Unit 5: Conductor Sizes, Wiring Methods, Voltage Drop

Copper wire is sized according to

Copper wire is sized according to

The AWG standard

AWG stands for

American Wire Gauge

Wires may be ______ or have a

stranded or have a single strand

Size No ___ and above are must be

8 and above must be stranded

Size of wire used depends on

maximum current to be carred

Conductor sizes typically used in residential wiring

14, 12, 10

What size wires are typically found in raceways and why

#10

flexibility and ease of handling and pulling

The CEC states that the minimum size for house wiring to be used is

No 14

Unit of diameter of conductors

mil

1 mil is

1/1000 (0.001) in

AWG sizes having <15 A protection

20, 18, 16

AWG size(s )with 15 A

14 AWG

Size with 20 A protection

12 AWG

AWG size with 30 A protection

10 AWG

AWG size with 40 A protection

8 AWG

AWG size with 50 A protection

6 AWG

AWG size with 70 A protection

4 AWG

AWG size with 100 and greater A protection

3 AWG And larger

20 AWG uses

phone wiring

18 AWG uses

low-voltage

thermostats, chimes, security, RC, home automation

16 AWG uses

same as 18 AWG

good for long runs

14 AWG uses

lighting and receptacle branch circuits

12 AWG uses

small appliance branch circuits

laundry receptacles

bathroom/workshop receptacles

some water heaters

10 AWG uses

clothes dryers

built-in ovens

cooktops

central air

some water heaters

some heat pumps

8 AWG used for

ranges

ovens

heat pumps

large clothes dryers

large central air

heat pumps

6 AWG used for

electric ranges

furnaces

heat pumps

4 AWG used for

furnaces

feeders to subpanels

3 AWG and larger used for

main service-entrance

feeders to subpanels

furnaces

Ampacity

maximum current a conductor can carry continuously under the conditions of use without exceeding its temperature rating

Ampacity value depends on

cross-sectional area

Al vs Cu

type of insulation

Al or Cu has better conductivity

Cu

Al resistivity compared to Cu

Al has 1.6x resistivity

Al or Cu creates a bigger voltage drop

Aluminum

Al most commonly used for

feeders and utility distribution systems

Dry location

location not normally subjected to dampness or wetness

may be temporarily subject to damp or wet conditions

Damp location

protected from weather and not subject to saturation with water or other liquids but subject to moderate degrees of wetness

Wet location

underground or in concrete slabs or masonry in direct contact with the earth

subject to saturation with water or other liquids

Which type of NMSC can be used for category 1 concealed wiring

NMW and NMWU can

Which type of NMSC can be used for wet and direct burial locations

NMWU

Which NMSC insulation is fungus and corrosion resistant

NMW and NMWU are

What is the weakest point in the conductive path that the installer is responsible for

wire connectors

Crimp connectors used to

splice and terminate #20-500kcmil Al-Al, Cu-Al, Cu-Cu

Wire Nut, wing nut, twisters, scotchlok connectors

connect wires in combinations of 18-6 AWG

Solderless connectors

sizes 4-500kcmil

used for one solid or one stranded conductor only

Compression connectors

used for #8 AWG-100kcmil

wire inserted into the end then crimped on with a tool

Split-bold connectors

connecting 2 conductors

taping one conductor to another

#10-1000kcmil

two solid and/or two stranded conductors only

Problems with aluminum connections

corrosion

oxidation

expansion and contraction

Expansion and contraction is referred to as

creep or cold flow

Two devices that can ONLY be used with Cu (not Cu-clad aluminum) when there are no markings on terminal or connector

30-amp or greater switch/receptacles

Wire connectors

Allowed voltage drop for feeders and branch circuits

3%

Allowed overall voltage drop

5%

Distance between a box and the first strap or stapling

300mm

Max distance between straps and stapling

1.5m

NMSC must extend at least

6mm into box

Inner edge bend radius of NMSC cable must not be less than

6x diameter of the cable

Cable must be protected if it is less than how many meters above ground

less than 1.5 m above ground must be protected

3 types of armoured cable

AC90

ACWU90

TECK90

Which types of armoured cable can be used at below service grade entry

ACWU90

TECK90

After cutting armoured cable, what must be done to protect the conductors from the metal edges

anti-shorts need to be placed at the cut end

When NMSC are bundled for distances over how many mm a correction factor must be used

over 600mm

When a distance of at least 32mm from edge of framing member cannot be maintained

use a face plate to protect the cable