Category Archive: Cable Assembly
The growing complexity of modern electronic and electrical systems, along with the ever increasing distance signals are required to travel, have increased the electrical interference in cables. In order to diminish the effects of signal interference in cables appropriate shielding is vital.
Types of Signal Interferences
The primary function or the shielding is to limit the signal from escaping the wire or cable. Besides, it also prevents external interference or signals from flowing into the wire. Depending on the kind of application, cables can be affected by different types of signal interferences. These include:
- Electrostatic interference
- Electromagnetic interference
- Radio frequency interference
Types of Cable Shielding Popularly Used in the Industry
Mentioned below are the most popular types of cable shielding that are used in the wire and cable industry today:
- Foil Shields: They are generally constructed of a Mylar and aluminum composite tape. They are lightweight, economical, and easy to use. They are normally grounded with a drain wire, and provide 100% shield coverage. Although foil shielding provides good flexibility, it can be damaged in high-flex applications.
- Braid Shields: This is the oldest form of shielding, and is still used in the industry. It is a woven pattern consisting of small gauge wires. Braid shields are mostly made up of bare, tinned, or silver plated copper, and aluminum or steel. They have a typical coverage of 55% to 95%.
- Spiral Shields: This shielding is made up of single strands of wires, which are spirally wrapped around the cable core. This shield is more flexible, and easier to terminate than the woven braid. They have a typical coverage of 95% to 98%. As they are most effective in the audio frequency range, they are typically used in audio and microphone cables.
- Tape Shields: This shielding is made from various types of materials. They normally comprise a laminate of aluminum and polyester layers, which is combined together with an adhesive. These shields are fragile, and offer considerable mechanical strength. Some of the popularly used tape shielding are:
- Bonded Aluminum Polyester
- Aluminum/Polypropylene (AP)
- Aluminum/Polyester/Aluminum (APA)
The cable shielding types mentioned above serve specific applications. Hence, you must consult a manufacturer or supplier to understand which shielding can suit your needs.
Cable harnesses and assemblies support a wide range of applications and industries. These assemblies and harnesses can be custom designed and manufactured, to meet the unique demands of each application. This has allowed researchers and collaborators to produce cable assemblies for the most demanding industrial systems and processes such as automation control and drive systems.
How Can Quality Harness and Cable Assemblies Help You?
If the cable assembly fails, it can bring the entire industrial operation to a dead stop. Hence, in order to avoid such situations, it’s critical to ensure reliability of the power systems along with the power cable assembly. Cables in industrial applications can also fail due to exposure to chemicals, heat, or excessive mechanical loads, leading to rupture and premature failure.
This is taken care of by using specialized insulation and jacketing materials to protect the cables against chemicals and heat. Besides, custom insulation is used to make cable assemblies resistant to oil, abrasion, harsh work environments, as well as mechanical stress. These features are in particular demand in food, beverage, and chemical industries.
Beneficial Attributes of Custom Cable Assemblies for Demanding Industrial Applications
Cable assemblies and wire harnesses are engineered with the following key attributes to withstand environmental extremes and mechanical abuse:
- Flexibility: Flexibility makes handling and routing the cables easier during the installation process. Flexible cable assemblies are less vulnerable to damage from bending. Unique stress-free cable assemblies are useful in installations requiring tight bend radius.
- Resistance: Cables assemblies with PVC jacket are ideal for applications that expose the cable to oil and moisture. Materials such as ABS and other plastic compounds are used to produce cable assemblies that are resistant to extreme temperatures and abrasion.
- Durability: Cable assemblies meant for industrial use must pass rigorous mechanical tests in order to ensure robustness, reliability, and longevity. This helps avoid premature failure of the cable assembly, which can become a costly and time-consuming affair in case of system breakdown.
So, if are looking for cable assemblies and wire harnesses with these attributes, contact a custom cable assembly and wire harness manufacturer today.
