WIKA Mobile Control GmbH & Co. KG

Certified: Innovative Complete Concept for Overload Protection in Cranes

Gantry and bridge cranes need to be able to move heavy loads easily and safely. Hirschmann MCS based in Ettlingen, Germany, a market leader in controllers and sensors for these applications, has therefore developed and obtained certification for an innovative complete overload protection concept.

PSV overload protection devices (originally introduced by PAT & Krüger, now Hirschmann MCS) have been a mainstay for decades. Recently, however, they have been superseded by the new cSCALE trueSafety controller. The individual cSCALE components have been perfectly harmonized with the fSENS force sensors. Both were recently certified under the latest versions of the EN ISO 13849 and EN 62061 standards as well as the EN 15011:2011+A1:2014 standard for bridge and gantry cranes, which covers all safety functions and sequences.

The certified system meets all of the requirements for overload protection according to EN 15011:2011. Overloads are reliably detected to ensure timely system cutout in critical situations while complying with PL d. This can happen in either of two different ways: indirectly with a delayed cutout to compensate for hysteresis, or immediately if the weight involved is greater. 

A large number of other functions can also be optionally enabled. They include a limit switch that protects hoists by blocking their upward motion when triggered (complying with PL d category 3), limiting wire rope layers in winches by blocking their downward motion, horizontal and vertical monitoring of unbalanced loads, cutout when the load falls short of a defined minimum, monitoring of proper functioning according to PLd, and monitoring of loads on individual ropes according to PL d. 

Once the system has been configured, it ensures maximum safety. Audible and visual alarms are activated in compliance with PLb, including a slack cable warning, sirens, and lamps. 

The browser-based service tool permits easy, user-friendly setting of parameters. The offered modules are robust enough to permit maintenance-free use in extreme environments, and the cSCALE controller is simple to integrate into existing crane control systems.