CAN CSA Z256-M87:2021 pdf download.Safety code for material hoists
Car or counterweight safeties means mechanical devices attached to the car frame, or to an auxiliary frame, or to the counterweight frame, to stop and hold the car or counterweight in case of prede-termined overspeed or free fall, or if the hoisting ropes slacken.
Type A safeties means safeties that apply a rapidly increasing pressure on the guide rails during the stopping interval, the stopping distance being very short due to the innerent design of the safety.
The operating force is derived entirely from the mass and the motion of the car or the counterweight being stopped. These safeties apply pressure on the guide rails through eccentrics, rollers, or similar devices, without any flexible medium purposely introduced to limit the retarding force and increase the stopping distance.
Type B safeties means safeties that apply a constant retarding force, or a gradually increasing retarding force, on the guide rails during the stopping interval, and that provide stopping distances that are related to the mass being stopped. Continuous tension in the governor rope may or may not be requirec to operate tie safety during the entire
topping interval. Minimum and maximum stopping distances are specified on the basis of governor tripping speed.
Type C safeties (Type A with oil buffers) means safeties tiat app’y a retarcing force curing the compression stroke of ore or more oU buffers interposed between the lower members of the car frame and a governor-operated Type A auxiliary safety plank applied on the guide rails. Tie stopping distance is ecual to the effective stroke of the buffers.
Type D safeties means safeties in which a freely ro:ating safety pinion, a governor, and a safety device are mounted on the car. The freely rotating pinion travels on a stationary racK mountec or the hoist structLre. The rotating pinion drives the governor and when tne downward speed of the car reaches the tripping value, the rotating governor activates the safety device, which ir turn br ngs the car to a gradual stop.
Safety circuit mears any circuit :hat directly or indirectly controls the supp!y o’ electric power 
the crive machine brake ard that includes one or more electrical protective switches.
Signal system rrears a system that will advise or indicate to tre attendant the floors at which stops are to be made.
Standard railing means a railing constructed of wood or metal, consisng of a smooth-surfaced top rail whose top surface is 1D65 mm (42 in) from the floor, and an intermeciate rai located approximately halfway between the top rail and the floor, and posts located no: more than 2.5 m (8 t) apart.CAN CSA Z256-M87 pdf download.