4 Drawbacks of conventional wiring harnesses and how ...

DISCLAIMER: The insights and opinions expressed in this article are solely my own.

Read more

Let's take a moment to explore the current design of wiring harnesses.

What leads to the design of a wiring harness? The evolution of electrical systems over the past half-century provides part of the explanation. As electrical systems have become more decentralized, so too have wiring harnesses adapted to these changes.

This complex web of wires, connectors, terminals, grommets, junction boxes, relay boxes, and protectors is crafted to transmit both electrical currents and digital information. However, this complexity is not without its challenges.

The Challenges

1. Corrosion: This is a significant concern, which explains the multitude of DIY guides on cleaning and managing corrosion in wiring harnesses. Metal contacts are essential components of a harness, and prolonged exposure to moisture and environmental elements can lead to corrosion. This leads to two adverse effects: weakened mechanical strength and increased electrical resistance, which could result in incorrect sensor readings or disrupted data flow. It's not uncommon for vehicles to be recalled due to corrosion issues.
2. Joints: Modern wiring harnesses often follow a point-to-point configuration, minimizing the use of midway wiring joints. These joints are seen as potential failure points. Manufacturers now favor custom-designed junction boxes that facilitate easier management of junctions and splits while utilizing more robust contact methods such as fastenings or even welding.
3. Weight: A standard wiring harness can weigh between 30 to 50 kg, especially when stretched over long distances. The bulk primarily comes from the metal conductors, along with insulating coverings and mounting solutions.
4. Manufacturability: Currently, assembling a wiring harness for a single vehicle demands approximately ten different physical handovers. This is largely due to the custom nature of each harness, as variations exist for each vehicle model and its sub-variants. Certain processes have been automated, such as cable cutting and creating twisted pairs, yet others remain partially automated, necessitating manual intervention. The dream of fully automating wire harness manufacturing still seems far off, but the potential exists if we reimagine the design approach with today's technology.

Source: Bloomberg

What is the fundamental purpose of wiring?

Essentially, the wiring harness serves two principal functions.

1. Power Distribution
2. Data Transmission

Power Distribution

Let's consider a hypothetical scenario. If we were to start from scratch, what would be the most efficient way to distribute electrical power within a vehicle? The ideal solution would be to eliminate the need for distribution altogether.

Alternatives such as phantom feeds, low-energy systems, and built-in power solutions stand out. The trend now favors abstracting functions within software. With more advanced ECUs (Electronic Control Units), the total number of ECUs is declining, as more functions are condensed into fewer units. Current electronic architectures are leaning towards a centralized model with fewer low-powered units managed by domain controllers.

An alternative to centralized management could involve distributing energy sources, such that each ECU has its own battery integrated into its hardware. However, this would introduce the question of how to charge and maintain these batteries. Additionally, OEMs (Original Equipment Manufacturers) typically compile a diverse array of ECUs from various suppliers.

However, these solutions are not universally applicable. Several considerations must be accounted for:

• The size of the wire correlates to the current requirement.
• The type and length of materials relate to voltage drop.
• Transients, Electromagnetic Compatibility (EMC), Antennas.
• Fusing concepts and distribution of power consumers.
• Will there be a single power source or multiple distributed ones?
• High voltage systems to support electric traction demands.

Data Transmission

Communication in modern vehicles predominantly occurs via the CAN (Controller Area Network). Developed in the late 1980s, CAN has been widely adopted as an industry standard. However, it has limitations regarding topology options and bandwidth, prompting a shift towards Ethernet solutions. The challenge lies in determining what will become the next industry baseline.

One potential approach is to achieve sufficiently high bandwidth to transmit diverse data types over a shared physical layer. This is reminiscent of the USB-C evolution seen in consumer technology. Additionally, recent EU regulations dictate that all future devices must adopt USB-C as the primary charging interface. A significant obstacle, akin to that seen in the smartphone sector, is reaching industry-wide consensus among OEMs, Tier 1, and Tier 2 suppliers within a defined timeframe. Rapid advancements in standards and technology make long-term forecasts challenging for both manufacturers and consumers.

