Cable harness manufacturing in Bulgaria
A group of cables or wires which are assembled into a single unit that transmits digital or analogue audio or video signals, electrical power, and/or data is known as a cable assembly/harness. Other commonly used terms for a cable harness include wire harness, cable assembly, wiring assembly or wiring loom. Using a cable harness provides many benefits when compared to having loose cabling or wiring – by binding or assembling wires and cables together the assembly immediately becomes safer, manageable and more secure. Furthermore, the utilisation of a cable assembly can lead to a much faster installation process than installing single cables. Depending on system requirements, cable assemblies can sometimes consist only of a simple bundle of loose wires grouped together into a single protective jacket. In other cases, the application may require a much more complex assembly of dozens of cables and wires, which can also branch off in different directions towards other junctions or termination points. Finally, cable harnesses contribute to increased efficiency by providing an opportunity for higher levels of reliability and stability of electrical devices and equipment. There are multiple options for cable assembly termination – with various fixings and connectors and sometimes directly onto a printed circuit board (PCB). The wide range of cables and connectors, offered by manufacturers, covers a variety of applications including control, data communication, appliance engineering, measurement, heating, industrial Ethernet, and factory automation.
In the current article we explore the different manufacturing stages of cable harness production, some of the applications of these products, global market trends and the conditions that Bulgaria offers for developing a business in this field.
Before a concept is ready for in-field use, wire harnesses go through many stages of design and manufacturing. Assembling a cable harness starts with cutting the wires to the required length, which is usually performed with a dedicated wire cutting machine. Next, the endings are stripped in order to expose the wire cores. The wires are then fitted with the necessary terminals or connector housings, which are available on the market in many different sizes and with various specifications. Following this, the wires are bundled into a harness, involving either a workbench or assembly board which must be set up according to design specifications.
It is possible to manufacture cable assemblies both by hand or machine and each method encompasses a lot of different procedures, such as routing and inserting wires through sleeves, taping the wires, crimping terminals onto wires, fastening strands with tape, clamps, or cable ties, etc. As many of the processes involved in designing and manufacturing cable harnesses require higher level of precision, a large number of them are still done manually or semi-automatically.
Some wire harnesses are very simple – just two wires with basic terminals on the end. Other wire harnesses are much more complex and involve multiple wires, connectors and terminals. Several factors should be taken into consideration when choosing a cable harness, including conductor size, stranding size, conductor colour, etc. One of the main advantages of cable harnesses is that they are small and light, which facilitates their easy installation and use. However, some applications require custom-designed shapes in addition to all the other elements: sheathing, mechanical fastening and overmoulded connectors, and strain reliefs.
One of the major applications of cable harnesses is in the automotive industry. Transmission of signals, that allow vehicles to function, is achieved through cable harnesses, which connect the engine management system, lighting, power steering, power brakes, audio and entertainment system, electric windows, air conditioning and so on into an efficiently operating unit. In view of the dozens of electronic units on board, an average vehicle has hundreds of metres of wires that connect devices and operate systems. Cable harnesses ensure that electricity and electronic signals are delivered through the entire vehicle.
Another important area of application of cable harnesses is manufacturing where complex wiring, cabling systems, and networks are used to drive automated and robotic production and assembly lines. Power and signal conductors for control of various systems within the same area or along the production line are connected through cable harnesses. They ensure connectivity and properly seal cabling and wires in order to guarantee that production is optimized to the maximum.
Cable harnesses are also utilized in healthcare, electronic medical equipment, devices, and instruments, which frequently are subject to heavy use, as well as varying degrees of high and low intensity. This requires the use of durable, adaptable, and biocompatible cable harnesses to ensure that devices such as defibrillators, drills, pacemakers, or imaging or radiological equipment are able to function on demand without failure. Due to the wide range of applications, cable harnesses for the medical sector come in all shapes and sizes. What makes cable harnesses for medical applications different to the ones used in other industries is the obligatory compliance with various regulatory controls and guidelines.
