Duty Rating
There are 6 main duty ratings for hoist, trolley, crab units and end carriage units, including ‘M3‘, ‘M4’, ‘M5‘, ‘M6‘, ‘M7‘ and ‘M8‘. When a duty rating increases this is achieved by the hoist unit incorporating much bigger and heavier duty components, such as the use of over rated motors to prevent output reaching the MAX ‘ED’ (Einschaltdauer – which means MAX duty factor) of the motors, eliminating burn out and labouring. Please see below the specifications of each duty rating:
- M3 is the lightest duty and most cost effective, designed for irregular heavy lifting (in relation to the crane’s safe working load) on the occasion when required, capable of lifting 63% of its MAX SWL up to approx. 1 hour per day of suspended operation, without decreasing parts longevity & overall life span.
- M4 is for standard use and operations of hoists and carriages, designed for lifting 63% of its MAX SWL up to approx. 2 hours per day of suspended operation, without incurring excessive wear and tear, and without decreasing the life span of parts and causing motor burn out. M4 is the industry standard and typical on most cranes.
- M5 is for more intense day-to-day hoist and carriage workloads lifting heavier items in relation to the MAX SWL. For example an M5 will lift 63% of its MAX SWL up to approx. 4 hours per day of suspended operation without decreasing parts longevity & overall life span.
- M6 are ‘super duty’ hoist and carriages, designed for consistent heavy-duty operations, capable of lifting 63% of its MAX SWL up to approx. 8 hours per day of suspended operation, without decreasing parts longevity & overall life span.
- M7 are ‘ultra duty’ hoist and carriages, designed for consistent heavy-duty operations, capable of lifting 63% of its MAX SWL up to approx. 16 hours per day of suspended operation, without decreasing parts longevity & overall life span.
- M8 is the highest duty for hoist and carriages, designed for 24/7 365 heavy-duty operations, capable of lifting 63% of its MAX SWL up to approx. 24 hours per day of suspended operation, without decreasing parts longevity & overall life span.