IEC 60320


IEC 60320, entitled "Appliance couplers for household and similar general purposes", is a set of standards published by the International Electrotechnical Commission that defines non-locking appliance couplers for connecting power supply cords to electrical appliances. These couplers are intended for use with devices operating at voltages up to 250 V and currents up to 16 A. The standard specifies various types of connectors, differentiated by shape and size, to accommodate different combinations of current ratings, temperature tolerances, and earthing requirements.
Unlike IEC 60309 connectors, IEC 60320 couplers are not keyed or color-coded to indicate voltage; it is the responsibility of the user to ensure that the appliance's voltage rating is compatible with the local mains supply. The standard uses the term coupler to refer collectively to both the appliance inlets and outlets, as well as the connectors on power supply cords.
The first edition of the standard was published in 1970 under the designation IEC 320. It was renumbered to IEC 60320 in 1994 as part of the IEC's revision and reorganization of its numbering system.

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.
  • 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 which is 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".
Non-rewirable plugs and connectors are typically permanently molded onto cords and cannot be removed or rewired without cutting the cords.
The standard uses the terms "male" and "female" only for individual pins and socket contacts, but in general usage they are also applied to the complete plugs and connectors. "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/jug plug” is also informally used to refer to regular temperature-rated C13 and C14 connectors.

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:
  • IEC 60320-1: General Requirements specifies two-pole and two-pole with earth couplers intended for the connection of a mains supply cord to electrical appliances. Beginning with the IEC 60320-1:2015 edition, this part also specifies interconnection couplers which enable the connection and disconnection of an appliance to a cord leading to another appliance, incorporating IEC 60320-2-2. At the same time, this part of the standard no longer includes standard sheets which were moved to a new part: 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 household and similar equipment. This section was withdrawn in January 2016. The general requirements for these items were incorporated into IEC 60320-1 and the standard sheets were moved to IEC 60320-3.
  • IEC 60320-2-3: Couplers with a degree of protection higher than IPX0 specifies couplers with some degree of liquid ingress protection. In its second edition published in 2018, the standard sheets were moved to IEC 60320-3.
  • IEC 60320-2-4: Couplers dependent on appliance weight for engagement.
  • IEC 60320-3: Standard sheets and gauges. First published October 31, 2014, this part initially included the standard sheets for both appliance couplers and interconnection couplers. In a 2018 amendment, the standard sheets for the IP couplers defined by 60320-2-3 were added. For appliance couplers the various coupler outlines are designated using a combination of letters and numbers, e.g., "C14". The connector supplies power to the appliance inlet. The appliance inlet is designated by the even number one greater than the number assigned to the connector, so a C1 connector mates with a C2 inlet, and a C15A mates with a C16A. Interconnection couplers have single letter designators, e.g., "F". They consist of a plug connector and an appliance outlet. The plug connector is the part integral with, or intended to be attached to, the cord, and the appliance outlet is the part integrated with or incorporated into the appliance or equipment or intended to be fixed to it, and from which the supply is obtained.

    Contents of standards

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 connector 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,, and, 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.