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(a) Dumbwaiter Cars.
(1) Cars shall be of solid or openwork construction on all sides except the necessary openings and of such strength and stiffness that they will not deform appreciably when the load leans or falls against the sides of the car.
(2) Nonmetal cars shall be reinforced with metal from the bottom of the car to the point of suspension.
EXCEPTION: Hand dumbwaiters.
(3) Metal car sections shall be riveted, welded or bolted together.
(4) The total inside height of the car shall not exceed 4 feet. The inside net floor area shall not exceed 9 square feet.
(5) Cars shall be provided with a platform and a solid car top.
(b) Structural Capacity Load. Driving machines, car and counterweight suspension means, and overhead beams and supports shall be designed and installed to sustain the car with a structural capacity load not less than that specified in Table 3079B, based on the inside net platform area or the rated load, whichever is greater, with the factors of safety specified in the respective rules applying to such parts. The motive power shall not be required to be sufficient to lift the structural capacity load.
TABLE NO. 3079B Minimum Allowable Structural Capacity Load Corresponding to Inside Net Platform Area Net Platform Area Structural Capacity in Square Feet Load in Pounds 4........................................... 100 5........................................... 150 6 1/4....................................... 300 9........................................... 500
(c) Rated Load.
(1) The rated load shall be not more than 500 pounds.
(d) Capacity and Data Plates.
(1) A metal plate shall be fastened in a conspicuous place in the car and shall give the rated load in letters and figures not less than 1/4 inch high, stamped, etched or raised on the surface of the plate.
(2) A data plate shall be attached inside or on the car top and indicate the following:
(A) Manufacturer's name and date of installation.
(B) Total weight of car.
(C) Rated speed.
(D) Wire rope data required by Section 3042(b)(1) for cabled dumbwaiters.
(E) The outside diameter and wall thickness of the finished plunger for hydraulic dumbwaiters.
(F) The height of data plate letters and figures shall be not less than 1/8 inch.
(e) Car and Counterweight Safeties.
(1) Car or counterweight safeties are not required except as specified in Section 3078(g).
(2) Governors and governor actuated safeties shall be approved as required for elevators in Design Sections 3105 and 3106. A field test shall be conducted witnessed by a representative of the division.
(3) Safeties actuated by breaking or slackening of the hoist ropes shall be drop tested on each installation. The test shall be witnessed by a representative of the division.
(4) The safety device need not be located below the car or the counterweight.
(f) Driving Machines and Sheaves.
(1) Driving machines shall be located in machine rooms or machine spaces and shall be one of the following types:
(E) Single Belt
(F) Chain Drive
(2) Driving machines and sheaves shall be designed with a factor of safety, based on the static load (the rated load plus the weight of the car, ropes, counterweights, etc.) of not less than:
(A) 6 for steel, and
(B) 9 for cast iron and other materials.
(3) Sheaves and drums used with suspension ropes shall:
(A) Be of metal with finished grooves, except that grooves of sheaves not used to transmit power, may be lined with rubber or other sound isolating material.
(B) Have a pitch diameter not less than 24 times the diameter of the rope where used with suspension ropes.
(4) Belts used as the driving means between the motor and the machine of power dumbwaiters shall comply with the following requirements:
(A) Where flat belts are used, the rated speed shall be not more than 50 feet per minute.
(B) Where multiple V-belts are used, the rated speed shall be not more than 150 feet per minute.
(5) Electric and hand driven machines shall be equipped with brakes as follows:
(A) Electric driving machines shall have electrically released brakes applied automatically by springs in compression or by gravity when the power is removed from the motor.
(B) Belt drive machines shall be equipped with a brake located so as to be effective in event of belt failure.
(C) Handdriving machines shall be equipped with hand brakes or automatic brakes which will sustain the car and its rated load. When the brake is applied, it shall remain locked in the "ON" position until released by the operator.
(6) Hydraulic driving machines shall conform to Section 3067, except they may be other than the direct plunger type.
(g) Car and Counterweight Guides and Guide Fastenings.
(1) Car and counterweight guide rails for power dumbwaiters shall be of metal of such design and strength, and so supported as to withstand without undue deflection the loads imposed upon them under normal conditions of service or upon application of a required safety device.
