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ELECTRICITY
for kitchens & baths
Electricity
Amber
Electricity
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We know that electricity behaves in a consistent predictable
manner, in given situations, but electricity has never clearly
been defined.
Atoms –neutrons, protons and electrons




Atoms are neutrally charged
Most of the weight of an atom is found in the protons and
neutrons.
Protons are more or less attached to the nucleus
Electrons revolve around the nucleus like planets revolve around
the sun
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Atom
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Some electrons, particularly in metals are loosely
bound and can detach and become “free electrons”

Free electrons as the name implies can move freely
from atom to atom

When a force or pressure is applied free electrons
begin to move
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The materials that allow this movement are called
CONDUCTORS
The three metals that make the best conductors:
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
Silver
Copper
Aluminum
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Copper Atom
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Silver atom
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Non Conductors or Insulators:




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
Dry Wood
Glass
Rubber
Mica
Asbestos
Semi-Conductors:

Silicon
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Charged Bodies
 Like charges repel
 Unlike charges attract
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Electrical energy is transferred through conductors
by means of movement of free electrons
A material’s ability to conduct current flow
determines whether it is a good or bad conductor
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Coulombs Law of Charge
 The amount of attracting or repelling force which acts
between two electrically charged bodies depends on two
things:
their charges
 the distance between them
Attraction is directly proportional to the product of their charges
And indirectly proportional to the square of the distance between
them

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The space in and around charged bodies in which their
influence is felt is called an
Electrical Field of Force
or an
Electrostatic Field
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+
+
like chargesrepel
-
+
opposite chargesattract
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The force that moves electrons in a conductor can be
called
 VOLTAGE
 Electromotive Force
 Difference in Potential
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Current that flows through
electrical conductors is directly
proportional to the difference
in potential

Current is directly proportional
to the applied voltage

Voltage increases – current
increases

Voltage decreases-current
decreases
voltage
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voltage
Six Methods of Producing Voltage
 Friction – Static electricity
 Pressure – Compression of crystals
 Heating – In copper electrons move away from the heat. In
iron they move to the heat.
 Light – Photoelectric cells
 Chemical Action - Batteries
 Magnetism
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Static Electricity
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When an atom looses zero or neutral charge it
becomes either positively or negatively charged.
When a material becomes charged it will keep its
positive or negative charge as long as it stays
isolated from other materials “Static Charge”
Once it comes in contact with another material the
negative charge will flow to the positive
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voltage
Chemical Production of voltage – that’s how batteries
produce voltage
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magnetism
Magnetism – a substance is said to be magnetic if it
attracts substances like iron, steel, nickel or cobalt
Three types of magnets:
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
Natural magnets - minerals like magnetite
Permanent magnets - bars of hardened steel that have
been magnetized
Electromagnets - soft iron core wound with coils of
insulating wire
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magnetism
Domain Theory of Magnetism – A substance becomes magnetic
when there is an unequal number of electrons spinning in
opposite directions.
When a number of such atoms are grouped together as in an
iron bar there is an interaction between the magnetic forces
in various atoms
The magnet force field around one atom affects adjacent atoms
thus producing a small group of atoms with parallel
magnetic fields
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magnetism
Iron for example has 26 electrons – 15 rotate in one
direction and 11 in the other, which causes a tiny
magnetic field.
 When these atoms group together their poles
become aligned in the same direction
 This cluster is called a “Domain” One cubic mm of
Iron can contain 10 million magnetic domains
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magnetism
Domains are oriented randomly within the iron bar until
an external magnetic field is applied
When this happens the domains orient themselves with
the magnetic field
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magnetism
magnet
S
S
N
S
N
S N
N
S N
S N
S
S N
S
N S N
S N S N
S N
S
N S N
S N S N
S N
S
N S N
S N S N
S N
S
N S N
N
N
S
S N S N
S N
bar being magnetized
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magnetism
S N
S N
S N
S N S N
S N
S
N S N
S N
S N
S N
S N S N
S N
S
N S N
S N
S N
S N
S N S N
S N
S
N S N
S N
S N
S N
S N S N
S N
S
N S N
magnetized bar
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Producing voltage with magnets
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charge
How do we measure charge?
Coulomb = 6.28 x 1018 electrons
6,280,000,000,000,000,000
Ampere = 1 coulomb of charge flow per second
Charge – the stuff inside conductors
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charge

