Prologue / Character / Intro

Theory

Ⅰ.
Basic Theory of Electricity

01 Why did our country's voltage change from 110V to 220V?
KEY WORD: voltage, electromotive force, voltage drop, power loss, power terminal, Ohm's law, power, power amount
02 What is current and how does it relate to wires?
KEY WORD: current, atom, electron, charge, electrostatics, Coulomb's law, wire, allowable current, wire cross-sectional area and temperature
03 What is the difference between direct current (DC) and alternating current (AC)?
KEY WORD: direct current, alternating current, skin effect, frequency, angular frequency, root mean square (RMS), instantaneous value, maximum value, average value
04 Why do electric heaters warm the surroundings without a flame?
KEY WORD: Resistance, series, parallel, combined resistance, Kirchhoff's laws, Wheatstone bridge circuit, Joule's law, heat, thermostat
05 Why don't you get shocked when you touch a live wire?
KEY WORD: Conductor, insulator, resistivity, insulation class, standard impact insulation strength
06 What are the essentials for electronic products?
KEY WORD: Resistance, inductance, capacitance, impedance, time constant, phase difference, lagging current, leading current, resonance
07 What is the power factor written on electronic products or lighting specifications?
KEY WORD: Power factor, active power, reactive power, apparent power, lagging power factor, leading power factor, power factor tariff
08 Why is there an adapter for the power cord?
KEY WORD: power conversion device, converter, inverter, diode, bridge rectifier circuit, regulator, harmonic
09 Why do large capacity air conditioners use three-phase power?
KEY WORD: 3-phase power, neutral wire, 3-phase 3-wire, 3-phase 4-wire, single-phase 3-wire, Y connection, Δ connection
10 What is the principle by which the electric motor rotates?
KEY WORD: Electric motor, magnetic field, Ampere's law, Fleming's left-hand rule, Arago's disk, electric motor principle, types of electric motors, starting method of electric motors

Ⅱ.
Power flow

01 Why do we need coal, uranium, or huge dams to generate electricity?
KEY WORDS: Power plant, generator, distributed power system, energy storage system, Faraday's law, Fleming's right-hand rule, generator principle
02 Why are transmission towers located in rural areas or over mountains?
KEY WORD: Transmission, Transmission Status, Transmission Tower Structure, ACSR, Direct Current Transmission (HVDC), Corridor, Corona, Line Constant, Inductive Interference Prevention
03 Why aren't substations marked in detail on the map?
KEY WORD: Substation, substation, transformer, gas-insulated substation, principle of transformation, transformer wiring, transformer capacity, parallel operation of transformers
04 Why are there utility poles standing on every street?
KEY WORD: distribution, distribution status, pole structure, service entrance, service line, demarcation point, pole transformer, neutral line
05 Why aren't there any utility poles in apartment complexes or college campuses?
KEY WORD: Undergrounding, underground cable, underground construction, underground line constant, transmission and distribution voltage drop, transmission and distribution voltage fluctuation

Ⅲ.
Utilization of substation facilities

01 What is the identity of the substation in the basement of a large building?
KEY WORD: Electrical safety manager, substation, substation conditions, substation transformer, substation circuit breaker, substation diagram, simple substation facility, substation facility lifespan
02 Why are broadcasting stations and large hospitals free from power outages?
KEY WORDS: emergency generator, blackout, emergency generator conditions, internal combustion engine, uninterruptible power supply (UPS)

Ⅳ.
Understanding Electricity Bills

01 What information does the electricity meter show?
KEY WORD: Electricity meter, power meter, mechanical meter, electronic meter, instrument transformer, CT meter, instrument transformer for power supply
02 What is the electricity rate system and contract power?
KEY WORDS: Electricity rates, cost-linked rates, seasonal and hourly differential rates, contracted power, power expansion work, peak power, average power, rate offset
03 Which home appliance consumes the most electricity?
KEY WORDS: Power consumption, standby power, electric range (induction), highlight, electricity saving

Practical section

V.
Electrical Applications and Safety

01 What is grounding and why is grounding necessary?
KEY WORD: Grounding, leakage current, grounding confirmation method, grounding effect, protective conductor, grounding conductor, types of grounding work, grounding according to the Korean Electrical Installation Regulations, equipotential bonding, grounding resistance
02 What is the relationship between lightning and electricity?
KEY WORD: lightning, thunderbolt, lightning rod, lightning arrester, lightning arrester components, overhead wire
03 What is the identity of the toad house somewhere in the house?
KEY WORD: Distribution board, circuit breaker, toad house, distribution board structure, wiring circuit breaker, leakage circuit breaker, residential circuit breaker, industrial circuit breaker, leakage current, surge protector
04 Why should I not use an octopus-style power strip?
KEY WORD: Power strip, types of power strips, precautions for power strips, allowable current, overload
05 Why should I not plug in with wet hands?
KEY WORD: Electric shock, human body impedance, electric shock current, how to respond to electric shock, electric shock prevention
06 What should I know when buying lighting?
KEY WORD: Lighting, luminous flux, illuminance, brightness, real index, color temperature, types of LED lighting, rail lights, raceway, sensor lights, occupancy detectors
07 What is the principle of a storage battery that can store electricity?
KEY WORD: battery, ion, manganese battery, alkaline battery, lithium-ion battery, dry cell, storage battery, lead-acid battery, charging method, storage battery capacity

