Normally closed contact symbol
Also called NC contact, Break contact, Relay contact NC
A contact that is closed while the relay is de-energised and opens when the coil is energised.
What the normally closed contact symbol means
A contact that is closed while the relay is de-energised and opens when the coil is energised.
ANSI and IEC symbols
Where you see it
Stop circuits, interlocks between contactors and fail-safe alarms.
What is written next to it
On a schematic, the normally closed contact usually carries the designator of the coil that operates it and often the terminal numbers (21-22).
Related symbols
Frequently asked questions
What does the normally closed contact symbol look like?
On ANSI drawings: Two parallel lines with a diagonal line through them. In IEC 60617: A blade resting against a fixed contact with a short upright.
Is the normally closed contact symbol the same in IEC and ANSI?
No. A blade resting against a fixed contact with a short upright. The IEC 60617 number is S00229.
Where is a normally closed contact used?
Stop circuits, interlocks between contactors and fail-safe alarms.
- In production since 2014
- Thousands of daily users
- On MODEC FPSO projects since 2016