IEC 60320


IEC 60320 Appliance couplers for household and similar general purposes is a set of standards from the International Electrotechnical Commission specifying non-locking connectors 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, temperature and earthing requirements. Unlike IEC 60309 connectors, they are not coded for voltage; users must ensure that the voltage rating of the equipment is compatible with the mains supply. The standard uses the term coupler to encompass connectors on power cords and power inlets and outlets built into appliances.
The first edition of IEC 320 was published in 1970.

Terminology

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 as follows.
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 and "female" to a . "Connectors" and "appliance outlets" are fitted with socket contacts, and "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 also have common names. The most common ones are IEC connector for the common C13 and C14, the figure-8 connector for C7 and C8, and 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.

Application

Detachable appliance couplers are used in office equipment, measuring instruments, IT environments, and 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 readily sold in another which uses an incompatible wall socket; this requires keeping track of variations throughout the product's life cycle from assembly and testing to shipping and repairs.
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 which is 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 easily, with a simple change of the power supply cord. The power supply cord can be replaced easily if damaged, because it is a standardized part that can be unplugged and re-inserted. Safety hazards, maintenance expenditure and repairs are minimized.

Standards

Parts of the standard

IEC 60320 is divided into several parts:
The standards define the mechanical, electrical and thermal requirements and safety goals of power couplers. The standard scope is limited to appliance couplers with a rated voltage not exceeding 250 V at 50 Hz or 60 Hz, and a rated current not exceeding 16 A. Further sub-parts of IEC 60320 focus on special topics such as protection ratings and appliance specific requirements.
Selection of a coupler depends in part on the IEC appliance classes. The shape and dimensions of appliance inlets and connectors are coordinated so that a connector with lower current rating, temperature rating, or polarization cannot be inserted into an appliance inlet that requires higher ratings. ; whereas connecting a Class I to a Class II appliance inlet is possible because it creates no safety hazard.
Pin temperature is measured where the pin projects from the engagement surface. The maximum permitted pin temperatures, are 70 °C, 120 °C, and 155 °C, respectively. The pin temperature is determined by the design of the appliance, and its interior temperature, rather than by its ambient temperature. Typical applications with increased pin temperatures include appliances with heating coils such as ovens or electric grills. It is generally possible to use a connector with a higher rated temperature with a lower rated appliance inlet, but the keying feature of the inlet prevents use of a connector with a lower temperature rating.
Connectors are also classified according to the method of connecting the cord, either as rewirable connectors or non-rewirable connectors.
In addition the standards define further general criteria such as withdrawal forces, testing procedures, the minimum number of insertion cycles, and the number of flexings of cords.
IEC 60320-1 defines a cord set as an "assembly consisting of one cable or cord fitted with one plug and one connector, intended for the connection of an electrical appliance or equipment to the electrical supply". It also defines an interconnection cord set as an "assembly consisting of one cable or cord fitted with one plug connector and one connector, intended for the interconnection between two electrical appliances".
In addition to the connections within the standards, as mentioned, there are possible combinations between appliance couplers and IEC interconnection couplers. Fitted with a flexible cord, the components become interconnection cords to be used for connecting appliances or for extending other interconnection cords or power supply cords.

North American ratings

North American rating agencies will certify IEC 60320 connectors for higher currents than are specified in the IEC standard itself. In particular, UL will certify:
Given the 120 V mains supply used in the United States and Canada, these higher ratings permit devices with C6 and C8 inputs to draw more than 114 V × 2.5 A = 285 W from the mains, and devices with C14 inputs to draw more than 1140 W from the mains.
This is exploited by high-powered computer power supplies, up to 1200 W output, and even some particularly efficient 1500 W output models to use the more popular C14 input on products sold worldwide.
Although less common, power bricks with C6 and C8 inputs and ratings up to 300 W also exist.

