More Information on Cords

Specifying International Cords
Selection of the appropriate power cord (plug or connector on cable) or cordset (plug, connector on cable) for each export market is one of the easiest steps the equipment designer takes to assure the product can be easily plugged-in and used by their global customers.

Choosing a cord involves four steps:

  1. Identify the correct plug for the country
  2. Determine the desired current rating of the power cord or cordset
  3. Choose the correct cable
  4. If a cordset, choose appropriate IEC 60320 power connector

World Plug and Socket Standards Back to the top
There are 13 standard plug/socket patterns used throughout the world for Class 1 (grounded) and Class 2 (ungrounded) applications with current ratings from 2.5–16A depending on country and agency. These standards are Continental Europe, Europlug, Argentina, Australia, China, Denmark, India/South Africa, Israel, Italy, Japan, North America, Switzerland, and the United Kingdom/Ireland. 100% of Interpower Cords are Tested. Cords are tested using the following procedures:

  1. Ground continuity is determined at 25A.
  2. Polarity and continuity are checked on each conductor to assure that line is connected to line, neutral to neutral, and ground to ground.
  3. High voltage breakdown tests are performed at 2500VAC for one second between the primary conductors and ground conductor.
  4. All plugs, connectors and cable are visually inspected for surface quality, moulding flash, markings, etc.
  5. Length of power cords/cordsets is checked on a random sample basis.

Measuring Power Cords and Cordsets Back to the top
Interpower Components Ltd. measures its power cords from the face of the connector or plug, not including pins, to the end of the cable, stripped or not. See illustration below.

Interpower cordsets are measured from the face of the connector to the face of the plug, not including pins. See illustration below.

Power Connections in Developing Countries Back to the top
Information on electrical systems used in developing countries is imprecise. Formal electrical standards, where they exist, frequently do not cover plugs and sockets or are ignored in the marketplace. Furthermore, with regard to voltages and frequencies, power generating and distribution systems have been installed at various times by different contractors. These systems occasionally produce power at different frequencies and provide different voltages for final distribution. Therefore, some cities—even individual buildings in those cities—may be supplied by two or more generating plants and power distribution systems, each with a different single-phase voltage and frequency.

Most third world electrical distribution systems are ungrounded. Three-contact, grounded plugs, while mateable with the sockets, are not necessarily providing the expected equipment ground. An alternative method of equipment ground is advisable in these cases.

An ungrounded version of the North American NEMA 5-15 plug is commonly used in Central America and parts of South America. It is, therefore, common for equipment users to use a Class 1 to Class 2 adapter similar to Interpower part number 88100011. Interpower Components Ltd. does not recommend cutting off the ground pin so that the plug can be mated with a two-pole, ungrounded socket. Another common international standard is the Europlug (XVII, 2.5A or CEE 7, 16A), both ungrounded versions of the Continental European (German Schuko) standard.

IEC 60320 Power Connections Back to the top
Whenever a detachable cordset is used, the mating connector must be included in the specification for the equipment. The connectors used throughout most of the world are defined in the IEC publication 60320. A common example is described as the standard sheets C13 (connector) and C14 (inlet). The C13 is rated by most agencies for service 10A at 70°C. UL and CSA allows its use up to 15A (220–240VAC). Cordsets with moulded-on cable connectors are available for most countries. These detachable cordsets make it easy for manufacturers to export products by using international plugs with the common IEC 60320 C13 connector.

For lower amperages, IEC provides 2.5A connectors, either grounded or ungrounded. The grounded IEC 60320 C5 (connector) and C6 (inlet) are available with nine international plugs in this catalogue. IEC 60320 C7 (connector) and C8 (inlet) are the ungrounded 2.5A connection. The C7 is commonly used with the Europlug and is available with five other international plugs. The C5, C6, C7, and C8 are rated at 70°C.

The IEC 60320 standard C19 (connector) and C20 (inlet), describes a connector rated at 16A/250VAC (20A in North America). It is rated at 70°C and permits detachable power connections for higher amperage requirements. A rewirable connector and inlet are shown on pages 127 and 209.

Accessory power connections, described in IEC 60320-2-2, can be powered almost anywhere in the world by using the accessory power system based on the international IEC 60320 connector pattern. Both 10–15A and 16–20A rated models are available. The NEMA 5-15R socket used by North American manufacturers for accessory power applications is not recommended for use on exported products.

Cable Considerations Back to the top
Determine jacket abrasion resistance needed for use on your product. Interpower power cords and cordsets are PVC jacketed and generally rated for use in off-the-floor office situations (Note: we can prepare made-to-order cable assemblies with rubber or TPE cable for harder service usage. Contact us for more information). See Cable Recommendations for assistance in specifying cable.

Shielded Cords Back to the top
The use of shielded cords and cordsets on products that will be sold internationally presents special problems from an agency approval point of view. The reason is that shielded cords are not specifically covered by existing cable standards. The equipment manufacturer may be forced to incur the extra costs in getting an application approval to use the shielded cordset. VDE has tested and approved shielded cordsets in the past and therefore in Germany, at least, this may not be an overwhelming problem. Other countries, however, may not accept shielded cordsets. In general, shielded cords should be avoided whenever possible. Shielded cords are available only on a special order basis.

