IEC 60364

IEC 60364 Electrical Installations for Buildings is the International Electrotechnical Commission's international standard on electrical installations of buildings. This standard is an attempt to harmonize national wiring standards in an IEC standard and is published in the European Union by CENELEC as "HD 60364". The latest versions of many European wiring regulations (e.g., BS 7671 in the UK) follow the section structure of IEC 60364 very closely, but contain additional language to cater for historic national practice and to simplify field use and determination of compliance by electrical tradesmen and inspectors. National codes and site guides are meant to attain the common objectives of IEC 60364, and provide rules in a form that allows for guidance of persons installing and inspecting electrical systems.

The standard has several parts:

  • Part 1: Fundamental principles, assessment of general characteristics, definitions
  • Part 4: Protection for safety
  • Part 5: Selection and erection of electrical equipment
    • Section 51: Common rules
    • Section 52: Wiring systems
    • Section 53: Isolation, switching and control
    • Section 54: Earthing arrangements, protective conductors and protective bonding conductors
    • Section 55: Other equipment (Note: Some national standards provide an individual document for each chapter of this section, i.e. 551 Low-voltage generating sets, 557 Auxiliary circuits, 559 Luminaires and lighting installations)
    • Section 56: Safety services
  • Part 6: Verification
  • Part 7: Requirements for special installations or locations
    • Section 701: Electrical installations in bathrooms
    • Section 702: Swimming pools and other basins
    • Section 703: Rooms and cabins containing sauna heaters
    • Section 704: Construction and demolition site installations
    • Section 705: Electrical installations of agricultural and horticultural premises
    • Section 706: Restrictive conductive locations
    • Section 708: Electrical installations in caravan parks and caravans
    • Section 709: Marinas and pleasure craft
    • Section 710: Medical locations
    • Section 712: Solar photovoltaic (PV) power supply systems
    • Section 713: Furniture
    • Section 714: External lighting
    • Section 715: Extra-low-voltage lighting installations
    • Section 717: Mobile or transportable units
    • Section 718: Communal facilities and workplaces
    • Section 721: Electrical installations in caravans and motor caravans
    • Section 722: Supplies for Electric Vehicles
    • Section 729: Operating or maintenance gangways
    • Section 740: Temporary electrical installations for structures, amusement devices and booths at fairgrounds, amusement parks and circuses
    • Section 753: Heating cables and embedded heating systems

See also

External links

BS 7671

British Standard BS 7671 "Requirements for Electrical Installations. IET Wiring Regulations", informally called in the electrical community The "Regs", is the national standard in the United Kingdom for electrical installation and the safety of electrical wiring in domestic, commercial, industrial, and other buildings, also in special installations and locations, such as marinas or caravan parks.In general, BS 7671 applies to circuits supplied at nominal voltages up to and including 1000 volts AC or 1500 volts DC. The standard therefore covers the 230 volt 50 Hz AC mains supply used in the UK for houses, offices, and commerce. It did not become a recognized British Standard until the publication of the 16th edition in 1992. The standard takes account of the technical substance of agreements reached in CENELEC The current version is BS 7671:2018 (the 18th Edition) issued in 2018 and comes into effect from 1 January 2019. BS 7671 is also used as a national standard by Mauritius, St Lucia, Saint Vincent and the Grenadines, Sierra Leone, Sri Lanka, Trinidad and Tobago, Uganda, Cyprus, and several other countries, which base their wiring regulations on BS 7671.

Bus duct

In electrical power distribution, a bus duct (also called busway), is a sheet metal duct containing either copper or aluminium busbars for the purpose of conducting a substantial current of electricity. It is an alternative means of conducting electricity to power cables or cable bus.

Originally a busway consisted of bare copper conductors supported on inorganic insulators, such as porcelain, mounted within a non-ventilated steel housing.

