WIKA Mobile Control GmbH & Co. KG

Load Moment IndicationqSCALE - solutions for overload protection

At a glance

  • Ensure safety
  • Prevent accidents
  • Reduce downtime

Overload protection - developed by the industry experts

WIKA Mobile Control safety systems for mobile machines protect man, machine and material. Our solutions prevent the operator from lifting excessive loads which could cause equipment collapse or tip over.

Whether you refer to these systems as an RCI (rated capacity indicator) or an LMI (load moment indicator), both terms describe systems that automatically monitor radius, load weight, and load rating. A Rated Capacity Limiter (RCL) takes it even one step further: this device not only warns crane operators, it actively limits movements of the crane that would result in an overload condition, while taking into account the dynamic effects during normal operational use.

Whatever you name it: Tell us about your project – and we will offer a suitable solution for your application.

qSCALE Systems for load moment indication (LMI)

From the load chart to overload protection

Load moment = outreach (m) x hook load (t)
With this basic mathematical equation, the current load moment of a mobile machine can be determined. The nominal load moment can be determined for any crane outreach with the maximum hook load, which can be found in the respective load chart provided by the crane manufacturer. Load moment indication is used to prevent the actual load moments during crane operation from exceeding the permissible nominal load moments – timely before the crane collapses or tips over as a result of the overload.

WIKA Mobile Control’s qSCALE RCL systems acc. to EN 13000 constantly compare the current load and crane outreach with the load chart of the crane and activate safety-related functions when the limit values are exceeded, such as the limitation of load moment-increasing movements or the cut-off of the entire mobile machine. This provides safety, prevents accidents and reduces downtime.



For small cranes, the integration of a standard qSCALE load moment indication is sufficient in most cases. For more complex machines, WIKA Mobile Control offers the individual project-related development of the RCL. When developing a complete safety system, customers can rely on the extensive WIKA Mobile Control portfolio of powerful and robust components. In addition to innovative LMB software, these include powerful controller, intuitive operating concepts and robust sensor technology. To preserve your flexibility, we integrate the qSCALE RCL safety solution in your tailored safety application. It’s also possible to easily combine it with other third-party hardware components.

Whatever your project requires - we will find a suitable overload protection solution for you!

qSCALE RCL trueSafety

A certified software library for rated capacity limitation in telescopic cranes with qSCALE Sx systems

Give your telescopic cranes certified safety – with qSCALE RCL trueSafety, the first-ever certified software library for these applications. The RCL calculation library and corresponding tools give you a vetted basis for quick and easy certification of applications and machines. As experienced specialists in load moment indication (also known as rated capacity limitation = RCL) for mobile cranes, we regularly set new, innovative standards.



  • qSCALE Sx

    Customized and certified system solutions for overload protection

  • Certified software solution qSCALE RCL trueSafety for qSCALE Sx systems 
  • Enables the safety-oriented mobile controller with PL d acc. to ISO 13849
  • Compliant with all specifications for safety-oriented embedded software (SRESW)
  • qSCALE RCL trueSafety library includes: RCL calculation program, RCL test program and RCL recording program
  • Certified development process, incl. review of all specifications documentation, architecture, module descriptions and module and integration tests
  • In combination with certified hardware (controller and sensors) for the certified rated capacity limitation for telescopic cranes
  • Applicable for telescopic cranes of the following types: Boom-only, fixed jib, folding or luffing jib and superlift
  • Qualified for integrating safety products into new mobile cranes in order to comply with the requirements of the European Machinery Directive (2006/42/EC), type-B-1 ISO 13849 standard, DIN EN ISO 61508 and DIN EN ISO 62061


qSCALE Sx and qSCALE Ix – two solutions, one mission

With qSCALE Sx and qSCALE Ix, WIKA Mobile Control offers two solutions for the load moment indication (LMI) of your mobile machine

Mobile machines are as diverse as their tasks. As a result, each machine series also requires an individually customized system solution for load moment indication. With qSCALE Sx and qSCALE Ix, WIKA Mobile Control offers two solutions that provide your mobile machine with the highest safety standards and reliable efficiency at the same time.

qSCALE Sx systems are highly individual and customized system solutions for your mobile application. They include a cSCALE control unit with integrated load moment indication – which we call qSCALE. Through variable modularity and scalability, qSCALE Sx systems offer functionalities for a wide range of individual solutions. In combination with robust sensors and user-friendly vSCALE HMI, you obtain an integrated safety system for the efficient control and monitoring of your mobile cranes – also available with certified RCL-C-library (qSCALE RCL trueSafety) for telescopic cranes.


  • qSCALE Sx

    Customized and certified system solutions for overload protection

  • qSCALE Ix

    Rated capacity indicator for telescopic cranes

qSCALE Ix systems are the configurable compact solutions for small and medium-sized telescopic cranes. They consist of a vSCALE HMI with integrated RCL, a cSCALE DIO I/O module and robust sensor technology. With this compact system you achieve maximum safety without any programming effort. The application of the RCL and the console, as well as the crane data project are easily configured. The user-friendly calibration process also saves time when preparing the machine for its initial setup and therefore supports the rapid deployment of your mobile application.

Both systems show the strength of WIKA Mobile Control: offering comprehensive system solutions – with support from vision to market launch. We are looking forward to advising you on your future project!


  • qSCALE Sx

    Customized and certified system solutions for overload protection

  • qSCALE Ix

    Rated capacity indicator for telescopic cranes

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