Cable harness

Last updated
A cable laced wiring harness installed in a component of a Tesla coil Cable lacing installation.jpg
A cable laced wiring harness installed in a component of a Tesla coil
Harness of car audio cables. Wire harness for aftermarket head unit.jpeg
Harness of car audio cables.

A cable harness, also known as a wire harness, wiring harness, cable assembly, wiring assembly or wiring loom, is an assembly of electrical cables or wires which transmit signals or electrical power. [1] The cables are bound together by a durable material such as rubber, vinyl, electrical tape, conduit, a weave of extruded string, or a combination thereof. [2]

Contents

Commonly used in automobiles, as well as construction machinery, cable harnesses provide several advantages over loose wires and cables. For example, many aircraft, automobiles and spacecraft contain many masses of wires which would stretch over several kilometers if fully extended. By binding the many wires and cables into a cable harness, the wires and cables can be better secured against the adverse effects of vibrations, abrasions, and moisture. By constricting the wires into a non-flexing bundle, usage of space is optimized, and the risk of a short is decreased. [3] Since the installer has only one harness to install (as opposed to multiple wires), installation time is decreased and the process can be easily standardized. [4] Binding the wires into a flame retardant sleeve also lowers the risk of electrical fires. [3]

Design

The design of a wire harness usually requires the effort of two main engineering disciplines that focus on different functioning requirements, mechanical engineering and electrical engineering. Mechanical engineering is the field that focuses on the physical parameters of a wire harness and its interaction with the environment it will endure during its lifetime. This considers the operating conditions the wire harness is meant to operate under, i.e. temperature, mechanical stress, environmental and chemical wear. This component considers the protective materials wire harnesses have like corrugated tubes, braided or silica sleeves.


Electrical engineering is the field the focuses on developing the logical, electrical and topological architecture of the wire harnesses. When designing the electrical wires that will be used one must consider the operating ratings of wires for communication protocols usually specified under the communication protocol's design standards developed by automotive entities like ASME, ISO or JASO. [5]

Production

Cable harnesses are usually designed according to geometric and electrical requirements. A diagram is then provided (either on paper or on a monitor) for the assembly preparation and assembly. [3]

The wires are first cut to the desired length, usually using a special wire-cutting machine. The wires may also be printed on by a special machine during the cutting process or on a separate machine. [6] After this, the ends of the wires are stripped to expose the metal (or core) of the wires, which are fitted with any required terminals or connector housings. The cables are assembled and clamped together on a special workbench, or onto a pin board (assembly board), according to the design specification, to form the cable harness. After fitting any protective sleeves, conduit, or extruded yarn, the harness is either fitted directly in the vehicle or shipped. [3]

In spite of increasing automation, hand manufacture continues to be the primary method of cable harness production in general, due to the many different processes involved, [3] such as:

It is difficult to automate these processes, with major suppliers still using manual means of production, only automating portions of the process. Manual production remains more cost effective than automation, especially with small batch sizes.

Pre-production can be automated in part. This affects:

A wire harness must also be manufactured with a terminal, defined as "a device designed to terminate a conductor that is to be affixed to a post, stud, chassis, another tongue, etc., to establish an electrical connection." [7] Some types of terminals include ring, tongue, spade, flag, hook, blade, quick-connect, offset and flagged. [8]

Pull test qualification of crimped end. Miraco Pull Test.jpg
Pull test qualification of crimped end.

Once a cable harness has been produced, it is often subject to various tests to ensure its quality and functionality. A test board can be used to measure the harness' electrical capabilities. This is achieved through the input of data about a circuit which one or more cable harnesses will be part of being programmed into the test board. The harness is then measured for its ability to function in the simulated circuit. [9]

Another popular test method for a cable harness is a 'pull test', in which the harness is attached to a machine that pulls the harness at a constant rate. This test then measures the cable harness' strength and electrical conductivity when pulled against a minimum standard to ensure that cable harnesses are consistently effective and safe. [10]

In sound engineering

The cable harnesses used in sound reinforcement and recording studios are called multicores , also known as snakes or looms. They carry audio signals between a mixing console and stage box. Modern digital mixing consoles typically use a single twisted pair cable rather than a traditional analog multicore.