Cable tray

In the electrical wiring of buildings, a cable tray system is used to support insulated electrical cables used for power distribution, control, and communication. Cable trays are used as an alternative to open wiring or electrical conduit systems, and are commonly used for cable management in commercial and industrial construction. They are especially useful in situations where changes to a wiring system are anticipated, since new cables can be installed by laying them in the tray, instead of pulling them through a pipe.

According to the National Electrical Code (NEC), a cable tray is a unit or assembly of units or sections and associated fittings forming a rigid structural system used to securely fasten or support cables and raceways.

Canadian Electrical Code

The Canadian Electrical Code, CE code, or CSA C22.1 is a standard published by the Canadian Standards Association pertaining to the installation and maintenance of electrical equipment in Canada.

The first edition of the Canadian Electrical Code was published in 1927. The current (24th) edition was published in 2018. Code revisions are now scheduled on a three-year cycle. The Code is produced by a large body of volunteers from industry and various levels of government. The code uses a prescriptive model, outlining in detail the wiring methods that are acceptable. In the current edition, the Code recognizes that other methods can be used to assure safe installations, but these methods must be acceptable to the authority enforcing the Code in a particular jurisdiction.

The Canadian Electrical Code serves as the basis for wiring regulations across Canada. Generally, legislation adopts the code by reference, usually with a schedule of changes that amend the code for local conditions. These amendments may be administrative in nature or may consist of technical content particular to the region. Since the Code is a copyrighted document produced by a private body, it may not be distributed without copyright permission from the Canadian Standards Association.

The Code is divided into sections, each section is labeled with an even number and a title. Sections 0, 2, 4, 6, 8, 10, 12, 14, 16, and 26 include rules that apply to installations in general; the remaining sections are supplementary and deal with installation methods in specific locations or situations. Some examples of general sections include: grounding and bonding, protection and control, conductors, and definitions. Some examples of supplementary sections include: wet locations, hazardous locations, patient care areas, emergency systems, and temporary installations. When interpreting the requirements for a particular installation, rules found in supplementary sections of the code amend or supersede the rules in general sections of the code.

The Canadian Electrical Code does not apply to vehicles, systems operated by an electrical or communications utility, railway systems, aircraft or ships; since these installations are already regulated by separate documents.

The Canadian Electrical Code is published in several parts: Part I is the safety standard for electrical installations. Part II is a collection of individual standards for the evaluation of electrical equipment or installations. (Part I requires that electrical products be approved to a Part II standard) Part III is the safety standard for power distribution and transmission circuits. Part IV is set of objective-based standards that may be used in certain industrial or institutional installations. Part VI establishes standards for the inspection of electrical installation in residential buildings.

Technical requirements of the Canadian Electrical Code are very similar to those of the U.S. National Electrical Code. Specific differences still exist and installations acceptable under one Code may not entirely comply with the other. Correlation of technical requirements between the two Codes is ongoing.

Several CEC Part II electrical equipment standards have been harmonized with standards in the USA and Mexico through CANENA, The Council for the Harmonization of Electromechanical Standards of the Nations of the Americas (CANENA) is working to harmonize electrical codes in the western hemisphere.

Consumer unit

A consumer unit is a type of distribution board (a component of an electrical power system within which an electrical power feed provides supply to subsidiary circuits).


In electrical engineering, a disconnector, disconnect switch or isolator switch is used to ensure that an electrical circuit is completely de-energized for service or maintenance. Such switches are often found in electrical distribution and industrial applications, where machinery must have its source of driving power removed for adjustment or repair. High-voltage isolation switches are used in electrical substations to allow isolation of apparatus such as circuit breakers, transformers, and transmission lines, for maintenance. The disconnector is usually not intended for normal control of the circuit, but only for safety isolation. Disconnectors can be operated either manually or automatically.

Unlike load switches and circuit breakers, disconnectors lack a mechanism for suppression of electric arcs, which occurs when conductors carrying high currents are electrically interrupted. Thus, they are off-load devices, with very low breaking capacity, intended to be opened only after current has been interrupted by some other control device. Safety regulations of the utility must prevent any attempt to open the disconnector while it supplies a circuit. Standards in some countries for safety may require either local motor isolators or lockable overloads (which can be padlocked).

