assigntment no.2 - types of wires and cables

8/11/2019 Assigntment No.2 - Types of Wires and Cables

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Mindanao University of Science and Technology

College of Engineering and Architecture

Building UT 2 (Mechanical and Electrical Systems)

Assignment #2

Submitted by

Ciara Mary B. Cansancio

B.S. Architecture 3A

Submitted to

Archt. Kenneth C. Arado


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Wire

Different than cable. Cable refers to two

or more wires or conductors grouped

together in a jacket.

Copper or tinned copper is the most

common conductor in home wiring

because it has minimum resistance at

reasonable cost.

Wire is grouped by gauge number,

running from 0000 to No. 40. The smaller

the number, the thicker the wire. For

home use, the most common gauges are

between 10 and 20.

Larger wire carries more current. Forcing

too much current through a wire willcause it to overheat and trip a breaker.

Wire is also characterized by letters that

correspond to the insulation type and

electrical capacity.

Grounding wire provides a path of least

resistance from the frame or case of an

appliance to the ground to guard against

electric shocks. Both two- and three-

conductor cables can carry grounding

wires.

Types of Wires

1. Triplex Wire

Triplex is an aerial cable that the utility

company uses to feed the power pole. This wire

ties to the wires sticking out of the weather

head on your service entrance pole. This wire is

aluminum in most cases and is connected by

the utility company.

2. Main Feeder Wires

These wires are usually type THHN wire and are

rated for 125% of the load required. These are

usually black insulated wires coming out of the

service weather head.

3. Panel Feed Wires

These wires are also type THHN, like the main

feeders. A typical 100-amp service would have a

#2 THHN set of wires. They would then be rated

at 125 amps. This would protect the wires if the

amperage was a full 100 amps.


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4. Non-Metallic Sheathed Wire (NM)

This wire, commonly called Romex, is a plastic

coated wire that has either two or three

conductors and a bare ground wire. This is the

typical wiring used in most homes. The rating

for this wire is either 15 amps, 20 amps, or 30

amps, depending on the installation.

5. Single Strand Wire

When your home is piped, youll have to have

another type of wire. Single strand wire is

insulated and many of these can be pulled into

the same pipe. Normally, youll be using THHN

wire for this installation.


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Cable

Refers to a collection of two or more

strands of wire or conductors. Basically,

cable has a hot line to carry the current

and a neutral line to complete the loop.

They often have a third wire as that acts

as a grounding wire.

Classified according to the number of

wires it contains and their size or gauge.

All cables are marked with a series of

letters followed by a number, a dash and

another number. The letters indicate the

type of insulation (cord, wire and

insulation). The first number indicates the

resistance of the wires in the cable, and

the number following the dash indicates

the number of individual conductors in

the cable.

If the designator G follows the series it

means that the cable is also equipped

with a non-current-carrying ground wire.

Hence, the designator USE 12-3/G

indicates an underground cable

containing three separately insulated

wires capable of carrying 20 amps ofcurrent plus a grounding wire.

The most common jackets are NM-B

(Non-Metallic Building Indoor), UF-B

(Underground Feed) and BX, which is

flexible metallic cable.

Different types of Cables

Armored Cable (AC)

It is a fabricated assembly of insulated conductors

enclosed in a flexible metal sheath. Armored cable

is used both on exposed and concealed work.

Metal Clad Cable (MC)

It is a factory assembled cable of one or more

conductors each individually insulated and

enclosed in a metallic sheath of interlocking tape

for a smooth or corrugated tube. This type of

cable is especially used for vice feeders, branch

circuit, and for indoor or outdoor work.

Mineral Insulated Cable (MI)is a factory assembly

of one more conductors insulated in a highly

compressed refractory mineral insulation

enclosed in a liquid and gas tight continuous


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copper sheath. This type of cable is only used in

dry, wet or continuously moist location as service

feeders or branch circuit.

Non-Metallic Sheathed Cable (NM)

It is also a factory assembly of two or more

insulated conductors having a moisture resistant,

flame retardant, and non metallic material outer

sheath. This type is used specifically for one or

two family dwellings not exceeding 3 storey

buildings.

Shielded Non-Metallic Sheathed Cable (SNM)

This type of cable is a factory assembly of two ormore insulated conductors in an extruded core of

moisture resistant and flame retardant material

covered within an over lapping spiral metal tape.

This type is used of hazardous locations and in

cable trails or in raceways.

Underground Feeder and Branch Circuit Cable

(UF)

It is a moisture resistant cable used for

underground connections including direct burial in

the ground as a feeder or branch circuit.

Service Entrance Cable

It is the types SE and USE. A single or multi-

conductor assembly provided with or without an

overall primarily used for service wire.

Power and Control Tray Cable (TC)

This is a factory assembled two or more insulated

conductors with or without associated bare or

covered grounding under a metallic sheath. This is

used for installation in metal surface or raceways.

Flat Conductor Cable (FCC)

Consists of three or more flat copper conductor

placed edge to edge separated and enclosed

within an insulating assembly. This type of cable is

used for individual branch circuits, especially in

hard smooth continuous floor surfaces and the

like.

Medium Voltage Cable (MV Cable)

It is a Single or multi-conductor solid dielectric

insulated cable rated at 2000 volts or higher. This

type is used for power system up to 35,000 volts.

assigntment no.2 - types of wires and cables

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