Mod 02: Electrical Conductors and Insulators

Electrical Conductors

SUBSTANCES WITH HIGH CONDUCTIVITY, which have very mobile electrons

copper, silver, and gold

Metals like ____, ____, and ___ are usually used for electrical conductors

Ichabod Crane

an American named ______ introduced the use of a waterwheel as a manufacturing process for wire drawing

True

(True/False) The use of wire can be traced as far back as 3,000 B.C.

Bare Conductor

a conductor having NO COVERING or insulation.

Covered Conductor

encased within a material of composition and thickness NOT RECOGNIZED BY CODE.

Insulated Conductor

encased within a material of composition and thickness RECOGNIZED BY CODE.

Good Conductors

1. Silver

2. Copper

3. Zinc

4. Aluminum

5. Nickel

6. Brass

7. Platinum

8. Iron

9. Tin

10. Lead

Insulators

Substances with low conductivity. They prevent the flow of electrons

glass, rubber, plastic, and air

Common insulators include ____, _____, _____, and ___; substances or materials

Class A

(Insulation Class)

(1) Cotton, silk, paper and materials of paper composition impregnated or immersed in an insulating liquid

(2) Molded/laminated materials with cellulose filler, phenolic resin, or similar resins

(3) Films/sheets of cellulose acetate or similar cellulose products

(4) Varnishes or enamel applied to conductors

Class B

(Insulation Class)

Consists of mica, asbestos, or fiberglass; all with a binder.

Class C

(Insulation Class)

Consists entirely of mica, porcelain, glass, quartz, or similar materials.

Class O

(Insulation Class)

Consists of cotton, silk, paper, or similar materials that are NOT impregnated or IMMERSED IN AN INSULATING LIQUID.

Insulating Materials

1. Rubber

2. Porcelain

3. Varnish

4. Slate

5. Glass

6. Mica

7. Latex

8. Asbestos

9. Thermoplastic

10. Oil

11. Wax

12. Dry air

13. Paper

14. Silk

15. Wood

Fair Conductors

1. Charcoal and coke

2. Carbon

3. Plumbago (Graphite)

4. Acid Solutions

5. Seawater

6. Saline Solutions

7. Metallic Ores

8. Living Vegetable Substances

9. Moist Earth

Partial Conductors

1. Water

2. Human Body

3. Flame

4. Linen

5. Cotton

6. Mahogany

7. Pine

8. Rosewood

9. Lignum Vitae

10. Teak

Insulators

1. Slate

2. Oil

3. Porcelain

4. Dry Paper

5. Silk

6. Sealing wax

7. Gutta Percha

8. Ebonite

9. Mica

10. Glass

11. Dry Air

Wires

electrical conductors which are 8 mm2 (No. 8 AWG) or smaller.

true

(True/False) Cables are LARGER than wires

wires

They are either solid, or stranded. A single conductor number 14 AWG, 12 AWG, 10 AWG, and 8 AWG are called ___.

American Wire Gauge

AWG meaning

True

(True/False) AWGS numbering is used in reverse order: the BIGGER the NUMBER, the SMALLER the SIZE

False

(True/False) Smaller-sized AWG wires ARE PERMITTED to be used in electrical circuits.

Solid Wire

Also known as SOLID-CORE or single-strand wire, consists of a one piece of wire on its entire cross section.

True

(True/False) Unlike stranded wire, solid wire HAS FLEXIBILITY than stranded wire.

Stranded Wire

Consists of a GROUP OF WIRES twisted to form metallic string. The total circular mil area is found by multiplying the circular mil area of each strand by the total number of strands.

Cord

Refers to insulated wire that is flexible.

Cables

electrical conductors LARGER THAN WIRES. A single Number 6 AWG to 0000 AWG.

True

(True/False) Two or more wires assembled in a single jacket are also CONSIDERED as a cable

stranded

Conductors with sizes from Number 6 AWG and larger are ____.

Notations of AWG for cables

0 AWG = 1/0 AWG

00 AWG = 2/0 AWG

000 AWG = 3/0 AWG

0000 AWG = 4/0 AWG

Bus, Busbar

A rigid electric conductor, usually a METAL BAR, hollow tube, or rod, which forms a connection between electric circuits.

Copper

Ductile, malleable, and an excellent conductor of heat and energy. HARDER THAN ZINC AND SOFTER THAN IRON. Approximately 50% of its total output is used for manufacturing electrical apparatuses and conductors.

Aluminum

It is produced by the FORMATION OF MANY METALS, such as feldspar, mica, alum, cryolite, clay, bauxite, and several forms of _____.

American Wire Gauge (AWG)

also known as Brown and Sharpe (B & S) Wire Gauge, is a U.S. standard set of non-ferrous wire conductor sizes.

Gauge

means diameter

True

(True/False) Since THICKER wire carries more current because it has less electrical resistance over a given length, THICKER WIRE IS BETTER FOR LONG DISTANCES.

Circular Mil (CM)

Unit of measuring cross-section size in American Wire Gauge (AWG).

Mil

means one-thousandth of an inch (0.001 in.).

1000

1 inch = _____ mils

1/1000

1 mil = _____ in

Square mil

square inch x 0.000001

Square inch

square mil x 1,000, 000

Square mil

circular mils x 0.7854

Circular mil

square mils x 1,273

Millimeter

inches x 25.4

Square mm

circular mils x 0.0005067

Heat-Resistant Rubber

RH

75°C

167°F

Dry locations

Moisture-Resistant Rubber

RW

60°C
140°F

Dry and Wet

Heat and Moisture-Resistant Rubber

RHW

75°C

167°F

Dry and Wet Locations

Heat-Resistant Latex Rubber

RUH

75°C

167°F

Dry Locations

Moisture-Resistant Latex Rubber

RUW

60°C

140°F

Dry and Wet Locations

Silicon-asbestos

SA

90°C

194°

Dry Locations

Thermoplastic

T

60°C

140°F

Dry Locations

Moisture-Resistant Thermoplastic

TW

60°C

140°F

Dry and Wet Locations

Heat-Resistant Thermoplastic

THHN

90°C

194°

Dry Locations

Moisture and Heat-Resistant Thermoplastic

THW

75°C

167°F

Dry and Wet Locations

Moisture and Heat-Resistant Thermoplastic

THWN

75°C

167°F

Dry and Wet Locations

Mineral Insulation (Metal-Sheathed)

MI

85°C

185°F

Dry and Wet Locations

Thermoplastic and Asbestos

TA

90°C

194°F

Switchboard wiring only

Varnished Cambric

V

85°C

185°F

Dry Locations

Asbestos and Varnished Cambric

AVA

110°C

230°F

Dry Locations

Asbestos and Varnished Cambric

AVL

110°C

230°F

General use and Wet Locations

Asbestos and Varnished Cambric

AVB

90°C

194°F

Dry Locations

Heat and Moisture-resistant Cross-Linked Polyethylene

XHHW

75°C

167°F

Dry and Wet Locations

Moisture, Heat, and Oil-Resistant Thermoplastic

THW–MTW

60°C

140°F

Dry and Wet Locations

Perfluoroalkoxy

PFA

Dry and damp locations. Dry-location – special application