basic Impulse LevelsContinue reading “Part 2: AC Power Distribution Systems & Standards”

Part 1: AC Power Distribution Systems & Standards

Published By Nikola Zlatanov Mr. Nikola Zlatanov spent over 20 years working in the Capital Semiconductor Equipment Industry. His work at Gasonics, Novellus, Lam and KLA-Tencor involved progressing electrical engineering and management roles in disruptive technologies. Nikola received his Undergraduate degree in Electrical Engineering and Computer Systems from Technical University, Sofia, Bulgaria and completed aContinue reading “Part 1: AC Power Distribution Systems & Standards”

Measurement Practices for Reliability and Power Quality: Appendix D and E

Published by John D. Kueck and Brendan J. Kirby, Oak Ridge National Laboratory Philip N. Overholt, U.S. Department of Energy Lawrence C. Markel, Sentech, Inc. Published in Measurement Practices for Reliability and Power Quality: A Toolkit of Reliability Measurement Practices, 2004 Prepared by Oak Ridge National Laboratory Oak Ridge, Tennessee 37831-6285 managed by UT-BATTELLE, LLCContinue reading “Measurement Practices for Reliability and Power Quality: Appendix D and E”

Part 9 Markets and the Provision of Basic Service

Published by John D. Kueck and Brendan J. Kirby, Oak Ridge National Laboratory Philip N. Overholt, U.S. Department of Energy Lawrence C. Markel, Sentech, Inc. Published in Measurement Practices for Reliability and Power Quality: A Toolkit of Reliability Measurement Practices, 2004 Prepared by Oak Ridge National Laboratory Oak Ridge, Tennessee 37831-6285 managed by UT-BATTELLE, LLCContinue reading “Part 9 Markets and the Provision of Basic Service”

Part 8 Standardizing Reliability and Power Quality Metrics

Published by John D. Kueck and Brendan J. Kirby, Oak Ridge National Laboratory Philip N. Overholt, U.S. Department of Energy Lawrence C. Markel, Sentech, Inc. Published in Measurement Practices for Reliability and Power Quality: A Toolkit of Reliability Measurement Practices, 2004 Prepared by Oak Ridge National Laboratory Oak Ridge, Tennessee 37831-6285 managed by UT-BATTELLE, LLCContinue reading “Part 8 Standardizing Reliability and Power Quality Metrics”