IEC 60309 is an international standard from the International Electrotechnical Commission for "plugs, socket-outlets and couplers for industrial purposes". The maximum voltage allowed by the standard is 1000 V DC or AC; the ambient temperature range is −25 °C to 40 °C. There is a range of plugs and sockets of different sizes with differing numbers of pins, depending on the current supplied and number of phases accommodated; the fittings are popular in open-air conditions. They are sometimes used in situations where their special capabilities are not needed, to discourage potential users from connecting domestic appliances to the sockets, as'normal' domestic plugs will not fit; the cable connectors and sockets are keyed and colour-coded, according to the voltage range and frequency used. The blue fittings are used for providing weather-proofed exterior sockets for outdoor apparatus. In camping situations, the large 32 A blue fittings provide power to static caravans, whilst the smaller blue 16 A version powers touring caravans and tents.
The yellow fittings are used to provide transformer isolated 110 V supplies for UK construction sites to reduce the risk of electric shock, this use spills over into uses of power tools outside of the construction site environment. The red three-phase versions are used for three-phase portable equipment. IEC 60309-1 "Plugs, socket-outlets and couplers for industrial purposes" specifies general functional and safety requirements. IEC 60309-2 "Dimensional interchangeability requirements for pin and contact-tube accessories" applies to plugs and socket-outlets, cable couplers and appliance couplers with pins and contact tubes of standardized configurations. IEC 60309-3 "Particular requirements for plugs, socket-outlets and appliance inlets for use in explosive gas atmospheres" was withdrawn in 1998. IEC 60309-4 "Switched socket-outlets and connectors with or without interlock" applies to self-contained products that combine within a single enclosure, a socket-outlet or connector according to IEC 60309-1 or IEC 60309-2 and a switching device, with a rated operating voltage not exceeding 1000 V DC or AC and 500 Hz, a rated current not exceeding 800 A.
IEC 60309-5 "Dimensional compatibility and interchangeability requirements for plugs, socket-outlets, ship connectors and ship inlets for low-voltage shore connection systems" applies to a single type of plug, socket-outlet, ship connector and ship inlet, intended to connect ships to dedicated shore supply systems described in IEC/IEEE 80005-3. The standardization was done by the CEE, which became IECEE in 1985 and is now part of the IEC; the industrial sockets were standardized in the 1960s in the CEE 17 series, adopted in the UK as BS 4343, which are now the IEC 60309 standard. The standard includes preferred current ratings and wire gauges for both International and North American applications. Series I preferred current ratings are: 16, 32, 63, 125, 250, 400, 630 and 800, with wire gauges specified as mm2. Series II preferred current ratings are: 20, 30, 60, 100, 200, 300, 350, 500 and 600, with wire gauges specified as AWG and circular mil. IEC 60309 connectors come in IP67 variants. In both cases, the rating applies when detached or mated, but not during the mating process.
The more common IP44 variant features a spring-loaded hinged cap over the socket. When a plug is inserted, the cap retains it in place. Fixed connectors are installed angled downward to prevent water entering; the IP67 variant includes a twist-lock ring which seals the two together. The two can be intermated, at the cost of the locking mechanisms. Plugs have cylindrical connector pins arranged in a circle, with the earth pin 2 mm larger than the others; this is surrounded by a circular shroud on the male connector, which fits into a matching recess on the female connector. The standard defines connectors with 3, 4 and 5 pins, but a non-standard variant with 7 pins is commercially available. Connectors rated at 63 A and 125 A may optionally be equipped with a 6 mm pilot contact; this smaller pin in the centre of the connector is shorter than the others, designed to'make' after all the other pins when connecting a plug and socket, to'break' first when disconnecting. It is used to switch off the load.