copper wire
The copper wire is full of
“charged stuff” but there is
no movement
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charge
battery
-
+
+
charge
-
battery
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The battery drives the ring of charge into motion, the charge
moves along like a drive belt, and the light bulb filament
“rubs” against the moving charge which makes it glow white
hot.
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charge
The higher the amperage the faster charge stuff moves
The more charge stuff that flows (though a larger wire)
the higher the amperage
A fast flow through a narrow wire can have the same
amps as a slow flow of charge through a bigger wire.
If you keep the speed constant and increase the size of
the wire you also increase the amperage
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watts
Watts is the name given to electrical flow – but what flows?
Energy
Energy is measures in joules
A joule of electrical energy can move from place to place
along the wires.
The amount of energy that flows in one second is one watt
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btu’s
Short for British thermal unit, an British standard unit of
energy. One Btu is equal to the amount of heat required to
raise the temperature of one pound of liquid water by 1
degree Fahrenheit at its maximum density, which occurs at
a temperature of 39.1 degrees Fahrenheit. One Btu is equal
to approximately 251.9 calories or 1055 joules.
As a rough guide, 1 joule is the absolute minimum amount
of energy required (on the surface of Earth) to lift a one
kilogram object up by a height of 10 centimetres.
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closed circuits
A closed loop of wire is not necessarily a circuit
unless voltage is present.
In any electric circuit where electrons move around,
three things are present:



Voltage
Current
Resistance
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closed circuits
The physical pathway for current flow is actually the
circuit and it’s resistance controls the amount of
current flow around the circuit.
By knowing any two of the three quantities, the
third can be calculated.
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Ohms Law – The current in a
circuit is directly proportional
to the applied voltage and
indirectly proportional to the
circuits resistance.
I = current measured in amperes
(amps)
E = Voltage
R = Resistance in Ohms
ohms law

E
I
R
ohms law
+
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-
battery
Battery = 1.5 volts
Resistance = 1.5 ohms
Amperes = ?
Amperes = 1
E
I
R
1.5
I
1.5
ohms law
+
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-
battery
Battery = 3 volts
Resistance = 1.5 ohms
Amperes = ?
Amperes = 2
E
I
R
3
I
1.5
ohms law
+
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-
battery
Battery = 1.5 volts
Resistance = 3 ohms
Amperes = ?
Amperes = .5
E
I
R
1.5
I
3
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ohms law
Another way of writing ohms law:
E
I
R
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watts
Power pertains to the rate at which work is being
done.
Work is done whenever a force causes motion
i.e. when voltage causes electrons to move in a circuit work
is done

The rate at which this work is done is called the
electric power rate and is measured in WATTS
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watts power
Watts = the amount of voltage across a circuit x the
current through the circuit
or
Watts = Volts x Amperes.
or
P= EI
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E
I
R
1
1
1
P  EI
watts power
E
I
R
2
2
1
P  EI
P  2 2
P  1WATT
P  4WATTS
Electricity
E
I
R
3
I
1.5
I 2
P  EI
P  3 2
P  6WATTS
watts power
E2
P
R
32
P
1.5
9
P
1.5
P  6WATTS
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watts power
2
E
P
R
E  10volts
R  1ohm
P  100watts
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watts power
PI R
2
I  10amps
R  1ohm
P  100watts
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watts power
15amp circuit *120volts =1800watts
100watt bulbs*10 =1000watts
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What is the
resistance in the
following example?
PI R
2
1800  152 R
1800  225 R
1800
 8OHMS
225
watts power
2
E
P
R
1202
1800 
R
14400
1800 
R
1800 R  14400
14400
R
1800
R  8OHMS
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Four types of circuits

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General Lighting
Small Appliance
Individual Appliance
Ground Fault Circuit Interrupter
circuits
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General Lighting