EXCEPTION: Dumbwaiters having a capacity of 20 pounds or less may have guides of wood or spring steel wires maintained in tension.
(2) Cars and counterweights of all dumbwaiters shall run in guides. The same set of guide rails may be used for both the car and counterweight.
(3) Guides shall be securely fastened to the hoistway.
(4) Guides for hand dumbwaiters may be of wood.
(5) Guide-rail joints shall be either tongued and grooved or doweled and fitted with splice plates.
(h) Counterweights. Counterweights may be of sectional construction, supported by tie rods provided they are secured by at least two tie rods. Tie rods shall have lock nuts secured by cotter pins.
(i) Means of Suspension and Fastenings.
(1) Cars and counterweights for power dumbwaiters except those having hydraulic or screw-type driving machines, shall be suspended by one or more iron or steel wire hoisting ropes or chains secured to the car or counterweight or rope hitch by babbitted sockets, rope clamps, or equally substantial fastenings.
(A) Suspension ropes shall be provided with a rope data tag conforming to Section 3042(c).
(B) Suspension chains shall be provided with data tags similar to Section 3042(c).
(2) Chains, where used, shall be roller, block, or multiple-link silent type.
(3) The factor of safety, based on the static load, of car and counterweight suspension means of power dumbwaiters shall be not less than the value specified in Table 3079I for the actual speed of the rope or chain corresponding to the rated speed of the dumbwaiter. The fastenings for the suspension means shall develop not less than the factor of safety required for the suspension means.
TABLE NO. 3079I Factors of Safety for Wire Ropes and for Chains Rope or Chain Speed Factor of Safety Feet per Minute For Ropes For Chains 50.................. 4.8 6.0 100.................. 5.2 6.5 150.................. 5.5 6.9 200.................. 5.9 7.4 250.................. 6.2 7.8 300.................. 6.6 8.3 350.................. 7.0 8.8 400.................. 7.3 9.1 450.................. 7.7 9.6 500.................. 8.0 10.0
(4) The suspension means for hand dumbwaiters shall conform to the following:
(A) Dumbwaiters having a rated load of more than 75 pounds shall be suspended by steel wire ropes or chains having a factor of safety of not less than 4 1/2.
(B) Dumbwaiters having a rated load of 75 pounds or less may be suspended by manila or braided-cotton ropes having a factor of safety of not less than 6.
(5) Wire ropes shall not be lengthened or repaired by splicing.
(6) The winding-drum ends of car and counterweight ropes or chains shall be secured inside the drum, and there shall be not less than one turn of the rope or chain on the drum when the car or counterweight has reached the extreme limit of its overtravel.
(j) Control and Operation of Power Dumbwaiters.
(1) Operation shall be of the automatic or continuous pressure type.
(2) Dumbwaiters equipped with winding-drum machines, shall be equipped with a slack-rope switch which will remove the power from the motor and brake if the car is obstructed in its descent.
EXCEPTION: Dumbwaiters installed before June 5, 1947.
(3) Operating devices shall be of the enclosed electric-type.
(4) When it is intended to discontinue for an extended period of time, the use of a dumbwaiter, the car and counterweight shall be landed satisfactorily and the power shall be disconnected.
(k) Terminal Stopping Devices for Power Dumbwaiters. Normal terminal stopping devices conforming to the requirements of Section 3039(a) shall be provided.
EXCEPTION: The switch contacts shall be directly opened mechanically. Arrangements which depend on a spring, or gravity, or a combination of both, to open the switch contacts, shall not be used.
(l) Hydraulic Dumbwaiters. Valves, supply piping, fittings and tanks for hydraulic dumbwaiters shall conform to Sections 3068 and 3069.
(Title 24, Part 7, Section 7-3079)
NOTE: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943, Health and Safety Code.
1. Amendment of subsection (f)(3), repealer and new subsection (j) filed 6-23-77; effective thirtieth day thereafter (Register 77, No. 26).
2. New Exception to subsection (k), statement prior to Note and Note filed 3-9-93; operative 4-8-93 (Register 93, No. 11).