Arc Flash Analysis

[zog]

So they just need a smart lawyer to show that the Company or their Union did not provide proficcient training. On the other hand I don't understand how can such people be called 'electricians' in the first place.

The 70E doesnt say anything about electricians, however, I agree that this is stuff every electrician should be required to know, wish I knew how to make that happen.

 

[weressl]

That is my problem with these calculations when you are working at or very close to the service equipment. The worst case will always be far in excess of the 40 cal/cm^2 that appears to be the maximum that you can work with PPE. How can anyone put a label on equipment like this when they know that the information does not cover all cases of utility operations and may result in injury or death to the person who relied on the label information?

So what is your solution?

I mean we all know that life is dangerous.

We get in our cars every day and don't know if a drunken idiot will wipe us out on the way. Matter of fact I venture to say that fewer people get injured or die working on live electrical equipment than die in automobil crashes. I think that the difference is in order of magnitudes. The whole issue just seem to be blown WAAAAAAAAAAAAAAAY out of proportion.

Well built, maintained and properly installed and handled electrical gear will seldom, if ever will produce an arc flash.

 

[weressl]

The 70E doesnt say anything about electricians, however, I agree that this is stuff every electrician should be required to know, wish I knew how to make that happen.

OSHA: The definition of​

​

??qualified person?? in final ? 1910.399 reads as follows: ??One who has received training in and has demonstrated skills and knowledge in the construction and operation of the electric equipment and installations and the hazards involved."
​

Note 1 to the definition of ​

??qualified person:?? ​

Whether an employee is considered to be a ??qualified person?? will depend upon various circumstances in the workplace. For example, it is possible and, in fact, likely for an individual to be considered ??qualified?? with regard to certain equipment in the workplace, but ??unqualified?? as to other equipment. (See 1910.332(b)(3) for training requirements that specifically apply to
qualified persons.)
​

Note 2 to the definition of ​

??qualified person:?? ​

An employee who is undergoing onthe-job training and who, in the course of such training, has demonstrated an ability to perform duties safely at his or her level of training and who is under the direct supervision of a qualified person is considered to be a qualified person for the performance of those duties.​

NFPA 70 2008:
Qualified Person. One who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved.
​

FPN: Refer to NFPA 70E​

?-2004, Standard for ElectricalSafety in the Workplace, for electrical safety trainingrequirements.​

 

[don_resqcapt19]

So what is your solution?
Well built, maintained and properly installed and handled electrical gear will seldom, if ever will produce an arc flash.

I don't have a solution...not sure that there is one at this point in time. As far as the possibility of an arc flash incident, it is my opinion, that the most likely time for the incident to occur is when someone is working on it, and in many cases, not because of what the worker is doing at the time of the arc flash, but as a direct result of what a previous worker has done.

 

[jim dungar]

I don't have a solution...not sure that there is one at this point in time.

In the past year most of my local utilities have begun providing their "present" and design short circuit values. On a 480V service day-day changes in the utility system rarely change the AFIE at the service entrance equipment - 99%(?) of the time it is always beyond 40cal/cm? PPE.

I typically calculate AFIE based on the utility provided level, a more realistic level (i.e. based on the service transformer with an infinite bus), and sometimes one based on a very low value; my report combines these multiple scenarios into a single worst case value. for example: I just did a study where the utility gave me a realistic value at 34.5kV (the service voltage). In this case, I chose to run scenarios at 50%, 100%, and 200% of this value, in most cases the AFIE changed slightly but in no case (100+ buses) did the HRC change. Based on this I feel comfortable that my study results will be valid until there has been a significant utility system change. Is this the correct solution? I don't know but multiple scenarios are better than basing PPE on an improbable/impossible fault current.

 

[zog]

OSHA: The definition of​

​

??qualified person?? in final ? 1910.399 reads as follows: ??One who has received training in and has demonstrated skills and knowledge in the construction and operation of the electric equipment and installations and the hazards involved."
​

Note 1 to the definition of ​

??qualified person:?? ​

Whether an employee is considered to be a ??qualified person?? will depend upon various circumstances in the workplace. For example, it is possible and, in fact, likely for an individual to be considered ??qualified?? with regard to certain equipment in the workplace, but ??unqualified?? as to other equipment. (See 1910.332(b)(3) for training requirements that specifically apply to
qualified persons.)
​

Note 2 to the definition of ​

??qualified person:?? ​

An employee who is undergoing onthe-job training and who, in the course of such training, has demonstrated an ability to perform duties safely at his or her level of training and who is under the direct supervision of a qualified person is considered to be a qualified person for the performance of those duties.​

NFPA 70 2008:
Qualified Person. One who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved.
​

FPN: Refer to NFPA 70E​

?-2004, Standard for ElectricalSafety in the Workplace, for electrical safety trainingrequirements.​

I dont see the point you are trying to make here.

 

[weressl]

I dont see the point you are trying to make here.

Quote:
Originally Posted by zog
The 70E doesnt say anything about electricians, however, I agree that this is stuff every electrician should be required to know, wish I knew how to make that happen.


The point is that you said 70E doesn't say anything about electricians, both OSHA and NEC has clear definitions and clarifications on WHO is qualified to work on live electrical equipment. If one is unfamiliar with short circuit and coordination studies and their significance then one can not be considered qualified by virtue of not being able to recognize the hazard.

Let me give a simple example: it is not sufficient to recognize that it is an explosive, one has to know the difference between a firecracker and a frag handgrenade.

How to make it happen? Education, education, education.

 

[zog]

The point is that you said 70E doesn't say anything about electricians, both OSHA and NEC has clear definitions and clarifications on WHO is qualified to work on live electrical equipment. If one is unfamiliar with short circuit and coordination studies and their significance then one can not be considered qualified by virtue of not being able to recognize the hazard.

.

It dosent say anything about electricans, being an electrician (Having an electrical license) has nothing to do with being "qualified" per OSHA or the 70E. 99% of the licensed electricians out there dont know anything about short circuit or coodrination studies, it is not part of the job for them. Same goes for an engineer that knows everything about the studies but knows little about the construction and operation of the equipment.

The employee (70E and OSHA are both employer-employee based) must be specifically trained on the equipment they are required to operate and/or maintain, they might be an electrician but can be a maintenence person, powerhouse operator, or security gaurd that is required to shut down the plant lighting at night.

I have taught classes to all of these groups that were specifically designed for the tasks and equipment thier jobs required. I have done 70E training for IBEW electricians, engineers, utility linemen, and mechanics (MCA), heck I even developed a course for car mechanics for part of the Hybrid certification program. The engineers, maintenance people, and electricians all knew about the same percentage of the required knowledge to meet the 70E requirements of "Qualified", they all knew different parts, put all 3 groups together and would cover it all, but all groups had alot to learn.

Qualified is not all emcompassing, you can be considered qualified on one peice of equipment but not on another. It is much easier for someone at a plant or commercial building to get qualified than a service person that sees different equipment everyday. Thats why "canned, off the shelf" 70E training programs dont work.