Disconnectors have provisions for a lockout-tagout so that inadvertent operation is not possible. In high-voltage or complex systems, these locks may be part of a trapped-key interlock system to ensure proper sequence of operation. In some designs, the isolator switch has the additional ability to earth the isolated circuit thereby providing additional safety. Such an arrangement would apply to circuits which inter-connect power distribution systems where both ends of the circuit need to be isolated.

A switch disconnector combines the properties of the disconnector and the load switch, so it provides the safety isolation function while being able to make and break nominal currents.

Earth leakage circuit breaker

An Earth-leakage circuit breaker (ELCB) is a safety device used in electrical installations with high Earth impedance to prevent shock. It detects small stray voltages on the metal enclosures of electrical equipment, and interrupts the circuit if a dangerous voltage is detected. Once widely used, more recent installations instead use residual current circuit breakers which instead detect leakage current directly.

Earthing system

In an electrical installation, an earthing system or grounding system connects specific parts of that installation with the Earth's conductive surface for safety and functional purposes. The point of reference is the Earth's conductive surface. The choice of earthing system can affect the safety and electromagnetic compatibility of the installation. Regulations for earthing systems vary considerably among countries, though most follow the recommendations of the International Electrotechnical Commission. Regulations may identify special cases for earthing in mines, in patient care areas, or in hazardous areas of industrial plants.

In addition to electric power systems, other systems may require grounding for safety or function. Tall structures may have lightning rods as part of a system to protect them from lightning strikes. Telegraph lines may use the Earth as one conductor of a circuit, saving the cost of installation of a return wire over a long circuit. Radio antennas may require particular grounding for operation, as well as to control static electricity and provide lightning protection.

Electrical busbar system

Electrical busbar systems (sometimes simply referred to as busbar systems) are a modular approach to electrical wiring, where instead of a standard cable wiring to every single electrical device, the electrical devices are mounted onto an adapter which is directly fitted to a current carrying busbar. This modular approach is used in distribution boards, automation panels and other kinds of installation in an electrical enclosure.Busbar systems are subject to safety standards for design and installation along with electrical enclosure according to IEC 61439-1 and vary between countries and regions.

Electrical code

An electrical code is a set of regulations for the design and installation of electrical wiring in a building.

The intention of a code is to provide standards to ensure electrical wiring systems that are safe for people and property.

Such wiring is subject to rigorous safety standards for design and installation. Wires and electrical cables are specified according to the circuit operating voltage and electric current capability, with further restrictions on the environmental conditions, such as ambient temperature range, moisture levels, and exposure to sunlight and chemicals. Associated circuit protection, control and distribution devices within a building's wiring system are subject to voltage, current and functional specification. To ensure both wiring and associated devices are designed, selected and installed so that they are safe for use, they are subject to wiring safety codes or regulations, which vary by locality, country or region.

The International Electrotechnical Commission (IEC) is attempting to harmonise wiring standards amongst member countries, but large variations in design and installation requirements still exist.

Electrical wiring

Electrical wiring is an electrical installation of cabling and associated devices such as switches, distribution boards, sockets, and light fittings in a structure.

Wiring is subject to safety standards for design and installation. Allowable wire and cable types and sizes are specified according to the circuit operating voltage and electric current capability, with further restrictions on the environmental conditions, such as ambient temperature range, moisture levels, and exposure to sunlight and chemicals.

Associated circuit protection, control and distribution devices within a building's wiring system are subject to voltage, current and functional specification. Wiring safety codes vary by locality, country or region. The International Electrotechnical Commission (IEC) is attempting to harmonise wiring standards amongst member countries, but significant variations in design and installation requirements still exist.

Emergency light

An emergency light is a battery-backed lighting device that switches on automatically when a building experiences a power outage. Emergency lights are standard in new commercial and high occupancy residential buildings, such as college dormitories, apartments, and hotels. Most building codes require that they be installed in older buildings as well.

