The most common type of cable used in houses is technically known as NMD 90 (Non-Metallic Dry service cable rated at maximum of 90 degrees Celsius).

It is usually a plastic white covered cable.

How is Wire Sized?

In Canada and the United States there is a standard by which we measure wire. This standard is the A.W.G. (American Wire Gauge).

The most common size of wire that you will be dealing with is a #14.

Wire sizes start at higher numbers such as #24 (small wire) and as the number decreases in value the wire increases in size. The largest wire you will likely need is a #3 gauge. This would be for your incoming service.

The following chart identifies wire/amperage/breaker sizes:

Wire Size	Rating (Amperage)	Breaker Size (Amps)
#14	15 A.	15 A.
#12	20 A.	20 A.
#10	30 A.	30 A.
#8	45 A.	40 A.
#6	65 A.	60 A.
#3	105 A.	100 A.

*All sizes are a maximum value and in accordance with the Canadian Electrical Code.

Types of Wire

Wire can be either solid of stranded. Most wiring you do in your home will be with solid wire.

Solid wire is easier to work with and takes less time to install. You will find stranded wire in extension cords and any wire gauge over a #10.

Most Commonly Used Cables and Their Uses

2-conductor #14

Plugs, Switched, Lights ,( approx 70 % of your house wiring)

3-conductor #14

3- way Switches, Split Receptacles

2-conductor #12

Selected Heaters , Air Compressors, etc. (anything that uses a maximum of 20 amps)

Kitchen Receptacles circuits (as per the new provisions in the Canadian Electrical Code)

3-conductor #10

– any device that requires a maximum of 30 amps (the most common application would be your electric dryer)

3-conductor #8

– maximum of 40 amps (the most common application would be your electric range)

Information that is being provide is for Educational Purpose, Any electric work that is needing to be done, should be done by a Licensed Electrician.