Electrical Theory II: AC Circuits and Transformers

What you'll learn

• Describe AC generation and sine waves, convert between peak, average and RMS values, use true-RMS meters, and add voltages and currents as phasors
• Calculate inductive and capacitive reactance and the impedance and phase angle of series and parallel RLC circuits, and work safely with stored energy
• Calculate series and parallel resonance, identify harmonic sources and their effects on neutrals, transformers and capacitors, and select detuned banks, reactors and filters
• Calculate real, reactive and apparent power and power factor, explain utility power factor charges, and size and install correction capacitors to code
• Measure single-phase and three-phase power with wattmeters and analyzers, interpret energy and demand billing, use measured demand to add load, and record power quality events safely
• Analyse wye and delta three-phase systems including 347/600 V and 120/208 V, calculate three-phase power, neutral currents and voltage unbalance, and verify phase rotation
• Explain neutral currents, multiwire branch circuits, open neutrals, system grounding methods and ground-fault current paths in AC systems
• Apply transformer ratios, ratings, losses, impedance, taps and polarity, connect single-phase, three-phase, buck-boost and instrument transformers, and protect them to code
• Connect and phase-check three-phase transformer banks, apply open-delta and paralleling rules, size transformers and perform acceptance tests
• Calculate AC voltage drop with effective impedance, size conductors to code limits, and check motor starting dips
• Calculate available fault current at transformers and along feeders, include motor contribution, and verify interrupting ratings, SCCRs and series ratings
• Troubleshoot AC systems methodically and apply the course to the electrical checks of a commercial building