ASME HST-4:2016 pdf download

ASME HST-4:2016 pdf download.Performance Standard for Overhead Electric Wire Rope Hoists
abnormal operating conditions: environmental conditions thatare unfavorable, harmful, or detrimental to the oper- ation of a hoist, such as excessively high or low ambient temperatures; exposure to weather, corrosive fumes, or dust-laden or moisture-laden atmospheres; and hazardous locations.ambient temperature: the temperature of the atmosphere surrounding the hoist. base or deck mounted: a type of mounting where the hoist is mounted to the top side of a horizontal supporting surface. beam: an overhead standard structural or specially fabri- cated shape on which the trolley operates. block, load: the assembly of hook or shackle, swivel, bear- ing, pins, sheaves, and frame suspended by the rope. This shall include all appurtenances reeved into the hoisting rope. brake: a device, other than a motor, used for retarding or stopping motion by friction or power means. brake, holding: a friction brake for a hoist that is automati- cally applied and prevents motion when power is off. brake, mechanical load: an automatic type of friction brake used for controlling loads in a lowering direction. This unidirectional device requires torque from the motor to lower a load but does not impose additional load on the motor when lifting a load. braking, control: a method of controlling speed by remov- ing energy from the moving body or by imparting energy in the opposite direction. braking, countertorque (plugging): a method of controlling speed by applying a variable motor torque in the direc- tion opposite to the direction that the motor is rotating due to being overhauled by the load. braking, dynamic: a method of controlling speed by using the motor as a generator, with the energy being dissi- pated by resistance. braking, eddy current: a method of controlling or reducing speed by means of an electrical induction load brake. braking, mechanical: a method of controlling or reducing speed by friction. braking, regenerative: a method of controlling speed in which the electrical energy generated by the motor is fed back into the power system.
ceiling mounted: a type of hoist mounting where the hoist is mounted to the underside of a horizontal supporting surface. chain, hand: the chain provided to control movement of a hand-chain-operated trolley. contactor: an electromechanical device for opening and closing an electric power circuit. control actuator: a manual means at the operating station by which hoist or trolley controls are energized. control enclosure: the housing containing the electrical control components. cushioned start: an electrical or mechanical method for reducing the rate of acceleration of trolley motion. drum: the cylindrical member around which the rope is wound for lifting and lowering the load. hazardous (classified) locations: locations where fire or explosion hazards may exist. Locations are classified depending on the properties of the flammable vapors, liquids, or gases, or combustible dusts or fibers, that may be present, and the likelihood that a flammable or combustible concentration or quantity is present (refer to ANSI/NFPA 70). Class 1 locations: locations in which flammable gases or vapors are or may be present in the air in quantities sufficient to produce explosive or ignitable mixtures. Class 2 locations: locations that are hazardous because of the presence of combustible dust. Class 3 locations: locations that are hazardous because of the presence of easily ignitable fibers or flyings, but in which such fibers or flyings are not likely to be in suspension in the air in quantities sufficient to produce ignitable mixtures. headroom: measured with the load hook at its upper limit of travel, headroom is the distance from the saddle of the load hookto the following locations (see Fig. 4-0.2-1): (a) centerline of the suspension holes on lug- suspended hoists (b) saddle of the top hook on hook-suspended hoists (c) wheel tread line on trolley-suspended hoists (d) supporting surface on base-, deck-, and ceiling- mounted hoists