Overhead crane electrical requirements

Minimizing risks of electrical hazards

This section regulates voltage, cabling, design and construction of pendant controls to protect lifting equipment operators and other personnel from electrical shock. These specifications support OSHA 29 CFR-1910 Subpart S, which lays out employers’ responsibilities to provide employees a workplace that minimizes the risk of arc-flash and other electrical hazards.

 

OSHA 1910.179 Overhead & Gantry Cranes Regulations
The following excerpt is taken directly from OSHA 1910.179*

Electrical Equipment

  • Wiring and equipment shall comply with subpart S of this part.
  • The control circuit voltage shall not exceed 600 volts for a.c. or d.c. current.
  • The voltage at pendant push-buttons shall not exceed 150 volts for a.c. and 300 volts for d.c.
  • Where multiple conductor cable is used with a suspended pushbutton station, the station must be supported in some satisfactory manner that will protect the electrical conductors against strain.
  • Pendant control boxes shall be constructed to prevent electrical shock and shall be clearly marked for identification of functions.

Equipment

  • Electrical equipment shall be so located or enclosed that live parts will not be exposed to accidental contact under normal operating conditions. 
  • Electric equipment shall be protected from dirt, grease, oil, and moisture. 
  • Guards for live parts shall be substantial and so located that they cannot be accidently deformed so as to make contact with the live parts.

Resistors

  • Enclosures for resistors shall have openings to provide adequate ventilation, and shall be installed to prevent the accumulation of combustible matter too near to hot parts.
  • Resistor units shall be supported so as to be as free as possible from vibration. 
  • Provision shall be made to prevent broken parts or molten metal falling upon the operator or from the crane.

Switches

  • The power supply to the runway conductors shall be controlled by a switch or circuit breaker located on a fixed structure, accessible from the floor, and arranged to be locked in the open position. 
  • On cab-operated cranes a switch or circuit breaker of the enclosed type, with provision for locking in the open position, shall be provided in the leads from the runway conductors. A means of opening this switch or circuit breaker shall be located within easy reach of the operator. 
  • On floor-operated cranes, a switch or circuit breaker of the enclosed type, with provision for locking in the open position, shall be provided in the leads from the runway conductors. This disconnect shall be mounted on the bridge or footwalk near the runway collectors. One of the following types of floor-operated disconnects shall be provided: 
  • Nonconductive rope attached to the main disconnect switch. 
  • An undervoltage trip for the main circuit breaker operated by an emergency stop button in the pendant pushbutton in the pendant pushbutton station. 
  • A main line contactor operated by a switch or pushbutton in the pendant pushbutton station. 
  • The hoisting motion of all electric traveling cranes shall be provided with an overtravel limit switch in the hoisting direction. 
  • All cranes using a lifting magnet shall have a magnet circuit switch of the enclosed type with provision for locking in the open position. Means for discharging the inductive load of the magnet shall be provided.

Runway conductors

  • Conductors of the open type mounted on the crane runway beams or overhead shall be so located or so guarded that persons entering or leaving the cab or crane footwalk normally could not come into contact with them. 

Extension lamps

  • If a service receptacle is provided in the cab or on the bridge of cab-operated cranes, it shall be a grounded three-prong type permanent receptacle, not exceeding 300 volts.

Electrical hazards pose potentially lethal consequences, but can easily lurk unnoticed. Over time, stress on equipment such as dangling pendant controls and cables, if not properly supported, may open employees to the risk of electrical shock. Contact us to inspect your equipment for compliance with safety standards and to take corrective action, if needed.

 

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*The foregoing OSHA regulations are not intended to be a comprehensive overview of all applicable regulations pertaining to the designated topic. State laws may mandate different safety and maintenance standards. Accordingly, please consult applicable state laws as well as original equipment manufacturer specifications for further guidance. The statements and descriptions contained herein constitute the opinion/recommendation of the seller and are not intended to create any express warranties.