Contactor Symbol: Coil, Main Contacts & Control

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• Read a contactor symbol, link its coil to the main and auxiliary contacts, and distinguish it from a relay or a manual disconnect.
• Original symbol illustrations, a reading check and feedback for learning.

What does this symbol mean?

A contactor is an electrically operated switch used to switch power circuits. Its coil and its main contacts are drawn as separate symbols that share one equipment tag, so the same tag links the operating coil to every contact it drives. A dashed link in a teaching diagram shows that functional association; it is not a conductor.

The drawing shows contact action and association, not coil voltage, contact rating, power rating or the number of poles. Main contacts and auxiliary contacts are both driven by the coil but serve different functions, so use the tag, legend and equipment schedule to tell a contactor apart from a relay or a manual disconnect.

See the symbol

How to read it in context

1. Find the coil symbol and its device tag, then locate every contact carrying the same tag on the other sheets.
2. Separate the main contacts (power path) from the auxiliary contacts (control and interlock paths) using the legend and the tag references.
3. Read each contact in its documented reference state and note NO or NC before tracing the control sequence.
4. Use the contactor schedule, coil data and manufacturer terminal diagram for voltage, coil type, ratings and terminal numbers. The drawing does not authorize wiring or energising.

Common look-alikes and mistakes

• A relay and a contactor both use a coil to drive contacts, but their purpose, ratings and applicable standards differ; read the tag, legend and schedule.
• The dashed linkage mark means association, not a conductor or a mechanical dimension.
• Main contacts and auxiliary contacts are driven by the same coil but are not interchangeable; one shared tag does not prove identical ratings.
• The symbol does not prove the present contactor state, isolation, absence of voltage or a safe work condition.

Try the symbol-reading check

Standards, sources and related symbols

These are independently drawn teaching diagrams. They help you read a drawing, but the project legend, applicable standard and equipment documentation control the actual meaning. Editorial source check: 29 October 2026.

• IEC 60617 — graphical symbols for diagrams
• IEC 60617 — graphical symbols for diagrams
• US Department of Energy — Engineering Symbology, Prints, and Drawings
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• Electrical Drawing Symbols: 4 Core Diagram Types
• Content responsibility and review status