Electrical Symbols Chart: IEC 60617 Reference for UK Electricians

One-way, two-way, intermediate, dimmer, key, PIR, pull-cord, timer, emergency stop, isolator and fan-isolator switch symbols to BS EN 60617.

One-Way Switch

A single switch that breaks or makes the live conductor to a load from one position. The most common domestic switch — used for a single lighting circuit controlled from one location.

Used in: Most lighting circuits, fans, immersion heaters, fixed loads with single control.

Two-Way Switch

A switch with two fixed contacts and one common, allowing control of the same load from two locations. Always used in pairs with a second 2-way switch (e.g. staircase, hall-and-landing).

Used in: Staircases, halls with two entries, long corridors, bedrooms with both door and bedhead switches.

Intermediate Switch

A four-terminal switch wired between two 2-way switches to give control from three or more locations. The strappers cross over inside the switch.

Used in: Long corridors with three or more entries, large open-plan areas, stairs with mid-landing switch.

Dimmer Switch

A switch with a variable resistor or electronic dimming module that controls light output. Specify type — leading-edge for incandescent, trailing-edge or LED-rated for modern LED drivers.

Used in: Living areas, dining rooms, bedrooms; check the dimmer is compatible with the driver type.

Double two-gang switch electrical symbol BS EN 60617

Double Switch (Two-Gang)

Two switches in one plate, each controlling a separate circuit. Often shown as a single symbol with two action lines or as two adjacent switch symbols on the drawing.

Used in: Bathrooms (light + extractor fan), kitchens (main light + over-cooker light), living rooms (two zones).

Pull-Cord Switch

A ceiling-mounted switch operated by a hanging cord. Required in zone 1 and zone 2 of bathrooms where wall switches inside the room are not permitted under BS 7671 Section 701.

Used in: Bathrooms (BS 7671 701.512.3 compliant), shower rooms, en-suites; also used for high-level switches.

Fan isolator three-pole switch electrical symbol BS EN 60617

Fan Isolator (3-Pole)

A 3-pole isolating switch that disconnects live, neutral and switched-live to a bathroom extractor fan. Required for safe maintenance — must be accessible but outside the bathroom zones.

Used in: Outside bathroom door, above the fan or in an adjacent room; needed on every extractor fan installation.

PIR occupancy sensor switch electrical symbol BS EN 60617

PIR Switch (Occupancy Sensor)

A switch incorporating a passive infrared movement sensor. Turns the load on when motion is detected and off after a programmed time-out. Often combined with a manual override.

Used in: Toilets, corridors, stairwells, loft hatches, security lighting; reduces energy use in low-occupancy areas.

Timer Switch

A switch that controls load duration — either a momentary push-to-time or a 24-hour/weekly programmable timer. Common for immersion heaters, towel rails, and outdoor lighting.

Used in: Hot water tanks, towel rails, security lights, irrigation systems, signage lighting.

Key-operated switch electrical symbol BS EN 60617

Key Switch

A switch operated only with a key — used where unauthorised operation must be prevented. Common in schools, retail, plant rooms and emergency override circuits.

Used in: School halls, server rooms, retail shutters, emergency overrides, alarm bypass switches.

Emergency Stop (E-Stop)

A latching push-button that immediately disconnects supply to dangerous equipment. Mushroom head, red on yellow background. Must be reset deliberately — twist-release or key-reset.

Used in: Workshops, kitchens (cooker isolation), production lines, lifts, swimming pool plant rooms.

Isolator (Switch-Disconnector)

A switching device that fully isolates a circuit or item of equipment for maintenance. Must be lockable in the OFF position per BS 7671 Section 537. Different from a functional switch.

Used in: Boilers, immersion heaters, EV chargers, solar PV DC isolators, sub-mains, plant equipment.

Heater 45A double-pole switch electrical symbol BS EN 60617

Heater Switch (45A DP)

A 45A double-pole switch with a neon indicator, used for high-load fixed appliances. Switches both live and neutral. Often labelled with the load it controls.

Used in: Electric showers, panel heaters, immersion tanks, towel rails — anything above 13A.

Socket Outlet Symbols(15)

Single 13A, double 13A, fused spur, switched fused spur, cooker, shaver, USB, data, telephone, TV, EV charger and outdoor IP66 socket symbols.

