Residential Wiring Unit 3 – Installation and Planning Chaps 9-12

INSULATION COLORS HOT WIRE– Dark colors (Black, Red, Blue) Brings electricity from the panel to the circuit. Is always hot. NEUTRAL WIRE – (White, Beige, Gray) Returns power to ground from the loads on the circuit. GROUNDING CONDUCTORS – (Bare or Green) Bonds the boxes and devices to ground.

Receptacles/ Outlets Receptacle / outlet is where we plug something in. They will have two brass screws attached by what is called a “break-away” and two silver attached screw terminals. The silver always get the neutral (white) wire and the brass get the switch-leg or hot wire.

Wiring Outlets (receptacles) Break- away supplies power to the 2nd screw so only one black and one white wire is needed to supply power to both parts of the outlet. Switch operated outlet– gets one switch-leg (yellow) wire and one neutral (white) wire. Hot outlet – gets one hot (black) wire and one neutral (white) wire. Split-circuit receptacle = both switch operated and hot

Ground-Fault Circuit Interrupter GFCI Opens the circuit if an unusual large current- to-ground is detected. Difference in current from the hot and neutral wire is detected. Required in bathrooms, outdoors, kitchen counters, wet bar, garages, unfinished basements protected outlet is wired only to the GFI – not the breaker box

Service Entrance Where the electricity enters the residence. Types of Service 1. Service Drop – overhead wires come down from the utility pole. Must be 12’ (12 feet) above residential driveways 2. Service Lateral – Wires are run underground from the utility pole to the residence. 120/240 Volt Service = 2 Hot + 1 Neutral Metering equipment – measures the use of electricity for the electric company, by how many Kwh is used.

Wire/Conductors You should strip ¾ - 7/8 ” for proper connections All splices are to be made within a box You are to have 6” excess wire at every opening The larger the AWG the smaller the wire

HAPPY VETERANS DAY THANK A VETERAN hdcA hdcA R8W-c R8W-c

Breakers Main is usually 100 amp service – 100 x 120 volts = 1200 watts total – 100 x 240 volts = 2400 watts total 15 amp breaker at 120v = (15 x 120) = 1800 watts 20 amp breaker at 120v = (20 x 120) = 2400 watts 30 amps at 120 v = 3600 watts Note: No more than 80% of available wattage should be used.

Try these 1.Will a 15 amp fuse blow with a 100 watt light bulb, a 2 watt clock, a 300 watt freezer, and an 8 watt electric razor on at the same time? 2. Will a 20 amp fuse blow with a 350 watt color TV, a 175 watt clothes washer and a 4000 watt dryer on it?

Grounding Grounding – the connection of all parts of wiring installation to the earth providing safety and protection of the system and the people installing and using the system. 1.) System Grounding – connection of one of the conductors (neutral) to the earth. This is done by attaching the neutral wire to all light sockets and all receptacles in the circuit. The neutral wires are then connected to the neutral bus bar in the service panel which is connected to ground by a ground rod 8feet deep and/or cold water piping. Bonding – connecting all metal parts of the system for good continuity.

Equipment Ground 2.) Equipment grounding – this is joining all metal parts of the wiring system and bonding it to the equipment grounding conductor. One conductor (green/bare) is grounded by connecting it to the grounding bus bar. The equipment ground protects the electrical equipment from damage during a ground fault ( a live conductor touches the box).

Electrical Prints and Specs Print – is a copy of a drawing that illustrates materials, locations, and methods used for installations. Electrical Print – uses symbols to represent fixtures, receptacles, switches and panels. It is used to order the equipment, determine the length of wires and cables needed, and inform the local inspector.

Print Scale A Scale is used to draw a floor plan on a smaller scale. For instance a home that is 30’x 40’ may be represented using a scale of ¼” = 1’ so the home drawn will measure 7 ½” x 10” (7 ½ x 48 = 360, 360/12 = 30’) (10 x 48 = 480, 480/12 = 40’) (ie. multiply the denominator (4) by 12 to get the size of the new drawing 1/48 th the size) ½” = 1” - 1/24 th 1/8” = 1’ – 1/72 nd

Practice scale ¼” =1’ – A wall 6” long on a drawing would actually be what? 24’ in real life – 12 x 4 = 48, 48 x 6 = 288, 288/12 = 24’ (6 x 4 = 24) – A wall 1/12” long on a drawing would actually be what? 6’ in real life – 12 x 4 = 48, 1.5 x 48 = 72, 72/12 = 6’ (1.5 x 4 = 6)