Additionally, harmonizing not only the physical layer but also the connector systems is imperative. Without this synchronization, we risk replicating the USB connector confusion widely recognized in the smartphone market.

Emerging connector systems like H-MTD (High-Speed Modular Twisted-Pair Data) demonstrate capabilities to transfer data at speeds of up to 56 Gbit/sec, showcasing favorable EMI properties. Connector manufacturers such as Rosenberger are already producing connectors tailored for this physical layer with optimized mounting strengths.

Another core enhancement would involve the efficient transfer of both power and data across the same physical layer. This concept, commonly found in audio technology, has IEEE standards that facilitate combined power and data transmission through twisted-pair cables—a method known as Power over Ethernet.

Increasingly, wireless solutions are becoming integrated into vehicles, with technologies that offer reliability, short-range connectivity, and built-in security features. However, these advancements bring forth new challenges, such as potential interferences—from wireless opportunities, NFC, BT, and WiFi. Achieving harmonization among these technologies and frequency bands remains crucial for broader industry adoption.

Consolidated Electronic Wire & Cable specializes in assembling various types of harnesses, and our experts are available to assist you in identifying the best fit for your specific needs. For especially complex or tailored requirements, we also provide custom harnesses.

Custom Wire Harnesses

Wires and cables are vital components for a wide array of contemporary home and industrial systems, and harnesses empower technicians to devise organized and meticulously fitted wiring solutions for any environment. Depending on the application's specific requirements, these harnesses can be tailored to support systems up to 600 volts (UL) or even higher (military), maintaining high performance in temperatures spanning from -65 °C (-85 °F) to 250 °C (482 °F).

When assessing new cable or wire harness options, it is critical to thoroughly consider the intended environment and the factors of temperature and exposure conditions. Review the numerous cable types that might be applicable; custom wire and cable harnesses can be crafted with virtually unlimited designs and material options, including:

• Wire ties
• Lacing
• Varied insulation materials
• Custom color options
• Heat-shrink coverings
• Custom labeling or barcoding
• Four-color ink stamping
• Individual tagging
• Independent circuit IDs
• Various fillers like polypropylene, nylon, and paper
• Custom shielding

We employ a strategic engineering method to determine the most suitable shielding and connectors for your project's requirements, keeping in mind all relevant regulatory standards to ensure the final harness is safe, reliable, and efficient.

Additional design factors include:

• The extent of continuous flexion the harness will endure

• Will the harness be used indoors or outdoors, and what specific conditions will it face?

  If you are seeking more information, please visit Suntex Electronics.

• The number of circuits and conductors needed for the assembly, alongside their specifications

• The voltage level it needs to support

• Potential hazards, including hazardous chemicals, corrosive substances, environmental conditions, and moisture

• Operating temperatures and potential fluctuations, including maximum, minimum, and average temperatures

• Local safety and environmental regulations influencing component selection, installation, and testing

• Routing, breakout patterns, and general shape

Applications of Wire Harnesses

Wire harnesses can address a diverse array of interconnection challenges and are prevalent across many industries. Any sector that requires efficient cable arrangements can leverage wire harnesses to enhance productivity and mitigate risks associated with disorganized wiring:

• Aerospace:

  Wire assemblies find application in various aerospace products, from drones to satellites, to ensure reliable power and communication transfer.

• Automotive:

  In automobiles, wire harnesses play an indispensable role in optimizing space under the dashboard, hood, and lighting systems, and assist technicians in identifying wires quickly.

• Medical:

  Healthcare facilities utilize wire harnesses to maintain organization and protection of wires in various equipment, including crash carts and imaging devices.

• Telecommunications:

  Harnesses optimize cable management in telecommunications apparatus, such as modems and routers, assuring efficient functionality.