This is useful as disconnecting under load will cause arcing which may cause damage to both the plug and socket, risk injury to the user. The pilot pin is located in the centre of main contact circle on 4- and 5-pin connectors. On 3-pin connectors, it is located on the contact circle opposite the ground pin; the other connectors are located 105° on either side of the earth pin, rather than 120° as in the smaller variants, to make room for the pilot pin. The standard specifies an additional, different design for extra-low voltages up to 50 V AC and currents of 16 or 32 A; this is larger than, the IEC 60906 DC connector. Three 6 mm pins 20.5 mm long are spaced aroun
IEC 62196 Plugs, socket-outlets, vehicle connectors and vehicle inlets – Conductive charging of electric vehicles known as CCS Combo, is a series of international standards that define requirements and tests for plugs, socket-outlets, vehicle connectors and vehicle inlets for conductive charging of electric vehicles and is maintained by the technical subcommittee SC 23H “Plugs, Socket-outlets and Couplers for industrial and similar applications, for Electric Vehicles” of the International Electrotechnical Commission. Plugs, socket-outlets, vehicle connectors and vehicle inlets according to this series of standards are used in EV supply equipment according to IEC 61851 series or IEC 62752 and in electric vehicles according to ISO 17409 or ISO 18246. Most plugs, socket-outlets, vehicle connectors and vehicle inlets according to this series of standards provide additional contacts that support specific functions that are relevant for charging of electric vehicles, e.g. power is not supplied unless a vehicle is connected and the vehicle is immobilized while still connected.
Several parts of this series of standards have been published as European standards which in turn have been published as British standards. Similar requirements are contained in SAE J1772, applied in the US; the following parts of IEC 62196 series have been published: IEC 62196-1 Plugs, socket-outlets, vehicle connectors and vehicle inlets – Conductive charging of electric vehicles – Part 1: General requirements IEC 62196-2 Plugs, socket-outlets, vehicle connectors and vehicle inlets – Conductive charging of electric vehicles – Part 2: Dimensional compatibility and interchangeability requirements for A. C. pin and contact-tube accessories IEC 62196-3 Plugs, socket-outlets, vehicle connectors and vehicle inlets – Conductive charging of electric vehicles – Part 3: Dimensional compatibility and interchangeability requirements for D. C. and A. C./D. C. Pin and contact-tube vehicle couplersAdditional parts of IEC 62196 are under preparation: IEC TS 62196-3-1 Plugs, socket-outlets, vehicle connectors and vehicle inlets – Conductive charging of electric vehicles – Part 3-1: Vehicle connector, vehicle inlet and cable assembly intended to be used with a thermal management system for DC charging IEC TS 62196-4 Plugs, socket-outlets, vehicle connectors and vehicles inlet – Conductive charging of electric vehicles – Part 4: Dimensional compatibility and interchangeability requirements for DC pin and contact-tube accessories for class II or class III applications IEC 62196-6 Plugs, socket-outlets, vehicle connectors and vehicle inlets – Conductive charging of electric vehicles – Part 6: Dimensional compatibility and interchangeability requirements for DC pin and contact-tube vehicle couplers for DC EV supply equipment where protection relies on electrical separation IEC 62196-1 provides a general description of the interface between an electric vehicle and a charging station as well as general mechanical and electrical requirements and tests for plugs, socket-outlets, vehicle connectors and vehicle inlets that are intended to be used for EV charging.
It does not describe specific designs. The first edition, IEC 62196-1:2003, was published in 2003; this edition was applicable to plugs, socket-outlets, connectors and cable assemblies for AC and DC charging of electric vehicles with rated voltages and rated currents as follows: - AC: up to 690 V, up to 250 A - DC: up to 600 V, up to 400 A. Typical connectors and inlets that were built according to this edition of the standard used spring-loaded butt contacts and were made by Avcon and Maréchal Electric; the second edition, IEC 62196-1:2011, was published in 2011. One significant change was the increase of the maximum voltage of connectors and cable assemblies for DC charging to 1500 V; the development of this edition was coordinated with the first edition of IEC 62196-2, which describes several configurations of pin-and-sleeve contacts for AC charging. The third edition, IEC 62196-1:2014, was published in 2014. One significant addition was the general description of a “combined interface” as used by the Combined Charging System.
