The following table provides the commonly used electrical wiring schematic symbols for coils and relays which comply with the IEC and BS Electrical Symbols.

CONTACTS & SWITCHES

The following table provides the IEC and BS Electrical Symbols for contacts.  We have included the Normally Open and Normally Closed status for each contact.

Normally Open Contact

(N/O)

Normally Closed Contact

(N/C)

Change Over or 2 way Contact

Made position

Limit Switch

(N/O)

Flow Switch

(N/O)

Time Delay

(N/O)

Delay on Closing

 

Thermal Switch -Overload

(N/O)

The following table provides the commonly used electrical wiring schematic symbols for Semi Conductors including diodes, capacitors and transistors.  

Diode

Diode Reverse Blocking

Diode Reverse Conducting

Light Emitting Diode

Transistor (PNP)

Bi-directional Triode Thyristor (Triac)