California Code of Regulations
Title 8 - Industrial Relations
Division 1 - Department of Industrial Relations
Chapter 4 - Division of Industrial Safety
Subchapter 4 - Construction Safety Orders
Article 14 - Construction Hoists
Section 1604.24 - Operating Devices and Control Equipment
Current through Register 2024 Notice Reg. No. 38, September 20, 2024
(a) Operation and Operating Devices.
Handles of lever-type operating devices of car-switch operation hoists shall be so arranged that they will return to the stop position when the hand of the operator is removed. Car-switch push-buttons shall be of the constant-pressure type so that when the hand is removed from the button the car will stop.
(b) Electrical Protective Devices.
Electrical protective devices shall be provided in accordance with the following requirements:
Hoists having winding-drum machines shall be provided with a slack-rope device equipped with a slack rope of the enclosed manually reset type which shall cause the electric power to be removed from the hoist driving-machine motor and brake if the hoisting ropes become slack.
Where generator-field control is used, means shall be provided to prevent the application of power to the hoist driving-machine motor and brake unless the motor-generator-set connections are properly switched for the running condition of the hoist. It is not required that the electrical connections between the hoist driving-machine motor and the generator be opened in order to remove power from the hoist motor.
Where generator-field control is used, a motor-field excitation switch shall be provided which shall cause the electric power to be removed from the hoist driving-machine motor and brake unless current is flowing in the shunt-field circuit of the hoist driving-machine motor.
An emergency stop switch shall be provided in the car and located in, or adjacent to, the car operating pane. When opened, this switch shall cause the electric power to be removed from the hoist driving machine motor and brake. Emergency stop switches shall have the following characteristics:
Broken-rope, tape, or chain switches shall be provided in connection with normal-terminal stopping devices located in machine rooms of traction hoists. Such switches shall be opened by a failure of the rope, tape, or chain.
A switch conforming to the requirements of Sections 1604.19(f), 1604.20(d)(1), and 1604.20(d)(3) shall be required where a car safety is provided.
A speed-governor overspeed switch shall be provided when required by Section 1604.20(d)(1) and shall conform to the requirements given under Sections 1604.20(d)(2) and 1604.20(d)(3).
Final-terminal stopping devices conforming to the requirements given under Section 1604.23(c) shall be provided.
Where reduced-stroke oil buffers are provided or car rated speed exceeds 300 feet per minute, emergency terminal stopping devices conforming to the requirements given under Section 1604.23(d) shall be provided.
Compensating-rope sheaves, when used, shall be provided with a compensating-rope sheave switch or switches mechanically opened by the compensating-rope sheave before the sheave reaches its upper or lower limit of travel, to cause the electric power to be removed from the elevator driving-machine motor and brake.
A primary magnetic contactor shall be provided for main power disconnect, in addition to the normal service disconnect switch as required by Section 1604.24(d). The primary magnetic contactor shall perform its power disconnect function upon any interruption of the final-terminal stopping devices and all other electrical safety devices.
Car door or gate electric contacts conforming to the requirements given under Section 1604.18(b) shall be provided for all hoists.
Normal-terminal stopping devices conforming to the requirements given under Section 1604.23(b) shall be provided for every hoist.
Means shall be provided to cause the electric power to be removed automatically from the hoist driving-machine motor and brake should a motor-generator set, driven by a DC motor, overspeed.
(c) Voltages Permitted in the Hoistway or on the Car.
The maximum system or circuit potential permitted on any equipment in the hoistway or on the car shall not be more than 440 volts (nominal). Where the potential exceeds 120 volts, a grounding conductor shall be incorporated in the traveling cable. The type and size of the grounding conductor and the grounding fastening means shall conform to the requirements of the Electrical Safety Orders.
EXCEPTION: Installations provided with an inherent grounding system for the car.
(d) Supply-Line Disconnecting Means.
A fused-disconnect switch or a circuit breaker shall be installed and connected into the power-supply line to each elevator motor or motors or to the motor of the motor-generator set. Disconnect switches or circuit breakers shall be of the manually closed multi-pole type arranged to be locked in the open position and their location shall conform to the requirements of the Electrical Safety Orders.
Disconnect means for hoists having a DC primary power supply and rheostatic control shall have the disconnect switch arranged so that its opening will directly open the driving-machine brake circuit.
Where circuit breakers are used as a disconnecting means, they shall not be of the instantaneous type and shall not be opened automatically by a fire alarm system.
(e) Phase-Reversal and Failure Protection.
Hoists having polyphase AC power supply shall be provided with means to prevent the starting of the hoist motor if the phase rotation is in the wrong direction, or there is a failure of any phase.
This protection shall be considered provided in the case of generator-field control having AC motor-generator driving motors, provided a reversal of phase will not cause the hoist driving-machine motor to operate in the wrong direction. Controllers whose switches are operated by polyphase torque motors provide inherent protection against phase reversal or failure.
(f) Devices to Make Electrical Protective Devices Inoperative.
The installation of condensers, the operation or failure of which will cause an unsafe operation of the hoist, is prohibited. No permanent device shall be installed, except as provided in this Standard, which will make any required electrical protective device inoperative.
(g) Driving Machine Brakes.
Driving machine brakes shall not be electrically released until power has been applied to the driving machine motor.
All power feed lines to the brake shall be opened, and the brake shall apply automatically when the following conditions prevail:
Under conditions (1) and (2) above, the application of the brake may occur on or before the completion of the slowdown and leveling operations.
The brake shall not be permanently connected across the armature or field of a DC hoist driving-machine motor.
(h) Control and Operating Circuit.
In the design and installation of the control and operating circuits, the following requirements shall be met:
EXCEPTION: The requirements of Section 1604.24(h)(2) do not apply to dynamic braking or to speed control switches.
(i) Absorption of Regenerated Power.
Where a power source is used which, in itself, is incapable of absorbing the energy generated by an overhauling load, means of absorbing sufficient energy shall be provided on the load side of each hoist power supply-line disconnecting means to prevent the hoist from attaining governor-tripping speed or a speed in excess of 125% of rated speed, whichever is less.
1. Change without regulatory effect amending subsections (b)(12) and (h)(3) and adding NOTE filed 12-28-2007 pursuant to section 100, title 1, California Code of Regulations (Register 2007, No. 52).
2. Amendment of subsection (a)(3), new subsections (a)(3)(A)-(D), repealer of subsection (b)(6), subsection renumbering and amend of newly designated subsection (b)(10) filed 7-17-2008; operative 8-16-2008 (Register 2008, No. 29).
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.