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Subchapter 6. Elevator Safety Orders
Article 8. Machinery and Equipment for Power Cable-Driven Passenger and Freight Elevators

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§3035. Car and Counterweight Safeties.

(a) Where Required and Located.

(1) The car of every elevator suspended by wire ropes shall be provided with one or more approved car safety devices of a type identified in section 3035(e). The safeties shall be attached to the car frame, and one safety shall be located within or below the lower members of the car frame (safety plank).

EXCEPTIONS: Existing elevators having a rise of not more than 15 feet that were:

1. Installed before January 1, 1925, or

2. Equipped with a safety device actuated by the slackening or breaking of the hoisting cables.

(2) All car safeties shall be mounted on a single car frame and shall operate only on one pair of guide rails, between which the frame is located.

(3) See Design section 3106 for details of approval of safeties.

(4) Every type of car-holding or counterweight safety device hereafter installed shall be field tested before a permit to operate is issued. This test shall be witnessed by an authorized representative of the Division of Industrial Safety, or the division may accept reports of witnesses recognized as competent by the division. This test shall demonstrate that the safety device will function as required by section 3035(c).

(b) Duplex Safeties.

(1) Where two (duplex) safeties are provided, the lower safety device shall be capable of developing not less than 1/2 of the force required to stop the entire car with rated load. See also Design section 3100(b). Duplexed safety devices shall be arranged so as to function approximately simultaneously. Complete details of the car frame and the safety device linkage shall be submitted to the division for approval.

(2) Type A or Type C safety devices shall not be used in multiple (duplexed).

(c) Function and Stopping Distance of Safeties.

(1) The safety device, or the combined safety devices where furnished, shall be capable of stopping and sustaining the entire car with its rated load from governor tripping speed. The weight of the entire car shall include any compensating ropes, traveling cables, and any other attachments to the car.

EXCEPTION: Safeties of elevators equipped with alternating current driving machines may have the full load test conducted at normal down speed by tripping the governor by hand. See section 3036(a)(1) for governor test required.

(2) Type B safeties shall stop the car with its rated load from governor tripping speed within the range of the maximum and minimum stopping distances as determined by the formulas in Design section 3106(a)(1).

(A) Table 3035 C and Figures 3106 A1 through 3106 A7 show the maximum and minimum stopping distances for various governor tripping speeds for reference.

(B) The distance the car traveled, after the safety device began to engage the rails until the car stopped, shall be measured by taking the average of the four rail marks and deducting the length of the safety jaw or wedge.

(3) During the field test, the controls shall be arranged so that the full power in the down direction shall be applied until the safety has fully applied.

(4) The field test on Type A safeties shall include the inertia test as outlined in Design section 3106(c)(3)(A).

(5) The field test of counterweight safeties actuated by a governor shall be conducted with no load in the car. See section 3035(d)(1) for drop test requirements where counterweight safeties are not governor actuated.

(6) A functional test may be required when inspection of the safety parts reveals conditions that may prevent the safety from operating as intended.



                      TABLE NO. 3035 C 
  Maximum and Minimum Stopping Distances Type B Car Safeties 
    With Rated Load, and of Type B Counterweight Safeties 

                  Maximum Governor      Stopping Distances 
Rated Speed in   Trip Speed in Feet       in Feet-Inches 
Feet Per Minute      Per Minute         Minimum    Maximum 
     0 to 125...........175               0-1        1-3 
     150................210               0-2        1-4 
     175................250               0-3        1-7 
     200................280               0-4        1-10 
     225................308               0-5        2-0 
     250................337               0-6        2-3  
     300................395               0-8        2-9  
     350................452               0-10       3-4  
     400................510               1-1        4-0  
     450................568               1-5        4-10 
     500................625               1-8        5-8  
     600................740               2-4        7-7  
     700................855               3-2        9-10 
     800................970               4-1        12-6 
     900...............1085               5-1        15-3 
     1000..............1200               6-3        18-6 
     1100..............1320               7-6        22-4 
     1200..............1440               8-11       26-4 
     1300..............1560               10-6       30-11 
     1400..............1680               12-2       35-7 
     1500..............1800               14-0       40-10 

(d) Counterweight Safeties. Where any space below the hoistway is used for a passageway or is occupied by persons, or if unoccupied is not permanently sealed against access, the following requirements shall be conformed to:

(1) Elevator counterweights shall be provided with safeties conforming to the requirements for car safeties.

EXCEPTIONS:

1. Where otherwise specified in section 3035, counterweight safeties may differ from car safeties.

2. For rated speeds of not over 150 feet per minute, counterweight safeties may be operated as a result of the breaking or slackening of the hoisting ropes and may be of the inertia or other approved type without governors.

