Power systems: formulas and calculations you should know for transformers and motors

1:05:30

Dan Carnovale, Director Eaton Experience Centers, demonstrates calculations that are key to understanding power systems and commonly used by electrical consultants. These formulas are focused on three-phase power components, specifically transformers and motors. Dan starts off by explaining the importance of the three-phase power analysis formula and why one-line diagrams are helpful to have. Transformer calculations cover: • Dry-type (standard and isolation transformers) • Pole-mounted transformers (single-phase and three-phase) • Pad-mounted transformers • Substation transformers Specifically, we calculate full load amps on the primary and secondary, fault current on the secondary, and breaker/fuse size and kA rating. Dan also talks about infinite bus and what that means for impedance. For motors starting calculations: • Simplified motor starting analysis (hand calculations and thresholds of concern) • Formal motor starting computer simulations • Demand charges • Motor inrush And lastly, Dan discusses the power triangle (real power, reactive power and apparent power) and give examples of power factor correction. This video is a great introduction to power system calculations or if you’ve ever asked yourself one of these questions: • How to calculate power, current, voltage? • How to calculate load current? • How do I calculate full load amps? • How do I calculate power factor? • How do I calculate power? • How do I calculate on a per unit system? • How do I calculate transformer ratings? • How do I calculate motor inrush current? • How do I calculate impedance? • How do I calculate demand charges? • Why do the lights flicker? • What is a per unit system? • What is power factor? • What is kVA? Thank you for watching one of our many educational videos on the topic of power systems. Schedule a visit to one of Eaton's Power Systems Experience Centers in either Pittsburgh or Houston to learn more! To learn more about Eaton products and our Power Systems Experience Centers: http://eaton.com/experience To view more educational videos from Eaton's Power Systems Experience Centers: http://videos.eaton.com/experience #powersystem #electricalengineering #engineering #eatonexperience #experiencecenter 0:00 - Introduction 1:28 - 3-phase calculations 5:35 - Transformer calculations 15:52 - Dry-type transformers 22:22 - Isolation transformers 28:40 - Pole-mounted transformers split-phase 35:00 - Pole-mounted transformers 3-phase 38:30 - Pad-mounted transformers 45:55 - Two transformers in series 50:38 - Motor starting analysis (in-rush current) 57:28 - Power factor 01:02:24 - Basic rules of thumb