ASME HST-1:2017 pdf free download – Performance Standard for Electric Chain Hoists
abnormaloperating conditions: environmental conditions thatareunfavorable, harmful, ordetrimentalto the opera- tion of a hoist, such as excessively high or low tempera- ture, exposure to weather, corrosive fumes, dust laden or moisture laden atmospheres, and hazardous locations. ambienttemperature: the temperature ofthe atmosphere surrounding the hoist. beam: an overhead standard structural or specially fabri- cated shape, on which the trolley operates. brake: a device, other than a motor, used for retarding or stopping motion by means of friction or power. brake, holding: a friction brake for a hoist that is automa- tically applied and prevents motion when power is off.
brake, mechanicalload:anautomatictypeoffrictionbrake used for controlling loads in a lowering direction. This unidirectional device requires torque from the motor to lower a load but does not impose any additional load on the motor when lifting a load. This type of brake may also be used as a holding brake if designed as such by the manufacturer. braking, control: a method of controlling speed by removing energy from the moving body or by imparting energy in the opposite direction. braking, dynamic: a method ofcontrolling speed by using the motoras agenerator, with the energybeingdissipated in resistors. braking, mechanical: a method ofcontrolling 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. chain, load: the load-bearing chain in a hoist.
chain, roller: a series ofalternately assembled roller links and pin links in which pins articulate inside the bushings, and the rollers are free to turn on the bushings. Pins and bushings are press-fit in their respective link plates. chain, welded link: a chain consisting of a series of inter- woven links formed and welded. NOTE: Load chain properties do not conform to those shown in ASME B29.1 or ASME B30.9. contactor: an electromechanical device for opening and closing an electric power circuit. control actuator: a manual means at the operating station by which hoist 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.
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 NFPA 70.
hoist: amachineryunitthatis used forliftingorloweringa freely suspended (unguided) load. hoist speed: the rate ofmotion that the load hook obtains while lifting rated load. hooksuspended: suspension ofhoistfrom a trolleyorrigid structure by means of a hook at top of hoist. idler sprocket: a freely rotating device that changes the direction of the load chain. This device is sometimes called idler wheel, idler sheave, pocket wheel, or chain wheel (see Figure 1-0.2-2). lift:themaximumverticaldistancethroughwhichtheload hook can travel, and is the total hook movement between its upper limit of travel and its lower limit of travel (see Figure 1-0.2-1). lifting devices, below-the-hook: devices that are not normally reeved onto the hoist chains such as hook-on buckets, magnets, grabs, and other supplemental devices used for handling certain types of loads. The weight of these devices is to be considered part of the load to be lifted.