HomeElectrical SymbolsMust-Know Electrical Symbols for Electricians

Must-Know Electrical Symbols for Electricians

Location Symbols for Installations

Machine, general symbol
* function etc
Load, general symbol
* details
Motor starter, general symbol
* Indicates type etc.
Socket-outlet, general symbol
 Twin Socket-outlet, general symbol
Switched socket-outlet
 Twin Switched socket-outlet
Switch, general symbol
2 way switch, single pole
Intermediate switch
Pull switch, single-pole
Push button
Clock, general symbol
Bell (Audible)
Buzzer (Audible)
Siren (Audible)
Horn
Telephone handset, general symbol
Making and breaking current
Switch
Switch- fuse
Fuse-switch
Isolating
Isolator (Disconnector), general symbol
Disconnector – fuse (fuse combination unit)
Fuse – disconnector
Making, breaking and isolating
Switch – disconnector
Switch – disconnector – fuse (fuse combination unit)
Fuse – switch – disconnector
Capacitor, general symbol
Inductor, coil, winding or choke
Inductor, coil, winding or choke with magnetic core
Semi Conductor Diode – general symbol
Microphone
Loudspeaker
Antenna, general symbol
Machine, general symbol
* Function M=Motor G=Generator
Generator, general symbol
Indicating instrument, general symbol
* function V = Voltmeter A = Ammeter etc.
Integrating instrument or Energy meter
* function Wh = Watt-hour
VArh = Volt ampere reactive hour
Lamp, or signal lamp, general symbol

Lamps & Lighting

The following table provides the commonly used electrical wiring schematic symbols for push-buttons and lamps which comply with the IEC and BS Electrical Symbols. We have included the Normally Open and Normally Closed status for each contact.

Lamp (Standard)
Lamp Standard
Filament Lamp
Lamp (Flashing)
Lighting outlet position – general symbol
Fluorescent luminaire
Wall mounted luminaire
Self – contained emergency lighting luminaire
Emergency lighting luminaire (or special circuit)
Light Emitting Diode (LED)

Connectors and Earthing

The following table provides the commonly used electrical wiring schematic symbols for connectors which comply with the IEC and BS Electrical Symbols. These connectors include plug and socket, coaxial, terminal and earth connectors.

Plug MaleSocket (plug female)
Coax Plug MaleSlow Operating Relay – Delay On
Wire Connections (Two Wires)Wire Connections (crossed)
Wires Crossing (Not Connected)Terminal Connector
Terminal BlockEarth Connection
Noiseless EarthProtective Earth
Chassis EarthEquipotentiality

General Symbols

AmmeterVoltmeter
Circuit BreakerSelector Switch
(N/O) Normally Open
(N/C) Normally Closed
Contactor
(N/C)
Contactor
(N/O)
Limit SwitchThermal Overcurrent
Mechanical InterlockVoltage Transformer
PotentiometerSolenoid Valve

Contacts and 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
(N/O)
Delay on re-opening
Thermal Switch – Overload
(N/O)
Thermal Switch – Overload
(N/C)
Temperature Switch
(N/O)
Temperature Switch
(N/C)
Pressure Switch
(N/O)
Pressure Switch
(N/C)

Push-buttons

The following table provides the commonly used electrical wiring schematic symbols for push-buttons and lamps which comply with the IEC and BS Electrical Symbols. We have included the Normally Open and Normally Closed status for each contact.

- Advertisement -
Normally Open PB
(N/O)
Normally Closed PB
(N/C)
Emergency Stop PB
(N/O)
Indication Contact
Emergency Stop PB
(N/C)
Pull Switch
(N/O)
Pull Switch
(N/C)
Turn/Rotary Switch
(N/O)
Turn/Rotary Switch
(N/C)

Coils and Relays

Electrical Symbols – Coils and Relays
The following table provides the commonly used electrical wiring schematic symbols for coils and relays which comply with the IEC and BS Electrical Symbols
Contractor Coil
Relay with AC Supply
Slow Release Relay
Delay Off
General Relay
(DC Supply)
Slow Operating Relay
Delay On
Mechanically Latched Relay

Semi Conductors

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

Contractor Coil
Relay with AC Supply
Slow Release Relay
Delay Off
General Relay
(DC Supply)
Slow Operating Relay
Delay On
Mechanically Latched Relay

Other Symbols

Three-phase winding – Star
Changer, general symbol
Converter, general symbolNotes:
(1) If the direction of change is not obvious, it may be indicated by an arrowhead on the outline of the symbol.
(2) A symbol or legend indicating the input or output quantity, waveform etc. may be inserted in each half of the general symbol to show the nature of change.
Rectifier
Inverter
Primary cell – longer line positive, shorter line negative
Battery
Fuse link, rated current in amperes
Md Nazmul Islam
Md Nazmul Islam
5+ years of experience in Android and iOS app development. Educational background in Electrical Engineering. Contributing to the EEE community through creative work at Voltage Lab. For any business development or discussion, feel free to follow and message me on LinkedIn (link below).

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