Every safety device applied as a result of the slackening or breaking of the hoisting cables shall be drop tested when installed. This test shall be witnessed by a representative of the Division of Industrial Safety, or the Division may accept reports of witnesses recognized as competent by the Division.

3. Existing counterweights equipped with safety devices actuated by the breaking or slackening of the counterweight ropes and which have a rated speed of not more than 250 feet per minute.

4. Wedge clamp safeties shall not be used for counterweight safeties unless they are arranged to be reset from the pit or the machine room.

(e) Identification and Classification of Types of Safeties. Car safety devices (safeties) are identified and classified on the basis of performance characteristics after the safety begins to apply pressure on the guide rails. On this basis, there are three types of safeties.

(1) Type A Safeties. Safeties which develop a rapidly increasing pressure on the guide rails during the stopping interval, the stopping distance being very short due to the inherent 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.

(2) Type B Safeties. Safeties which apply limited pressure on the guide rails during the stopping interval, and which provide stopping distances that are related to the mass being stopped and the speed at which application of the safety is initiated.

Retarding forces are reasonably uniform after the safety is fully applied. Continuous tension in the governor rope may or may not be required to operate the safety during the entire stopping interval. Minimum and maximum distances are specified on the basis of governor tripping speed.

(3) Type C Safeties (Type A with Oil Buffers). Safeties which develop retarding forces during the compression stroke of one or more oil buffers interposed between the lower members of the car frame and a governor-operated Type A auxiliary safety plank applied on the guide rails. The stopping distance is equal to the effective stroke of the buffers.

(f) Safeties to Stop Ascending Cars or Counterweights Prohibited. Safeties shall not stop an ascending car or counterweight.

(g) Governor Actuated Safeties and Car Safety Mechanism Switches Required.

(1) Car safeties and counterweight safeties, where provided shall be actuated by separate approved governors.

EXCEPTIONS:

1. Speed governors are not required for the operation of counterweight safeties of elevators having a rated speed of not more than 150 feet per minute.

2. Existing elevators that comply with the exceptions to section 3035(a)(1).

(2) Car safeties shall be provided with a switch, operated by the car safety mechanism when the safety is applied.

EXCEPTION: Existing elevators which comply with the exceptions to section 3036(d)(2).

(h) Limits of Use of Various Types of Safeties.

(1) Type A (Instantaneous) Safeties. Type A safeties may be used on elevators having a rated speed of not more than 150 feet per minute. When overspeed occurs, with the hoisting ropes intact, such safeties shall be actuated by the governor.

On the parting of the hoisting ropes (free fall), Type A governor-operated safeties shall apply without appreciable delay; and their application shall be independent of the speed action of the governor and of the location of the break in the hoisting ropes (inertia application) and may be accomplished by the use of a governor and governor rigging having a sufficiently high value of inertia to apply the safety on free fall independently of the speed action of the governor.

(2) Type C (Combination Instantaneous and Oil Buffer Safety). Type C Safeties may be used subject to the following requirements:

(A) The rated speed shall be not more than 500 feet per minute.

(B) The oil buffers shall conform to all requirements specified in Section 3031 for oil buffers, except that the stroke shall be based on governor tripping speed and on an average retardation not exceeding 32.2 feet per second per second.

(C) After the buffer stroke has been completed, provision shall be made for an additional travel of plunger or piston of not less than 10 percent of the buffer stroke to prevent excessive impact on the buffer parts and the auxiliary safety plank.

(D) Where the distance between guide rails exceeds 8 feet, the safety shall be provided with two oil buffers of substantially identical calibration; and the buffers shall be so located as to develop minimum stresses in the auxiliary safety plank during safety operation.

Buffers shall be located in line with and symmetrically between the guide rails.

(E) The auxiliary safety plank shall be so designed that the maximum stresses in the plank shall not exceed those specified for similar car frame members in Design section 3101(a)(4).

(F) The rail-gripping device of the auxiliary safety plank shall be so arranged and connected as to prevent the plank from being out of level more than 1/2 inch in the length of the plank when the safety is operated to stop the car.

(G) An electric switch shall be provided and so arranged and connected that the elevator cannot be operated by means of the normal operating device if any buffer is compressed more than 10 percent of its stroke.

(H) Means shall be provided to prevent operation of the elevator by means of the normal operating device if the oil level in any buffer is below the minimum allowable level.

(3) No car-holding safety device shall be used for a greater total load or speed than that specified in the approval. The weight of the independent car counterweights, where used, may be deducted from the total load of the car and capacity in determining the load on the safety device.

(4) Observation elevators shall have safeties of the type that do not require access to the car or hoistway for resetting. Safeties on elevators exposed to the weather shall have corrosion resistant parts of all points where corrosion could prevent the device from functioning as intended.