Ⅵ.
Basics of Electrical Work

01 How to use hand tools and measuring instruments for simple electrical work?
KEY WORD: Electrical safety rules, hand tools, multimeter, clamp meter, insulation resistor, grounding resistance tester (earth tester)
02 What are the types and characteristics of electrical wiring work?
KEY WORD: Electrical wiring work, wire protection work, wire support work, other work, insulated wire, cable, types of wire, cross-sectional area of ​​wire
03 What are the types and characteristics of wire protection work?
KEY WORD: Conduit, metal conduit construction, flexible conduit construction, synthetic resin conduit construction, cable duct system, cable trunk system
04 What are the types and characteristics of wiring support work and other work?
KEY WORD: Cable tray system, insulator construction, cable construction method, busbar trunking system, power track system
05 How is the allowable current of the wire selected?
KEY WORDS: Permissible temperature of wires, method of applying permissible current, voltage drop, construction method, wire cross-sectional area, and circuit breaker selection
06 How are overcurrent protection devices such as circuit breakers selected and installed?
KEY WORD: Circuit breaker, circuit breaker operating characteristic curve, TN system, TT system, automatic power cutoff, electric shock protection, short-circuit protection device, circuit breaker installation, number of circuit breakers
07 How should outlets and switches be wired?
KEY WORD: outlet, switch, internal wiring, wiring, outlet box, wire connection method, wire covering, outlet wiring, switch wiring

supplement

KEY WORD: SI units, basic mathematics, electrical wiring diagram symbols, circuit breaker rated current calculation table
1 SI unit? Prefix
2 Units of electricity and Greek letters
3 Basic Mathematics for Understanding Electricity
4 How to read electrical wiring diagram symbols
5. Allowable current values ​​for electrical wiring work and design
6 Circuit breaker rated current calculation table
7 Electrical Engineer Career Handbook

Index

Wait a minute!
▶ Basic theory of electricity
Why do we use 220V for household voltage? / How can we prevent unpleasant static electricity? / What should we be careful of when traveling abroad and shopping overseas? / What would happen if there was no resistance? / Why do inverter air conditioners save electricity? / How should I read the nameplate on the motor?

▶ Power flow
How do running trains get their electricity? / Are transmission towers dangerous to humans? / Why did KEPCO designate magpies as pests?

▶ Understanding Electricity Rates
Are electric cars really economical? / How to easily save electricity at home?

▶ Electrical Applications and Safety
How are dust and water resistance ratings for electronic products classified? / What are the pros and cons of LED lighting?

▶ Basics of Electrical Work
What do the various certification marks on electrical materials and products mean? / What are electrical engineering licensees and electrical engineering technicians?

Structure and features of this book

01.
I chose to write about my curiosity about electricity.

This book was written to convey knowledge about electricity in a more easy and fun way, using curiosity about electricity as a material to break away from the vagueness and difficulty of electricity.
Instead of the rigid writing style of existing engineering books, we presented a new paradigm for engineering textbooks by writing in as lucid a manner as possible.
In addition, supplementary explanations are provided in the comment section to make it easier to understand parts that are difficult to understand.

02.
It reflects the Korean Electrical Installation Code (KEC).

This book covers the grounding system and protective device selection methods, construction methods, and allowable current of wires according to wiring, which are important topics covered in the Korea Electrical Installation Code (KEC), and provides easy-to-understand explanations to help you prepare for all electrical-related tests.
Additionally, the electricity rates required for daily life were revised in 2021, and the calculation method for electricity rates was covered in detail.

03.
It combines basic electrical theory and practice.

It starts with basic electrical theory and explains in detail how this theory is applied in practice in an easy-to-understand way.
Based on this, it can be used to not only cultivate basic knowledge of electricity, but also to apply it in practical work after obtaining a license.
The figures given in various tables throughout the book are essential in actual electrical work, so it is definitely worth keeping for any electrical professional.

04.
The concept is explained in detail so it is easy to understand.


The greatest strength of this book is that I tried to write in an easy-to-understand way, avoiding difficult words as much as possible.
Additionally, important electrical terms are written in both Chinese characters and English to help you understand how the terms originated.
In addition, existing Japanese electrical terms were written in Korean as much as possible, and explanations for these terms were also organized so that even if confusion about terminology arises while studying with other textbooks, this book can be easily understood.

05.
Includes as many color illustrations and photographs as possible.

In an age of images where understanding through text alone is limited, full-color illustrations and photographs were inserted to make it easier to understand the content.
The author's illustrations and photos taken on-site, which are consistent with the theory, help readers understand the content of the text more easily, creating a vivid composition that has never been seen in electrical textbooks before.

06.
We compiled this by identifying readers' curiosity through big data.


The author has been analyzing the search terms used by users who visit the blog and the posts they are most interested in, and has come to know which parts of the biography they find difficult and confusing. Based on this, he has written about the parts that are itchy like a filial son.
Additionally, the revised edition has enriched the content of the book by addressing in more depth the parts that first-edition readers wanted to know more about.

07.
Basic electrical mathematics is explained.

Electricity is a field that requires mathematical knowledge, so most people find it difficult and avoid it because of this.
Here, basic electrical mathematics is explained in an easy-to-understand way so that simple calculations can be made.
The appendix, 'Basic Mathematics for Understanding Electricity', covers mathematics at a level that will allow readers to understand the content of this book without difficulty. This is written so that even those with limited mathematical knowledge can easily understand the content of this book by reading the appendix carefully and then reading the main text.