Topic 2 Reading Blueprints and Drawings SCO 2.14

SCO Students will be expected to: – 2.14 read and interpret electrical draw ings [1.401][1.402][1.403][2.401][2.402]

Why? The purpose of this outcome is to provide an introduction to the basic electrical symbols used on floor plans.

Electrical drawings are used by carpenters to build the structures needed to hold the electrical devices. They are used by electricians to plan circuits and wiring runs, and to place electrical boxes and wires for the electrical rough-ins

Electrical Devices Switches : 1.A single-pole switch is one switch that controls one light or a group of light fixtures. It has two screw terminals on the side plus one green screw for the ground wire. 2.A three-way switch has two switches that control the same fixture or fixtures. It has two like colored screws, one darker-colored screw, and one green screw for the ground wire.

Electrical Devices - Switch

Electrical Device Symbols

Electrical Devices - Receptacle Outlets A duplex outlet, your standard outlet, is called a duplex because it has two places to plug into. Non-grounded outlets are duplex outlets without the third hole below the two vertical slots. This outlet doesn't have a ground wire running to it. If you have any equipment that requires a ground, it is best to get the outlet grounded than to use one of the adaptors.

Duplex Receptacle

Non-grounded Receptacle

A GFCI or Ground Fault Circuit Interrupter is most easily recognized by the two buttons in the middle of the outlet. It is used wherever water is nearby - kitchen, bathroom, outside outlets, and in unfinished basements, due to its sensitive nature to power surges.

Ground Fault Circuit Interrupter

A switched outlet is a duplex outlet that is controlled by a switch or dimmer. In most cases only one-half of the outlet is switched. A single outlet, this outlet has only one spot to plug something into it. It is commonly used where a dedicated piece of equipment will be used near water. A clothes washer is the most common use in a residential home.

Switched Receptacle

Single Receptacle

Wiring Plan This plan for wiring a kitchen includes a 15-amp circuit for lights, some controlled by three-way switches. A 20-amp refrigerator circuit has been added, as well as two 20-amp small- appliance circuits and a 20- amp circuit for the dishwasher and garbage disposer. The range has its own circuit.

Assignment Given an Electrical Drawing, examine it and make a list of the: – Locations and number of 120 volt receptacles – Locations and number of lights – Locations and number of switches and the devices they control, distinguishing single, and three-way switches