In the earlier blog post, we explored the testing processes for intermittent failure. The two main types of test equipment discussed were PC-based and those operated via microprocessors. In this post, we will explore the causes for intermittent failure.
The following contact-to-contact failures can be seen in cable assemblies:
- When tin or lead contacts are used, a common problem that occurs is micro fretting. Here, oxides are formed when the two metals come in contact with each other. When testing for electrical conductivity or performing other regular tests, this problem will not be detected. Hence, cable assembly manufacturers need to take additional care to avoid micro fretting.
- When an incorrect force mates with the contacts, an intermittent failure can occur. This could be for several reasons like contaminated contacts, wear and tear of contacts, etc. The same problem could occur if there are some manufacturing defects with the contacts. For example, insufficient locking of crimped pins.
Below are some of the contact-to-wire failures that can occur:
- Cable assemblies featuring crimped connections can suffer from manufacturing defects. Hence, it is important to test the crimped connections using crimp pull testing, or any other relevant test.
- Improper soldering processes can be a major cause for intermittent failure. Proper soldering processes have to be followed to ensure reliable connections.
Contact-to-Contact & Contact-to-Wire Failure
If the cable assembly witnesses mating or bonding between two contacts or contacts and wires, respectively, then the assembly will experience weak or no electrical connection. This leads to an intermittent failure.
Cable assemblies and wire harnesses are tested thoroughly to ensure smooth functioning. If an assembly shows repetitive failures, it is easy for cable assembly test equipment to detect it. However, if the problem lies in intermittent failures, then it might be a little more challenging. Finding out the root cause for intermittent failure will allow you to eliminate them altogether.
The importance of cabling systems in industrial organizations has grown over the years. In 2015, a market research report by IBISWorld stated that there are over 300 wire and cable manufacturers across America. These companies employ over 27,000 people, and earn an industry revenue of $416bn. Needless to say, the number of cabling systems being used across the country is an extremely large number. However, with many wire and cabling systems in use, there are bound to be a variety of health and safety issues. In this post, we will take a look at certain cable environmental concerns, and solutions to the same.
Primary Cable Environmental Problems
Generally, there are two primary environmental concerns when looking at industrial wire and cable. These points are discussed below in detail.
- Fire Hazards: Most wire and cable systems are stored in plenum spaces in buildings. These are areas that allow for air circulation to support heaters and air conditioners. Unfortunately, these become potential fire hazards, as the plastic material used as shielding jackets can burn easily, and release toxic gases. As the cables are in the plenum spaces, they can also help spread fire and gases throughout the building.
- Manufacturing Materials: In this point, we shall discuss three important materials – copper, lead, and Poly Vinyl Chloride (PVC).
- Copper: Although a popular material used to manufacture cables, copper is also regarded as a great environmental hazard. The mining and processing of copper results in emissions of nearly 130 gigajoules of energy. It also leads to environmental degradation, as nearly 80% of the rock surface around copper deposits is regarded as waste.
- PVC: Poly vinyl chloride is a common material used for jacketing and shielding cables. PVC is a plastic derived from fuel. Due to this, the production, use, and disposal of PVC cables can release toxic gases and chemicals. PVC manufacturing processes also produce explosive greenhouse gases like chlorine and vinyl chloride monomer.
- Lead: In cable manufacturing, lead accounts for 2-8% of the jacket structure. Being a toxic element, the chaffing and deterioration of cables can lead to the additive getting loose and accumulating on ceilings, floors, and walls of buildings.
The fact is, these materials are intrinsic to the creation of the industrial cables. However, certain preventive measures have been taken by the US Government to try and reduce the problems associated with these concerns.
- Codes and Standards: The National Fire Protection Association (NFPA) created certain standards, which limited the use of hazardous materials in cable manufacturing processes. These include:
- NFPA 90A (2002)
- NFPA 5000 Building Code (2003)
- National Electrical Code or NEC (2005)
- NFPA 13 Sprinkler Systems (1999, and revised in 2002)
Limited combustible cable networks are also produced by cable manufacturers. These cables comprise FEP (Fluorinated Ethylene Propylene) as the primary manufacturing material for the cable as well as the jacket. FEP is known for creating low smoke in case of a fire. Manufacturers are also focusing on creating cables without lead as the primary material.