Single 13A switched socket outlet electrical symbol BS EN 60617

Single 13A Socket Outlet

A single 13A switched socket to BS 1363. The basic socket symbol — a semicircle with a line indicating switched. UK standard for general-purpose socket circuits.

Used in: General-purpose outlets, behind appliances, individual radial circuits, kitchen specifics.

Double 13A switched socket outlet electrical symbol BS EN 60617

Double 13A Socket Outlet

A twin 13A switched socket — two outlets on one back box. Drawn as two semicircles back-to-back. Standard outlet for living spaces, bedrooms and offices.

Used in: Bedrooms (typically 2-4 doubles), living rooms, kitchens, offices — the workhorse outlet.

Fused connection unit unswitched electrical symbol BS EN 60617

Fused Spur (Unswitched)

A Fused Connection Unit (FCU) with internal fuse providing local protection for a fixed appliance. Unswitched version — no front rocker. Used where switching is not needed at the spur.

Used in: Boilers, extractor fans, central heating pumps, doorbells, fixed wireless access points.

Switched fused connection unit FCU electrical symbol BS EN 60617

Switched Fused Spur

A Fused Connection Unit with a front-panel switch + neon indicator. Allows local isolation of the fixed appliance without resorting to the consumer unit. Most common FCU type.

Used in: Towel rails, immersion heaters, garden lighting, alarms, garage door operators.

Unswitched spur outlet electrical symbol BS EN 60617

Unswitched Spur (Non-Fused)

A connection outlet without integral fuse — relies on the upstream circuit fuse or breaker for protection. Often a flex outlet plate for permanently-wired flex-connected appliances.

Used in: Flex outlets behind built-in ovens (separately fused), wall-hung TVs, fixed kitchen kit.

Cooker 45A outlet electrical symbol BS EN 60617

Cooker Outlet (45A)

A 45A cooker connection point — usually a 45A DP switch with optional 13A socket above the worktop, feeding the cooker outlet plate behind the appliance.

Used in: Electric range cookers, double ovens, hobs over 7.2 kW; supplied on its own radial circuit.

Shaver Socket

A bathroom-compliant socket with built-in isolating transformer to BS EN 61558-2-5. Permitted in bathroom zone 2 because the transformer galvanically isolates the user from earth.

Used in: Bathrooms, en-suites, hotel rooms — the only socket type permitted in bathroom zones.

USB charging socket outlet electrical symbol BS EN 60617

USB Socket

A 13A socket outlet with integrated USB-A or USB-C charging ports. Combines mains and low-voltage charging in one back box. Specify USB-C PD for modern devices.

Used in: Bedside, desks, hotel rooms, kitchen islands — anywhere phones and tablets need charging.

Data RJ45 ethernet socket electrical symbol BS EN 60617

Data Socket (RJ45)

A structured cabling outlet to BS EN 50173. Cat 5e (1 Gb/s), Cat 6 (1 Gb/s longer reach), or Cat 6A (10 Gb/s). Terminated in an RJ45 module.

Used in: Office desks, WiFi access points, CCTV camera locations, hard-wired smart home devices.

Telephone master socket electrical symbol BS EN 60617

Telephone Socket

A telephone master or extension socket. UK master socket has BT engineer test socket; extensions are wired to the master. Increasingly replaced by RJ45 data sockets.

Used in: Legacy phone wiring, fax machines, alarm phone diallers, FTTC modems.

TV aerial coaxial socket electrical symbol BS EN 60617

TV Aerial Socket

A coaxial outlet for TV aerial, FM/DAB radio or satellite. Multi-output back boxes can combine TV + FM + satellite in one face plate.

Used in: Living rooms, bedrooms, kitchens; satellite outlets need separate F-type connectors.

Communications cabinet rack electrical symbol BS EN 60617

Comms Cabinet Outlet

A communications/networking cabinet — typically a 12U or 18U wall-mounted rack housing the patch panel, network switch, router and structured-cabling termination.

Used in: Loft, plant room, under-stairs; central termination point for all data sockets in a building.

EV Charger Outlet

An electric vehicle charge point to BS 7671 Section 722. Typically 7.2 kW single-phase or 22 kW three-phase, with Type 2 (Mennekes) socket or tethered lead.

Used in: Driveways, car parks, fleet depots; needs dedicated circuit + Type A RCD or RDC-DD per 722.531.

