We utilize many free standing Jib Cranes (10' to 12' tall) that have 120VAC powered hoists. Our typical installation is that the hoist is wired using a cord & plug from the hoist fastened to the boom using a festoon method. The festoon cable terminates to a junction box at the crane column or post. That junction boxed is wired back to a circuit panel. Here's where my confusion comes in....During our annual crane inspections, the crane service notes each installation described above as a "FAIL" grade for 'lack of a floor mounted switch or circuit breaker'.
OSHA Standard is - OSHA 1910.179(g)(5)(i) 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.
ASME Standard is - ASME B30.11-1.9.5(a) The electrical supply to runway or monorail conductors shall be controlled by a switch or circuit breaker located on a fixed structure, accessible from the floor, with provision for being locked in the open position.
Our electrical contractors' interpretation - The state of WI says where disconnects are required for equipment, they must be within sight and within 50’ of the load they serve. Cord and plug connections are an acceptable means to complete this task. I’m thinking you meet the requirements. An additional safety step would be to put the jib on a lockable disconnect but since the plug can be physically separated from the outlet this would not be required.
When asked for their reason for failure, the crane service said they are applying our installations to the OSHA/ASME standards shown above. My "not an electrician" interpretation of the OSHA & ASME standards are they could be interpreted as applying to a bridge or monorail crane with open conductor bars, which we do not have, that cannot be used with a cord/plug where the hoist can be used to disconnect power & lock out the hoist.
I appreciate your feedback and clarity.
OSHA Standard is - OSHA 1910.179(g)(5)(i) 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.
ASME Standard is - ASME B30.11-1.9.5(a) The electrical supply to runway or monorail conductors shall be controlled by a switch or circuit breaker located on a fixed structure, accessible from the floor, with provision for being locked in the open position.
Our electrical contractors' interpretation - The state of WI says where disconnects are required for equipment, they must be within sight and within 50’ of the load they serve. Cord and plug connections are an acceptable means to complete this task. I’m thinking you meet the requirements. An additional safety step would be to put the jib on a lockable disconnect but since the plug can be physically separated from the outlet this would not be required.
When asked for their reason for failure, the crane service said they are applying our installations to the OSHA/ASME standards shown above. My "not an electrician" interpretation of the OSHA & ASME standards are they could be interpreted as applying to a bridge or monorail crane with open conductor bars, which we do not have, that cannot be used with a cord/plug where the hoist can be used to disconnect power & lock out the hoist.
I appreciate your feedback and clarity.