Power Cords & Cordsets Approvals and Markings Back to the top
Most international and North American agencies test and approve moulded plugs separately from moulded appliance connectors. The agencies normally specify on the approval documents a limited range of cable types, which are acceptable for use with moulded plugs or IEC 60320 connectors. A typical cordset will have two or three separate approval documents. One will describe the moulded plug and the type(s) of cable that is (are) acceptable. The second will reference the moulded connector, again with reference to one or more specific cable types. The third will cover the cable itself. Specific World Requirements • Europe—Most European agencies require that agency markings be moulded directly into moulded plugs and connectors. The cable itself will have the required marks either on the jacket or on the primary insulation. Alternatively it will incorporate a colour-coded thread to identify the manufacturer.

•Australia—The Australian agencies require that an approval number be moulded into the plug and appliance connector and that the cable be surface marked with information that also includes this approval number.

•United States—UL does not require that their mark be moulded directly into the cord; however, it does require surface marking of the cable with the manufacturer’s file number. Furthermore, cords are normally be tagged on the cartons or in bundles with markings that conform to UL regulations.

•Canada—CSA’s requirements are similar to UL’s except that they require a CSA label on each cord that conforms to CSA requirements.

Australian Medical Requirements Back to the top
Australian medical equipment used in Australia must meet AS/NZS 3200 series. There are no special requirements for cordsets, only preferences. All Australian cordsets must use a plug approved to AS/NZS 3112 and a connector approved to IEC 60320-1, or the equivalent Australian standard. Cordsets for use in Australian medical applications are preferred by hospitals to have a clear, transparent plug and orange, flexible cable. These plugs and connectors must carry an Australian approval. Interpower cords carry Department of Fair Trading.

North American Hospital-Grade Cord Standards and Requirements
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Cords used with North American medical equipment must be hospital-grade. The plug makes the cord hospital-grade. Commonly known as hospital-grade plugs, they are subject to special requirements contained in the following standards: Medical equipment standards: UL 60601-1 and CAN/CSA C22.2 no 21; Power supply cord standards: UL 817 and CAN/CSA C22.2 no 21; Attachment plug standards: UL 498 and CAN/CSA C22.2 no 42.

The hospital-grade plug pattern conforms to the NEMA 5-15 standard; however, (1) the blades must be solid instead of folded brass, (2) the blades are usually nickel-plated, and (3) the plug includes an internal cable retention device or strain relief to prevent any stress to the plug’s internal connections. It is imperative that the ground connection be reliably maintained to protect the patient and medical staff. Although many hospitals prefer that the plug be clear so that internal connections can be inspected visually, the UL and CSA standards do not mandate clear plugs, nor do they provide any restrictions on colour. Grey is another common colour for hospital-grade plugs and cords.

North American Hospital-Grade Approvals Back to the top
Interpower North American hospital-grade cords and cordsets carry the “green dot” signifying that they have been designed and tested for grounding reliability, assembly integrity, strength and durability. They are approved by UL and CSA to UL 817 and CAN/CSA C22.2 no 21 as hospital-grade power cords and cordsets. Specifically, UL 60601-1 sections 57.2 and 57.3 require that “patient care equipment” used in the “patient vicinity” must use hospital-grade attachment plugs. “Patient care equipment” and “patient vicinity” are defined in UL 60601-1 sections 2.12.19 & 2.12.20.

There are no specific maximum lengths for cords noted in the standards listed above, yet the equipment must pass the leakage current test requirements in UL 60601-1 and CAN/CSA C22.2 no 21. Cord length has an affect on leakage current within a system.

Please note that Interpower recommends using power cords incorporating the IEC brown, blue and green/yellow conductor colour coding in place of the traditional North American black, white, green conductor colour coding. Wiring various country specific power cords to equipment before export, including shipment to the U.S., is simplified when < standardising on the IEC colour coding system. Both the U.S. and Canadian national electrical codes, as well as UL and CSA standards, allow the use of the IEC brown, blue, and green/yellow conductor colour coding. It is no longer necessary to use the black, white, and green colour coding in primary insulation.

Danish Hospital-Grade Requirements Back to the top
The Danish hospital-grade cords are recommended for use in medical applications and specifications are being added to the standard SB 107-2-D1, which was published at the end of 2003. The socket is designed to prevent “normal equipment” from being connected and disrupting the mains circuit in specific medical settings.

International Medical Markets Back to the top
International markets, including European medical equipment used in these markets, typically must meet EN/IEC 60601-1. At this time, there are no special performance or construction requirements for cordsets used in these applications. Cordsets typically will be Class 1 (with ground), PVC, and black in colour. We offer the common Continental European, Argentine, British, Chinese, India/South African, Israeli, Italian, Japanese, and Swiss cordsets.

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