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Posted By: Ron NEC 645 Might Not be for You - 12/21/05 02:01 AM
Link to an interesting article. At least I think so. http://www.csemag.com/article/CA6290839.html
Posted By: dereckbc Re: NEC 645 Might Not be for You - 12/23/05 03:43 AM
I hear that Shapiro guy is a real jerk. :> )
Posted By: Trumpy Re: NEC 645 Might Not be for You - 12/23/05 09:10 AM
Hey!, that's not very nice.
Posted By: Ron Re: NEC 645 Might Not be for You - 12/23/05 01:12 PM
Right back at ya [Linked Image]
Trumpy, When you know where it's coming from, it makes it all alright [Linked Image]

[This message has been edited by Ron (edited 12-23-2005).]
Posted By: Bill Addiss Re: NEC 645 Might Not be for You - 12/23/05 02:23 PM
Thanks Ron!

[Linked Image]
Bill
Posted By: dereckbc Re: NEC 645 Might Not be for You - 12/23/05 06:51 PM
Trumpy relax. That Shapiro guy and I know each other and it was an inside joke between friends. :LOL:
Posted By: jwhite Re: NEC 645 Might Not be for You - 12/23/05 07:10 PM
Where does the author of that article get off saying that only articles 1-4 of the nec are required.

This one statement alone makes me doubt his credibility.
Posted By: Ron Re: NEC 645 Might Not be for You - 12/23/05 08:11 PM
Per 90.3, Chapters 1-4 apply generally to all electrical installations. That makes it mandatory. Chapters 5-8 do not generally apply, and only supplement or modify Chapters 1-4. Chapters 5-8 only apply when that application or equipment arise, so Chapters 5-8 are not mandatory for every situation, only those that they apply.

The statement was in context of the article, to reflect the idea of an optional Article 645.

The entire quote is "First, only chapters 1 through 4 of the NEC are mandatory. Secondly, chapters 5, 6 and 7 apply to special occupancies, special equipment or other special conditions. These chapters describe applications in which certain additional requirements are necessary or in which certain exceptions can be made to the requirements of the previous four chapters."
I think when taken in context of the entire text of the article, the statement is OK.
Posted By: jwhite Re: NEC 645 Might Not be for You - 12/23/05 09:06 PM
I disagree ron,
that should have been better worded. it is very misleading and my be quoted in other than computer room cases.
Posted By: Trumpy Re: NEC 645 Might Not be for You - 12/23/05 09:28 PM
Not a problem at all, dereckbc.
[Linked Image]
That first post of yours certainly made me look twice at the time!. [Linked Image]
Posted By: dereckbc Re: NEC 645 Might Not be for You - 12/23/05 09:42 PM
jwhite maybe a better question is why or when should 645 be applied. IMO it never has to be applied unless one chooses too. I design data and telephone switching centers, and I would never freely choose to apply 645.

[This message has been edited by dereckbc (edited 12-23-2005).]
Posted By: e57 Re: NEC 645 Might Not be for You - 12/24/05 01:14 AM
SF Fire Marshals seem to like 645, EPO's on UPS batteries have become a pet peev. I guess they had a UPS fire a while back with no method of shut off.
Posted By: Ron Re: NEC 645 Might Not be for You - 12/24/05 02:00 AM
If the leniencies in 645 are not being used, I'd be interested to find out what code the SF fire marshal's are using to require an EPO. Maybe it is a local amendment.
Posted By: e57 Re: NEC 645 Might Not be for You - 12/24/05 08:42 AM
For them, I think they just want a visably marked means of shut off of the load. As they show up to a fire, (assuming here, there a few fire-fighters here who could elaborate) one of the first things they do is shut off power in the building, or portions of it. But all of the things on the UPS stay energized... Last set up was a 30kw 208v APC UPS, and lighting inverter (forget what that one was) but also 208v. Fire inspection went like this, "smoke detector, batteries - how do I shut off every electrical source in this room?" Thier sign off holds up occupancy... For a simple class 2 circuit, not worth it. Like I said, fire marshal, not electrical inspector. And, from what I understand, they had a fire in a room and could not shut off power after the batteries, and this is a result of a big pow-wow about it.

(Side note: they often want horn/stobes moved for reasons like this... "If I were sitting at this desk, I would only be able to see half of that strobe." Like the 110 db horn, and the rest of the building in disco lighting is not a clue to lean back a little, and realize the fire alarm in going off. - And, "I realize that is an exit path, but feel that way is a better way out, you'll need to change the arrows to that direction." Special order arrow specific signs, and change all the escape route signage. If they have to come back, they'll start changing more stuff. Or find yourself there predawn with a lumen meter. Its best to get them out of your hair quick.)
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