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 Post subject: Article 130.2 Electrically Safe Working Conditions - Exception
PostPosted: Fri Mar 23, 2012 1:42 pm 

Joined: Wed Nov 10, 2010 5:26 pm
Posts: 5
In the 2012 edition of 70E, there is an exception noted near the start of Article 130.2 that reads:

"Where a disconnecting means or isolating element that has been properly installed and maintained is operated, opened, closed, removed, or inserted to achieve an electrically safe work condition for connected equipment or to return connected equipment to service that has been placed in an electrically safe work condition, the equipment supplying the disconnecting means or isolating element shall not be required to be placed in an electrically safe work condition provided a risk assessment is performed and does not identify unacceptable risks for the task."

This is confusing to me. It's not a FPN or Informational Note but an exception to the rule. Does anyone know why this was added or what it means?

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PostPosted: Fri Mar 23, 2012 4:20 pm 
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1. It is absolutely the poorest written paragraph I've seen. At best, it is confusing.

2. In the 2009 70E, in Article 110, there was a set of rules that essentially either referred you to Article 120 (electrical LOTO) for safe working conditions, or to Article 130 for energizing work. The trouble is that a lot of the hazard analysis procedures and other applicable material was located in various subsections of Article 130. So the 70E Committee in the 2012 edition decided to move the material from Article 110 into 130.

Now the problem this creates is that previously when creating a safe working condition, you follow Article 120. You don't need an EEWP and you are not restricted in any way from testing for absence of voltage because Article 130 does not apply. However, you still had to do the hazard analysis which led to some confusion.

It is my understanding that in order to clear this up, the 70E Committee migrated everything into Article 130. Now this created a "circular logic" problem because in order to achieve a safe working condition, you had to work on energized equipment (the energized side of the disconnect). In addition, it would be stupid to fill out an EEWP every time you did an electrical LOTO in order to achieve a safe working condition....creating a situation where the purpose of the EEWP process (an administrative control to limit exposures) ceases to function.

So the way that I have chosen to interpret the exception is that it applies when achieving a safe working condition and returning from that condition. In effect, it creates another exception. Technically it's not really an exception because this certainly qualifies as "infeasibility" can't keep infinitely looping through moving upstream. Second, by placing the exception in the beginning of the section, and since 70E is written from "general to specific", it also implies that an EEWP is not needed every single time you perform LOTO.

Frankly, one or two clauses can easily be deleted out of that paragraph and it cleans it up, makes it much more clear, and doesn't change the meaning at all.

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PostPosted: Mon Mar 26, 2012 5:54 pm 
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I think this passage is to eliminate a bit of circular logic, best explained by an example.

You need to work on an MCC bucket, so you open the switchgear breaker that supplies the MCC. Only now you can't close the switchgear breaker as its on an energized bus. So you go upstreem and open the main distribution breaker supplying the switchgear. Only you can't close that breaker so you go upstream to the medium voltage gear supplying that breaker distribution gear. Only you can't close the medium \voltage gear, so you go to the utility substation and shutdown half the town. It goes on and on, until eventually you have to throw a breaker on an energized bus. The difference here is one of 'greater hazard', because as you work up you will be typically moving to higher IE levels, although this is not always true. That at least, is what I take from it. You can close the switch you used to isolate the work without having to move further upstream.

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