• Information Technology:

  Almost all IT equipment—including computers and servers—incorporates wire harnesses to streamline organization and facilitate ease of identification and installation.

• Construction:

  Wire harnesses are commonly used in construction to provide insulation and organization for building wiring.

• Manufacturing:

  CNC machines and powered manufacturing tools depend on wire harnesses to structure internal and external wiring pathways.

• Robotics and Automation:

  Virtually all automated equipment and robotics utilize wire harnesses for the safe routing and protection of vital wiring.

Advantages of Using Wire Harnesses

Wire harnesses are widely utilized due to the substantial benefits they bring to wiring systems. Among the many advantages, they provide the following efficiencies:

• Reduce costs when compared to multiple separate assemblies

• Enhance organizational structure, especially in complex wiring setups that involve extensive cables

• Shorten installation times for extensive wire networks

• Shield conductors from environmental hazards whether outdoors or indoors

• Contribute to a safer work environment by tidying up excess wiring, optimizing space, and reducing tripping hazards

• Enhance safety measures by mitigating risks associated with shorts or electrical fires

• Lower installation and maintenance times by streamlining connections and logically organizing components

The myriad benefits of wire harness systems derive from straightforward design principles. Protective sheaths defend against abrasion and external hazards, minimizing the risk of workplace accidents. Connectors, clips, lacing, and other organizational methods significantly cut down on the necessary physical space for wiring while ensuring that technicians can easily access the required components. For equipment or vehicles that frequently engage with extensive wiring networks, wire harnesses offer undeniable advantages.

High-Quality Materials

Beyond effective organization, a well-constructed wire and cable harness must deliver reliable insulation and shielding for the inner conductors. Several durable harness materials exist, and identifying the most suitable for your needs is crucial.

Some commonly used insulating materials include:

• PVC, or polyvinyl chloride
• SR-PVC, semi-rigid polyvinyl chloride
• Cellular polyethylene
• EPDM, or ethylene propylene diene monomer
• TPE/TPR, thermoplastic elastomers
• PE, or polyethylene
• LPDE and HDPE, both low and high-density polyethylene
• Foamed polyethylene
• PU, or polyurethane, along with blends of polyurethane and nylon
• Low-smoke plenum copolymers
• Polypropylene (PP) and foamed (cellular) polypropylene
• FEP, or fluorinated ethylene propylene
• TFE, or tetrafluoroethylene
• PTFE, or polytetrafluoroethylene
• ETFE Tefzel
• PVDF Kynar
• ECTFE Halar
• IRR/PVC, or irradiated polyvinyl chloride
• XLPE, or cross-linked polyethylene
• Vinyl

When selecting among these and other options, consider environmental factors such as operational temperature and moisture levels. For instance, moisture presence might necessitate the use of water-resistant materials like polyethylene to protect the conductors.

Cable & Wire Harness Solutions

At Consolidated, we have been assisting clients in developing tailored solutions for over a century. Our custom harnesses and assemblies are utilized across various applications, backed by cutting-edge production facilities.

In accordance with relevant industry standards and specifications like IPC/WHMA-A-620, there are countless possibilities to engineer a harness or assembly to meet specific project demands. With numerous options available for shielding, fillers, materials, identification methods, and styles, achieving the most efficient organizational solution is purely a matter of strategic engineering.

Our catalog features an extensive range of robust, high-performance cable and wiring harnesses designed to streamline multi-wire systems across industries. Our custom harness services are personalized for each client, with our technicians leveraging decades of multidisciplinary experience to devise the most suitable strategy for each operation. Whether your cabling is intended for a household appliance or a cutting-edge aircraft, our assemblies can improve organization and security at a competitive price.

To discover more about our custom wire and cable harness solutions and how we can assist with your upcoming project, please explore our comprehensive eBook, 'Creating a Custom Cable,' or connect with our team today.

Contact us to discuss your needs concerning Wire Harness Supplier. Our knowledgeable sales team is ready to help you find the best options to meet your requirements.