The development of this edition was coordinated with the first edition of IEC 62196-3, which describes connectors and inlets for DC charging. IEC 62196-2 extends IEC 62196-1 and describes specific designs of plugs, socket-outlets, vehicle connectors and vehicle inlets that are intended to be used for AC charging of electric vehicles in the modes 1, 2 and 3 as described by IEC 61851-1; the specific designs are grouped into three configurations. The designs are described with sufficient detail to allow compatibility between products of different manufacturers; this configuration consists of a vehicle coupler. Because the original design was made by the manufacturer Yazaki and first published in SAE J1772, it is colloquially known as the “Yazaki connector” or “J1772 connector”, it features a round housing, which has a notch on the vehicle inlet for proper orientation, with five pin-and-sleeve contacts for two AC conductors, a protective conductor and two signal pins that are used for the control pilot function and for proximity detection.
When inserted into the vehicle inlet, the connector is held in place by a mechanical latch, part of the connector. IEC 62196-2 describes this configuration with an operating current up to 32 A, allowing a maximum current of 80 A only for applications in the US, where this higher operating current is described by SAE J1772; this configuration only supports single-phase charging. It is used
A 19-inch rack is a standardized frame or enclosure for mounting multiple electronic equipment modules. Each module has a front panel, 19 inches wide; the 19-inch dimension includes the edges, or "ears", that protrude on each side which allow the module to be fastened to the rack frame with screws. Common uses include computer server, broadcast video, lighting and scientific lab equipment. Equipment designed to be placed in a rack is described as rack-mount, rack-mount instrument, a rack mounted system, a rack mount chassis, rack mountable, or simply shelf; the height of the electronic modules is standardized as multiples of 1.752 inches or one rack unit or U. The industry standard rack cabinet is 42U tall; the term relay rack appeared first in the world of telephony. By 1911, the term was being used in railroad signaling. There is little evidence; the 19-inch rack format with rack-units of 1.75 inches was established as a standard by AT&T around 1922 in order to reduce the space required for repeater and termination equipment for toll cables.
The earliest repeaters from 1914 were installed in ad-hoc fashion on shelves, in wooden boxes and cabinets. Once serial production started, they were built into custom-made one per repeater, but in light of the rapid growth of the toll network, the engineering department of AT&T undertook a systematic redesign, resulting in a family of modular factory-assembled panels all "designed to mount on vertical supports spaced 19½ inches between centers. The height of the different panels will vary... but... in all cases to be a whole multiple of 13⁄4 inches". By 1934, it was an established standard with holes tapped for 12-24 screws with alternating spacings of 1.25 inches and 0.5 inches The EIA standard was revised again in 1992 to comply with the 1988 public law 100-418, setting the standard U as 15.9 mm + 15.9 mm + 12.7 mm, making each "U" 44.50 millimetres. The 19-inch rack format has remained constant while the technology, mounted within it has changed and the set of fields to which racks are applied has expanded.
The 19-inch standard rack arrangement is used throughout the telecommunication, audio, video and other industries, though the Western Electric 23-inch standard, with holes on 1-inch centers, is still used in legacy ILEC/CLEC facilities. Nineteen-inch racks in two-post or four-post form hold most equipment in modern data centers, ISP facilities, professionally designed corporate server rooms, they allow for dense hardware configurations without occupying excessive floorspace or requiring shelving. Nineteen-inch racks are often used to house professional audio and video equipment, including amplifiers, effects units, headphone amplifiers, small scale audio mixers. A third common use for rack-mounted equipment is industrial power and automation hardware. A piece of equipment being installed has a front panel height 1⁄32 inch less than the allotted number of Us. Thus, a 1U rackmount computer is 1.721 inches tall. 2U would be 3.473 inches instead of 3.504 inches. This gap allows a bit of room above and below an installed piece of equipment so it may be removed without binding on the adjacent equipment.
