Standard symbols, units and graphical symbols for general electrical purposes.

The following symbols are extracted mainly from IEC 60617, supplemented by references from other Standards.

General symbols

	Direct Current (or d.c.)
	Alternating Current (or a.c.)
2	two-phase alternating current
2N	two-phase alternating current with neutral
3	three-phase alternating current
3N	three-phase alternating current with neutral
IPXX	IP number (See index of protection
	Fault (indication of assumed fault location)
	Class II appliance (Equipment in which protection against electric shock does not rely on basic insulation only, but in which additional safety precautions such as supplementary insulation are provided, there being no provision for connection of exposed metalwork of the equipment to a protective conductor, and no reliance upon precaution to be taken in the fixed wiring of the installation).
	Class III appliance (Equipment in which protection against electric shock relies on supply at SELV and in which voltages higher than those of SELV are not generated)
	Safety isolating transformer. Class III equipment must be supplied from a safety isolating transformer to BS 3535. The safety isolating transformer will have this identifying mark upon it.
	Isolating transformer
	Protective earth, general symbol (preferred to )

Symbols for use in schematic wiring diagram

	Transformer, general symbol
	General Wiring, with joint

Identification of specific conductors

	Operating device, general symbol (coil)
	Make contact - normally open
	Break contact - normally closed
	Manually operated switch, general symbol
	Three-phase winding - delta
	Three-phase winding - star
	Changer, general symbol Converter, general symbol Notes: (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 the change
	Rectifier
	Inverter
	Battery of primary or secondary cell - longer line positive, shorter line negative
	Fuse link, rated current in amperes
	Capacitor, general symbol
	Inductor, coil, winding or choke
	Inductor, coil, winding or choke with magnetic core
	Semi Conductor Diode - general symbol

Making and breaking current

	Switch
	Switch-fuse
	Fuse-switch

Isolating

	Isolator (Disconnector), general symbol
	Disconnector - fuse (fuse combination unit)
	Fuse - disconnector
	Circuit-breaker suitable for isolation

Making, breaking and isolating

	Switch - disconnector
	Switch - disconnector - fuse (fuse combination unit)
	Fuse - switch - disconnector

Meters

	Voltmeter
	Ammeter
	Integrating instrument, or Energy meter * function Wh=Watt-hour VArh=Volt ampere reactive hour

Location symbols for Installations

	Machine general symbol * function M=Motor G=General
	Motor Starter, general symbol
	Star-delta starter
	Socket-outlet, general symbol
	Switched socket-outlet
	Switch, general symbol
	2 way switch, single pole
	Intermediate switch
	Pull switch, single-pole
	Lighting outlet position, general symbol
	Fluorescent luminaire, general symbol
	Emergency lighting luminaire (or special circuit)
	Self-contained emergency lighting luminaire
	Push button with indicator lamp
	Lamp, or signal lamp, general symbol
	Clock, general symbol
	Acoustic signalling device, general symbol (e.g. bell
	Buzzer
	Telephone handset, general symbol
	Microphone
	Loudspeaker
	Antenna, general symbol
	Generator, general symbol