Interpower Connections May 2009 edition looks specifically at how to design and specify cable for either domestic or international markets. This "How To" article shows you the differences you need to know concerning North American, International and European HAR, Japanese and Chinese cable. To also assist you with specifying the correct cable, Interpower Corporation is offering, for free, our North American and International Cable wall-chart. You can download the wall-chart as a PDF, print it off and post it wherever you would like. Future editions will look at other subjects that we hope will be of interest to both experienced and new designers alike. Should you have a question that Interpower Connections has yet to answer, please email us at info@interpower.com.
Cable Used Around the World and What You Need to Know
Specifying the correct flexible cable for international markets can be a challenge, due to the fact that there is no single cable standard accepted by every nation. In fact, there are four different cable standards used in the major world markets. While there are some commonalities between these standards, there are also some important differences. A discussion of how to specify cables for the correct market, and the differences in the cable standards, will help the designers clarify their choices.
The following basic steps are important when specifying cable for a specific market:
- Specify the appropriate cable standard or global market: North American, European/International, Japanese, or Chinese.
- Specify the correct number of conductors needed for an application (3, 4, or 5 typically)
- Specify the correct size or ampacity rating needed for the application, based on the typical requirements of the cable standard. It is important when doing this to use the correct terminology and nomenclature as dictated by a particular standard.
- Specify the correct jacket type and cable characteristics as required for a specific application. Again, it is important to be familiar with the correct basic terminology or codes for a given cable standard.
In order to follow these basic steps, it is helpful to have knowledge of the basic differences and requirements for each of the major cable types, and be able to adapt these basic rules to each cable standard.
- North American Cable: The North American market consists primarily of the United States, Canada, and Mexico. The cable types used for this market are specified in the tri-national cable standard UL 62, CSA C22.2 No. 49, NMX-J-436-ANCE. North American cable is constructed and sized using the American Wire Gauge (AWG) system. Cable in this system is sized by the number of conductors and a size designation number (ex. 18/3 AWG or 3x18AWG). The gauge number uses an inverse relationship to the size, where the larger the designator number, the smaller the actual cable size. For example, when comparing an 18/3AWG cable to a 10/3AWG cable, the 10/3 cable is actually much larger, despite the smaller size designator number. Standards dictate ampacity ratings for the different designated sizes. Because of constructional differences in the cable and difference in rating guidelines between the different standards, North American cable ampacity ratings do not necessarily match up with other international ratings systems, and may seem low in comparison to size/ampacity relationships of other standards.
The size designation of North American cable is followed by a series of letters, such as “SJT” or “SOW.” These letters indicate the characteristics of the cable, such as the jacket type, water/chemical resistance, and abrasion resistance. These designations are stamped on the exterior jacket for quick and easy reference for the end user, along with the pertinent UL/CSA references, as listed under UL 62 and CSA 49.
The outer jacket on North American cable is typically PVC, thermoplastic, or rubber. Each jacket type offers advantages and disadvantages to the end user. Thermoplastic cable is usually more cost effective than rubber, as well as lighter weight. This makes it an attractive choice for use with items such as household appliances. Rubber cable can be more costly, but does have its advantages. Rubber tends to be more durable, with high levels of water and abrasion resistance. These factors make it an attractive choice for outdoor applications. However, some newer types of thermoplastic cable, also exhibit some of these characteristics. The wise designer would do well to carefully review his requirements against some of the newer cable types before making a final selection. The inner conductors for North American cable have either thermoplastic or rubber jackets, in accordance with the outer jacket
For single-phase cable, the conductor color coding is typically: line (black), neutral (white) and ground (green). However, these colors are not required, as per UL60950 and UL60601. In fact, UL is now allowing the same color code as seen in international cable: line (brown), neutral (light blue) and ground (yellow/green striped) on the conductors.
When specifying North American cable:
- Determine the number and AWG size of conductors you will need.
- Determine the appropriate color code you need to specify.
- Determine the jacket material and designation code needed to meet the physical and environmental conditions of the application.
- International (European) Cable: International cable is similar in appearance to North American cable, but there are a number of important differences. International cable is referred to as “harmonized,” or simply “HAR.” This comes from the standards to which the cable is constructed: CENELEC HD-21 and IEC 60227, and HD-22 and IEC 60245. “HD” (Harmonized Document), which is the European Union’s effort to provide consistency in manufacturing cable. HD-21 and IEC 60227 are the standards for PVC-jacket cable and HD-22 and IEC 60245 are the standards for rubber cable. As is the case for North American cable, each jacket type offers advantages and disadvantages.
