Load limiters for cranes
A load limiter is a device that has been designed particularly for fitting existing overhead cranes and hoists with a dead end wire rope connecting directly into the function of the lifting system.
To find the correct load limiter you need to:
1: find the lifting capacity (e.g. 20 T)
2: find the number of layers on drum (e.g. 4)
3: divide the lifting capacity with the number of lays (20 T divide by 4 = 5 T)
4: find the wire diameter (e.g. 10 mm)
Mechanical load limiters
Mechanical load limiters are connected to the crane via the hoist. For example when the load exposes the wire to an overload, a spring will collapse and thereby remove the pressure on a button which activates and stops the hoist.
Electrical load limiters
Works like mechanical load limiters; a force is constantly measured e.g. how much power the electrical motors pull when overload activates the hoist.
Load limiter - chain hoist
Chain hoists works like a car in 'neutral' - when the hoist is overloaded the clutch is deactivated and a mechanical break is activated and carry the item whereupon the hoist motor keeps running.