The mounting holes were tapped with a particular screw thread. When rack rails are too thin to tap, rivnuts or other threaded inserts can be used, when the particular class of equipment to be mounted is known in advance, some of the holes can be omitted from the mounting rails. Threaded mounting holes in racks where the equipment is changed are problematic because the threads can be damaged or the mounting screws can break off. Tapping large numbers of holes that may never be used is expensive. Examples include telephone exchanges, network cabling panels, broadcast studios and some government and military applications; the tapped-hole rack was first replaced by clearance-hole racks. The holes are large enough to permit a bolt to be inserted through without binding, bolts are fastened in place using cage nuts. In the event of a nut being stripped out or a bolt breaking, the nut can be removed and replaced with a new one. Production of clearance-hole racks is less expensive because tapping the holes is eliminated and replaced with fewer, less expensive, cage nuts.
The next innovation in rack design has been the square-hole rack. Square-hole racks allow boltless mounting, such that the rack-mount equipment only needs to insert through and hook down into the lip of the square hole. Installation and removal of hardware in a square hole rack is easy and boltless, where the weight of the equipment and small retention clips are all, necessary to hold the equipment in place. Older equipment meant for round-hole or tapped-hole racks can still be used, with the use of cage nuts made for square-hole racks. Rack-mountable equipment is traditionally mounted by bolting or clipping its front panel to the rack. Within the IT industry, it is common for network/communications equipment to have multiple mounting positions, including table-top and wall mounting, so rack mountable equipment will feature L-brackets that must be screwed or bolted to the equipment prior to mounting in a 19-inch rack. With the prevalence of 23-
The IEEE Standard for Floating-Point Arithmetic is a technical standard for floating-point arithmetic established in 1985 by the Institute of Electrical and Electronics Engineers. The standard addressed many problems found in the diverse floating-point implementations that made them difficult to use reliably and portably. Many hardware floating-point units use the IEEE 754 standard; the standard defines: arithmetic formats: sets of binary and decimal floating-point data, which consist of finite numbers and special "not a number" values interchange formats: encodings that may be used to exchange floating-point data in an efficient and compact form rounding rules: properties to be satisfied when rounding numbers during arithmetic and conversions operations: arithmetic and other operations on arithmetic formats exception handling: indications of exceptional conditions The current version, IEEE 754-2008 revision published in August 2008, includes nearly all of the original IEEE 754-1985 standard plus IEEE 854-1987 Standard for Radix-Independent Floating-Point Arithmetic.
The current version, IEEE 754-2008 published in August 2008, is derived from and replaces IEEE 754-1985, the previous version, following a seven-year revision process, chaired by Dan Zuras and edited by Mike Cowlishaw. The international standard ISO/IEC/IEEE 60559:2011 has been approved for adoption through JTC1/SC 25 under the ISO/IEEE PSDO Agreement and published; the binary formats in the original standard are included in the new standard along with three new basic formats, one binary and two decimal. To conform to the current standard, an implementation must implement at least one of the basic formats as both an arithmetic format and an interchange format; as of September 2015, the standard is being revised to incorporate errata. An IEEE 754 format is a "set of representations of numerical values and symbols". A format may include how the set is encoded. A floating-point format is specified by: a base b, either 2 or 10 in IEEE 754. A format comprises: Finite numbers, which can be described by three integers: s = a sign, c = a significand having no more than p digits when written in base b, q = an exponent such that emin ≤ q+p−1 ≤ emax.