Outdoor weatherproof IP66 socket electrical symbol BS EN 60617

Outdoor IP66 Socket

A weatherproof socket to IP66 ingress protection. Hinged cover seals against dust and powerful water jets. Must be RCD protected per BS 7671.

Used in: Gardens, sheds, outdoor power tools, Christmas lights, pond pumps, EV charging from a standard socket.

Floor Socket (Floor Box)

A flush-mounted socket installed in the floor — typically a floor box with two 13A sockets and data outlets. Used in open-plan offices where wall outlets are too distant.

Used in: Open-plan offices, conference rooms, retail floor displays, exhibition halls.

Lighting Symbols(13)

Pendant, ceiling, downlight, wall, bulkhead, high bay, fluorescent, LED strip, emergency, twin-emergency, exit sign, outside light and PIR sensor symbols.

Pendant Light

A ceiling-mounted light suspended on a flex or chain from a rose. The most common domestic light fitting — drawn as a circle with a cross.

Used in: Living rooms, bedrooms, dining rooms, hallways; the default UK domestic light point.

Flush ceiling light electrical symbol BS EN 60617

Ceiling Light (Flush)

A flush-mounted ceiling light — the fitting sits directly against the ceiling rather than suspended. Common in kitchens, bathrooms and low-ceiling rooms.

Used in: Kitchens, bathrooms, hallways with low ceilings, loft conversions.

Recessed downlight electrical symbol BS EN 60617

Downlight (Recessed)

A recessed downlight set into the ceiling void. Fire-rated downlights are required where they breach a fire-rated ceiling (e.g. flats, loft conversions, above habitable rooms).

Used in: Kitchens, bathrooms (zone-rated), corridors, retail; the modern UK lighting default.

Wall mounted light fitting electrical symbol BS EN 60617

Wall Light

A wall-mounted light fitting. Symbol drawn against the wall line of the plan. Often used with dimming or two-way switching for ambience.

Used in: Bedrooms (bedside), living rooms, hallways, staircases, restaurants.

Bulkhead Light

A robust enclosed light fitting designed for outdoor or utility use. Typically IP65 with a polycarbonate diffuser. Common with integrated PIR sensor for security.

Used in: External walls, garages, sheds, plant rooms, communal stairwells.

Outside Light

An external light fitting, typically IP44 or higher. Includes wall lights, post lights, ground-mounted spike spots, soffit downlights and porch lights.

Used in: Front and rear of houses, gardens, pathways, garages; usually with PIR or photocell control.

PIR motion sensor for lighting control electrical symbol BS EN 60617

PIR Sensor (Lighting)

A passive infrared sensor that detects movement and switches connected lights on. Separate from a PIR switch — the sensor is the input to a relay or control module.

Used in: Security lighting, corridors with extended throw, large rooms with multiple zones.

Emergency Light

A non-maintained emergency light to BS 5266. Off in normal use; switches on automatically when the mains supply fails. Tested monthly and annually per BS 5266-1.

Used in: Escape routes, stairwells, plant rooms, kitchens, places of assembly.

Twin Emergency Spot

A self-contained emergency luminaire with two adjustable spotlights and an internal battery. Provides high-output emergency illumination of escape routes on mains failure.

Used in: Open-plan offices, retail floors, plant rooms, warehouses, large halls.

Exit Sign

A maintained or non-maintained emergency exit sign to BS EN 1838. Indicates the direction of escape; runs on battery during mains failure for at least 3 hours per BS 5266.

Used in: Above doors on escape routes, change-of-direction points, top of staircases.

Fluorescent batten light fitting electrical symbol BS EN 60617

Fluorescent Fitting (Batten)

A linear fluorescent or LED-batten fitting. Most modern installations now use LED battens — same symbol applies. Lamp length specified separately (typically 1.2 m or 1.5 m).

Used in: Garages, plant rooms, workshops, kitchens, commercial corridors, retail back-of-house.

LED strip light electrical symbol BS EN 60617

LED Strip Lighting

A linear LED tape or strip light. Requires a constant-voltage driver (usually 12 V or 24 V DC). Often dimmable via the driver or via 0-10V / DALI control.

Used in: Under-cabinet kitchens, cove lighting, stairs, bathroom mirrors, retail display shelves.

