Frequently Asked Questions

Helpful answers to frequently Asked Questions from the Overhead Material Handling experts at OMH. Check back frequently for added useful information. Click “Contact Us”. We can answer your question.

QUESTION
We always recommend 4 bar electrification, especially when inverters are used. Is there an official NEC position?

ANSWER
NEC Section 610.61 was revised in the 2005 edition to no longer permit trolley and bridge frames to be considered electrically grounded through the trolley and bridge wheels to their respective tracks. This was allowed in the past. A separate grounding conductor must be provided for new installations. We are interpreting this to mean new systems. Existing 3 conductor 3 phase systems can be repaired, modified or even extended. Additional cranes can be added to an existing system using 3 conductors. When variable frequency drives are used, we insist on 4 conductors.

QUESTION
What are the OSHA required inspections for cranes and hoists in regular use and what is the frequency?

ANSWER
Section 1910.179 of the federal regulations (OSHA) section (j)(1) specifically states: Frequent Inspections-Daily to Monthly intervals and Periodic Inspections-1 to 12 month intervals. There are also some items that require inspections daily. In section (n) there are items that are requiring inspections daily. We are interpreting this to mean the following:

Each manufacturer has requirements for their equipment depending on the crane or hoist class and duty cycle.

At a minimum, crane operators are required to perform a non-documented inspection of a crane or hoist at the start of their crane shift. Also, each crane or hoist in regular use must be inspected once a month with a signed report in accordance with the frequent inspection requirements of section (j). Each crane or hoist in regular use must be inspected once a year with a signed report in accordance with the periodic inspection requirements of section (j).

This means eleven monthly and one annual inspection per crane per year as a minimum with signed reports. The operator is required to know how to perform the operational check and must be the one to do so. The manufacturer may require more inspections for your crane.

QUESTION
What are the OSHA required inspections for below the hook devices in regular use and when must a sling be taken out of service?

ANSWER
Section 1910.184 of the federal regulations (OSHA) section (e)(3)(i) specifically states: Periodic inspection of alloy steel chain slings at 12 month intervals and a signed report must be maintained in accordance with section (e)(3)(ii). In section (d) there is also a requirement for daily inspections. We are interpreting this to mean the following:

Any sling used in conjunction with other material handling equipment for the movement of material by hoisting, should be inspected daily before use and cannot be used in excess of the rated capacity of the weakest component.  The sling and all fastenings and attachments are to be inspected for damage or defects by a competent person designated by the employer. Section (a) clearly identifies types of slings to include alloy steel chain, wire rope, metal mesh, natural or synthetic fiber rope (conventional three strand construction) and synthetic web (nylon, polyester and polypropylene).

Though it is a requirement to permanently attach the size, grade, rated capacity and reach on each chain sling, OSHA details when to retire any type of sling identified in section (a): Slings with defective welds; increased length; cracked, spread or twisted hooks; deformation, deterioration or damage must be immediately removed from service. No sling assembly should be used without a legible rated capacity tag firmly affixed.