Starting Residential Wiring

 The most important element in wiring. Safety is proper grounding.  Grounding is the connection of all parts of a wiring circuit to ground. This provides protection to persons, the electrical system itself, and the building.  Electrical circuits are grounded by driving a ground rod at least eight feet deep into the earth or connecting to a metallic cold water pipe at least 10 feet in length or a buried ground plate.

 Where electricity enters the residence.  Contains the hot bar, neutral bar, grounding bar (bonded), and circuit breakers.  Is grounded through grounding rod 8 feet deep or to the cold water piping or both.

 Circuits are prone to over-currents due to overloads or short circuits.  Fuses and Breakers – Devices that stop the flow of electricity within short circuits or overflows.  Overloads – Too many devices on one circuit.  Short circuits – When two conductors unintentionally touch each other or create a path.

 Safety – Ensure that circuit is disconnected and dead before beginning work on it.  Use tools correctly and for their intended purpose.  Remove all jewelry, watches, and rings to avoid metal-to-metal contact with energized circuits.  Keep the work area dry and free of debris.  Ensure all electrical equipment is properly grounded.

 Gets updated every 3 years  Article 90.4 allows Local municipalities are given the power of attorney to interpret Code  Article – requires 6” excess wire for every opening

 NEC Articles 110 and 300 cover device wiring  Connections –  must be clean and secure contact to devices  All connections must be made within boxes or enclosures  Hooks –  hooks are clockwise and should be clean and secure under the screw  Splices –  Are to be made clockwise and covered with caps of equal or greater insulation

 Insulation colors help other electricians understand the work that has been completed.  HOT WIRE– Dark colors (Black, Red, Blue)  Brings electricity from the panel to the circuit.  Is always hot.  NEUTRAL WIRE – (White, Gray)  Returns power to ground from the loads on the circuit.  SWITCH LEG WIRE– Colors other than HOT or NEUTRAL (Yellow)  Supplies power from the switch to its load.  TRAVELER WIRE– Same as switch leg.  Pathway from one switch to another switch.  GROUNDING CONDUCTORS – (Bare or Green)  Bonds the boxes and devices to ground.

 Solid or Stranded  Copper or Aluminum  Aluminum- can corroded due to oxidation and expansion  (if al is used you must go one wire size larger)  THHN  THHW – for wet locations

 Will tell  AWG Size  Voltage rating  Insulation type  Number of conductors  Manufacturer name or trademark  Outer finish

 Fill allotment – Article 314  number of conductors allowed in certain size boxes  Add fittings, grounding wires and all devices  Ampacity – safe current carrying capacity of a wire and it’s heat dissipation ability  Voltage Drop - loss of voltage due to length, diameter of wire and ambient temperature

 Contain wires, conduit boxes, connectors, conduit  Conduit bends – there are times when conduit needs to be bent around something in the wall. Here are three common bends (there are many others)  StubBack to BackOffset

 Romex is Non metallic cable  ENT – Electrical Nonmetallic Tubing – plastic that is usually blue (hence aka. Smurf)  PVC – Nonmetallic rigid conduit

 EMT – Electrical Metallic Tubing  Not threaded  RMC - Rigid Metallic Conduit  Can be threaded

 Flexible metallic tubing  Can be bent without using tools  greenfield is a common name

 Contains a hot, neutral and bare (bonding) wires  Can NOT be used for commercial garages, movie theaters, elevators  Has an Anti-short bushing