Industry quality standard

Although customer specifications take the highest priority when creating cable harnesses of a certain quality, [11] in North America if no such specifications are found the quality standards of a cable harness are standardized by the IPC's publication IPC/WHMA-A-620 for minimal requirements for cable harnesses. [12] This publication is reviewed frequently to ensure that the standards published remain of an acceptable standard in light of potential changes to the industry or technology that may occur. [11] The IPC/WHMA-A-620 publication has standards for a wide range of elements within a cable harness, including but not limited to electrostatic discharge protection, conduit, installation and repairs, crimping, pull-test requirements, and other operations that are critical to the production and function of cable harnesses. [12] The standards mandated by the IPC differ based on a product's classification under one of three defined product classes. [13] These classes are:

Related Research Articles

<span class="mw-page-title-main">Electrical connector</span> Device used to join electrical conductors

Components of an electrical circuit are electrically connected if an electric current can run between them through an electrical conductor. An electrical connector is an electromechanical device used to create an electrical connection between parts of an electrical circuit, or between different electrical circuits, thereby joining them into a larger circuit. Most electrical connectors have a gender – i.e. the male component, called a plug, connects to the female component, or socket. The connection may be removable, require a tool for assembly and removal, or serve as a permanent electrical joint between two points. An adapter can be used to join dissimilar connectors.

<span class="mw-page-title-main">Electrician</span> Tradesperson specializing in electrical wiring

An electrician is a tradesperson specializing in electrical wiring of buildings, transmission lines, stationary machines, and related equipment. Electricians may be employed in the installation of new electrical components or the maintenance and repair of existing electrical infrastructure. Electricians may also specialize in wiring ships, airplanes, and other mobile platforms, as well as data and cable lines.

<span class="mw-page-title-main">UL (safety organization)</span> Global safety certification company

The UL enterprise is a global safety science company headquartered in Northbrook, Illinois, composed of three organizations, UL Research Institutes, UL Standards & Engagement and UL Solutions.

Electrical wiring in North America follows the regulations and standards applicable at the installation location. It is also designed to provide proper function, and is also influenced by history and traditions of the location installation.

<span class="mw-page-title-main">National Electrical Code</span> Electrical wiring standard

The National Electrical Code (NEC), or NFPA 70, is a regionally adoptable standard for the safe installation of electrical wiring and equipment in the United States. It is part of the National Fire Code series published by the National Fire Protection Association (NFPA), a private trade association. Despite the use of the term "national", it is not a Federal law. It is typically adopted by states and municipalities in an effort to standardize their enforcement of safe electrical practices. In some cases, the NEC is amended, altered and may even be rejected in lieu of regional regulations as voted on by local governing bodies.

<span class="mw-page-title-main">Electrical wiring</span> Electrical installation of cabling

Electrical wiring is an electrical installation of cabling and associated devices such as switches, distribution boards, sockets, and light fittings in a structure.

<span class="mw-page-title-main">Twist-on wire connector</span>

Twist-on wire connectors are a type of electrical connector used to fasten two or more low-voltage electrical conductors. They are widely used in North America and several European countries in residential, commercial and industrial building power wiring, but have been banned in some other jurisdictions.

<span class="mw-page-title-main">Modular connector</span> Electrical connector commonly used in telephone and computer networks

A modular connector is a type of electrical connector for cords and cables of electronic devices and appliances, such as in computer networking, telecommunication equipment, and audio headsets.

<span class="mw-page-title-main">Western Union splice</span> Method of joining electrical cable

The Western Union splice or Lineman splice is a method of joining electrical cable, developed in the nineteenth century during the introduction of the telegraph and named for the Western Union telegraph company. This method can be used where the cable may be subject to loading stress. The wrapping pattern design causes the join to tighten as the conductors pull against each other.

<span class="mw-page-title-main">IPC (electronics)</span> Trade association for electronics

IPC is a trade association whose aim is to standardize the assembly and production requirements of electronic equipment and assemblies. It was founded in 1957 as the Institute of Printed Circuits. Its name was later changed to the Institute for Interconnecting and Packaging Electronic Circuits to highlight the expansion from bare boards to packaging and electronic assemblies. In 1999, the organization formally changed its name to IPC with the accompanying tagline, Association Connecting Electronics Industries.

<span class="mw-page-title-main">Fiber-optic cable</span> Cable assembly containing one or more optical fibers that are used to carry light

A fiber-optic cable, also known as an optical-fiber cable, is an assembly similar to an electrical cable but containing one or more optical fibers that are used to carry light. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable is used. Different types of cable are used for optical communication in different applications, for example long-distance telecommunication or providing a high-speed data connection between different parts of a building.

<span class="mw-page-title-main">Screw terminal block</span> Device for electrical wire connection

A screw terminal is a type of electrical connection where a wire is held by the tightening of a screw.

