Determining the duty or service classifications when specifying new cranes and hoists can be tricky due to the fact that there are numerous standards that use different methods of determining duty ratings. To compound that complexity, equipment being sold by various suppliers might be rated to domestic and/or foreign standards.  Bear in mind also that there is no direct oversite, such as Underwriters Laboratory for electrical devices, that actually inspect and verify the true service class of the equipment manufactured by a supplier.  So the rated duty cycle advertised by a crane or hoist supplier is not highly regulated.  Because the honor system benefits the dishonorable in the short run, we recommend that purchasers carefully scrutinize offerings from potential suppliers to ensure that they are getting equipment that will meet their duty and service requirements.   This article will explain the various standards and how they apply to various equipment.   The standards covered in this article include AISE, CMAA, FEM, HMI, and ISO.

This article will explain the various standards and how they apply to various equipment.

Determine the Operating Group of the Hoist

To select correct crane duty, crane structure, and mechanical components, the user must identify and pass on the following information to the supplier:

  1. Average lifts and trolley and bridge movements made in an hour.
  2. The average length of each movement.
  3. Estimate the load lifted each time.
  4. Total operating hour per day.