Appliance couplers

The dimensions and tolerances for connectors and appliance inlets are given in standard sheets, which are dimensioned drawings showing the features required for safety and interchangeability.
ConnectorAppliance inletDiagramPin spacing,
centres 		Earth contactAppliance classRewirable
connector
allowed?		Max. current
Max. pin temp.
PolarizedRemarks and example uses
C1C26.6II0.270Found on many electric shavers, for example.
C3C410II2.570Similar connector to C5/C6, but with a key ridge instead of an earthing conductor, withdrawn from standard.
C5C610
4.5 		I2.570Many small switched-mode power supplies used for laptops. Commonly referred to as a "clover-leaf" or "Mickey Mouse" connector due to its shape.
C7C88.6II2.570Domestic audio, video, radio equipment and doubly insulated power supplies. C8 inlet is 10 mm deep, C8A and C8B inlets are 15.5 mm deep. Commonly referred to as "figure 8" or "infinity" in the UK. There is a similar polarized connector having one squared side,, but this is not part of the standard.
C9C1010II670This kind of coupler is used by Roland Corporation for a couple of synthesizer and drum-computer models and by Revox for many older models of their hi-fi equipment. Was also used heavily on Marantz hi-fi equipment in the 1980s and 1990s.
C11C1210II1070Similar to C9 with a slot in the connector, withdrawn from standard.
C13C1414
4 		I1070Very common on personal computers and peripherals. Commonly but incorrectly referred to as a "kettle cord", but kettles in countries using 120V require the C15/C16.
C15C1614
4 		I10120For use in high-temperature settings. Also used in Cisco Catalyst series switches, Cisco MDS9500 series rack-mounted SAN switches, HP Procurve switches, Dell PowerConnect switches and early Xbox 360 power supplies.
C15AC16A14
4 		I10155For use in very-high-temperature settings, such as some stage lighting instruments. Similar to C15/C16, but the top is narrowed to exclude the C15 cord connector.
C17C1814II1070Xbox power supply some vacuum cleaners, CPAP machines, audio equipment, televisions, medical devices.
C19C2013
8 		I1670Common for supply of power to enterprise-class servers, UPSs, datacenter rack-mounted power-distribution units and other equipment that draws too much current for C13/C14 type to be used.
C21C2213
8 		I16155High-temperature variant of C19/C20
C23C2413II1670Ungrounded variant of C19/C20

C1/C2 coupler

The C1 coupler and C2 inlet were commonly used for mains-powered electric shavers. These have largely been supplanted by cordless shavers with rechargeable batteries or corded shavers with an AC adapter.

C5/C6 coupler

This coupler is sometimes colloquially called a cloverleaf coupler or "Mickey Mouse".
The C6 inlet is used on laptop power supplies and portable projectors, as well as on some desktop computers and recent LCD televisions from LG.

C7/C8 coupler

Commonly known as a "figure-8", "infinity" or "shotgun" connector due to the shape of its cross-section, or less commonly, a Telefunken connector after its originator.
This coupler is often used for small cassette recorders, battery/mains-operated radios, battery chargers, some full-size audio-visual equipment, laptop computer power supplies, video game consoles, and similar double-insulated appliances.
A C8B inlet type is defined by the standard for use by dual-voltage appliances; it has three pins and can hold a C7 connector in either of two positions, allowing the user to select voltage by choosing the position the connector is inserted.
A similar but polarized connector has been made, but is not part of the standard. Sometimes called C7P, it is asymmetrical, with one side squared. Unpolarized C7 connectors can be inserted into the polarized inlets; however, doing so might be a safety risk if the device is designed for polarized power. Although not specified by IEC 60320, and not clear whether any formal written standard exists, the most common wiring appears to connect the squared side to the neutral, and the rounded to the hot line. Note: Clause 9.5 was added to IEC 60320-1:2015, this requires that "It shall not be possible to engage a part of a non-standard appliance coupler with a complementary part of an appliance coupler complying with the standard sheets in any part of IEC 60320."
Apple uses a modified version of this connector, with the receptacle having a proprietary pin that secures the adapter in place and provides grounding. The cabled adapter provides grounding through a slide-in connector, while the angled AC adapter does not provide grounding.

C13/C14 coupler

Most desktop computers use the C14 inlet to attach the power cord to the power supply, as do many instrument amplifiers, monitors, printers and other peripherals.
A power cord with a suitable power plug on one end and a C13 connector on the other is commonly called an IEC cord. IEC cords are used to power many pieces of electronic equipment, including computers, instrument amplifiers, professional audio equipment and virtually all professional video equipment.
There are also a variety of splitter blocks, splitter cables, and similar devices available. These are usually un-fused.
These cables are sometimes incorrectly referred to as a "kettle cord" or "kettle lead", but the C13/14 connectors are only rated for 70 °C; a device such as a kettle requires the C15/16 connector, rated for 120 °C.
A cable consisting of a C13 and C14 connector is commonly mislabeled as an "extension cord", which although that is not the intended purpose, it can be used as such.
The C13 connector and C14 inlet are commonly found on computers, servers, routers, and switches. Power cord sets utilizing a C13 connector and a C14 plug are commonplace in data centers to provide power from a PDU to a server. These data-center power cables are now offered in many colors.. Colored power cables are used to color-code installations.

