Proper Wire Sizing and Protection of the Circuit

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Proper Wire Sizing and Protection of the Circuit
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Fuse

• A one time use device that protects the circuit
  from overloading. If the circuit is overloaded
  the fuse will blow (the filament in the fuse
  will melt in two)
• The size of fuse used will depend on the size of
  wire that is being used in the circuit

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Circuit Breaker

• Device that is used to keep the circuit from
  becoming overloaded. Overloaded circuits become
  hot and can catch fire. Will trip if
  overloaded
• The size of breaker depends on the size wire that
  is being used on the circuit.

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Wire Size and Breaker Size

• Wire Size Breaker Size
• 14 15
• 12 20
• 10 30
• 8 40
• 6 55

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Wire sizes

• AWG American Wire Gauge a standard for
  designating the size of electrical wire
• The larger the number, the smaller the diameter
  of the wire.
• The smaller number, the larger the diameter of
  the wire

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House Wiring

• Most circuits in houses are either size 14 or 12.
• Larger appliances such as dryers and ranges use
  larger wire (10 or 8)

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Wire Size Labeling

• NEC state that all electrical conductors have the
  following info stamped on the wire
• AWG Size Voltage Rating
• Insulation Type Testing Agency
• Number of Conductors

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Example of Commmon Wires

• 12/2
• 12/2 wg
• 12/3 wg
• 14/2
• 12/2 wg
• 14/3 wg