One 15 amp circuit per 600 square feet


Rule of thumb – 12 outlets
Or one 20 amp circuit per 800 square feet
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circuits
Rule of thumb – 16 outlets
Lights in kitchens and baths must be permanently
wired.
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circuits
Small Appliance Circuits serve receptacles for plugin appliances such as toasters, blenders and coffee
makers. The Code requires two 20 amp circuits in
the kitchen and one or more in the pantry and
dining or family rooms.
These circuits may not be used for lighting
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circuits
Individual Appliance Circuits are dedicated to
devices that draw enough current to warrant their
own circuit.
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Appliance
circuits
Voltage
Breaker Capacity Amps
Garbage Disposer
120
20
Electric Range/Cooktop
Gas Range/Cooktop
Dishwasher
Electric Tankless
Hot Water
Refrigerator
Microwave Oven
Exhaust Fan
240
120
120
50
20
20
240
120
120
120
30
20
20
20
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circuits
Ground Fault Circuit Interrupter Circuits are
required for receptacles within 6 feet of a water
source, such as a faucet or showerhead.
Most receptacles mounted above a kitchen
countertop or bath lavatory fall into that category.
Electricity

Wiring
Kitchen Wiring
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Dedicated circuit for the dishwasher
Dedicated circuit for the disposer
Dedicated circuit for the microwave (if built in)
At least two 20 amp dedicated small appliance circuits
for the outlets serving the countertops
All outlets serving the countertop surface to be GFCI
protected
Dedicated range/cooktop/oven circuits
Lighting Circuit
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
circuits
Adding Circuits to the Breaker Panel

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

Consult your electrician
Replace breakers with wafer or mini breakers
Add a branch panel piggybacked to main panel
If it’s an old fuse panel replace it
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wire
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wire
Electrical Symbols
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outlet symbols
SINGL E R EC EP T A C L E O UT L ET
SINGL E R EC EP T A C L E O UT L ET
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outlet symbols
D UP L EX R EC EPT A C L E O UT L ET
SP L IT - C IR C UIT
WP
WEA T HER PR O O F
R EC EP T A C L E
O UT L ET
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EL EC T R IC R A NGE/
C O O K T O P O UT L E T
symbols
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outlet symbols
FL O O R SING L E
R EC EP T A C L E
O UT L ET
FL O O R D O UB L E
R EC EP T A C L E
O UT L ET
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outlet symbols
G R O UND FA UL T C IR C UIT
INT ER UP T ER R EC EP T A C L E
O UT L ET
F
G FC I
FA N O UT L ET
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outlet symbols
SP EC IA L P UR P O SE O UT L ET
WIR ED D IR EC T
DW
HEA T L A MP
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WA L L SC O NC E
lighting symbols
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T R A C K L IG HT ING
lighting symbols
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HA NG ING C EIL ING FIX T UR E
lighting symbols
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lighting symbols
LO W V O LTA GE
T R A NSFO R M ER
T
L
B UIL T - IN L O W V O L T A GE
T A S K L IG HT
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R EC ESS ED C EIL ING
V A P O R L IG HT
lighting symbols
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T EL EV IS IO N
O UT L ET
TV
lighting symbols
CA B LE
O UT L ET
C
Electricity
B UIL T - IN FL UO R ES C ENT
T A S K L IG HT
lighting symbols
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R EC ESS ED C EIL ING
D O WN L IG HT ING
lighting symbols
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symbols
C L O C K HA NG ER
R EC EP T A C L E
C
special purpose
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symbols
FA N
R EC EP T A C L E
special purpose
T EL EPHO NE O UT L ET
F
INT ER C O M
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symbols
special purpose
T HER MO ST A T
G A S S UP P L Y
G
T
SMO K E D ET EC T O R
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symbols
HEA T R EGIS T ER
special purpose
Electricity
switch symbols
S
Single pole switch
S2
S3
S4
Double pole switch
SD M
Single pole switch w/
dimmer
Three way switch
w/dimmer
S3 D M
Three way switch
Four way switch