High bay industrial light fitting electrical symbol BS EN 60617

High Bay Light

A high-output LED or HID light fitting designed for high-ceiling industrial spaces (typically 6-15 m mounting height). Wide-beam or narrow-beam reflectors depending on layout.

Used in: Warehouses, factories, gymnasiums, indoor sports halls, large retail spaces.

Distribution Board Symbols(14)

Consumer unit, distribution board, sub-main, MCB, MCCB, RCD, RCBO, SPD, meter, contactor, main isolator, busbar chamber, changeover and generator changeover symbols.

Consumer Unit

A domestic consumer unit (fuseboard) to BS EN 61439-3. Houses the main switch, RCD/RCBO/MCB protective devices, and (since 2018) SPD and AFDD where required.

Used in: Domestic origin of the installation — typically meter cupboard, under-stairs, garage or hallway.

Distribution Board

A three-phase or single-phase distribution board to BS EN 61439-3 (commercial). Holds MCBs, RCBOs and MCCBs serving final circuits in commercial and industrial buildings.

Used in: Commercial buildings, offices, schools, retail; one per floor or department typically.

Sub-main distribution board electrical symbol BS EN 60617

Sub-Main Board

A distribution board fed by a sub-main from the main switchboard. Sub-divides the installation into manageable zones; reduces voltage drop on long runs.

Used in: Large buildings, multi-tenant offices, plant rooms, lift motor rooms, sub-zones.

MCB (Miniature Circuit Breaker)

A Miniature Circuit Breaker to BS EN 60898. Protects against overload and short-circuit fault current. Types B, C and D differentiate by magnetic trip characteristic.

Used in: Every domestic + commercial final circuit; standard protection device on distribution boards.

MCCB moulded case circuit breaker electrical symbol BS EN 60617

MCCB (Moulded Case CB)

A Moulded Case Circuit Breaker to BS EN 60947-2. Higher current ratings (typically 100-1600 A) and higher breaking capacity than MCBs. Used as main incomers or for large feeders.

Used in: Main switchgear, sub-main feeders, large motor circuits, three-phase distribution.

RCD (Residual Current Device)

A Residual Current Device to BS EN 61008. Detects imbalance between live and neutral (earth-fault leakage) and trips. 30 mA RCDs provide additional protection against electric shock.

Used in: Bathrooms, kitchens, outdoor sockets, EV chargers — anywhere BS 7671 requires additional protection.

RCBO residual current breaker with overcurrent electrical symbol BS EN 60617

RCBO (RCD + MCB Combined)

A Residual Current Breaker with Overcurrent protection to BS EN 61009. Combines RCD + MCB in one device. Each circuit has individual earth fault and overload protection.

Used in: Modern consumer units — preferred to split-load RCD arrangements; one trip = one circuit affected only.

SPD (Surge Protection Device)

A Surge Protective Device to BS EN 61643-11. Type 1 (lightning current), Type 2 (transient overvoltage), Type 3 (point of use). BS 7671 443.4 risk assessment usually requires Type 2 at origin.

Used in: New installations + rewires — Type 2 at consumer unit origin; Type 1 where lightning protection is fitted.

Contactor

An electromagnetically-operated switch for high-current loads. Coil energised = contacts close. Used to control motors, heating, lighting circuits and timed loads remotely.

Used in: Immersion heaters with off-peak timer, motor starters, large lighting banks, HVAC plant.

Main Switch / Isolator

A main switch-disconnector at the origin of the installation. Disconnects all live conductors (including neutral on TT/IT) and must be lockable in OFF position.

Used in: Origin of every installation — domestic consumer unit, commercial main switchboard.

Electricity Meter

The utility electricity meter — point of supply, owned by the meter operator. Modern smart meters communicate consumption to the supplier automatically.

Used in: Meter cupboard, garage external wall, riser cupboard; the boundary of utility responsibility.

Changeover Switch

A switch that transfers a load between two sources (typically mains and generator). Manual or automatic (ATS). Always break-before-make to prevent backfeeding the grid.

Used in: Standby generators, UPS bypass, dual-supply critical loads, farms, remote homes.

Generator automatic transfer switch ATS electrical symbol BS EN 60617

Generator Changeover (ATS)

An Automatic Transfer Switch that detects mains failure and switches to a standby generator without manual intervention. Synchronised return-to-mains when supply restored.

Used in: Hospitals, data centres, telecoms, agricultural sites with standby plant.

