Inflection Point Engineering Electrical Engineering Curriculum

Transformers

Module from the Electrical Engineering Curriculum curriculum.

Module 3 - Transformers · Learning Objectives · 1. Apply IEEE C57.12.00 rating standards for liquid-filled power transformers · 2. Select dry-type (cast coil, VPI) vs oil-filled by location and cost · 3. Size taps (+/-2x2.5% typical) for source voltage variation · 4. Compute impedance-based fault current contribution · 5. Specify cooling class: OA, FA, FOA (increased forced-air ratings) · Transformer Types and Applications

Type Cooling Typical Size Location Cost Notes
Pad-mount liquid-filled OA 500-10000 kVA Outdoor Moderate Utility service
Substation liquid-filled OA/FA/FOA 10-100+ MVA Outdoor High Plant service
Dry type cast coil AA 30-15000 kVA Indoor/outdoor Higher Electrical rooms
Dry VPI AA 75-5000 kVA Indoor Moderate Low fire risk
Auto-transformer OA/AA Any Indoor/outdoor Lower When ratio <3:1

Source: Electrical_Engineering_Curriculum_v1.xlsx · Sheet: Transformers