More Information on Cable
When is Cable Needed?
There are times when a power cord or cordset is not readily available for a given application. The plug may be unavailable in a moulded configuration. There may be times when the designer or manufacturer would prefer to wait until just prior to shipping to install a plug on the equipment. If the equipment requires more than 3.0–3.5 KVA (kilovolts), or is using three-phase power, a moulded-on plug/socket system may not be available. When one of these cases exists, it may be preferable to simply order the required cable.
Cable Types Compared
While there are some commonalities between North American and international cable, there are also some important differences. A discussion of these issues will help the designers clarify their choices.
Interpower North American Cable
North American cable specified by the number and gauge of conductors. The gauge uses an inverse relationship to the size, so the larger the number, the smaller the cable. For example,
a small gauge North American cable with three conductors might be 3 x 18AWG (American Wire Gauge). This may also be expressed as 18/3AWG. A cable sized 3 x 10 (10/3) would be larger, despite the smaller number.
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 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 cable insulated with thermoplastic elastomer, such as Interpower flexible North American cable, also exhibit some of these characteristics. Designers may want to carefully review requirements against some of the newer cable types before making a final selection.
North American cable is often manufactured with jute or paper filler. This filler acts to make the cable stronger and enhances the round shape during the extruding process. However, it also makes the cable more labor intensive to deal with when assembling on it, as the filler must be stripped and trimmed away. For this reason, fillerless cable is now often the cable of choice for equipment designers. The fillerless cable will require less preparation and is also somewhat smaller than filled cable. The additional space savings can prove significant in designs where space is limited. In order for Interpower 3 x 18AWG cable to meet the tensile requirements, a strand of Kevlar™ is run down the length of the cable inside the ground wire in place of the filler. All other sizes of Interpower fillerless cable contain no Kevlar™ or filler of any kind.
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 colour coding is typically: line (black), neutral (white) and ground (green). However, these colours are not required, as per UL60950 and UL60601. In fact, UL is now moving to: line (brown), neutral (light blue) and ground (yellow/green striped) colour coding on the conductors. Each conductor is sized in accordance with the AWG system.
Interpower International 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 “harmonised,” or simply “HAR.” This comes from the standards to which the cable is constructed: CENELEC publications HD-21 and HD-22. “HD” (Harmonised Document), which is the European Union’s effort to provide consistency in manufacturing cable. HD-21 is the standard for PVC-jacket cable and HD-22 is the standard for rubber cable. As is the case for North American cable, each jacket type offers advantages and disadvantages.
Harmonised conductors are measured in square millimeters. This measurement comes from the cross section measurement of each conductor. Hence, the size is expressed as mm2, such as 1.5mm2. Because the standards and methods of measuring are different, harmonised cable sizes do not correspond with North American sizes. It is also worth noting that harmonised cable does not have filler. Harmonised cable does not have as high a tensile strength as a similar North American cable.
Like North American cable, the inner conductors of harmonised cable are made of material consistent with the outer jacket. All harmonised cable will be colour-coded line (brown), neutral (light blue) and ground (yellow/green striped). These conductors are sized with the mm2 measurement.
The property designations for harmonised cable are also quite different from North American cable. See our chart on International “Harmonised” Cable Designations. 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. Harmonised cable standards allow for an inner conductor jacket to display the markings, or a simple coloured thread to run throughout the length of the cable. This thread only identifies the cable manufacturer. It does not provide any structural information.
Interpower Shielded Cable
Interpower carries both North American and international shielded cable. Shielded cable is similar to unshielded cable in its manufacture, except it has an added aluminum “shield” that runs the length of the cable. In North American cable, the shield is commonly in a sheet form (foil), with an aluminum drain wire. It sometimes comes in a braided wire mesh. International shielded cable is available only with a braided wire shield.
The aluminum acts to pick up stray electrical charges, usually from “bleeding off” within the cable, where the charge may cause interference. Commonly, the aluminum is attached to the ground of the cable to facilitate dispersal of the stray charge. It is important to note that international standards do not call for, nor do they recognise shielded cable. The cable may be built to harmonised standards, but it will not carry any approvals. North American shielded cable, on the other hand, will carry UL and CSA approvals.