(i) Application and Release of Safeties.

(1) Safeties shall be applied mechanically. Electric, hydraulic, or pneumatic devices shall not be used to apply the safeties required by this section, nor to hold such safeties in the retracted position.

(2) The application of the safety to stop the car, with its rated load centered on each quarter of the platform symmetrically with relation to the center lines of the platform, shall not cause the platform to be out of level more than 3/8 of an inch per foot in any direction.

EXCEPTION: Type C safeties.

(3) When car safeties are applied, no decrease in tension in the governor rope nor motion of the car in the down direction shall release the safeties; but such safeties may be released by the motion of the car in the up direction.

(4) Safeties shall be so designed that on their application the forces which provide the stopping action shall be compressive forces on each side of the guide rail section.

(j) Minimum Permissible Clearance Between Rail Gripping Faces of Safety Parts. In the normally retracted position of the safety, the distance between the rail-gripping faces of the safety parts shall be not less than the thickness of the guide rail plus 0.14 (9/64) inch; and the clearance on any side between the gripping face and the guide rail shall be not less than 0.0625 (1/16) inch as measured on the side of the rail toward which the car frame is pressed with sufficient force to take up all clearances in the guide shoe assembly. Safety jaws, while in the retracted position, shall be so restrained as to prevent a reduction of this minimum clearance.

(k) Maximum Permissible Movement of Governor Rope to Operate the Safety Mechanism.

(1) For all drum-operated safeties, the movement of the governor rope, relative to the car, required to operate the safety mechanism from its fully retracted position to a position where the safety jaws begin to exert pressure against the guide rails, shall not exceed the following values based on rated speed.

200 feet per minute or less...........................42 inches

201 to 375 feet per minute............................36 inches

Over 375 feet per minute..............................30 inches

(2) Drum-operated car safeties, requiring continual unwinding of the safety drum rope to fully apply the safety, shall be so designed that not less than three turns of the safety rope will remain on the drum after the overspeed test of the safety has been made with rated load in the car.

(l) Minimum Factors of Safety and Stresses of Safety Parts and Rope Connections. See Design section 3106(d) for design factors of safety.

(m) Corrosion Resistant Bearings in Safeties and Safety Operating Mechanisms. Bearings in safeties and of the safety operating mechanism shall be of corrosion-resistant construction with one or both members of a bearing made of, or electroplated with, a corrosion-resistant material.

(n) Marking Plates for Safeties. A metal plate or plates shall be securely attached to each safety so as to be readily visible, and shall be marked in a legible and permanent manner with letters and figures not less than 1/4 inch in height indicating the following:

(1) The type of safety.

(2) The maximum tripping speed in feet per minute for which the safety is designed to be used.

(3) The maximum weight in pounds for which the safety is designed to be used with the car frame in which it is installed.

(4) The name of the manufacturer and the identifying number of the safety.

(5) The date of the initial safety test required by section 3035(a)(4) witnessed by a representative of the division.

(o) Governor Rope Releasing Carriers. The governor-rope releasing carrier on the car (or on the counterweight) shall be set to require a tension in the governor rope, to pull the rope from the carrier, of not more than 60 percent of the pull-through tension developed by the governor; and the carrier shall be designed so that the pull-out tension cannot be adjusted in a normal manner to exceed the amount specified. Tension in the governor rope required to pull the rope from the carrier shall not exceed 300 pounds.

(p) Rail Lubricants and Lubrication Plate. Rail lubricants or coatings which will reduce the holding power of the safety or prevent its functioning as required in section 3035(c) shall not be used.

Where lubricants are to be used, a metal plate shall be securely attached to the car crosshead in an easily visible location, and shall carry the notation "CONSULT MANUFACTURER OF THE SAFETY FOR THE CHARACTERISTICS OF THE RAIL LUBRICANT TO BE USED."

If lubricants other than those recommended by the manufacturer are used, a safety test shall be made to demonstrate that the safety will function as required by section 3035(c).

(q) Compensating Rope Tie Down. For rated speeds of 800 feet per minute or more, a device shall be provided to tie the car and counterweight together to limit the jump of the car or counterweight as a result of buffer engagement or application of car or counterweight safety.

HISTORY

1. New subsection (h)(4) filed 10-25-74; effective thirtieth day thereafter (Register 74, No. 43).

2. Amendment of subsections (c)(1), (d)(1), Exception No. 2, and (j) filed 6-23-77; effective thirtieth day thereafter (Register 77, No. 26).

3. Editorial correction replacing 1440 with 1200 in TABLE No. 3035 C (Register 91, No. 24).

4. Editorial correction of subsections (h)(2)(D) and (i)(4) (Register 95, No. 26).

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