Objectives Provide Overview of Build Electric Systems Learn Fundamentals of Electric Circuits

What do you need to know about Building Electric Circuits Fundamentals Basic principles of the grid Terminology and basic principles of the building circuits Where to learn about this: - In Class - Textbook Chapters 10 & 11, and later Chapter 13 - Reading assignment is complementary to the class material - It is mandatory and will be checked in the course Quiz

What is the NEC? National Electrical Code National Electrical Corporation A kind of cookie National Energy Code A manufacturer of plasma televisions

Electrical Codes National Electrical Code (NEC) Focus on safety Prepared by National Fire Protection Association Part of the national and state building codes Library website Tao and Janis - Section 13.7 Focus on safety

AC DC Direct Current (DC) Alternating Current (AC) Sign matters Alternating Current (AC) Switching polarity Which are the following? Photovoltaic solar cell Automobile alternator Household outlet Outlet in ECJ Battery High voltage lines

AC terms Frequency, f [Hz] Resistor [Ω –ohm] Wall outlet? Fluorescent light? Clock? Electric resistance heater? Resistor [Ω –ohm] Capacitor (plates separated by dielectric) Inductor (coil of wire) Transformers

Why use AC? Easier to generate 7/10/2019 Why use AC? Easier to generate Able to use inductors and capacitors in meaningful way Voltage changes much easier Lower distribution losses ARE 346N

Transformers Change - Voltage [E] and - Current [I] Across a transformer I1E1 = I2E2 Es/Ep = Ns/Np

Ref: Tao and Janis (2001)

Basic about Circuits Ohm’s, Kirchov’s Laws, relations between current voltage resistance, …… We need to master this: as it defines basics for all electric systems (High voltage or Low voltage) It is part of the FE exam that you will take soon or later

Fundamentals of Engineering (FE) Exam The FE exam is the step in the process to becoming a professional licensed engineer (P.E.) https://ncees.org/engineering/fe/ General FE exam: Section 14. Electricity, Power, and Magnetism: A. Electrical fundamentals (e.g., charge, current, voltage, resistance, power, energy) B. Current and voltage laws (Kirchhoff, Ohm) C. DC circuits D. Equivalent circuits (series, parallel, Norton’s theorem, Thevenin’s theorem) E. Capacitance and inductance F. AC circuits (e.g., real and imaginary components, complex numbers, power factor, reactance and impedance) G. Measuring devices (e.g., voltmeter, ammeter, wattmeter