A tacho generator with an additionally attached mechanical overspeed switch are used for speed measurements and overspeed monitoring at the hoisting gear.
The design of the mechanical overspeed switch dictates a switching tolerance of ± 75 rpm, which leads to inaccuracy at the desired switching point. Moreover, the mechanical overspeed switch only reacts to speeds at 700 rpm and above.
The signal quality of the tacho generator does not offer the precision required.
The customer looked for a replacement solution that corresponds to current state of the art technology.