Convenience Devices

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Items and markings that are found on switches are also found on outlets (Figure 2-1).

Figure 2-1.  Basic receptacles

Figure 2-1.   Basic receptacles

A grounded electrical system, where all components and devices are grounded, offers maximum protection from electrical shock and equipment damage. The electrical layout in Figure 2-2 is a very simple branch circuit, but all circuits work basically the same. Notice in the figure that the grounding wire, which is either green or bare, is attached to the green hexagonal terminal.

Figure 2-2.  Electrical layout

Figure 2-2.   Electrical layout

The grounding blade on appliances and extension cords is designed so that plugs will be grounded before current is applied to the blade of the male plug. As you can see in Figure 2-3, the grounding blade is longer than the current-carrying blade.

Figure 2-3.  Grounding blade

Figure 2-3.   Grounding blade

The grounding blade and the green grounding screw are tied together along with the mounting bracket. As you can see in Figure 2-4, the grounding blade hits the grounding terminal first. This helps to prevent electrical shook by allowing current to flow to ground in case of a fault.

Figure 2-4.  Grounding terminal

Figure 2-4.   Grounding terminal

When a switch circuit with a split wired duplex receptacle is needed, the most common setup has a split hot or ungrounded terminal and a common neutral or grounded bar. The top of the outlet is always hot. The bottom outlet is controlled by a switch. This is useful, for example, in the kitchen. The garbage disposal and the dishwasher are plugged into the same receptacle, the garbage disposal is controlled by the switch and the dishwasher has constant power but the two devices share a common neutral (Figure 2-5).

Figure 2-5.   Split hot terminal and common neutral bar

Figure 2-5.   Split hot terminal and common neutral bar

Content provider: U.S. Army, David L. Heiserman
Publisher: SweetHaven Publishing Services

Copyright 2005, SweetHaven Publishing Services
All Rights Reserved.

Revised: April 19, 2005