For engineers tasked with designing control panels and electrical systems, a thorough understanding of electrical formulas and symbols is essential. Whether you are calculating current and voltage or interpreting detailed schematics and diagrams, the common formulas and symbols below provide the foundation upon which most designs are built.
But with so many different equations and symbols to keep track of, it can be challenging to memorize them all. In this article, we’ll explain some of the most important electrical formulas and electrical symbols that engineers must know to create accurate and effective control panel designs and drawings. Whether you’re a seasoned pro or just starting out in the field, this guide will provide you with the knowledge and tools you need to succeed.
Common Electrical Formulas
Keep the Electrical Formula Key in mind when referencing the formulas below, as the abbreviations are used throughout.
Ohm’s Law helps us calculate the relation between voltage, current, and electrical resistance. Ohm’s Law helps us calculate the relation between voltage, current, and electrical resistance.
For calculating AC & DC Electric Formulas, we must first realize that, depending on the type of current in your circuit, Alternating Current or Direct Current formulas will be used. This Electric Power, also known as AC Power and DC Power, can be calculated using the formulas in this table.
For quick reference, we’ve provided the values for some of the most common calculations in the chart above for you here.
To find the Efficiency or Power Factor for Single-Phase or Three-Phase Alternating Current, you can use the formulas in the table below.
To determine the Voltage Drop of your Single-Phase or Three-Phase installation, use these simple calculations. Remember to reference the Key at the top of the page if necessary.
Below are some common Standard to Metric length conversions that are very useful when calculating voltage drop for various electrical runs
We use this Temperature Conversion Formula often when converting temperatures between Celsius to Fahrenheit or vice-versa, Fahrenheit to Celsius.
Common Electrical Symbols
Electrical symbols are an essential tool for engineers working on control systems design. These common symbols provide a universal language for representing various electrical components and circuits, making it easier to communicate design ideas and collaborate with other professionals. We’re taking a closer look at some of the most commonly seen electrical symbols found in circuit diagrams (electrical circuit diagrams), schematic diagrams, and other engineering work and explore their meanings and applications.
In electrical drawings, you will find various symbols for Switches, Pushbuttons, Pilot Lights, Contacts, Coils, Overload Relays, Inductors, and Transformers. We’ve illustrated what these electrical symbols represent for easy reference in the graphic below.
Below you’ll find easy reference illustrations for AC Motors, Schematic Wiring, DC Motors, Resistors, and Supplementary Contact Symbols.
This illustration features common electrical symbols that identify Static Switching Control Devices and Power Connections.
Sources: https://www.engineeringtoolbox.com/electrical-formulas-d_455.html, Siemens quickSTEP Online Courses – Basics of Control Components