The numerical value of such a finite number is s ×. Moreover, there are two zero values, called signed zeros: the sign bit specifies whether a zero is +0 or −0. Two infinities: +∞ and −∞. Two kinds of NaN: a quiet NaN and a signaling NaN. For example, if b = 10, p = 7 and emax = 96 emin = −95, the significand satisfies 0 ≤ c ≤ 9,999,999, the exponent satisfies −101 ≤ q ≤ 90; the smallest non-zero positive number that can be represented is 1×10−101, the largest is 9999999×1090, so the full range of numbers is −9.999999×1096 through 9.999999×1096. The numbers − b1 − emax are the smallest normal numbers; some numbers may have several possible exponential format representations. For instance, if b=10 and p=7, −12.345 can be represented by −12345×10−3, −123450×10−4, −1234500×10−5. However, for most operations, such as arithmetic operations, the result does not depend on the representation of the inputs. For the decimal formats, any representation is valid, the set of these representations is called a cohort.
When a result can have several representations, the standard specifies which member of the cohort is chosen. For the binary formats, the representation is made unique by choosing the smallest representable exponent allowing the value to be represented exactly. Further, the exponent is not represented directly, but a bias is added so that the smallest representable exponent is represented as 1, with 0 used for subnormal numbers. For numbers with an exponent in the normal range, the leading bit of the significand will always be 1. A leading 1 can be implied rather than explicitly present in the memory encoding, under the standard the explicitly represented part of the significand will lie between 0 and 1; this rule is called implicit bit convention, or hidden bit convention. This rule allows the binary format to have an extra bit of precision; the leading bit convention cannot be used for the subnormal numbers as they have an exponent outside the normal exponent range and scale by the smallest represented exponent as used for the smallest normal numbers.
Due to the possibility of multiple encodings, a NaN may carry other information: a sign bit and a payload, intended for diagnostic information indicating the source of the NaN. The standard defines five basic formats that are named for their numeric base and the number of bits used in their interchange encoding. There are two decimal floating-point basic formats; the binary32 and binary64 formats are the double formats of IEEE 754-1985 respectively. A conforming implementation must implement at least one of the basic formats. The
IEC 60906-1 is an international standard designed "to provide a standard for a safe and practical 16 A 250 V AC system of plugs and socket-outlets that could be accepted by many countries as their national standard if not in the near future." The standard was published by the International Electrotechnical Commission in 1986. Although it looks similar to the Swiss SEV 1011 plug, its dimensions are different; as of July 2014, only South Africa has introduced a standard based on IEC 60906-1. Brazil used it as the basis for its NBR 14136 standard, but this is not compatible with IEC 60906-1. In 2017 the European Union published recommendations advising against the harmonisation of domestic plug and socket systems in the EU. IEC 60906-1 plugs and socket-outlets are rated 16 A, 250 V AC and are intended for use on distribution systems having nominal voltages between 200 V and 250 V AC. IEC 60906-1 defines both 3-pin connectors for Class I appliances and 2-pin versions for Class II appliances; the IEC 60906-1 plugs are smaller than any other European plug with 16 A rating, being only larger than the 2.5 A Europlug and providing much more reliable contact.
The sockets are small enough that two can be installed in the space taken by a single Schuko or BS 1363 socket. The socket has a 12 mm high rim, to exclude incompatible plugs, it ensures that the protective-earth pin establishes contact before neutral pins. Sockets are required to have shutters for neutral apertures; as it uses the same 19 mm pin spacing as most existing European systems, it would be possible to design sockets that can accept both the traditional plug as well as the IEC 60906-1 Class I and II plugs, thereby enabling a smooth transition to the new system. However, the IEC 60906-1 standard explicitly discourages the use of multi-standard sockets, claiming that such sockets are to create safety problems when used with plugs from other countries. IEC 60906-1 plugs are similar in size and shape to the Europlug, with the front profile being a flat hexagon, they are nominally 35.5 mm wide. The 3-pin Class I plug is 17 mm high; the parallel side faces are 26 mm apart, the two pairs of side faces are orthogonal to each other.
