Reading equipment symbols consistently is essential when a drawing connects process equipment, electrical controls, and field installation work. This motors and generator symbols CAD legend provides a practical visual reference for identifying common drivers, generators, rotating equipment, and motor-operated devices in engineering documentation.
Use the downloadable DWG alongside your project template, P&ID symbol library, electrical drafting standards, and equipment schedule. The legend supports drafting and review; it does not replace the project specifications, equipment data sheets, control narratives, or engineering verification required for design decisions.
This Motors & Generators Symbols Legend CAD sheet is a clean reference for P&ID, electrical, and process/MEP drawings. It includes common symbols used to represent motors, generators, drivers, and rotating equipment, helping your diagrams stay consistent and easy to read for designers, installers, and commissioning teams.
The legend typically includes:
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Motor symbols (standard motor, AC motor, DC motor, step motor)
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Generator symbols (generator, AC generator, DC generator)
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Motor-generator (MG) set symbol
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Gear symbol for driven equipment
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Diesel motor driver symbol
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Motor-driven turbine and turbine symbols
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Motor-operated valve (MOV) symbol for actuated valves in piping systems
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Basic electric motor representations used in schematics
Use this CAD legend for:
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P&ID and process diagrams
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MEP equipment schedules and control diagrams
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Electrical single-line / control documentation (as a symbol reference)
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Standard templates for drafting teams and QA checks
How to use the motors and generator symbol legend
Begin by identifying the function of the symbol in the drawing. A motor generally indicates an electrical driver, while a generator indicates equipment that produces electrical power. A driver symbol may instead represent the prime mover or mechanical source associated with rotating equipment. Context from nearby tags, lines, valves, notes, and control signals is necessary before assigning a detailed equipment meaning.
Match the symbol to the drawing type
- P&IDs: Use the legend to recognize equipment drivers, motor-operated valves, turbines, and related process items. Confirm the symbol against the project P&ID conventions and the equipment tag.
- Electrical drawings: Treat the icons as graphical references within control documentation or single-line diagrams. Verify connections, protection, switching, and power-system information from the applicable electrical documents.
- MEP and control diagrams: Coordinate motor, generator, and actuator symbols with equipment schedules, sequences of operation, and controls point lists.
- CAD standards: Keep the downloaded DWG with the project block library or drafting reference set so reviewers can compare symbol usage during QA checks.
Distinguish equipment function from symbol appearance
Similar-looking symbols can represent different equipment functions, such as an AC motor, DC motor, step motor, generator, motor-generator set, diesel driver, or turbine. The symbol communicates a drafting convention, not every operating characteristic. Use the associated equipment tag, specification, and control logic to confirm the intended application.
Why the motor-operated valve symbol matters
A motor-operated valve symbol links an actuated piping component with its electrical or control function. On coordinated drawings, review the valve tag, actuator information, power or control references, and process duty together. This helps prevent a symbol from being interpreted as a manually operated valve or as a standalone motor.
Related reference topics
This resource can be paired with internal references for P&ID symbols, valve symbols, piping terminology, flange and fitting references, electrical single-line diagrams, and CAD/DWG drafting standards. Linking these topics near the download gives readers a clear path from symbol identification to drawing coordination.
Frequently asked questions
What is included in this CAD legend?
The legend includes common symbols for motors, generators, motor-generator sets, gears, diesel drivers, turbines, motor-operated valves, and basic electric motor representations.
Can this legend be used for P&IDs?
Yes. It is intended as a reference for P&IDs and process diagrams, but the project-specific P&ID legend and drafting requirements take precedence when they differ.
Is the DWG a complete electrical design?
No. The DWG is a symbol reference. Electrical design information such as circuits, protection, controls, ratings, and connections must come from the applicable project documents and engineering review.
How should a symbol be confirmed during drawing review?
Compare the symbol with the equipment tag, nearby notes, control signals, process connections, equipment schedule, and project legend. Do not infer unshown performance or design information from the icon alone.
What does an MOV symbol represent?
An MOV symbol represents a motor-operated valve in a piping or control context. Confirm its actuator, power, control, and fail-action information from the project documentation.