Hoist cars shall be suspended by steel wire ropes attached to the car frame or passing around sheaves attached to the car frame specified in Section 1604.16.
Exception: Exceptions are hoists with rack and pinion machines.
The crosshead data plate required by Section 1604.21(b) shall bear the following wire rope data:
A metal data tag shall be securely attached to one of the wire rope fastenings. This data tag shall bear the following wire rope data:
A new tag shall be installed at each rope renewal. The material and marking of the rope data tag shall conform to the requirements of Section 1604.21(d), except that the height of the letters and figures shall be not less than 1/16 -inch.
A log shall be kept by the employer at the work site office which will indicate the following:
The factors of safety of the suspension wire ropes shall be not less than shown in Table 5. Figure 5 gives the minimum factors of safety for intermediate rope speeds. The factor of safety shall be based on the actual rope speed corresponding to the rated speed of the car. The factor of safety shall be calculated by the following formula:
f= | S x N |
W |
where
S = Manufacturer's rated breaking strength of one rope.
N = Number of runs of rope under load (see Note).
W = Maximum static load imposed on all car ropes, with the car and its rated load at any position in the hoistway.
NOTE: In the case of multiple roping, the number of runs of rope (N) under the load will be: twice the number of ropes used, for 2:1 roping; three times the number of ropes used, for 3:1 roping, etc.
Table 5 Minimum Factors of Safety for Suspension Wire Ropes | ||||
Rope Speed (feet per minute) | Minimum Factor of Safety | |||
50.......................... | ..........................7.60 | |||
75.......................... | ..........................7.75 | |||
100.......................... | ..........................7.95 | |||
125.......................... | ..........................8.10 | |||
150.......................... | ..........................8.25 | |||
175.......................... | ..........................8.40 | |||
200.......................... | ..........................8.60 | |||
225.......................... | ..........................8.75 | |||
250.......................... | ..........................8.90 | |||
300.......................... | ..........................9.20 | |||
350.......................... | ..........................9.50 | |||
400.......................... | ..........................9.75 | |||
450.......................... | ..........................10.00 | |||
500.......................... | ..........................10.25 | |||
550.......................... | ..........................10.45 | |||
600.......................... | ..........................10.70 |
The minimum number of hoisting ropes used shall be three for traction hoists and two for drum type hoists.
Where a car counterweight is used, the number of counterweight ropes used shall be not less than two.
The term "diameter," where used in Section 1604.25, shall refer to the nominal diameter as given by the rope manufacturer.
The minimum diameter of hoisting and counterweight ropes shall be 1/2 -inch.
Suspension rope equalizers may be used.
Car suspension ropes of winding-drum machines shall have the ends of the rope secured to the drum or drum flange by means of clamps or tapered sockets or by other means approved by the enforcing authorities.
Wire suspension ropes of drum type machines shall have not less than three wraps of the rope on the drum when the car is resting on the fully compressed buffers.
Suspension wire ropes shall not be lengthened or repaired by splicing.
Hoisting and counterweight wire ropes shall be attached to cars and counterweights by means of zinc-coated or galvanized drop forged fist grips or equal and wire rope thimbles, or by approved special fastening devices. When fist grips are used, the minimum number, spacing, and tightening torque shall be in accordance with the instructions of the grip manufacturer. Grips shall be periodically checked and retightened to the recommended torque.
When extra wire rope is carried on top of the frame of the hoisting platform, a drum and clamp tie down or equivalent type anchor device, which will not damage or deform the wire rope, shall be used.
Babbitted rope sockets shall be prohibited except on permanent passenger or freight elevators which are temporarily being used as construction personnel hoists.
Fig. 5
Factors of Safety of Suspension
Wire Ropes of Personnel Hoists
If one wire rope of a set requires replacement, the entire set of ropes shall be replaced. Wire rope shall be removed or replaced immediately if it has one or more of the following defects:
Governor ropes shall be replaced on the same basis as hoisting ropes. (These ropes are lightly loaded and may show little or no wear. Inspectors should check for fatigued wires in strand valleys by bending over a small radius.)
Cal. Code Regs. Tit. 8, § 1604.25