# 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

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