Like Schuko and Europlug, the line and neutral pin are 19 mm long and on centres spaced at 19 mm. The pins have a diameter of 4.5 mm, intermediate between Europlug. In common with the Europlug there is an insulating sleeve around the base of the line and neutral pins; the 3-pin version has a round protective-earth pin of the same length and diameter as the line and neutral pins, but with no insulating sleeve. The protective-earth pin's center is offset 3 mm from the center point between the line and neutral pin. South Africa is the only country to have incorporated IEC 60906-1 plugs and sockets into its own national standards as SANS 164-2. SANS 164-2 was made the preferred standard in 2013, replacing the older SANS 164-1 but according to the South African Bureau of Standards electrotechnical standards development manager, the new plugs and sockets would have "a long, long phase-in period, more than 20 years". According to the National Institute of Metrology Standardization and Industrial Quality in Brazil, the Brazilian Association of Technical Standards "began discussing the creation of a standard for plugs and sockets... in the 1980s, based on the draft international standard based on IEC 60906-01.
It was concluded with wide participation of the manufacturers of plugs and sockets and of electrical and electronic equipment, in July of 1998, with the publication of the norm ABNT NBR 14136."There are a number of non-compliance issues with IEC 60906-1. Brazil uses both 127 V and 220 V mains supplies, but rather than using the IEC 60906-2 standard for the lower voltage it uses NBR 14136 for both. Whereas IEC 60906-1 specifies a single 16 A rating with 4.5 mm pins, NBR 14136 has both 10 A and 20 A ratings, the 10 A plug has a pin diameter of 4 mm, the 20 A plug is 4.8 mm. NBR 14136 does not require shutters on the apertures, a further source of non-compliance with IEC 60906-1; the 10 A socket will accept only 10 A plugs, Europlugs, while the 20 A socket will accept both 10 A and 20 A plugs, plus Europlugs. In the 1990s the EU requested CENELEC to devise a harmonized socket system for Europe. In 1995 that attempt was abandoned as it was not possible for CENELEC delegates to agree an acceptable solution, CENELEC forecast that converting European households and factories to a common standard would cost about $125 billion.
In response to a suggestion that the European Commission introduce a common system across the whole of the EU, the Commission's Regulatory Fitness and Performance programme issued recommendations in 2017. REFIT found that "the harmonisation of plug and socket outlet systems in Europe, by introducing changes in national wiring legislations important transitional periods", that the cost to "replace the old socket-outlets" was estimated at 100 billion Euro, "generating a huge environmental impact, producing some 700 000 tons of electrical waste". REFIT does not recommend harmonising the plugs and socket-outlet systems in Europe. Modern injection moulding technology enables robust and safe plugs to be smaller than the Schuko and BS 1363 systems, which were designed in the early
IEC 60320 Appliance couplers for household and similar general purposes is a set of standards from the International Electrotechnical Commission specifying non-locking appliance and interconnection couplers for connecting power supply cords to electrical appliances of voltage not exceeding 250 V and rated current not exceeding 16 A. Different types of connector are specified for different combinations of current and earthing requirements. Unlike IEC 60309 connectors, they are not coded for voltage; the first edition of IEC 320 was published in 1970. Appliance couplers enable the use of standard inlets and country-specific cord sets which allow manufacturers to produce the same appliance for many markets, where only the cord set has to be changed for a particular market. Interconnection couplers allow a power supply from a piece of equipment or an appliance to be made available to other equipment or appliances. Couplers described under these standards have standardized current and temperature ratings.
The parts of the couplers are defined in the standard. Connector: "part of the appliance coupler integral with, or intended to be attached to, one cord connected to the supply". Appliance inlet: "part of the appliance coupler integrated as a part of an appliance or incorporated as a separate part in the appliance or equipment or intended to be fixed to it". Plug connector: "part of the interconnection coupler integral with or intended to be attached to one cord". Appliance outlet: "part of the interconnection coupler, the part integrated or incorporated in the appliance or equipment or intended to be fixed to it and from which the supply is obtained". Cord set: "assembly consisting of one cable or cord fitted with one non-rewirable plug and one non-rewirable connector, intended for the connection of an electrical appliance or equipment to the electrical supply". Interconnection cord set: "assembly consisting of one cable or cord fitted with one non-rewirable plug connector and one non-rewirable connector, intended for the interconnection between two electrical appliances".