Interpower Three-phase Cable
For most products and most designs, single-phase cable is all that is required. Single-phase cable has three conductors: the line, the neutral and the ground. It is called single-phase due to having only one line conductor. However, some projects may require multi-phase cable.
Three-phase cable is similar in construction to single-phase, but it will have two additional line conductors. Three-phase cable has either four or five conductors, in a three-line, one-neutral and one-ground set up. Interpower carries four-conductor cable with a ground and three line conductors.
Three-phase cable is manufactured to the same specifications as single-phase cable and subject to the same standards. Interestingly, in the past, international cable added extra leads in a black colour, regardless of whether one or two more conductors were being added. However, cable standards in Europe have been changed to implement a uniform conductor colour code (HD 308 52). By April 1, 2006, all cable must be converted to the new system in which one of the black conductors will be replaced with a grey conductor to better distinguish the line conductors. For North American cable, the first extra conductor is red and the second is orange. It is also worth noting that UL and CSA do not test cable larger than 10AWG. The applications for 8 gauge and larger cable become user specific, because of its sheer size and capacity.
Interpower Flexible and Oil Resistant Cables
As was noted earlier, Interpower now offers cables that offer alternatives to standard rubber. One type is TPE (Thermoplastic Elastomer). TPE offers a very flexible plastic jacket that can withstand extreme cold. Additionally, it is ultra-violet resistant, abrasion resistant, and withstands most chemicals. These features make it an attractive choice for cable that will be exposed to the elements.
Another thermoplastic cable that may suit the designer’s need is oil resistant cable rated at 600V. The oil resistant rating includes most petroleum-based products. This cable offers good abrasion resistance, as the jacket is rated for heavy-duty use.
Value Added and Made-to-Order Assemblies
Custom Lengths
Interpower Components Ltd. is well equipped to provide cable packaged to your company’s specifications. We maintain a large inventory of every cable described in this catalogue. We can deliver your order on spools in quantities that you specify. We can also deliver cable cut to length so that you eliminate scrap. This service is well suited with large cables that are expensive and difficult to handle.
Stripping
Interpower Components Ltd. uses stripping equipment that makes it easy to strip all of the cables listed in this section. Our stripping machines strip conductors up to 50cm. We can also cut and strip conductors to specified lengths and apply crimp terminations which one can specify from a wide variety that we maintain in stock. Standard stock terminations include: ultrasonic weld, ring terminals, spade terminals, straight-style disconnects, flag-style quick disconnects, and ferrules. Our cable stripping and crimp termination services are particularly attractive with large rubber jacketed cable that is difficult to strip and handle.
Terminations
Interpower Components Ltd. can make your complete power cable assemblies by terminating the cable with any of the following: straight blade or locking type plugs and connectors, international plugs and connectors, IEC 60309 high power pin and sleeve devices, IEC 60320 connectors, and related devices.
Manufacturing
Our skilled assemblers work in a well-equipped, comfortable manufacturing facility that is ISO 9001 Certified. Continuous training enables our assemblers to perform the wide variety of work that moves through our shop. This assures a quick turnaround time and cable assemblies that will meet your specifications. Assuming that appropriate materials are specified, our power cable assemblies are UL recognised or listed and CSA certified.
Please note that although we can use components certified by agencies other than UL and CSA, complete cable assemblies must be submitted to the agency with the equipment for testing. They will be given an applications approval at that time. This reflects the fact that other agencies use a more restrictive approval process for rewirable power cable assemblies than UL and CSA.
Finally, Interpower Components Ltd. maintains lot code traceability on all components used in manufacturing power cable assemblies. This allows our customers to meet the high demands for quality and traceability placed on them by their customers.
Label and Packaging Services
Interpower Components Ltd. offers a wide variety of special services to benefit you and your customer. Special labeling is available for any power cord or cordset, with a wrap label, flag label, or hot stamp. We can also provide special packaging for all of your parts, in the way of individual
bagging, hanking, coiling, or boxing. For further convenience, individually boxed and bagged parts can be labeled on the package. We can also add the CE Marking to assemblies targeted for European markets.
Proposition 65
Warning: This product contains chemicals, including lead, known to the State of California to cause cancer, birth defects, or other reproductive harm. Wash hands after handling.