What does dual limit mean for cranes?

[SanSimon]

Dual limit for cranes refers to a dual height limiter. Below is an introduction about the dual height limiter: 1. Introduction to height limiter: A height limiter should be installed in the lifting mechanism. When the lifting device reaches the designed upper limit position, it should automatically cut off the lifting power source. Above this limit position, there should be sufficient remaining height to accommodate the requirements of the lifting braking distance. A second-level lifting height limiter can also be installed to prevent overtravel and top collision. 2. Hazards of height limiter failure: During operation, if the crane operator fails to pay attention to the actual lifting height of the hook, it may cause over-winding and top collision of the lifting mechanism, leading to the cutting and breaking of the lifting wire rope, which is the direct cause of the hook and load falling. The failure of the upper lifting limit is also an important factor causing over-winding and top collision of the lifting mechanism.