Wire harnesses are collections of electrical wires, cables, and subassemblies covered by exterior sheaths that are used to connect devices to their power source. Their sheaths both protect the internal components from environmental hazards—such as physical damage and moisture—and organize them. The key components of wire harnesses include:
  • Connectors
  • Terminals
  • locks
  • Wires
  • cables
  • Outer coverings
When choosing a wire harness, it’s essential to keep in mind the capacities of each component to ensure your devices are powered safely. The following article outlines the types of components typically employed in wire harnesses and their selection considerations.

Types of Wire Harness Components

wiring harness componentsThere are several types of wire harness components, each of which is available in multiple variations to suit different applications. These components include:
  • Wire: The wire carries the current or signal that powers a device. The wire’s capacity needs to meet or exceed the voltage or bandwidth it’s expected to transmit. Most wires are copper and can have a specially chosen coating.
  • Connectors: Wire connectors are available in several varieties and sizes to connect different types of wires. While they are usually plastic they can be made from a variety of elements including metal and ceramic.
  • Fuses: Fuses stop surges of power from overloading or damaging devices on the receiving side of the fuse. Different harnesses use different classes of fuses. They are generally rated for 32 volts or less and vary based on their amperage rating.
  • Grommets: Grommets are insulators to keep moisture out of the connector.  A grommet can be attached with the terminal or can be a part of the connector.
  • Outer coverings/Insulators: Also referred to as tubes and sleeves, insulators provide some degree of abrasion resistance, environmental protection, and protection from electrical shock. They can be made of various materials such as nylon or polyolefin.
  • Relays: Relays turn higher amperage circuits on or off. This quality allows harnesses to power multiple things. Like fuses, they vary based on amperage requirements.
  • Strain Relief: Usually added to the outside of the connector.  It is designed to prevent the force of pulling of the wires in the connector which could allow the terminal to pull out of the connector making a bad connection.  Strain relief can also be added at extreme bend radius which again can put undue force on wire and the terminal inside of the connector
  • Terminals: Terminals are the metal parts that are attached to the end of the wire to be inserted into the connector or to be attached to a point on the connecting equipment.
  • Ties: Cable ties and clamps keep the wires inside of the harness attached to from a stream of wires to a particular direction.  It can also be used to attach to a structure at fixed points to minimize movement.
  • Locks: Locks are inserted into the connector to prevent the terminal attached to the wire from being pulled out of the connector.  It can also assure complete insertion of the terminal into the connector.

Industries Served by Wire Harnesses

Wire harnesses play an essential role in almost every industry. Some of the most common industries that use wire harnesses include:
  • Aerospace
  • Automotive
  • Electronics
  • Household appliances
  • Manufacturing
  • Refrigeration

What to Look for in Wire Harness Components

When selecting a wire harness for a product or system, there are a number of factors to keep in mind. In addition to considering the working and environmental requirements of the application, industry professionals need to be aware of any applicable industry standards or requirements.

Qualities to Look for in Wire Harness Components

When choosing a wire harness, some of the component qualities to consider include:
  • Type of wire (including material, length, and gauge)
  • Sheath, conductor, and insulation material
  • Voltage and current capacities
  • Organization of the assembly (especially orientation and EMI canceling design features)
  • Environmental capabilities (e.g., indoor/outdoor, resistance to moisture, chemicals, heat)
  • Safety certification (for all applicable safety and industry-specific regulations)

Wire Harness Assembly Solutions from Precision Manufacturing Company

At Precision Manufacturing Company, Inc., we specialize in supplying wire harnesses for a wide range of industrial applications. Our services include:
  • Harness subassembly prefabrication
  • Integration and installation of wire or cable harnesses
  • Reverse engineering
  • Component customization
  • Wire processing, cutting, and stripping services
Our company is UL listed, IPC WHMA A 620, and ISO 9001:2008 certified. Every product solution comes with quality inspection, documentation, and special packaging services, so you know the wire harness is built for long-lasting performance. For more information about our wire harness assemblies and services, visit our capabilities page. To learn more or to partner with us on your next project, contact us or request a quote.

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