Electrical symbols appear in schematics for devices and locations that include electrical wiring and components. These symbols are often found in electrical schematics for house and business designs as well as in electrical schematics for devices such as computers and televisions. The symbols help to explain the abstract nature of electrical schematics and help designers plan current and future designs.
Current Distribution Symbols
Current distribution uses the "~" symbol to signify the relationship between alternating current m-phases and frequency. The term "1~50 Hz," for example, signifies a single-phase alternating current with a frequency of 50 hertz. The term "3~50 Hz" states a three-phrase alternating current with a frequency of 50 hertz.
A long, straight line signifies direct current. For example, the term "110 V ---- 110 V" states a direct current relationship between two 110-volt sources.
A "+" symbol shows positive polarity while "-" shows negative polarity.
Common Outlet Symbols
Outlet symbols are defined using a circle. If the circle has a line extending from it, the outlet is placed on a wall. If no line exists, the outlet is intended for a ceiling. Any letters in the circle determine the type of outlet. If no letters are used, then it is a general outlet.
Common letters include "F" for fan outlets, "J" for junction boxes, "L" for lamp holder, "S" for pull switch, "X" for exit light and "B" for blanked outlet.
A circle with no outer line and a center black dot signifies a floor outlet.
Powered wires are displayed with straight single lines on electrical schematics. Different types of lines show different types or locations of these wires. A staggered line shows an underground line, while a line with alternating short and long dashes shows wires concealed in floors. Solid lines mean existing wires, and lines with a long dash and three short dashes mean planned wiring. A circle intersecting a solid line designates an overhead line.
Line intersections can be shown using three common symbols. Two lines intersecting as well as one line "crossing" another using an inverted "U" mean that the lines are not connected. Two lines intersecting with a solid dot on the intersection point means that the two lines are connected.
Building Floor Plan Symbols
The construction of a new building, whether a small one-bedroom home or a huge shopping mall, is a demanding and labor-intensive process...
About 3-Phase House Wiring
Many people don't put much thought into electricity. We simply flip a switch or plug something in. In order for our electrical...
About 110 Volt House Wiring
110 Volt AC (Alternating Current) is the standard wiring system in all U.S. homes. This current runs our applances, gives us light...
Electrical Signs & Symbols
Electrical signs and symbols are used in plans to show the different kind of electrical elements used. Primarily used by architects and...
277 Volt Vs. 208 Volt
Anytime you hear of voltages like 120/208 and 277/480, bear in mind that these are three-phase voltages and are not available to...
How to Draw an Electrical Floor Plan With Circuits
Drawing accurate, detailed electrical floor plans is one of the essential steps in applying for an electrical-wiring permit. Standard symbols indicate the...
How to Read Electrical Prints
Print reading for electrical drawings can be challenging because you have to memorize and become familiar with electrical symbols. In addition, there...
What Is the Meaning of Floor Plan Symbols?
Looking at a floor plan for the first time can be like encountering the alphabet of a foreign language. While some aspects...
List of CAD Symbols
Computer-aided design applies technology to the art and craft of draftsmanship. Drafting tables have given way to large-screen computers and blueprint-sized printers....