From initial enquiry to prototype in just three months – the customised central electrical unit of the 5035 wheel loader is a prime example of the benefits of a long-standing, well-coordinated partnership between a construction machinery manufacturer and a specialist electronics developer. The result is a compact construction vehicle featuring an equally compact and robust electrical unit.

Kramer-Werke GmbH manufactures all-wheel-steered wheel loaders, telescopic wheel loaders and telehandlers for the construction, agriculture and recycling industries. The company is headquartered in Pfullendorf, in the Sigmaringen district of Baden-Württemberg (Germany), and celebrated its 100th anniversary in 2025. In its sector, the company operates in a globally competitive market, while also addressing the current technological challenges of sustainability and digitalisation, for example through electric and hybrid powertrains or innovative automation solutions. To successfully meet these diverse challenges, having a strong and reliable partner is essential for Kramer. The construction machinery manufacturer has found that partner in Würth Elektronik ICS.

Collaboration between Würth Elektronik ICS and Kramer began back in 2002. “For more than 20 years, we have been developing and manufacturing customised central electrical units for Kramer’s wheel loaders and telehandlers.” Our product portfolio is exceptionally diverse. “These include individual components, electronic control units, standard and customised central electrical units, as well as the REDline Power Boxes and HV PDUs,” says Philipp Zinner, Sales Manager responsible for Kramer at Würth Elektronik ICS.

One example of the successful collaboration between the two companies is the customised central electrical unit developed for the 5035 compact wheel loader.

A tightly scheduled project

For the redesign of the compact wheel loader, Kramer approached Würth Elektronik ICS with a project request to adapt the central electrical unit. As usual, the partner received the design drawings and circuit diagram and immediately set about implementing the component selection, the mounting concept, and development of a detailed layout. As in previous projects, a double-sided printed circuit board was selected to save space. Additional SMD components were also integrated to eliminate the need for external circuitry and simplify assembly.

“The project was already at an advanced stage, so our timeframe was extremely tight,” recalls Markus Wawak, Technical Project Manager at Würth Elektronik ICS. “Thanks to short, efficient decision-making processes and close communication on both sides, we were able to make rapid progress.” The long-standing collaboration paid off: Experience gained from previous projects – such as the use of different connectors to prevent incorrect assembly – were directly incorporated into the development process. Despite thorough preparation, adjustments were still required. The layout changes were implemented promptly. Thanks to fast communication and flexible responses to technical changes, component procurement was accelerated, ensuring the prototype was completed on schedule. Just three months after the initial request, the prototype of the central electrical unit was successfully installed in the wheel loader prototype.

Customised central electrical unit: efficient, low-maintenance and durable

The customised central electrical unit reliably connects the battery disconnect switch to the protected electrical loads in the vehicle, ensuring safe and efficient power distribution. It meets the highest electrical performance requirements, including current-carrying capacity, and its robust press-fit technology makes it ideally suited for demanding applications in harsh environments. The encapsulated version, in particular, provides outstanding protection for the electronics against dust, moisture and mechanical stress – a key advantage, especially on unpaved construction sites. The PCB-based system was precisely tailored to the customer’s specific requirements, taking into account individual design and space constraints to ensure seamless integration into the vehicle. In addition, the solution stands out for its quick and straightforward installation and its clear, well-structured design, which makes it easier to maintain and more user-friendly for the end user.

A successful partnership and future projects

 “In the course of the central electrical unit project for model 5035, Würth Elektronik ICS demonstrated outstanding communication and exceptional flexibility in implementing technical modifications,” says Norbert Liebmann, vehicle electrical and electronic systems specialist at Kramer-Werke GmbH. “For us, Würth Elektronik is a competent and dependable partner – both technologically and commercially. The collaboration is built on mutual trust and a long-standing, successful partnership. Another joint project is already in the planning stage, with the first prototypes featuring solutions from Würth Elektronik ICS scheduled for production in 2026.”