Busbar Chamber

A metal enclosure containing busbars to interconnect multiple sub-main cables — typically at the main switchboard. Allows tap-offs to feed distribution boards without joint boxes.

Used in: Main switchboards, riser shafts, multi-tenant feeder distribution.

Safety + Fire + Security Symbols(17)

Smoke detector, heat detector, CO detector, fire alarm, sounder beacon, break-glass, emergency call point, CCTV, access control, door entry, motion detector, junction box symbols.

Smoke Detector

An optical or ionisation smoke detector to BS EN 14604 (single-station, domestic) or BS 5839-1 (fire alarm system). Interlinked types signal one another via wire or RF.

Used in: Every level of a domestic property, escape routes, places of assembly per regulations.

Heat Detector

A fire detector that triggers on a fixed temperature (typically 58°C) or rate-of-rise. Used where smoke detectors would false-alarm (kitchens, garages, dusty areas).

Used in: Kitchens, garages, lofts, plant rooms, smoking areas; never in dwellings without an SD elsewhere.

CO Detector

A carbon monoxide detector to BS EN 50291. Required in rooms with combustion appliances under the Smoke and CO Alarm Regs 2022 (England) and similar in Wales/Scotland.

Used in: Living rooms with gas fires, bedrooms above garages, rooms with solid-fuel stoves or boilers.

Fire Alarm Sounder

A fire alarm sounder to BS EN 54-3. Produces minimum 65 dB at the bedhead per BS 5839-1, with the fire-alarm tone defined in BS 5839 Annex E.

Used in: Commercial premises, HMOs, places of assembly; covered by fire risk assessment.

Sounder + Beacon

A combined audible + visual alarm device to BS EN 54-23. The visual indicator is required for the hearing impaired and in high-noise environments where audible signals alone may not be heard.

Used in: WCs, plant rooms, factories, schools, disabled refuge areas, swimming pools.

Manual Call Point (Break Glass)

A manual call point to BS EN 54-11. The break-glass/press-glass element used to manually trigger the fire alarm system. Sited near exits and on escape routes.

Used in: Every fire-alarm system; on escape routes, at exits, at landing levels.

Emergency Call Point (Disabled WC)

A disabled-toilet emergency assistance alarm to BS 8300. Pull-cord activator + reset button + indicator outside the WC. Required under Building Regs Part M.

Used in: Accessible WCs in commercial buildings, hospitality, public buildings.

Disabled Refuge Alarm

A two-way emergency voice communication point at a disabled refuge to BS 5839-9. Allows people awaiting evacuation to communicate with the main control room.

Used in: Stairwells in multi-storey commercial buildings, evacuation lift lobbies.

Motion detector intruder alarm electrical symbol BS EN 60617

Motion Detector (Security)

A PIR or microwave motion detector for an intruder alarm system to BS EN 50131. Typically wall-mounted at 2.0-2.4 m with coverage of 12 m × 12 m for standard PIR.

Used in: Hallways, large rooms, garages; works with door contacts to form a complete zone.

CCTV security camera electrical symbol BS EN 60617

CCTV Camera

A CCTV camera — typically IP (PoE-powered, RJ45) or analogue HD. Modern installations are IP cameras over Cat 6 with PoE+ for pan-tilt-zoom models.

Used in: Building entrances, car parks, retail floors, secure perimeters; data + power on one Cat 6 cable.

Access control card reader electrical symbol BS EN 60617

Access Control Reader

A proximity card, fob or biometric reader controlling a maglock or electric strike. Networked to a central controller. Often integrated with the fire alarm for auto-release on alarm.

Used in: Office entrances, server rooms, restricted-access plant rooms, multi-tenant lobbies.

Door entry intercom panel electrical symbol BS EN 60617

Door Entry Panel

An audio or video door entry panel at a main entrance. Connects to handset stations inside the building. Modern systems are IP-based over Cat 6.

Used in: Flats, apartments, gated developments, offices with controlled entry.

Door Release Button

A green push-button that releases an electrically-locked door from inside (the egress side). Required where access control restricts movement out of a space.

Used in: Inside doors with maglocks/strikes, server rooms, secure office areas.

Bell / Door Chime

A domestic bell or chime triggered by a push-button at the door. Often supplied via a 12 V transformer in modern wired systems, or battery for wireless.

Used in: Front door, back door, tradesperson entrance; symbol used on domestic drawings.

