62 - Do I need to specify a 200% neutral on my panelboard and transformer if I have a lot of harmonics?

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What are harmonics? Harmonics are distortions that that occur at a multiple of the fundamental frequency in a power system, which in the US is a 60 hertz sinusoidal wave. Sources of harmonics include non-linear loads that typically include power electronics such as variable frequency drives (VFDs) and LED lights. Current harmonics cause excess heating of transformers and cables, and damage electrical equipment. Harmonics can also cause voltage distortion, often resulting in the misoperation of equipment during critical applications. Calculating harmonics and measuring harmonics are critical steps in selecting the best harmonic solution to reduce the total harmonic distortion or THD on a power system to comply with the IEEE-519 standard. • Neutral Sizing: We emphasize the importance of oversizing the neutral in panel boards and transformers in scenarios with high third harmonic loads, such as computers or LED lights, to prevent overheating issues. This is due to the triplen harmonics adding up on the neutral, potentially leading to currents up to 180% of the phase current. • Harmonic Mitigation: We highlighted that modern computer power supplies are power factor corrected, which significantly reduces total harmonic distortion. This development makes the concern of third harmonics in computer power supplies less critical than years ago, suggesting a shift in considerations for neutral sizing in certain applications. • Transformer Connections: If you do have significant triplen harmonics, you’ll have to oversize not just the neutral but also the connections all the way back to the transformer. This includes ensuring the tabs inside the transformer are appropriately sized to handle the increased neutral load. This is common practice in k-rated and harmonic mitigating transformers. Eaton’s Harmonic Frequently Asked Question’s FAQs collection of videos hosted by Dan Carnovale can help individuals from all different levels of education understand what harmonics are and explain many different solutions for mitigating harmonics on an electrical power system. Dan Carnovale P.E. has decades of experience in power quality and harmonics and is a recognized electrical industry expert in power quality and power systems. He is the creator and director of Eaton’s Power Systems Experience Centers (PSEC) in Pittsburgh PA and Houston TX. The PSECs provide visitors with live demonstrations of hands-on power quality and harmonic situations and solutions that can be seen first-hand in the Power Quality Lab. Visit Eaton’s harmonics knowledge website featuring harmonic solutions, harmonic calculators, access to white papers, and more: https://www.eaton.com/harmonics See our entire harmonics FAQs playlists: https://www.youtube.com/watch?v=U36ywxWHIy8&list=PL8XobqCtN9Z8maXVw0kYDLjmhBO275-bE&pp=gAQBiAQB For an educational overview of harmonics in person, visit one of Eaton’s Power Systems Experience Centers: http://eaton.com/experience #harmonics #powerquality #electricalengineering #electricalsafety #eatonexperience #experiencecenter