- Abandoned Cable Disposal: The NEC published many articles in 2002 and 2005 on the removal and disposal of abandoned cables. Generally, cable removal is performed during building renovation. Used cables are sent to organizations that specialize in cable handling, recycling, and disposal. The cables are stripped of copper cladding and PVC jackets.
With the above mentioned measures, there can be a possibility to reduce the number of environmental concerns associated with industrial wires and cables.
Towards the end of the 20th century, most wire harnessing processes, including insertion of wires into the connectors and bundling of wires, were done manually. Due to the lack of wire harness assembly automation, the manufacturing process took longer than other cable assemblies. Depending on the complexity of the wire harness, production time spanned from a few days to several weeks.
Although, complete automation cannot be done for insertion of terminated wires into connector housings, fully automated equipment and procedures are now available for cutting, stripping, and crimping of wire.
Complete Automation of Wire Harness Assembly
Recently, a system has been introduced that can automatically produce a complete custom wire harness from start to finish. It comprises a set of flexible machines, which can also take care of the insertion of terminated wires into assembly connectors.
This system can automatically cut, strip, and crimp wires of different gauges. It is equipped with sensors on the presses for quality control. Also, it can be fitted with a combination of stations, such as crimping presses and seal assembly stations.
Besides this, there are other innovations that can be used to simplify the wire insertion process. There are systems that use vision-guided lasers to command assemblers where to insert the wires. Also, certain procedures use computer-guided wire assembly and test systems to perform wire insertion. Such innovations have only further strengthened the efforts of automating cable assembly processes.
Beneficial Applications of Automating Cable Assembly Processes
Cable assembly automation can be helpful in various ways. Following are the major beneficial applications of automating cable assembly and wire harnessing processes:
- Fitting of terminals onto wires
- Soldering or tinning of the wire ends
- Plugging of wires into connector housings
- Testing a wire harness for electrical functionality
- Crimping terminals on one or both sides or the wires
- Specialized cutting machines for cutting and stripping the ends of individual wires
Considering the potential benefits and the solutions being introduced to solve this problem, it is safe to say that the future of wire harness assembly automation looks bright.
Electro-mechanical assembly manufacturing is a subdivision of Electronic Manufacturing Services (EMS). These are designed to support all stages of turnkey manufacturing, from prototyping to production.
As a leading electro-mechanical assembly manufacturer, Carr Mfg. Company has the capabilities to produce a variety of assemblies. These include box-builds, daughter cards, custom cable assemblies, printed circuit boards, and power distribution units. Customers can benefit by working with an electro-mechanical manufacturer.
Advantages of Working with an EMS Provider
There are a variety of benefits that can be accrued by choosing EMS. The benefits are found in all aspects of the manufacturing process such as choosing of materials, designing, and production. The details of these benefits are given below.
- Complete Engineering and Design Support: The biggest advantage of EMS is that the manufacturer provides complete support for the design and engineering processes. Basic designs can be integrated via a design database. AutoCAD, 3D modeling, and similar software can be used when designing a custom electro-mechanical assembly. Multi- engineering platforms are used for analysis to create intelligent engineering designs.
- Detailed Document Control: The use of multiple engineering platforms also allows for the creation of detailed documents regarding various aspects. These include Bill of Materials (BOM), product specifications, prototyping, and testing.
- Prototyping: When a prototype of the assembly is produced, it can be used to evaluate the construction and performance before production begins. The EMS team can test the prototype’s design, the materials used in the construction, and whether it will meet safety regulations, among others. The biggest advantage of prototyping and testing is that if any defects are found, they can be rectified before production starts.
- Engineering and Manufacturing to Cost: Due to the previous points, the total expenditure for all services, and the production of a custom electro mechanical assembly will be considerably less than other providers’ products.
