Arc Flash and Safety suggestions

As per OSHA and NFPA, the best practice to reduce the arc flash hazard is DE-energization of electrical equipment, but still, there are some possibilities of arc flash even equipment is de-energized, these possibilities are

?   Mislabeling of shut off equipment

?   Contacts of the switch not properly or completely open

Now just think we proposed that switching off any electrical equipment is the best way to say the worker, but do you realize that what about the worker who is going to off the switch, is he or she not exposed to arc flash hazard? At that time may be worst arc flash occur and result in at the site worker causality or injury!

In our region, unfortunately, the incidents rates are not available or ambiguous, so let see what is the incident rates in most developed country of world, in America as per OSHA during 1992 to 1998 there were over 12,500 arc flash incidents with one or more injuries, now on the basis of these records the NFPA and OSHA advised remedies to secure worker from arc flash, these are

?   Proper knowledge of work, the worker must have the expertise to handle a job and must have a knowledge of all involved hazard in an assigned job

?   Proper PPE, but remember PPE is the last line of defense, PPE is only for damage control

Now just review IEEE Paper by D.R. Doan, H.L. Floyd, and T.E. Neal, “Comparison of methods for selecting personal protective equipment for arc flash hazards”, IEEE Transactions on Industry Applications”, The typical ratio of arc flash incidents with the potential for injury to OSHA recordable injuries is 1 in 200. That is, for every 200 OSHA recordable injuries, companies can expect one arc flash incident with a potential for injury. It is a good policy to understand the safety record and statistics of any company you visit; this will help you understand what to watch for to keep yourself safe.

As per my own data, during my years of service in one utility, I found more than 2000 minor major accidents in about 7 years, what is the action against the involved employees? They were fired from the jobs, although most of them were doing their jobs without any safety training(our past management transferred some experience employees to new department of safety, they were without any basic safety training, most of them were surplus employees, and what they did, they simply used their powers as threats to other departments employees), when asked why you did this mistake, most of them replied they had no such issues or problems in past, and they thought it because they had never trained for damaging effects of equipment aging.

This is our story but just see D.R. Doan and R.A. Sweigart, “A Summary of Arc Flash Hazard Calculations”, IEEE Transactions on Industry Applications, Volume 39, Issue 4, July-Aug. 2003, Page(s):1200 – 1204, in this paper Author summarized the results from arc flash hazard assessments at 33 industrial sites for a large chemical company. Nearly 10,000 pieces of equipment were studied, and the distribution of arc flash incident energy values at different levels is shown in Figure given below, For any arc flash hazard over 1.2 calories per square centimeter (cal/sqcm)(just imagine impact of 40 cal/sqcm, which occurs averagely in arc flash), flame-resistant (FR) clothing is required by OSHA and NFPA70E. An incident energy value of 1.2 cal/sqcm is the point where the skin of the worker would have the onset of a second-degree burn and would require medical attention. One cal/sqcm is roughly equivalent to holding the tip of the finger in a lighter flame for one second.

If the typical exposures for normal industrial work are taken into account, the estimated exposures of workers to these hazards has a different distribution that is shown in Figure given above is because workers are more likely to be switching or troubleshooting the lower energy equipment, such as motor control centers or panelboards. Higher energy equipment is switched less frequently. About 2% of the exposures are over 40 cal/sqcm.

Decision makers or players and responsibilities or actions?

?   Government bodies, due to our bureaucratic structure it is not possible that they can develop such actions, that is why I put a government body in action category, they can instruct their departments to adopt Safety Suggestion

?   Consultants, again here we need to see the economics, we cannot employee western companies as they are expansive, but we have a large number of Pakistan based safety experts working in gulf, and gulf have one of the best safety training structure, government body can hire these consultants for the training and consult purposes, the standards of IEEE, OSHA, NFPA, UKAS, IEC etc. are not such easily understandable and they are most of the time specifying only upper layer of knowledge , the consultant helps industries by defining and implementing the basic purpose of the standards.

?   Industrial Sector, there we have such a problem, in most of the industries the safety culture is only for the purpose of promotion of brand, executive of such industries for the sake of safety hire some officers and designed departments, but most of the time compromise the safety on profit, as at the end of the day their performance is measured with respect to the annual profit and income, in gulf they have classical model of LTI free years, they announced incentives for the best performers in the safety field, Government bodies can endorse safety violation fees at the time of license renewal or license issuance. 

?   PEC and Pakistan building corporation or association, they both are key players in terms of technical assistance, both bodies can help Government body in the development of approved consultant list which can be helpful in implementation and training purposes.

More players and action we defined here, but still, a lot of other ingredients need to be added here, but before that basic action defined above we need to adopt.