Extractor Fan

A wall- or ceiling-mounted extract fan. Bathroom fans typically interlocked with the light circuit and overrun timer; kitchen fans on a separate switch.

Used in: Bathrooms, kitchens, WCs, utility rooms; needs 3-pole isolator for safe maintenance.

Thermostat

A room thermostat controlling heating. Mechanical, electronic or smart (Wi-Fi). Wired thermostats need a 230 V supply or a low-voltage transformer.

Used in: Living room or hallway typically; one zone per heating loop.

Junction Box

A wiring junction box where cables are joined. Must be accessible per BS 7671 526.3 unless maintenance-free (MF) type. Modern MF boxes use spring terminals.

Used in: Loft cables, behind sockets, lighting circuits, above accessible ceilings.

Containment Symbols(9)

Conduit, trunking, busbar trunking, cable tray, cable tray drop, floor trunking, underfloor trunking, riser and floor box symbols.

Conduit

A round metal or PVC conduit containing cables. Sizes 16, 20, 25, 32 mm OD per BS EN 61386. Symbol drawn as a single line, often labelled with size and number of cables.

Used in: Surface or buried; commercial wiring, plant rooms, industrial, where cables need protection.

Trunking

A rectangular cable enclosure with removable lid. PVC, metal or compartmented. Higher fill capacity than conduit; allows easy cable additions without rewiring.

Used in: Offices, commercial corridors, server rooms; mini-trunking for surface-wired domestic installations.

Busbar Trunking

A factory-built busbar system to BS EN 61439-6. Tap-off boxes connect distribution boards or large loads along the run. High current capacity, low impedance.

Used in: High-rise risers, factories, large commercial buildings — replaces multiple sub-main cables.

Cable Tray

A perforated metal tray supporting cables along its length. Open-top, allowing heat dissipation. Common sizes 50-600 mm wide.

Used in: Plant rooms, service corridors, ceiling voids in commercial; supports SWA and multi-core cables.

Cable Tray Drop

A vertical section of cable tray dropping from a horizontal run to floor level or equipment. Drawn as a tray with directional indication of descent.

Used in: Drops from ceiling-mounted tray to equipment, riser corners, multi-storey transitions.

Floor Trunking

Trunking installed on the floor surface, typically with a low-profile ramp section. Used where furniture layouts demand power and data at floor level.

Used in: Open-plan offices with fixed desk grids, exhibition halls, retail floor displays.

Underfloor Trunking

Trunking cast into the floor screed with periodic outlet boxes for floor sockets. Allows discrete power and data delivery without surface-mounted runs.

Used in: Open-plan offices, conference rooms, retail concourses — installed at the screed pour.

Vertical electrical riser containment symbol BS EN 60617

Vertical Riser

A vertical shaft containing sub-main cables, busbar trunking, and other services running between floors. Fire-stopped at every floor penetration.

Used in: Multi-storey commercial buildings, hotels, hospitals, residential blocks.

Floor Box (Multi-Service)

A flush-mounted floor outlet housing two 13A sockets, one or two RJ45 data outlets, and optional audio/video connections. Hinged lid keeps the floor flush.

Used in: Open-plan offices, conference rooms, restaurant floors — discreet desk-level access.

Equipment Symbols(9)

Motor, transformer, UPS, generator, fan, pump, AHU, lift, sub-main and panel board symbols for installation drawings.

Electric Motor

An electric motor — typically three-phase induction. Symbol shows a circle with "M" inside. Specify phase, voltage, kW and starter type (DOL, star-delta, soft starter, VFD).

Used in: HVAC fans, pumps, lift drives, escalators, industrial machinery.

Transformer

A two-winding transformer — symbol shows two coupled coils. Step-up or step-down depending on turns ratio. Used for LV-LV (e.g. 230-12V) or HV-LV (e.g. 11kV-415V).

Used in: Doorbells, garden lighting (low voltage), 11 kV-415 V substations, isolating transformers.

UPS (Uninterruptible Power Supply)

An online or line-interactive UPS. Maintains supply to critical loads during mains failure (typically 10-30 minutes) until generator starts or supply restored.

Used in: Data centres, server rooms, hospital ITU, telephone exchanges, security systems.

Sub-Main

A sub-main supply — a cable feeding a distribution board from a higher-level board. Sized to handle the maximum demand of all downstream final circuits.

