Best design practices for wiring harness

Designing wire harnesses is a critical aspect of many industries, including automotive, aerospace, and industrial machinery. A wire harness consists of a bundle of wires, connectors, and other components that are used to transmit electrical signals and power throughout a system. To ensure that wire harnesses are designed to the highest standards, engineers must follow specific guidelines to ensure that they are reliable, cost-effective, and meet the performance requirements of their applications.

In this blog post, we will explore the guidelines for designing wire harnesses. We will discuss the importance of proper planning, wire selection, routing, termination, and testing.

Why good wiring harness design matters?

Good wire harness design is critical to the success of many industries, including automotive, aerospace, and industrial machinery. A well-designed wire harness can provide several benefits, including:

• Improved reliability: A good wire harness design can improve the reliability of a system by ensuring that all wires and connectors are properly routed, secured, and terminated. This can help to minimize the risk of electrical shorts, open circuits, and other wiring issues that can lead to system failures.

• Increased durability: A wire harness that is properly designed can also be more durable and resistant to wear and tear. This is because the wires and connectors are secured and protected from external forces, such as vibration and abrasion.

• Better performance: A wire harness that is designed to meet the specific performance requirements of a system can help to improve its overall performance. This is because the wires and connectors are selected and routed to minimize electrical losses and maximize signal integrity.

• Cost savings: A good wire harness design can also result in cost savings by reducing the need for maintenance and repairs. By minimizing wiring issues, a well-designed wire harness can help to reduce downtime and increase productivity.

• Compliance with industry standards: A wire harness that is designed to comply with industry standards, such as IPC/WHMA-A-620, can help to ensure that the system is safe, reliable, and meets the requirements of regulatory bodies. 

Read about : What is wiring harness?

Best practices for wiring harness design 

Designing a wire harness is a critical process that requires careful consideration of several factors to ensure that the harness meets the requirements of the system and the industry standards. 

By considering these factors, engineers can design wire harnesses that are not only reliable and cost-effective but also easy to service and maintain, compliant with safety and EMC regulations, and well-documented for manufacturing and testing. Following best design practices for wiring harnesses is critical to ensuring the performance, reliability, and safety of systems that rely on them.

Here are some factors to consider before designing a wire harness:

Electrical performance

The wire harness must meet the electrical performance requirements of the system. This includes the voltage, current, and signal integrity. The wire gauge, insulation, and shielding must be selected to meet these requirements.

Environment

The wire harness must be designed to withstand the environmental conditions in which it will operate. This includes factors such as temperature, humidity, vibration, and exposure to chemicals and other contaminants.

Durability

The wire harness must be durable and able to withstand the rigors of its intended use. This includes selecting materials that are resistant to wear and tear, abrasion, and impact.

Serviceability

The wire harness must be designed to be easily serviced and maintained. This includes the accessibility of the wires and connectors, the use of color coding and labeling, and the ease of replacing individual components.

Manufacturing

The wire harness must be designed with manufacturability in mind. This includes the selection of components that are readily available, the use of standard connectors, and the simplification of the assembly process.

Cost

The wire harness must be designed to meet the cost constraints of the project. This includes the selection of cost-effective materials and components, as well as the optimization of the design for efficient production.  

Connector selection

The selection of the appropriate connectors is critical to the performance and reliability of the wire harness. Factors such as the number of pins, mating cycle life, and current-carrying capacity should be considered when selecting connectors.

Wire selection

The selection of the appropriate wire size, type, and insulation material is essential to ensure that the wire harness can handle the electrical load and environmental conditions it will be exposed to. 

Routing and placement

The next factor to consider is the routing and placement of the wires and connectors. This includes ensuring that the wires are properly routed to minimize electrical losses and signal interference. The connectors should also be placed in a way that is easy to access and maintain. 

Termination methods

The next factor to consider is the termination methods for the wires and connectors. This includes soldering, crimping, or insulation displacement. The termination method should be selected based on the type of wire and connector, as well as the electrical performance requirements.

Testing

The wire harness should be tested to ensure that it meets the electrical performance requirements and environmental conditions. Testing can include electrical testing, continuity testing, and environmental testing.  

Safety

Safety is a critical factor to consider when designing a wire harness. The wire harness should be designed to prevent electrical shock, fire hazards, and other safety risks.

Electromagnetic compatibility (EMC)

The wire harness should be designed to minimize electromagnetic interference (EMI) and ensure that the system is compliant with EMC regulations. 

Assembly

The wire harness should be designed with assembly in mind. This includes selecting components that are readily available, using standard connectors, and designing the harness in a way that is easy to assemble.

Documentation

Finally, engineers should ensure that the wire harness is thoroughly documented. This includes creating a detailed bill of materials (BOM), wiring diagrams, and other documentation that will be useful during manufacturing, testing, and maintenance.

Conclusion

To sum up, designing a wiring harness requires careful attention to detail and adherence to best practices. A well-designed wiring harness can ensure reliable performance, minimize the risk of failure and downtime, and reduce manufacturing and maintenance costs.