Incandescent light bulbs were originally used in emergency lights, before fluorescent lights and later light-emitting diodes (LEDs) superseded them in the 21st century.

Extra-low voltage

Extra-low voltage (ELV) is an electricity supply voltage in a range which carries a low risk of dangerous electrical shock. There are various standards that define extra-low voltage. The International Electrotechnical Commission member organizations and the UK IET (BS 7671:2008) define an ELV device or circuit as one in which the electrical potential between conductor or electrical conductor and earth (ground) does not exceed 50 V a.c. or 120 V d.c. (ripple free). EU's Low Voltage Directive applies from 50 to 1,000 V a.c. and from 75 to 1,500 V d.c.

The IEC and IET go on to define actual types of extra-low voltage systems, for example SELV, PELV, FELV. These can be supplied using sources including motor / fossil fuel generator sets, transformers, switched PSU's or rechargeable battery. SELV, PELV, FELV, are distinguished by various safety properties, supply characteristics and design voltages.

Some types of landscape lighting use SELV / PELV (extra-low voltage) systems. Modern battery operated hand tools fall in the SELV category. In more arduous conditions 25 volts RMS alternating current / 60 volts (ripple-free) direct current can be specified to further reduce hazard. Lower voltage can apply in wet or conductive conditions where there is even greater potential for electric shock. These systems should still fall under the SELV / PELV (ELV) safety specifications.

Junction box

An electrical junction box is an enclosure housing electrical connections, to protect the connections and provide a safety barrier.

National Inspection Council for Electrical Installation Contracting

The National Inspection Council for Electrical Installation Contracting (NICEIC) is one of several organisations which regulates the training and work of electrical enterprises in the UK. The NICEIC is one of several providers given Government approval to offer Competent Person Schemes to oversee electrical work within the electrical industry.

Certsure LLP (which is owned by Electrical Safety First, a registered charity, and the Electrical Contractors’ Association (ECA), the electrotechnical industry trade body) trades under the certification brands NICEIC and ELECSA.


In an electric power system, overcurrent or excess current is a situation where a larger than intended electric current exists through a conductor, leading to excessive generation of heat, and the risk of fire or damage to equipment. Possible causes for overcurrent include short circuits, excessive load, incorrect design, or a ground fault. Fuses, circuit breakers, lifersensors and current limiters are commonly used overcurrent protection (OCP) mechanisms to control the risks.

Ring main unit

In an electrical power distribution system, a ring main unit (RMU) is a factory assembled, metal enclosed set of switchgear used at the load connection points of a ring-type distribution network. It includes in one unit two switches that can connect the load to either or both main conductors, and a fusible switch or circuit breaker and switch that feed a distribution transformer. The metal enclosed unit connects to the transformer either through a bus throat of standardized dimensions, or else through cables and is usually installed outdoors. Ring main cables enter and leave the cabinet. This type of switchgear is used for medium-voltage power distribution, from 7200 volts to about 36000 volts.

The ring main unit was introduced in the United Kingdom and is now widely used in other countries. In North American distribution practice, often the equivalent of a ring main unit is built into a pad-mounted transformer which integrates switches and transformer into a single cabinet.

Section 42

Section 42 can refer to :

Section 42 of the Australian constitution

In the US - Section 42 of the Internal Revenue Code - details the Low-Income Housing Tax Credit

English Law - A section of the Mental Health Act 1983 dealing with involuntary commitment

English Law - Section 42 of the Offences against the Person Act 1861 (now replaced) dealt with common assault and battery

In engineering, Section 42 of IEC 60364 standard defines Thermal protection criteria for electrical installations

Steel wire armoured cable

Steel wire armoured cable, commonly abbreviated as SWA, is a hard-wearing power cable designed for the supply of mains electricity. It is one of a number of armoured electrical cables – which include 11 kV Cable and 33 kV Cable – and is found in underground systems, power networks and cable ducting.

IEC standards
ISO/IEC standards

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