Used in: Multi-storey commercial, large dwellings, outbuildings, garages; sized for voltage drop on long runs.

Industrial extraction fan electrical symbol BS EN 60617

Industrial Fan

A large-volume fan — axial, centrifugal or in-line. Drawn on plans where the electrical supply termination is shown. Often supplied via local isolator.

Used in: Mechanical extract, HVAC plant rooms, smoke ventilation, industrial process exhaust.

Pump

A pump driven by an electric motor — water, heating circulator, condensate, sewage. Symbol typically shows pump body with electrical termination point.

Used in: Boiler plant, water boosting, pond / pool plant, lift hydraulics, fire-fighting wet risers.

Air Handling Unit (AHU)

An air handling unit containing fans, filters, coils and dampers. Electrically intensive — fan motors, heating/cooling coil pumps, controls all need supply.

Used in: Plant rooms serving HVAC for commercial buildings, hospitals, retail, hotels.

Lift / Elevator

A lift drive — supplied from a dedicated three-phase circuit with its own isolation per BS 7671 Section 530. Lift motor rooms require lockable disconnection.

Used in: Multi-storey commercial + residential; needs locked main isolator inside motor room.

Motor control centre MCC panel board electrical symbol BS EN 60617

Panel Board (Motor Control Centre)

A motor control centre or control panel housing multiple motor starters, contactors, and overload protection. PLC-controlled in modern installations.

Used in: Industrial plant rooms, water treatment, factory production lines, large HVAC plant.

Mechanical + HVAC Symbols(8)

Boiler, water heater, panel heater, air conditioning, fan coil unit, towel rail, heater and hand dryer symbols where electrical supply is required.

Boiler

A heating boiler — gas, oil, or electric. Even gas/oil boilers need a 230 V supply for pumps, controls, and ignition. Supplied via switched fused spur.

Used in: Kitchens, utility rooms, garages, lofts; needs local 3A fused isolation per BS 7671.

Water Heater (Immersion)

An electric water heater — usually a 3 kW immersion in a hot water cylinder, or instantaneous undersink/handwash unit. Supplied from a dedicated radial.

Used in: Hot water cylinders (in airing cupboard), under sinks, point-of-use in remote washrooms.

Panel Heater

A wall-mounted electric panel heater — convection, fan-assisted, or radiant. Sizes typically 0.5-2.5 kW. Often timer/thermostat controlled.

Used in: Offices, holiday lets, supplementary heating, garages — wherever wet heating is impractical.

Air Conditioning Unit

An air conditioning unit — split system or VRV/VRF. Indoor unit + outdoor condenser. Electrical supply usually fed to the outdoor unit which powers the indoor head.

Used in: Server rooms, offices, retail; needs F-gas certified installer; isolator local to outdoor unit.

Fan Coil Unit (FCU)

A fan coil unit — local fan + heating/cooling coil supplied from a central plant. Provides zone-level temperature control in commercial HVAC.

Used in: Offices, hotels, hospitals; typically ceiling-mounted with low-voltage controls + 230 V fan supply.

Electric Towel Rail

A heated towel rail with an integral element. Typically 100-600 W. Supplied via switched fused spur outside the bathroom; must be RCD-protected.

Used in: Bathrooms, en-suites, utility rooms; FCU outside the bathroom or zone 3 with IPX4.

Electric heater electrical symbol BS EN 60617

Heater (General)

A general-purpose electric heater symbol — covers radiant, convection, fan and oil-filled portable heaters. Supplied via switched fused spur or socket.

Used in: Domestic supplementary heating, offices, workshops, garages.

Hand Dryer

A commercial hand dryer — typically 1.5-2.5 kW. Supplied via switched fused spur with local isolation. RCD protected per BS 7671 411.3.3.

Used in: Commercial WCs, restaurants, schools, hospitality; needs 2.5 kW supply on its own spur.

Solar PV + Renewables Symbols(5)

Solar panel, inverter, battery storage, generator and EV distribution symbols for prosumer installations (BS 7671 Section 712).

Solar photovoltaic PV panel electrical symbol BS EN 60617

Solar PV Panel

A solar photovoltaic panel. Typical residential modules 360-450 W. Arrays wired in series strings (matching inverter MPPT voltage window) and parallel to scale capacity.

