When the Bobcat telehandlers were completely revised in recent years, the electrical system of the vehicles was also taken into consideration. Würth Elektronik ICS is one of the development partners that supported that improvements. The result is a set of compact fuse and relay boxes that minimize the amount of wiring required.

The Bobcat brand is known worldwide for its extensive range of compact machines used in construction, agriculture, landscaping, demolition and many other industries. The Stage V emission standard for diesel engines was one of the reasons for the manufacturer to completely redesign the Bobcat telescopic handlers under the name R-Series. The first models were introduced in 2021.

Opportunity for a leaner electrical system

In the old design, relays and fuses were integrated into the wiring harness by using hard wired fuse blocks. Installing the wiring harness was challenging, not only due to its large diameter. Frequently, some wires and cables proved to be too short during assembly and maintenance situations, occasionally being pulled out of the terminals. David Pasquier, EV & Electrical Function Leader at Bobcat EMEA, and his team based in Pontchateau, France, recognized the drawbacks of the previous wiring harness and had a clear wish list for improvements. They wanted relays and fuses to be housed centrally in sealed enclosures and sought new, reliable solutions for reduced cabling, tool-free access and ease of maintenance. Würth Elektronik ICS, a specialist in power distribution, signal transmission and the control and display of functions in mobile machines and commercial vehicles, offered its services to meet these needs.

Individual solution as standard

“It is common practice in the mobile machinery and commercial vehicle industry to develop individual solutions for electrical and electronic equipment. However, we also know from our many years of experience that you don't have to reinvent the wheel every time. With our REDline Power Boxes, we have developed a platform for power distribution solutions in standard housings,” explains Jean-Baptiste Delcroix, Head of Product Management at Würth Elektronik ICS. “This approach of configuring customer-specific solutions on the basis of a platform rather than developing them from scratch offers a huge time-to-market advantage. We have succeeded in convincing Bobcat of the advantages of this concept - in this specific case, the REDline Power Box Twin.”

Its size and flexibility make the REDline Power Box Twin the ideal main power distributor for vehicle electrics. The fully sealed housing (IP66 / IP69K: dustproof / protection against high-pressure water jets) measures 280 x 192 x 74 mm and contains a circuit board with space for all the necessary relays and fuses. Up to four external power connections are available.

The features of the fuse and relay box were specified, and David Pasquier had his prototypes within eight weeks. Würth Elektronik ICS qualified the product in advance with regard to market requirements, including environmental tests such as vibration and shock, temperature and humidity resistance and aging tests. Thermal imaging test of the circuit board, salt spray and IP tests were also carried out in accordance with the customer's specifications.

In the cabin

REDline Power Box Twin is now used as a fuse and relay box between the battery switch and various consumers on the R-series telescopic handlers. It is located under the right-hand armrest on construction machines with a narrow cab and the compact range for the agricultural and construction machinery market. On telehandlers with wider cabs for the agricultural market, it is located in the entrance area.

Würth Elektronik ICS contributed also a solution to enhance the design of the revised, more comfortable cabs of the Bobcat telehandlers: They provided a 6 Way Symbol Cluster, a display module featuring six individually configurable LED symbols for vehicle information including indicators, low and high beam, fog light, parking light and engine pre-heater. This module is positioned on the center console at steering wheel height and ensures readability under all lighting conditions. The robust, dust- and splash-proof (IP54) and space-saving solution fulfil the customer requirements such as IP protection, EMC compliance according to EN 13309:2010 and ECE R10.

Conclusion

Bobcat appreciates Würth Elektronik's contribution and new projects are already under development. David Pasquier welcomes the improvement in power distribution, the reduction in the cable harness and the lower assembly costs. He sees these measures as a solution to quality problems that can occur with conventional fuse boxes and cable harnesses. As a technical detail, he likes the solder-free contacting of the components on the circuit board using press-fit technology. Würth Elektronik ICS has been a leader in this field for 40 years and knows how to utilize the outstanding mechanical and electrical properties of this connection technology for its customers. However, Mr Pasquier has particular praise for the way challenges are dealt with: “One example of good cooperation that has stuck in my mind concerns the change in housing material due to supply bottlenecks following the COVID pandemic. The Würth-Elektronik team communicated the difficulties in procuring the raw material in question and suggested alternative solutions with a corresponding validation plan. This shows seriousness and foresight.”