The following table provides the commonly used electrical wiring schematic
symbols for coils and relays which comply with the IEC and BS Electrical
Symbols.
Contactor Coil
Relay with AC Supply
Slow Release Relay - Delay Off
General Relay (DC Supply)
Slow Operating Relay - Delay On
Mechanically Latched Relay
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
Fused Switch Open Contact
(N/O)
Limit Switch
(N/O)
Limit Switch
(N/C)
Flow Switch
(N/O)
Flow Switch
(N/C)
Time Delay
(N/O)
Delay on Closing
Time Delay
Flow Switch
(N/O)
Delay on re-opening
Thermal Switch -Overload
(N/O)
Thermal Switch -Overload
(N/C)
Temperature Switch
(N/O)
Temperature Switch
(N/O)
Pressure Switch
(N/O)
Pressure Switch
(N/C)
SEMI CONDUCTORS
The following table provides the commonly used electrical wiring schematic
symbols for Semi Conductors including diodes, capacitors and transistors.
Electrical Symbols