As an electro-mechanical assembly manufacturer, all of our processes are performed while adhering to the regulations laid down in UL, ROHS, and ISO 9001. At Carr Mfg. Company, customers are assured of high quality, well-designed electro-mechanical assemblies.
Continual advances in technology have led to the design and manufacturing of powerful and durable electrical equipment. These are being used in extreme applications with rough terrains and harsh weather. Examples of such industries include agriculture, aerospace, and oil and gas. Custom cables are required to support the performance of electrical equipment when they are used in extreme conditions. For such requirements, cable assembly manufacturers offer over molded cable assemblies.
What are Over Molded Cable Assemblies?
These are cable assemblies that have been manufactured using the plastic over molding procedure. In this case, the over molding procedure comprises injecting molten plastic into a mold cavity, and solidifying it into a plastic component. This component is used to encapsulate connectors used in cable assemblies. The over molded component is meant to be used either as a junction, or as a back shell. Over molded cable back shells can be designed in various types. These include:
Which Plastic Materials are used in the Custom Cable Molding Process?
Depending on the needs of the application, customers can choose from different plastic materials. However, the most popular ones offered by custom cable manufacturers include:
- Polyvinyl chloride (PVC)
What are the Benefits of Custom Molded Cables?
Custom cable molding can provide different benefits and opportunities in terms of design and performance.
- It can provide strain relief to the connectors
- A variety of design configurations can be created
- Over molding can improve the cables’ pull strength
- Design elements like aesthetics and environmental characteristics can be enhanced
For customers, over molded cable assemblies can provide diverse design and manufacturing options to meet the needs of eclectic industrial applications. Contact your cable assembly manufacturer for more details.
Cable assembly testing is a detailed process, where the product is put through various tests to check whether it meets or exceeds the application’s requirements and specifications. In this post, we shall take a look at some common cable testing processes.
Types of Cable Assembly Testing
Cable assemblies can be designed to meet either the customer’s specifications, or the regulations of safety and quality standards. Irrespective of the specifications, there are a few common tests that are performed on all assemblies. These are given below.
- Electrical Testing: This is the most important test that needs to be performed. The cables should be tested for open wires, incorrect wiring, and the possibility of the cable shorting out. There is a simple way to perform all three tests. The connector of the assembly needs to be linked to an electrical fixture with the help of a mating connector. This will allow you to check for shorts between shields and conductors, and ensure proper wire pin placement.
- Visual Testing: As the name suggests, this test involves examining all the physical features of the cable, and ensuring that there are no signs of deterioration, damage, or corrosion. The cable is also examined when it is installed in equipment. There are a wide range of points that come within this test, including:
- Checking supply intake before removing assembly cover
- Examining accessories for signs of damage
- Ensuring that enclosures are properly secured
- Inspection of sockets and connectors
- Checking if assembly complies with application specifications
- Mechanical Testing: The tests in this phase are designed to evaluate the mechanical properties of the cable. They analyze whether the cables can meet a variety of application requirements. These can include elongation, tensile strength, and crush and impact resistance.
- Signal Integrity Testing: As the name suggests, the tests in this phase analyze signal strength, and whether the cable can maintain it in an application. Features of these tests include error testing, crosstalk, and whether the signal strength can be maintained with the addition of splices, filters, or connectors.
Cable assembly testing procedures ensure that the products adhere to all industry standards, and meet application requirements. When working with a cable assembly manufacturer, always enquire about his testing procedures and the various standards he complies with. This will help you in finding the right manufacturer to work with.
Custom cable assemblies are an important factor to consider in most industrial projects. Designing a custom cable assembly is a time consuming process. This can have a huge impact on the finances of the project. While quality is always the first priority, there are some ways in which the expenses of the design and manufacturing processes can be reduced. Read to know more.
Important Documentation Required
Before we look at the cost saving suggestions, there are two important documents that need to be reviewed:
- Bill of Materials List: This list allows you to analyze the various materials that are used in the assembly. It can be used as the starting point for cost savings.
