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(a) Each independent hoisting unit of a crane shall be equipped with at least one self-setting brake, hereafter referred to as a holding brake, applied directly to the motor shaft or some part of the gear train.
(b) Each independent hoisting unit of a crane, except worm-geared hoists, the angle of whose worm is such as to prevent the load from accelerating in the lowering direction, shall, in addition to a holding brake, be equipped with control braking means to prevent over-speeding.
(c) Holding brakes for hoist motors shall have not less than the following percentage of the full load hoisting torque at the point where the brake is applied:
(1) 125 percent when used with a control braking means other than mechanical.
(2) 100 percent when used in conjunction with a mechanical control braking means.
(3) 100 percent each if two holding brakes are provided.
(d) Holding brakes on hoists shall have ample thermal capacity for the frequency of operation required by the service.
(e) Holding brakes on hoists shall be applied automatically when power is removed from the brake holding mechanism.
NOTE: Dynamic braking controls of d-c motors may maintain power at the brake holding mechanism (coil) if the power supply to the crane is interrupted while a load is being lowered. The holding brakes need not be applied automatically in this situation, since the operator can stop or control the lowering speed of the load in a normal manner.
(f) Holding brakes shall be provided with adjustment means to compensate for wear.
(g) The wearing surface of all holding-brake drums or discs shall be smooth.
(h) Each independent hoisting unit of a crane handling hot metal and having power control braking means shall be equipped with at least two holding brakes.
(i) A power control braking means such as regenerative, dynamic or counter-torque braking, or a mechanically controlled braking means shall be capable of maintaining safe lowering speeds of rated loads.
(j) The control braking means shall have ample thermal capacity for the frequency of operation required by service.
NOTE: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
1. Repealer and new section filed 7-17-75; effective thirtieth day thereafter (Register 75, No. 29).
2. Amendment of subsection (f) filed 8-29-86; effective thirtieth day thereafter (Register 86, No. 39).
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