Should you use the manufactures size of wire?

Answer 1

The wire size is dependent upon the load current. Different size wires have a maximum safety capacity e.g. #14 - 15 amps, #12 - 20 amps. Over current on the wire could cause the insulation to fail so the current must remain within the wire specifications For 110v devices:

Depends on what you are wanting it to power. Lighting is normally 14/2 since it takes a lot of 60 watt bulbs to get to the 1800 watts off a 15 amp breaker. 12/2 for receptacles that will need more power because you can get 2400 watts from the 20 amp breaker.

Once you move to the 220v devices, you get to the */3 wire. Check the power requirements of the device to determine the gauge needed.

Answer 2

The amount of current that a load will draw determines the size of the wire. Rule of thumb: 1mm square for 6A

Answer

By referring to the wiring regulations for your country.

Answer 3

The question arises as to what is the alternative to using manufactured wire sizes. Wire sizing is set out by a standards association. They establish what the diameter size of the wire will be and what the maximum amperage capacity that size of wire will carry. When the manufacturer produces a specific size of wire they are governed to produce a diameter of wire that the standards association has laid out. This specific wire ratio to amperage size is then used for electrical code books so that all installations will remain standard through out the code book's enforced area.

Answer 4

The size fuse that needs to be used varies with different situations. In the US you would use the National Electrical Code book (Article 240 - Overcurrent Protection), to determine the size.

Answer 5

V equals I times r