Although the terms "male" and "female" are sometimes applied to these connectors, the terms are not used in the standards themselves. Gender references for connectors refer only to the contacts, not the complete connectors. "Male" refers to a pin contact and "female" to a socket contact. "Connectors" and "appliance outlets" are fitted with socket contacts, "appliance inlets" and "plug connectors" are fitted with pin contacts. Each type of coupler is identified by a standard sheet number. For appliance couplers this consists of the letter "C" followed by a number, where the standard sheet for the appliance inlet is 1 higher than the sheet for the corresponding cable connector. Many types of coupler have common names; the most common ones are IEC connector for the common C13 and C14, the figure-8 connector for C7 and C8, cloverleaf connector or Mickey Mouse connector for the C5/C6. Kettle plug is a colloquial term used for the high-temperature C16 appliance inlet. "Kettle plug" is sometimes mistakenly used to refer to regular temperature-rated C13 and C14 connectors, which should not be used with heating appliances.
Detachable appliance couplers are used in office equipment, measuring instruments, IT environments, medical devices, among many types of equipment for worldwide distribution. Each appliance's power system must be adapted to the different plugs used in different regions. An appliance with a permanently-attached plug for use in one country cannot be sold in another which uses an incompatible wall socket. Instead, a country-specific power supply cord can be included in the product packaging, so that model variations are minimized and factory testing is simplified. A cord, fitted with non-rewireable connectors at both ends is termed a cord set. Appliance manufacturing may be simplified by mounting an appliance coupler directly on the printed circuit board. Assembly and handling of an appliance is easier if the power cord can be removed without much effort. Appliances can be used in another country with a simple change of the power supply cord; the power supply cord can be replaced if damaged, because it is a standardized part that can be unplugged and re-inserted.
Safety hazards, maintenance expenditure and repairs are minimized. IEC 60320 is divided into several parts: IEC 60320-1: General Requirements specifies two-pole and two-pole with earth couplers intended for the connection of a supply cord to electrical appliances; as from IEC 60320-1:2015 this part applies to interconnection couplers which enable the connection and disconnection of an appliance to a cord leading to another appliance. This part of the standard no longer includes standard sheets which have been moved to a new part first published in 2014: IEC 60320-3. IEC 60320-2-1: Sewing machine couplers specifies couplers which are not interchangeable with other couplers from IEC 60320, for use with household sewing machines, they are rated no higher than 2.5 A and 250 V AC. IEC 60320-2-2 Interconnection couplers for similar equipment; this section was withdrawn in January 2016. The general requirements for these items are now included in IEC 60320-1 and the standard sheets are part of IEC 60320-3.
IEC 60320-2-3: Couplers with a degree of protection higher than IPX0 specifies couplers with some degree of liquid ingress pro
IEC 61400 is an International Standard published by the International Electrotechnical Commission regarding wind turbines. The 61400 is a set of design requirements made to ensure that wind turbines are appropriately engineered against damage from hazards within the planned lifetime; the standard concerns most aspects of the turbine life from site conditions before construction, to turbine components being tested and operated. Wind turbines are capital intensive, are purchased before they are being erected and commissioned; some of these standards provide technical conditions verifiable by an independent, third party, as such are necessary in order to make business agreements so wind turbines can be financed and erected. IEC started standardizing international certification on the subject in 1995, the first standard appeared in 2001; the common set of standards sometimes replace the various national standards, forming a basis for global certification. Small wind turbines are defined as being of up to 200 m2 swept area and a somewhat simplified IEC 61400-2 standard addresses these.