Harmonized cable is sized in square millimeters. This measurement comes from the diameter taken from the circumference of a cross section of each conductor. Hence, the size is expressed as mm², such as 1.50mm². Size increments are designated within the standards, and vary as the cable size increases. Because the standards and methods of measuring are different, harmonized cable sizes do not correspond with North American sizes. Like North American cable, the inner conductors of harmonized cable are made of material consistent with the outer jacket. All single phase harmonized cable will be color-coded line (brown), neutral (light blue) and ground (yellow/green striped).
The property designations for harmonized cable are also quite different from North American cable. See our chart on International “Harmonized” Cable Recommendations. A series of numbers and letters will indicate the jacket material, ratings, and size of the cable. These markings may be found on the outer jacket. However, unlike North American UL markings on cable, the “HD” designators are not always located on the outer jacket of the cable. Harmonized cable standards allow for an inner conductor jacket to display the markings, or a simple colored thread to run throughout the length of the cable. This thread only identifies the cable manufacturer. It does not provide any structural information.
When specifying International cable:
- Determine the number and size of conductors you will need. Remember, these cables do not correspond to AWG sizes directly, so AWG designations should not be used.
- Remember, only the brown, blue, green/yellow color code is allowed for this cable.
- Determine the jacket material and designation code needed to meet the physical and environmental conditions of the application. This information makes up the Harmonized code identifier, which can be used to help in specifying the cable.
- Japanese Cable: This cable is specified to meet the JIS C3306 requirement. Japanese cable is very similar to International cable in that it is sized by cross-sectional and listed in mm² (Ex. 2.00mm²). However, the size scale is slightly different than the international cable, and thus covers sizes that the international cable standard does not. Another key difference is that Japanese regulations require the cable to carry the Japanese PSE approval marking. This essentially eliminates the possibility of using common sized international cable in place of the Japanese cable and ensures that cable will be purchased from Japanese suppliers. Another difference is typically seen in the color code. Japan commonly allows the use of two main color codes in single phase, three wire cable: the common black(L), white(N), green(G) seen in North American cable, and an alternate of black(L), white(N), and red(G). Finally, Japanese cable has lettered codes, similar to UL, but with different arrangements and meaning, e.g. VCTF.
When specifying Japanese cable:
- Determine the number and size of conductors you will need in the Japanese system (mm²).
- Determine the appropriate color code you need to specify.
- Determine the jacket material and designation code needed to meet the physical and environmental conditions of the application.
- Chinese: China uses the same basic cable system as Japan, with the main exception being that their own national approval agency’s mark be on the cable. In the case of China, this means the CCC approval mark must be on the cable. In the instance of the Chinese cable, it also differs from the Japanese cable in color code. The Chinese follow the international color coding system of brown(L), blue(N), green/yellow(G). Chinese cable has also specified lettered code types, e.g. RVV.
When specifying Chinese cable:
- Determine the number and size of conductors you will need in the Chinese system (mm²).
- Be sure that the cable carries the CCC approval for China and utilizes the international color code.
- Determine the jacket material and designation code needed to meet the physical and environmental conditions of the application.
Most other regions of the world use one, or a combination, of these cable standards listed above in their countries. Many undeveloped countries simply use what is available on the open market already, rather than formulate their own standards. There may be a few other requirements out there that are yet unknown, or changes in the works. However, we are confident that this guidance will help you in satisfying most of your cable requirements. Next time you need to specify cable for a major market or application, use the information and tips provided here, to ease your way through the specification process. back to top
Any Length of Cable, Any Quantity—No Problem... Seriously!
At Interpower Corporation we make designing your equipment for worldwide markets EASY! Interpower Corporation offers a wide variety of North American and international Harmonized cable with various lengths and no minimum order requirements. That means any length of cable, whether it be a 5 foot section or an entire reel, no minimum order requirements and you can place your order online at www.interpower.com. If your order is placed by noon Central Standard Time, we offer same day shipments if you need it in a hurry. Interpower Corporation also offers labeling and packaging services as well as various stripping and termination configurations. Call our Customer Service department today about our value added options at (800) 662-2290. Why stock cable when you can let Interpower be Your Warehouse! back to top
North American and International Cable Wall Chart
Here is your chance to request your free copy of our North American and international cable wall chart. The Interpower Cable wall chart will make it easy for you to specify the cable you need, when you need it. With this handy wall chart, you will be able to find the Interpower part number you need, easily and quickly. back to top