C15/C16 coupler

Some electric kettles and similar hot household appliances like home stills use a supply cord with a C15 connector and a matching C16 inlet on the appliance; their temperature rating is 120 °C rather than the 70 °C of the similar C13/C14 combination. The official designation in Europe for the C15/C16 coupler is a "hot-condition" coupler.
These are similar in form to the C13/C14 coupler, except with a ridge opposite the earth in the C16 inlet, and a corresponding valley in the C15 connector. For example, an electric kettle cord can be used to power a computer, but an unmodified computer cord cannot be used to power a kettle.
There is some public confusion between C13/C14 and C15/C16 couplers, and it is not uncommon for C13/C14 to be incorrectly referred to as "kettle plug" or "kettle lead".
In European countries the C15/C16 coupler has replaced and made obsolete the formerly common types of national appliance coupler in many applications.

C15A/C16A coupler

There is also a C15A/C16A coupler, with an even higher temperature rating.

C17/C18 coupler

Similar to C13/C14 coupler, but unearthed. A C18 inlet accepts a C13 connector, but a C14 inlet does not accept a C17 connector.
The IBM Wheelwriter series of electronic typewriters are one common application. Three-wire cords with C13 connectors, which are easier to find, are sometimes used in place of the two-wire cords for replacement. In this case, the ground wire will not be connected.
The C17/C18 coupler is often used in audio applications where a floating ground is maintained to eliminate hum caused by ground loops. Other common applications are the power supplies of Xbox 360 game consoles, replacing the C15/C16 coupler employed initially, and large CRT televisions manufactured by RCA in the early 1990s.

C19/C20 coupler

Earthed, 16 A, polarized. This coupler is used for supplying power in IT applications where higher currents are required, as for instance, on high-power workstations and servers, power to uninterruptible power supplies, power to some power distribution units, large network routers, switches, blade enclosures, and similar equipment. This connector can also be found on high-current medical equipment. It is rectangular and has pins parallel to the long axis of the coupler face.

Withdrawn and other standard sheets

C3, C4, C11 and C12 standard sheets are no longer listed in the standard.
Standard sheet C25 shows retaining device dimensions. Sheet C26 shows detail dimensions for pillar-type terminals, where the end of the screw bears on a wire directly or through a pressure plate. Sheet 27 shows details for screw terminals, where the wire is held by wrapping it around the head of a screw.

Interconnection couplers

Interconnection couplers are similar to appliance couplers, but the appliance outlet is built into a piece of equipment, while the plug connector is attached to a cord. They are identified by letters, not numbers, with one letter identifying the plug connector, and the alphabetical next letter identifying the mating appliance outlet. For example, an E plug fits into an F outlet.
The dimensions and tolerances for plug connectors and appliance outlets are given in standard sheets, which are dimensioned drawings showing the features required for safety and interchangeability.
Plug connectorAppliance outletDrawingPin spacing,
centres 		Earth contactAppliance classRewirable
connector
allowed?		Max. current
Remarks and example uses
AB10
4.5 		I2.5Commonly referred to as a "clover-leaf" or "Mickey Mouse" connector due to its shape.
CD8.6II2.5Not polarized. Commonly referred to as a "figure of 8" or "figure 8".
EF14
4 		I10Very common for power distribution on computer and instrument equipment racks, used to be common as a means of connecting power from a PC to a monitor.
GH14II10Ungrounded variant of E/F
IJ13
8 		I16Common on enterprise-class servers and datacenter rack-mounted power distribution units.
KL13II16Ungrounded variant of I/J

Cables with a C13 connector at one end and a type E plug connector at the other are commonly available. They have a variety of common uses, including connecting power between older PCs and their monitors, extending existing power cords, connecting to type F outlets strips and connecting computer equipment to the output of an uninterruptible power supply. Type J outlets are used in a similar way.