<span class="mw-page-title-main">Pothead</span> High-voltage electrical connection device

A pothead is a type of insulated electrical terminal used for transitioning between overhead line and underground high-voltage cable or for connecting overhead wiring to equipment like transformers. Its name comes from the process of potting or encapsulation of the conductors inside the terminal's insulating bushing.

<span class="mw-page-title-main">Crimp (electrical)</span> Solderless electrical connection which uses physical pressure

An electrical crimp is a type of solderless electrical connection which uses physical pressure to join the contacts.

Electrical system design is the design of electrical systems. This can be as simple as a flashlight cell connected through two wires to a light bulb or as involved as the Space Shuttle. Electrical systems are groups of electrical components connected to carry out some operation. Often the systems are combined with other systems. They might be subsystems of larger systems and have subsystems of their own. For example, a subway rapid transit electrical system is composed of the wayside electrical power supply, wayside control system, and the electrical systems of each transit car. Each transit car’s electrical system is a subsystem of the subway system. Inside of each transit car there are also subsystems, such as the car climate control system.

The Wiring Harness Manufacturer's Association is a trade group for American manufacturers of wiring harnesses, electronic cable assemblies, and cord sets, along with their suppliers and distributors. It publishes the widely used standard IPC/WHMA-A-620 Acceptability of Electronic Wire Harnesses and Cables jointly with IPC.

<span class="mw-page-title-main">Copper conductor</span> Electrical wire or other conductor made of copper

Copper has been used in electrical wiring since the invention of the electromagnet and the telegraph in the 1820s. The invention of the telephone in 1876 created further demand for copper wire as an electrical conductor.

<span class="mw-page-title-main">Electrical conduit</span> Tube used to protect and route electrical wiring in a building or structure

An electrical conduit is a tube used to protect and route electrical wiring in a building or structure. Electrical conduit may be made of metal, plastic, fiber, or fired clay. Most conduit is rigid, but flexible conduit is used for some purposes.

<span class="mw-page-title-main">Electrical busbar system</span> Modular approach to electrical wiring

Electrical busbar systems are a modular approach to electrical wiring, where instead of a standard cable wiring to every single electrical device, the electrical devices are mounted onto an adapter which is directly fitted to a current carrying busbar. This modular approach is used in distribution boards, automation panels and other kinds of installation in an electrical enclosure.

References

  1. "Cable Harnessing | Cable Harness | Cable Assembly & Assemblies". www.cableharnessing.co.uk. Retrieved 2019-04-06.
  2. LeGere, Bob. "CABLE ASSEMBLY AND A WIRE HARNESS: What's the Difference?". www.iconnsystems.com. Retrieved 2019-04-06.
  3. 1 2 3 4 5 6 "Everything on Wire Harnesses You Need to Know". Wunsch Technologies. Retrieved 2019-04-06.
  4. "Benefits And Applications Of Automotive Wire Harnesses". Miracle Electronics Devices Pvt. Ltd. 2017-03-28. Retrieved 2019-04-06.
  5. Kobayashi, Masakazu, Yoshiya Hirano, and Masatake Higashi. "Optimization of assembly processes of an automobile wire harness." Computer-Aided Design and Applications 11.3 (2014): 305-311.
  6. Bennington, Steve (6 February 2018). "Printing wiring harnesses and disrupting and industry or two". LinkedIn. Retrieved 7 April 2019.
  7. "Helpful Guide of Wire Harness Manufacturing Terms, Tools and Tips". Falconer Electronics Inc. Retrieved 7 April 2019.
  8. Hall, Nicole (2017-07-26). "Various Types of Wire Terminals When Building a Wire Harness". Falconer Electronics. Retrieved 2019-04-06.
  9. "How Is a Cable Harness Designed?". Wirafe. 2018-10-29. Archived from the original on 2019-04-07. Retrieved 2019-04-06.
  10. "Pull-test standards and methods". Mecmesin. Retrieved 2019-04-06.
  11. 1 2 3 4 "Do You Know the Industry Quality Standard of Wire Assemblies?". Wirafe. 2018-09-24. Archived from the original on 2019-04-07. Retrieved 2019-04-07.
  12. 1 2 IPC Product Assurance Task Group & WHMA Industry Technical Guidelines Committee (20 March 2002). "Requirements and Acceptance for Cable and Wire Harness Assemblies" (PDF). IPC. Retrieved 7 April 2019.
  13. 1 2 3 4 5 IPC Product Assurance Task Group & WHMA Industry Technical Guidelines Committee (20 March 2002). "Requirements and Acceptance for Cable and Wire Harness Assemblies" (PDF). IPC. p. 6. Retrieved 7 April 2019.