What is the best way to get started?

I am an electrical engineer who works for an OEM who produces industrial machinery. I have been asked to research Arc Flash calculations and what we need to do for NFPA70E compliance for our manufacturing plant. Is there a formal training format that reviews the data necessary to collect on the single line schematic of our plant, what information is essential before beginning calculations, and how to perforrm the calculations correctly?

From the sound of your question, it would seem you plan on doing the study yourself. First ask yourself if your prior training is up to the task. Like coordination and short circuit studys, it's not just numbers and equations in the end but also some understanding of electrical system design. If you're up to the task, then the collection of data to perform the study is the hardest part of the job, particularly in an older plant. You'll need cable sizes, lengths, breaker settings, relay settings, etc. before you begin the study.

It's good to know how to do the equations by hand and understand what they are doing, but for a system of any size you may want to consider purchasing software. The other advantage of this is once the model of the system is complete in the software, you can use it for relay coordination, short circuit, and many other studies. Each time you make a change to the electrical system, the new study is just a minor revision to the one line in the model.

If you decide to do the software route, most companies provide some basic training on how to use the software in a study including answering the questions you ask. I know EasyPower does this and I suspect the others do as well. You can go to the EasyPower web site for more info on this. Good Luck with your study - they can provide some interesting discoveries about your electrical system.

TxEngr

I read the articles.... Thank you. I also realized as I was reading you are also the author and have an extensive background. It mentioned in the first article that you are a training instructor. I will check out your website for training programs. Do you have any formal recommendations for software or are you in a position that you need to remain nuetral? After reading the articles and thinking about the time frame upper management is "thinking" this task should take, I do believe I need to manage the expectations here also. Thank you.

TxEngr:
Thank you for your information. You are correct, the intention is to be trained so that I can perform the calculations and also help direct our other manufacturing facilities in getting ready for their analysis. Have you personally used the EasyPower software? I would like to understand the calculations so manually running calculations are intended but I also see the benefit of using software for future plant changes and knowing the calculations may need to be updated as addition and changes take place. I will check out the EasyPower web site to see what they offer. Thank you again.

AA -

Yes, I personally use EasyPower software. This is my second industrial facility where I've used it. I'm currently completing the study for our plant which has 70+ medium voltage breakers, 120+ low voltage power circuit breakers with more than 50 MCCs. The last plant was about three times this size but we had several engineers working on the study. I agree with learning about the equations, but to do a facility with much equipment could become tedious. Also, if you're going to carry this to other plants, it's going to take up much of your time. In that case, I would definitly buy some software. Each package has it's advantages and I'm sure some of the folks here can give their opinion. I personally like EasyPower for it's user interface and ease of use. But my reference point is the SKM software back in the DOS days and their software has changed dramatically since then in terms of ease of use. Good luck with your study and you've found a great resource at this forum. I know I've learned a lot since coming here.

TxEngr

AA?,

Your task is to get in compliance with 70E, so the very first thing to do is get the standard, obviously. But the reason I bring this up is that there's allot of work to do with matters other than the Arc-Flash calcs in order to get 70E complaint. In fact, you can get compliant without ever doing an analysis by following the "tables" alternative method for PPE requirements shown in 70E. Not that I recommend that at all, but it goes a long way towards a quick-fix.


As far as doing the calculations yourself, if you're capable, interested and qualified, have at it! It's an exciting career choice. But it's really just that, a career choice. You'll need to get very involved in the analysis in order to be technically correct. And you must be correct.... imagine being on a witness stand defending your calculation of HRC 2 over HRC 3 in an Arc-Flash incident.

My software of choice is SKM, having used it for 17 years. We have SKM and EasyPower at work.. some prefer EasyPower. Having as much experience with SKM as I do, I can attest that if you set out to do the analysis, SKM software and Tech support will give you the confidence needed to present technically-correct information.

John M

I worked with our corporation to purchase ESA's Easypower software unlimited buses with a corporate license for 2 seats at a time and installed the license on our network.

I had one of the largest one-lines ever seen by most. ESA did some debugging because of my structured layout and quantity of buses or impedance points that was modeled. The software works out great for our company.

I encourage you to attend the week training ESA offers. I worked with the software for a couple of years before taking the training. I still learned a lot of tricks to the trade during the training.