It is possible to use the IEC 61400-1 standard for turbines of less than 200 m2 swept area. The standards for loads and noise are used in the development of prototypes at the Østerild Wind Turbine Test Field. In the U. S. standards are intended to be compatible with IEC standards, some parts of 61400 are required documentation. The U. S. National Renewable Energy Laboratory participates in IEC standards development work, tests equipment according to these standards. For U. S. offshore turbines however, more standards are needed, the most important are: ISO 19900, General requirements for offshore structures ISO 19902, Fixed steel offshore structures ISO 19903, Fixed concrete offshore structures ISO 19904-1, Floating offshore structures – mono-hulls and spars ISO 19904-2, Floating offshore structures - tension-leg platforms API RP 2A-WSD, Recommended practice for planning and constructing fixed offshore steel platforms - working stress design. In Canada, the previous national standards were outdated and impeded the wind industry, they were updated and harmonized with 61400 by the Canadian Standards Association with several modifications.
An update for IEC 61400 is scheduled for 2016. For small wind turbines the global industry has been working towards harmonisation of certification requirements with a "test once, certify everywhere" objective. Considerable co-operation has been taking place between UK, USA, more Japan and other countries so that the IEC 61400-2 standard as interpreted within e.g. the MCS certification scheme is interoperable with the USA and other countries. Wind turbines are designed for specific conditions. During the construction and design phase assumptions are made about the wind climate that the wind turbines will be exposed to. Turbine wind class is just one of the factors needing consideration during the complex process of planning a wind power plant. Wind classes determine which turbine is suitable for the normal wind conditions of a particular site. Turbine classes are determined by three parameters - the average wind speed, extreme 50-year gust, turbulence. Turbulence intensity quantifies how much the wind varies within 10 minutes.
Because the fatigue loads of a number of major components in a wind turbine are caused by turbulence, the knowledge of how turbulent a site is of crucial importance. The wind speed increases with increasing height. In flat terrain the wind speed increases logarithmically with height. In complex terrain the wind profile is not a simple increase and additionally a separation of the flow might occur, leading to increased turbulence; the extreme wind speeds are based on the 3 second average wind speed. Turbulence is measured at 15 m/s wind speed; this is the definition in IEC 61400-1 edition 2. For U. S. waters however, several hurricanes have exceeded wind class Ia with speeds above the 70 m/s, efforts are being made to provide suitable standards. IEC 61400-1:2005+AMD1:2010 Design requirements IEC 61400-2:2013 Small wind turbines IEC 61400-3:2009 Design requirements for offshore wind turbines IEC 61400-4:2012 Design requirements for wind turbine gearboxes IEC 61400-11:2012 Acoustic noise measurement techniques IEC 61400-12-1:2005 Power performance measurements of electricity producing wind turbines IEC 61400-12-2:2013/COR1:2016 Power performance of electricity-producing wind turbines based on nacelle anemometry / Corrigendum 1 IEC 61400-12-1:2017 Power performance measurements of electricity producing wind turbines / Remote sensing devices like Sodar & lidar measurements IEC 61400-13:2015 Measurement of mechanical loads IEC TS 61400-14:2005 Declaration of apparent sound power level and tonality values IEC 61400-21:2008 Measurement and assessment of power quality characteristics of grid connected wind turbines IEC 61400-22:2010 Conformity testing and certification IEC 61400-23:2014 Full-scale structural testing of rotor blades IEC 61400-24:2010 Lightning protection IEC 61400-25-1:2006 Communications for monitoring and control of wind power plants - Overall description of principles and models IEC 61400-25-2:2015 Communications for monitoring and control of wind power plants - Information models IEC 61400-25-3:2015 Communications for monitoring and control of wind power plants - Information exchange models IEC 61400-25-4:2008 Communications for monitoring and control of wind power plants - Mapping to communication profile IEC 61400-25-5:2006 Communications for monitoring and control of wind power plants - Conformance testing IEC 61400-25-6:2010 Communications for monitoring and control of wind power plants - Logical node cla