Used in: Roof-mounted residential + commercial PV; BS 7671 Section 712 + MCS standards apply.

PV Inverter

A solar PV inverter converting DC from the array to AC for grid synchronisation. Single-phase up to ~3.68 kW (G98), three-phase above (G99). Hybrid types include battery interface.

Used in: Loft, plant room, garage wall; close to consumer unit for short AC tails.

Battery energy storage system BESS electrical symbol BS EN 60617

Battery Storage

A battery energy storage system (BESS) — typically lithium iron phosphate (LFP). Sizes 5-15 kWh domestic, up to MWh commercial. AC-coupled or DC-coupled to PV.

Used in: Domestic time-shifting, off-grid systems, commercial peak-shaving; MCS Battery Storage required.

EV charger distribution board electrical symbol BS EN 60617

EV Distribution Board

A dedicated distribution board for one or more EV chargers — usually with load management, dynamic load balancing, and Type A RCDs or RDC-DD per BS 7671 722.531.

Used in: Multi-bay car parks, fleet depots, apartment block charging; serves 3-100+ chargers.

Generator

An on-site generator — diesel, gas or biogas. Used as standby for grid failure or as primary supply off-grid. Symbol shows a circle with "G".

Used in: Standby for hospitals, data centres; primary for remote off-grid sites; CHP for industrial.

Controls + BMS Symbols(5)

BMS controller, control panel, lighting control, sensor and humidity sensor symbols for smart building installations.

BMS Controller

A Building Management System (BMS) controller — central or distributed unit that schedules HVAC, lighting and other plant. BACnet, Modbus or proprietary protocols.

Used in: Commercial offices, hospitals, schools; centralises control of all building services.

Control Panel

A local control panel — typically housing a PLC, contactors, overloads, and HMI for a discrete piece of plant or process line.

Used in: Industrial plant, water treatment, packaging lines, kitchen extract control.

Lighting Control Module

A lighting control module — DALI gateway, KNX dimmer, Lutron QS module, or wireless mesh controller. Schedules, scenes, daylight harvesting and occupancy linkage.

Used in: Offices, retail, hospitality, schools; smart lighting saves 30-50% on energy vs static control.

BMS sensor occupancy temperature electrical symbol BS EN 60617

Generic Sensor

A generic BMS sensor input — temperature, CO2, occupancy, light level. Wired back to a BMS controller or PLC. 0-10 V, 4-20 mA or digital bus.

Used in: Above ceiling, in ducts, on walls; BMS scheduling depends on accurate sensor placement.

Humidity Sensor

A relative humidity sensor — typically 0-100% RH range. Used to control extract fans, HVAC dampers, dehumidifiers; common in bathrooms, swimming pools, archives.

Used in: Bathroom fan control, indoor air quality monitoring, art gallery + archive HVAC.

Architectural Symbols(6)

Door (left/right/double), window, stairs and north arrow symbols used on electrical installation drawings to show building context.

Door left-hinged architectural symbol electrical drawing

Door (Hinged Left)

An architectural door symbol showing a left-hinged swing. Used on electrical layout drawings to show building context — wall switch positions relate to door swing.

Used in: Electrical layout plans, fire alarm zone plans, emergency lighting drawings.

Door right-hinged architectural symbol electrical drawing

Door (Hinged Right)

An architectural door symbol showing a right-hinged swing. Used to indicate the door swing direction relative to electrical accessories on the drawing.

Used in: All electrical layout drawings; tells the installer which side of the door switches go.

Double Door

A double-door symbol — both leaves shown. Used for main entrances, large reception doors, fire exits and accessible-width openings.

Used in: Main entrances, lobbies, fire escapes, accessible refuge points.

Window

A window symbol shown on the wall line. Helps the installer locate fittings relative to natural light, identify external walls, and avoid cabling routes through openings.

Used in: External walls on layout drawings, daylight-harvesting lighting plans.

Stairs

An architectural stairs symbol showing tread direction. Two-way switching at top and bottom of stairs is the textbook BS 7671 use case for the symbol.

Used in: Stairwells; emergency lighting + two-way switching are the obvious requirements.

North Arrow

A compass north indicator. Critical on solar PV drawings (orientation determines yield), CCTV camera plans (sun glare avoidance), and general drawing orientation.

Used in: Solar PV system designs, CCTV / external lighting plans, all professional electrical drawings.