Tag: NFPA 70

The Twenty Year Rule

The Twenty Year Rule

twenty year rule While conducting our overhead lifting safety training it never fails that we get a comment to the effect of,

We’ve been doing it this way for over twenty years. We never had an accident.  And, now you are telling me it’s wrong?”

Just because you have been lifting a certain way for the past twenty years and never had an accident only means that you have been lucky. When performing safety training we emphasize all the safety standards and regulations that are applicable. They all serve a purpose.

When performing safety training we emphasize all the safety standards and regulations that are applicable. They all serve a purpose.

ANSI/ASME B30 Safety Standards for overhead lifting began in 1916 as an eight page safety code – now 94 years old. Crane Manufacturers Association of America (CMAA) began as Electric Overhead Crane Institute (EOCI) in 1927 and published their first standard in 1948 –  62 years old. ANSI/NFPA 70, otherwise known as the National Electric Code began in 1897 – 113 years old. Article 610 of the NEC is specifically written for overhead cranes and hoists. For our friends north of the border, the CSA standard B167.08 began in 1964  – 46 years old. Finally, let us not forget OSHA, which began in 1970, making it 40 years old.  OSHA enforces two federal regulations for overhead lifting:  CFR 1910.179 for cranes and 1910.184 for slings. Between all these organizations and safety standards there is a total of 355 years of experience. 355 years trumps your 20 every time.

These organizations were not put together to make your life miserable.  You can’t take short cuts the way you have been doing the past twenty years.  These organizations include people that are involved in all facets of overhead lifting, including riggers and production and construction personnel that perform overhead lifting as part of their job.  They want you to be safe in your work habits and environment so that you can go home at the end of your shift or work day to your family.

This blog post was written by Larry Lynn, former Product Trainer for Columbus McKinnon Corporation.

Grounding of Overhead Crane Systems

Grounding of Overhead Crane Systems

Grounding of Overhead Crane Systems
Grounding is a critical part of a safe installation.

In 1995, the Bureau of Labor Statistics reported that electrocutions accounted for 6% of all worker deaths. The most common OSHA electrical violation is the improper grounding of equipment and circuitry. It routinely hits the top 25 in terms of OSHA citations.

Our customer service group periodically receives calls with questions concerning grounding requirements for overhead cranes. Over the years it has been customary to ground through the crane and trolley wheels, through the crane girders and runways to the building steel.

In the 2005 edition of ANSI/NFPA 70 National Electric Code grounding requirements changed.  Article 610, Cranes and Hoists, Section 610.61 Grounding clearly states, “The trolley frame and bridge frame shall not be considered electrically grounded through the bridge and trolley wheels and its respective tracks.  A separate bonding conductor shall be provided.” The terms “shall and shall not” make the fourth conductor for ground mandatory. It does not matter if the electrification is festoon cable or insulated conductor bar.

Question: “My hoist will be running on a jib or a monorail. Do I still have to run a ground?”

The simple answer is, “Yes!”  The scope of Section 610.1  is quite clear; it covers cranes, monorail hoists, hoists and all runways.  ANSI/ASME B30 Safety Standards define cranes for overhead hoists. In essence, if a hoist is supported by an overhead structure such as a monorail, jib, bridge, or gantry, it is a crane. Whether the crane is portable, like a roll around gantry, or a permanent installation, it is a crane and needs a separate conductor for ground.

Grounding is a critical part of a safe installation.  More and more cranes are equipped with electronics; remote controls, variable frequency, electronic monitoring devices, etc. These need grounding for their protection. Current follows the path of least resistance.  If a short to ground exists, do you want the crane operator to be the ground?  All it takes is one hand on the lower block and the circuit is complete.  Be safe, run the ground.

This blog post was written by Larry Lynn, former Product Trainer for Columbus McKinnon Corporation.