- Specifications List: Having this list will allow you to inspect every material and component of the cable assembly. It can easily help you find certain areas where cost savings can be done without compromising on the assembly’s quality.
Cost Saving Suggestions
With the above mentioned documents, you will find it easier to consider the following points.
- Choose the Right Raw Materials: Raw materials such as labels, connectors, shrink tubes, etc. are usually ordered in bulk by the assembly manufacturer. He then has to understand the best combination of raw materials that will support the assembly’s performance. This can result in high time and money expenditure. Rather, it would be wiser for the manufacturer to decide on the materials beforehand, and then order a shipment.
- Choose the Correct Connectors: Different types of connectors are used in cable assemblies. The way the connectors are installed in the assembly, whether crimped or hand soldered, will have an impact on the cost. Understand the transmission characteristics that the assembly is required to handle. This will allow you to choose the right connectors and thus save costs.
- Saving Costs with Wires: Many times, costly wiring, which may not actually be required, are used to create cable assemblies for applications. Wiring is chosen based on the certifications it adheres to (UL, CSA, AWM, etc.). By ensuring the certification for the application is correct, it will be easy to find the right wires, and thus, create a certain amount of savings.
- Cable Conductors: A rule of thumb when concerning conductors is that the smaller the connector, the less costly it will be. However, the small size should not hinder the transmission of electricity. Also, the conductor strands should be chosen based on the needs of the application. The number can be small but should meet application requirements. The overall cost will reduce due to this.
By keeping the above points in mind, it will be possible for you to create a decent amount of savings from the cable assembly manufacturing operation.
Industrial cable assemblies are ought to operate under high stress conditions, containing elevated temperatures, dust, moisture content, harsh chemicals and solvents. To withstand all these unfavorable industrial conditions, individual cables must be insulated in an assembly. A good insulation not only protects cable assemblies from the harshest environments, but also enhances their service life.
This blog is meant to familiarize you with the commonly used insulation materials in industrial cable assemblies.
Thermosetting and Thermoplastic Insulation Materials
Cable assembly insulating materials are broadly categorized as thermosetting and thermoplastic. Let us understand the types of insulations under these categories.
- Thermosetting Insulating Materials – Thermosetting insulating materials are generally chosen for high temperature applications. The material features good coefficient of friction, excellent color-ability, and good cold temperature compatibility.
The following listed are the commonly used thermosetting insulation materials in the manufacture cable assemblies.
- Styrene-Butadiene Synthetic Rubber (SBR)
- Butyl Synthetic Rubber
- Cross-Linked Polyethylene Insulation
- Ethylene-Propylene Rubber (EPR)
- Fluorinated Ethylene Propylene Rubber (FEP)
- Neoprene Synthetic Rubber
- Thermoplastic Insulating Materials – The material melts when exposed to extreme heat. This allows them to be remolded repeatedly, that is not the case with thermosetting materials. Compared to thermosetting materials, thermoplastics possess better electrical properties. Also, they are light weight, easy to work with, and economical. The commonly used thermoplastic materials used in the manufacturer of industrial cable assemblies are:
- Thermoplastic Polyvinyl Chloride (PVC)
- Thermoplastic Polyethylene (PE)
Factors to Consider When Choosing the Insulating Materials
Choosing the right insulating material is essential to enhance the overall reliability, functionality and service life of the final assembly. Several performance factors must be considered when choosing the right insulating materials. These include:
- Dielectric constant
- Insulation power factor
- Insulation resistance
- Ozone resistance
- Toughness and flexibility
- Tensile, compressive, and impact strengths
- Resistance to abrasion and moisture
- Expansion and contraction
- Compatibility with ambient, operating, emergency overload
- Stability of materials on exposure to oils, acids, and alkalis
Choose the best insulation material that is qualified in terms of performance, durability, compatibility with the application area, and also budget. Always remember that good insulation adds to the reliability and safety of your cable assemblies.