HMI Hoist Duty Classifications

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Hoist Duty Typical Areas of Application Operational Time Rating
Uniformaly Distributed Work Periods Infrequent Work Periods
Max on Time
(Min/Hr)
Max #
(Starts/Hr)
Max on Time
(Cold Start)
Max #
(Starts/Hr)
H1 Powerhouse and Utilities, infrequent handling, hoists used primarily to install and service heavy equipment. Loads frequently approach capacity and hoist is idle for long periods between use. 7.5 minutes (12.5%) 75 15 minutes 100
H2 Light machine shop fabricating, service and maintenance. Loads and utilization randomly distributed, and capacity loads handled infrequently. Total running time not over 12.5% of the work period. 7.5 minutes (12.5%) 75 15 minutes 100
H3 General machine shop fabricating, assembly, storage and warehousing. Loads and utilization randomly distributed. Total running time no over 25% of work period. 15 minutes (25%) 150 30 minutes 200
H4 High volume handling of heavy loads frequently near capacity in steel warehousing, machine and fabricating shops, mills and foundries, with total running time not over 50% of the work period. Manual or automatic cycling operations of lighter loads with capacity loads handled infrequently such as in heat treating and plating operations, with total running time frequently at 50% of the work period. 30 minutes (50%) 300 30 minutes 300
H5 Bulk handling of material in combination with buckets, magnets or other heavy attachments. Equipment often cab operated and duty cycles approaching continuous operation are frequently necessary. Equipment is engineered per application. 60 minutes (100%) 600 *Not applicable *Not applicable