Achieving reliable global connectivity calls for an infrastructure that is capable of instantaneously transmitting and receiving data from all corners of the world. Specialized cable harnesses are widely used in communication systems for an array of technologies and applications. They are integral components in the assembly of hubs, routers, repeaters, modems, peripheral equipment, optical networks, broadband networks, etc. Cable harnesses are also used for wireless communication applications, including DSL routers, satellite receivers, and RF solutions.
Military class wire harnesses are often used in equipment designed for and subjected to extreme environments and conditions. These cable assemblies should meet stringent specifications and must be manufactured or approved for demanding military applications.
Global market conditions
According to a report by market research and advisory company Technavio, the global wire harness market is expected to grow by USD 33,95 billion during the 2020 – 2024 period with an estimated compound annual growth rate (CAGR) of 4,70%. Depending on the application the market is divided into automotive, telecom, medical segments and others. Analysts predict a significant increase in cable harness sales through the forecast period, mainly driven by the dynamically expanding electric mobility sector, the rise in global automotive sales, the increased focus on road safety and emission reduction due to enforcement of regulations, and investments in telecommunication infrastructure. Market growth will also be impacted by trends such as progress in the development of innovative materials and emergence of cable harness manufacturing through 3D printing technology. On the other hand, challenges such as frequent changes in market dynamics leading to shorter product life cycle of cable harnesses, emphasis on public transport to curb greenhouse gases reducing the sales of passenger vehicles, and availability of counterfeit products can have a significant negative influence on the market.
In order to improve their market presence, many manufacturers and suppliers are increasing investments towards expanding capacity, enhancing marketing and sales, bettering distribution networks, logistics and warehousing.
The sector in Bulgaria
The cable harness sector in Bulgaria consists of a number of multinational and local companies, some of which employ between 3000 and 5500 highly qualified specialists in the area of electronics and electrical engineering. Manufacturing plants are relatively unevenly dispersed all over the country’s territory, with several factories located in the northwestern region (Vratsa, Mezdra), the southeastern area (Yambol, Sliven, Karnobat, Burgas), the south-southwestern region (Karlovo, Samokov, Dimitrovgrad, Rakovski), the north-northeastern parts (Ruse, Pleven, Targovishte), Gabrovo, Sofia, etc.
The activities of the major part of the companies operating in Bulgaria are directed towards the manufacturing of cable harnesses for the automotive industry with main clients such as Volkswagen Group, Renault, Ford, Daimler and others. The remaining enterprises produce wire harnesses for a wide range of electronic and electric appliances. In addition, most companies also offer services like high precision cable cutting to the desired length, stripping of the outer and inner insulation of the wires of multicore cables, crimping, twisting and tinning, marking, sorting and coiling of processed cables. Players in the sector are flexible and capable of coping with various challenging requirements in order to completely satisfy their customers’ needs. One of the common trends among cable harness manufacturers in Bulgaria is the rise in investments focused on the introduction of modern production equipment, as well as on process automation, which is of paramount importance for achieving higher competitiveness.
Multinational companies cite a couple of motives for choosing Bulgaria as their operating site. First and foremost is the availability of highly qualified and at the same time affordable work force. Secondly, cable harness manufacturers can take advantage of the attractive possibilities offered by the country’s largely strategic location. When choosing a specific region, some of the companies have also taken in consideration the availability of technical high schools and universities, situated in the vicinity of the plant, which could potentially provide the specialists needed for different engineering departments of the factories.
On the other hand, over the last year rising labour costs have forced a couple of cable harness manufacturers to relocate their plants to destinations with cheaper work force, such as Ukraine, Morocco or Tunisia, or to focus their business on higher value-added products. This is why as a loss prevention measure a small number of the companies operating in Bulgaria rent their buildings so in case production becomes economically unviable at some point, relocation will not have too significant of an impact on the overall activity of the enterprise.
LATEST issue 1/2021
The thermal characteristic of the protected object is crucial; for example the electric cable, the wiring harness or the semiconductor switch in the connected control unit. Instead of safety fuses or electro-magnetically triggered mechanical contacts, electronic fuses contain semiconductor switches along with their control logic including protective and diagnostic functions