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| Grade the 2015 Edition of NFPA 70E https://brainfiller.com/arcflashforum/viewtopic.php?f=33&t=3775 |
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| Author: | Jim Phillips (brainfiller) [ Sun Aug 23, 2015 5:25 pm ] |
| Post subject: | Grade the 2015 Edition of NFPA 70E |
NFPA 70E continually improves with each edition. The 2018 Edition is well underway and many committee volunteers are involved to make it all happen. Most of the time, a new edition will have changes that clarify existing language, introduce new requirements, or perhaps reorganize sections - all to continually improve this important standard. However sometimes, changes and new or revised language might leave a person scratching their head. Since the school season is beginning, we'll use the academic grading scale. A, B, C, D, F. What grade would you give the 2015 Edition of NFPA 70E? A = Highest Grade and F = Lowest Grade |
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| Author: | jcp@pfeiffereng.com [ Tue Aug 25, 2015 1:54 pm ] |
| Post subject: | Re: Grade the 2015 Edition of NFPA 70E |
1. Dropping category 0 - 1n effect category 0 and 1 have been combined for my studies. I used category 0 labels often for nothing more that to mark that a give panel, etc. has been included in the study. Under most situations it is easy to see that anything downstream of a point in the model will be always category 0. But this isn't always true. For instance when you have a large motor downstream of an MCC and the motor is 100 hp or more, out say 500 feet, you many find that the disconnect switch at the motor has a high incident energy level. I have found this in a chemical plant. 2. Setting up two separate label formats, one for use when you develop the computer model and calculate incident energy and the other format when you use the table method. I personally prefer to have both the category and the incident energy level on the same label. I have been teaching arc flash for about 15 years and now I have to rework my training to explain his change. No mater what I say it will cause confusion with some maintenance people. It's been hard enough to get the arc flash training to stick with some individuals and how I will have to through in a new wrinkle. This change provides no safety benefit, only confusion. 3. 70E seems to keep moving closer and closer to stating that the table method is equal to the calculation method. I'm reviewing one new table method listed on this site a few months ago and so far it looks good. But my workload had not allowed me to finish the review. I have also sent to several people an example where the 70E table method failed badly. |
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