Electrical control diagram symbols are used to represent components and functions in circuit diagrams clearly and consistently. This page provides a practical guide to commonly used electrical symbols based on international standards such as BS EN 60617, BS 3939, and IEC standards. It includes symbols for conductors, earth connections, resistors, capacitors, inductors, control devices, and signal elements. These symbols are essential for engineers, technicians, and students working with electrical schematics, control panels, and automation systems.
symbols shown below are generally based on BS 7845:1996 , BS 3939 and BS EN 60617
The diagrams are produced using symbols as building block combining functional symbols
with symbols for variability and operation and material.. The number of symbols are very
large and BS EN 60617 includes many fields from power generation to solid state electronics.
The symbols below are just a selection related to the fields related to general engineering provided as a general guide.
For details showing proportions and sizes reference to the standards is necessary
Following are typical symbols associated with conductors..
Following are typical symbols associated with Earth..
Following are typical symbols associated with Variables applied to conductors and electrical elements..
Following are typical symbols associated with Electrical Resistors..
Following are typical symbols associated with Capacitors & Inductances..
Following are typical symbols associated with Operators ..
Following are typical symbols associated with Operators ..
Following are typical symbols associated with Control gear ..
Below are common questions about electrical control diagram symbols, standards, and usage in engineering drawings.
Electrical control diagram symbols are standardized graphical representations of electrical components such as switches, resistors, relays, and conductors used in circuit diagrams.
Common standards include IEC 60617 (international), BS EN 60617 (UK), and BS 3939. These define symbols used in electrical schematics and control diagrams.
Standard symbols ensure consistency and clarity in electrical drawings, allowing engineers and technicians to understand circuits regardless of location or manufacturer.
IEC symbols are widely used internationally and in Europe, while ANSI symbols are more common in North America. The symbols may differ in appearance but represent the same functions.
Grounding symbols represent different types of earth connections such as protective earth, chassis ground, and signal ground, each with a slightly different graphical symbol.
Resistors are typically shown as rectangular or zigzag shapes, while capacitors are represented by parallel lines. Variations indicate adjustable or polarized components.
Control gear symbols represent devices such as relays, contactors, switches, and circuit breakers used in electrical control systems.
They are used in circuit diagrams, control panels, industrial automation systems, electrical schematics, and maintenance documentation.