#Example of single line diagram series#

Starting at the top, you will notice that a transformer is feeding power to the whole system. To explain this easier, we have divided the single line into three sections. This helps to keep the voltages and their paths straight. When interpreting a single line diagram, you should always start at the top where the highest voltage is and work your way down to the lowest voltage. Lets go through a industrial single line diagram. Non-circuit breaker type transfer switch.One circuit breaker representing a main device and other circuit breakers representing feeder circuits usually in a common enclosure.

#Example of single line diagram series#

The symbol is a combination of a normally open contact (switch), overload relay, motor and disconnect device.Ī series of circle symbols representing meters usually mounted in a common enclosure. The symbol is a combination of a fuse and disconnect switch with the switch in the open position. The symbol is frequently shown in conjuction with a transfer switch. Protects a motor should an overload condition develop. Additional motor information is commonly printed next to symbol, such as horsepower, RPMand voltage.Ĭan represent a single contact or single pole switch in the open position for motor controlĬan represent a single contact or single pole switch in the closedposition for motor control Represents a motor and is also shown with an “M” inside the circle. Represents a battery in an equipment package Represents potential transformers usuallymounted in assembled equipment. Represents current transformers mounted in assembled equipment. Represents a switch in low or medium/high voltage applications (open position shown) Represents a fixed mounted low voltage circuit breaker. Additional information is normally printed next to symbol indicating winding connections, primary /secondary voltages and KVA or MVA ratings. Represents a variety of transformers from liquid filled to dry types. This chart shows the most frequently used symbols. To interpret one-lines you first need to be familiar with the electrical symbols. We use universally accepted electrical symbols to represent the different electrical components and their relationship within a circuit or system. It is very versatile and comprehensive because it can depict a very complicated three-phase system. A single line can show all or part of a system. The single-line diagram is very simplified and should be used primarily to learn (in very broad terms) the function of each of the various components as a part of the total system.We usually depict the electrical distribution system by a graphic representation called a single line diagram (SLD). There are no interconnections shown for selected components as were shown on the block diagram (for example, alternator to voltage regulator and back to the battery). Second, the single-line diagram shows all components in a single line (figure 3-9). The first difference is that the single-line diagram uses symbols, rather than labeled blocks, to represent components. There are two major differences between the single-line diagram and the block diagram. When used with text material, it gives you a basic understanding of the functions of the components of a system. SINGLE-LINE DIAGRAM The single-line diagram is used basically for the same purpose as the block diagram. There are block diagrams that show strictly mechanical components or both mechanical and electrical components. The illustrated block diagram is of the electrical system only. The engine is a mechanical rather than an electrical function. Note that the engine is not shown in the block diagram as the prime mover for the alternator.

This completes the cycle until the engine is shut down and started again. At the same time, the alternator supplies power back through the voltage regulator to the battery for charging purposes. It supplies power through the ignition switch to the coil, from the coil to the distributor, and finally from the distributor to the spark plugs. (This is accomplished through a belt and pulley system attached to the engine's crankshaft.) The alternator now takes over as the power supplier for the ignition system. The running engine acts as the prime mover for the alternator. Once the engine is running, the starter is no longer required. From the coil, power is supplied to the distributor and finally to the spark plugs for ignition. Power is also supplied, through the ignition switch, to the coil. The starter is turned by power from the battery when the ignition switch is turned to the START position. The battery is the initial source of power for the starter and ignition systems.