Elevator Troubleshooting & Repair. David Herres. Читать онлайн. Newlib. NEWLIB.NET

Автор: David Herres
Издательство: Ingram
Серия:
Жанр произведения: Физика
Год издания: 0
isbn: 9780831195281
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for attaching an inspector’s pressure gage while the tank is in service.

      (e) Liquid Level Detector: Tanks are to be provided with a means to render the elevator inoperative if for any reason the liquid level in the tanks falls below the permissible minimum.

      (f) Handholes and Manholes: Tanks are to be provided with a means for internal inspection.

      (g) Piping and Fittings for Gages: Piping and fittings for gage glasses, relief valves, and pressure gages are to be of a material that will not be corroded by the liquid used in the tank.

      ■ Section 4.6, Terminal Stopping Devices, provides that terminal stopping devices are to conform to the requirements of 3.9.1.

      ■ Section 4.7, Operating Devices and Control Equipment, provides in 4.7.1, Operating Devices, that operating devices are to conform to the requirements of 3.10.1 and 3.10.2, Top-of-Car Operating Devices, which state that top-of-car operating devices are to be provided and are to conform to the requirements of 3.10.3, except for un-counterweighted elevators having a rise of not more than 15 feet. The bottom normal terminal stopping device is permitted to be made ineffective while the elevator is under the control of the top-of-car operating device.

      ■ 4.7.3, Anti-creep Leveling Devices, states that each elevator is to be provided with an anti-creep leveling device conforming to the following provisions:

      (a) It is to maintain the car within three inches of the landing irrespective of the position of the hoistway door.

      (b) For electrohydraulic elevators, it is required to operate the car only in the up direction.

      (c) For maintained pressure hydraulic elevators, it is required to operate the car in both directions.

      (d) Its operation is permitted to depend on the availability of the electric power supply provided that:

      (1) the power supply line disconnecting means required by 3.10.5 is kept in the closed position at all times except during maintenance, repairs, and inspections; and

      (2) the electrical protective devices required by 4.7.4(b) do not cause the power to be removed from the device.

      ■ 4.7.4, Electrical Protective Devices, states that electrical protective devices, conforming to the requirements of 3.10.4, where they apply to hydraulic elevators, are to be provided and operate as follows:

      (a) The following devices are to prevent operation of the elevator by the normal operating devices and also the movement of the car in response to the anti-creep leveling device:

      (1) Stop switches in the pit

      (2) Stop switches on top of the car

      (3) Car side emergency exit door electric contacts, where such doors are provided

      (b) The following devices are to prevent the operation of the elevator by the normal operating device, but the anti-creep leveling device required by 4.7.3 is to remain operative:

      (1) Emergency stop switches in the car

      (2) Broken rope, tape, or chain switches on normal terminal stopping devices when such devices are located in the machine room or overhead space

      (3) Hoistway-door interlocks or hoistway-door electric contacts

      (4) Car door or gate electric contacts

      (5) Hinged car platform sill electric contacts

      (6) In-car stop switch, where permitted by 3.10.4(t)

      ■ 4.7.5, Power Supply Line Disconnecting Means, states that they are to conform to the requirements of 3.10.5.

      ■ 4.7.6, Devices for Making Hoistway-Door Interlocks or Electric Contacts, or Car Door or Gate Electric Contact Inoperative, states that they are to conform to the requirements of 3.10.7.

      ■ 4.7.7, Control and Operating Circuit Requirements, states that they are to conform to the requirements of 3.10.9 and 3.10.12.

      ■ 4.7.8, Emergency Operation and Signaling Devices, states that they are to conform to the requirements of Section 3.1.1.

      ■ Section 4.8, Additional Requirements for Counterweighted Hydraulic Elevators, provides that they are to be roped so that the counterweight will not strike the overhead work when the car is resting on its fully compressed buffer. Counterweighted hydraulic elevators are to conform to the requirements of Section 3.2 where applicable. Where counterweights are provided, counterweight buffers are not to be provided.

      ■ Section 4.9, Additional Requirements for Roped-Hydraulic Elevators:

      ■ 4.9.1, Top Car Clearance, states that roped-hydraulic driving machines, whether of the vertical or horizontal type, are to be so constructed and so roped that the piston will be stopped before the car can be drawn into the overhead work. The top car clearance is to meet the requirements of 2.4.4.

      ■ 4.9.2, Top Counterweight Clearance and Bottom Counterweight Runby, states that where a counterweight is provided, the top clearance and the bottom runby are to conform to the following:

      (a) Top Clearance is not to be less than the sum of the following:

      (1) The bottom car runby

      (2) The stroke of the car buffers used

      (3) Six inches

      The minimum runby specified is not to be reduced by rope stretch.

      ■ 4.9.3, Protection of Spaces Below Hoistway, states that where the hoistway does not extend to the lowest floor, the space below the pit is to be enclosed with permanent walls or partitions to prevent access.

      ■ 4.9.4, Piston Stops, states that piston stops are to be provided to bring the piston to rest at either end of the piston travel from maximum speed in the up direction, under full pressure without damage to the driving machine, piston, piston joints, cylinder, cylinder couplings, or any other part of the hydraulic system.

      For rated speeds exceeding 100 feet per minute where a solid metal stop is provided, means other than the normal terminal stopping device are to be provided to retard the car to 100 feet per minute with a retardation not greater than gravity, before striking the stop.

      ■ 4.9.5, Piston Connections, states that:

      (a) Equalizing Crosshead: Where more than one piston is used on the puller-type roped hydraulic elevators, an equalizing crosshead is to be provided for the attachment of the rods to the traveling sheave frame to ensure an equal distribution of the load to each rod.

      (b) Equalizing or Cup Washers are to be provided under piston rod nuts to ensure a true bearing.

      (c) Piston rods of the puller-type hydraulic elevators are to have a factor of safety of not less than eight based on the cross-sectional area at the root of the thread of the material used. A true bearing is to be maintained under the nuts of both ends of the piston rod to prevent eccentric loadings on the rod.

      ■ 4.9.6, Car Safety Devices, states that car safety devices conforming to the requirements of Section 3.5, except 3.5.2 are to be provided. Counterweight safeties are not to be provided.

      ■ 4.9.7, Car Speed Governors, states that car speed governors conforming to the requirements of Section 3.6 are to be provided.

      ■ 4.9.8, Sheaves, states that sheaves are to be cast iron or steel and are to have finished grooves for ropes.

      The traveling sheaves are to be guided by means of metal guides and guide shoes. The guide shoes are permitted to be equipped with nonmetallic inserts. Sheave frames, where used, are to be constructed of structural or forged steel and are to be designed and constructed with a factor of safety not less than eight for the material used. Single continuous straps (known as U-strap connection) are not to be used for frames or as connections between piston rods and traveling sheaves.

      ■ 4.9.9, Slack-Rope Device: Roped-hydraulic elevators are to be provided with a slack-rope device and switch of the enclosed, manually reset type that will cause the electric power to be removed from the pump motor and the valves if the hoisting ropes become slack or