Every crane needs an overload limiter which limits the maximum load for which the crane is designed.
There are two systems, which can be used to limit the overload of the crane:
– electromechanical systems (deformation of the spring activates the end switch and the crane stops)
– electronic systems (the signal from the sensor conveys the message to the crane processor that the crane is overloaded, resulting in a stop)
By default, the SWF Krantechnik GmbH supplies rope hoists with an electromechanical overload device, which is pre-set at 110 % of the rated overload as a production standard.
If requested by the client or in special cases, the NOVA MASTER processor is installed:
– in process cranes, which operate 24/7 and must keep a load record with the number of starts, or where the rest of the life-span is calculated in accordance with the FEM standard
– if the hoist frequency regulator is built-in together with the lifting power-drive, the NOVA MASTER acts as a communication module between the drive and the regulator
– when working in »tandem« with two hoists, the New Master processor calculates the individual and total weight on the hooks
– if it is necessary for protection against loose cord
– if the wish is to be able to see the weight of the load on the display
– when working with a crane in load restriction areas
– when wishing to control and record extraordinary events such as:
- number of events that caused an overload of the crane
- number of events in which the user pressed the STOP button
- quick and uncontrolled load increase (shock load) – for example: load overturn