Electrical symbols according to IEC 60617
The most common symbols in control panel schematics, what each detail of the drawing means and the rules that make everyone read them the same way.
What IEC 60617 is
IEC 60617 is the international standard for graphical symbols in electrical diagrams. It used to be published in printed parts (IEC 60617-2 to IEC 60617-13); today it is an online database that IEC keeps up to date, with about 1,900 symbols. In Europe it is adopted as EN 60617.
Each symbol has a reference number, a name, a drawing and rules of application. How symbols are placed in a document (orientation, drawing of connections, reading direction of texts) is set by another standard: IEC 61082-1.
The most common symbols
Contacts are drawn vertically, with the supply at the top. The red label is the device class letter according to IEC 81346-2, explained in our IEC 81346 designation guide.
The semicircle, cross and bar on the fixed contact are called function qualifiers: with them, the same basic contact becomes that of a contactor, a circuit breaker or a disconnector.
Rules for drawing them
- Rest position. Everything is drawn de-energised and unoperated: a NO contact is shown open even if it is closed while the machine runs.
- Mechanical link. The dashed line joins parts that move together, such as a push button and its contact.
- Detached representation. The coil sits in the control circuit and its contacts in the power circuit, sometimes on other sheets. They are tied together by the same designation (for example -Q2) and a cross-reference table under the coil.
- Orientation. Symbols can be rotated or mirrored without changing their meaning. Texts are placed so they read from the bottom or from the right of the drawing.
Terminal marking
Coil and contact terminals are always numbered the same way, so the wiring can be understood without looking at the device:
| Element | Terminals |
|---|---|
| Coil | A1 – A2 |
| Main contacts | 1-2 · 3-4 · 5-6 |
| NO auxiliary contact | 13-14 · 23-24 · 33-34… |
| NC auxiliary contact | 21-22 · 31-32 · 41-42… |
On auxiliary contacts, the first digit is the sequence number and the second gives the function: 1-2 for NC and 3-4 for NO. This marking is set by the switchgear standard IEC 60947-1.
IEC versus ANSI
In North America, ANSI/IEEE 315 symbols and ladder diagrams, drawn horizontally, are used. The most visible differences:
| Element | IEC 60617 | ANSI/IEEE 315 |
|---|---|---|
| NO contact | ||
| NC contact | ||
| Coil |
If you work for that market, check which standard the customer requires before starting the project.
Symbols in FaseCAD
FaseCAD ships with a symbol collection and an editor to create your own. If you draw a new one, follow these rules: connections at the top and bottom, rest position and the IEC 60617 function qualifiers.
IEC 81346 designation guide FAQ
Common questions
Where can I see all the symbols?
In the IEC 60617 database, available by paid subscription. Switchgear manufacturers usually include their devices' symbols in their catalogues and CAD libraries.
Why is the NO contact drawn open if the machine is running?
Because the schematic shows the rest position: de-energised and unoperated. That way everyone starts from the same situation when following the circuit.
Are IEC 60617 and EN 60617 the same?
In content, yes: EN 60617 is the European adoption of the IEC 60617 symbols.
Links
- IEC 60617 DB · Database of graphical symbols for diagrams (official IEC page)
- IEC 61082-1:2014 · Rules for preparing documents used in electrotechnology (official IEC page)
- Electronic symbol on Wikipedia
- Reference designation according to IEC 81346 · FaseCAD guide