Relay coil symbol
Also called Contactor coil, Control relay, CR, K
The coil of a relay or contactor. When it is energised it changes over every contact with the same designator.
What the relay coil symbol means
The coil of a relay or contactor. When it is energised it changes over every contact with the same designator.
ANSI and IEC symbols
A circle with the relay designator inside, such as CR or M for a motor starter.
ANSI SVGWhere you see it
Control relays, contactors, motor starters and interposing relays.
What is written next to it
On a schematic, the relay coil usually carries its designator, such as CR1 or K1, and the coil voltage, such as 24 V DC.
What gets checked before energising
Before the circuit is energised, the checks on a relay coil usually cover the coil voltage, and that each contact changes state when the coil is energised. Each check is recorded against the tag, so the circuit can be energised and handed over with its evidence. See the ITR guide.
Related symbols
Frequently asked questions
What does the relay coil symbol look like?
On ANSI drawings: A circle with the relay designator inside, such as CR or M for a motor starter. In IEC 60617: A rectangle, with the designator such as K1 beside it.
Is the relay coil symbol the same in IEC and ANSI?
No. A rectangle, with the designator such as K1 beside it. The IEC 60617 number is S00305.
Where is a relay coil used?
Control relays, contactors, motor starters and interposing relays.
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