Understanding Symbols Associated with Electrical Work

I was never good at languages, but you need to be if you are going to work with electrical systems. Specifically, you need to understand the unique symbols found in electrical systems.

When a person looks on a jumble of wires in the back of an electronic device, or even within the walls of his own home, he often shakes his head in confusion. He thinks that he would need to be a trained electrician to make any sense of it all. The truth is that a trained electrician would see a jumble of wires as a jumble of wires also. In most cases, the electrician is going to rely on a blueprint rendition of the electrical circuits. These blueprints reduce the entire electrical system to a series of schematic symbols.

Using these schematic symbols, the circuit logic of an electrical system can be understood and the necessary work performed. Reading blueprints and having knowledge of the schematic symbols used is a basic part of the training of an electrician. The symbols are standard in most cases, although slight variations might exist in some schematic drawings. In the case of variations, the electrician must be familiar with all symbols used.

An electrical system must be closed in order to operate. This means that current must flow with disturbance through the system. However, in order to perform various tasks current can be shut off to certain parts of the system and turned on to others through the use of switches and relays. The current activates various mechanisms within the system such as controllers and motors. All of this activity must be reduced to the blueprint. Schematic symbols are used to represent all of these various components of the system.

The schematic drawing represents a circuit. The basic unit of any electrical circuit is the conductor. This is most often a wire. A straight line is generally used to represent the conductor in a schematic drawing. When two lines cross without a symbol, this represents two wires that are not connected. In order to show a connection, a dot is used where the two wires intersect. The presence of a dot indicates the connection and shows that current passes through both wires at this point. Some schematics indicate non-connecting wires by showing a semi-circle bridge at the intersection. This is done to avoid confusion and insure the reader understands that the wires do not connect at that point.

A normal electrical schematic of a complex system might contain as many as 66 standard symbols. Each represents a different component of the system. In a case where a symbol is needed to represent something not covered by standard schematic symbols, a key must be included on the drawing. With an understanding of schematic symbols and an accurate blueprint in hand, the electrician can make sense of even the most rat nest jumble of wires.