ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
Increasing demand factors in residential
by gfretwell - 03/28/24 12:43 AM
Portable generator question
by Steve Miller - 03/19/24 08:50 PM
Do we need grounding?
by NORCAL - 03/19/24 05:11 PM
240V only in a home and NEC?
by dsk - 03/19/24 06:33 AM
Cordless Tools: The Obvious Question
by renosteinke - 03/14/24 08:05 PM
New in the Gallery:
This is a new one
This is a new one
by timmp, September 24
Few pics I found
Few pics I found
by timmp, August 15
Who's Online Now
1 members (Scott35), 266 guests, and 14 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 2 of 3 1 2 3
Joined: May 2002
Posts: 1,716
R
Member
Just exactly what (how much)did you edit?
Do you really think any one will buy all of these NFPA documents?
Even if you're a member and can access them free, who but an attorney (with their support staff) would try to research every standard you provided?

I simply ask that answers be practical and somewhat (I know this can be relevant)concise


Roger

Joined: Jan 2002
Posts: 119
S
Member
Dnkldorf
Thanks for the kind words. Let me take a stab at a “short” answer to your question about oxygen as an accelerant.
Quote
I somehow remember a fireman telling me one time that Oxygen was an accelerant. If this is true, wouldn't that in considerable amounts be enough to reclassify some divisions or areas to another?
Oxygen is not technically an "accelerant." An accelerant is:
Quote
A substance, such as a petroleum distillate, that is used as a catalyst, as in spreading an intentionally set fire.
Typically, the use of the word catalyst in the above definition refers to a source of fuel. Oxygen is not a fuel. However, oxygen is required for a fire to happen. In fire engineering there is a concept called the "fire tetrahedron." This concept is used to explain that for any fire to occur there must be four elements present: Fuel, Heat, Oxygen, and an uncontrolled chain reaction. If you can remove (or control the presence) of one of these four elements, a fire will not occur or will be extinguished. The firefighter was probably simplifying this for purposes of explanation.

An Oxidizer for the record is:
Quote
a chemical that initiates or promotes combustion in other materials, thereby causing fire either of itself or through the release of oxygen or other gases.
So… oxygen must have a source of fuel to initiate or promote a fire. If there is a sufficient fuel source present or expected to be present then yes, it would be prudent to possibly classify the area. You have to have an adequate level of fuel present not just “some” fuel.

Ahh but my post is getting long again! [Linked Image] Which brings me to Roger’s comments.

Roger
Quote
Just exactly what (how much)did you edit?
Not much, but, when you are trying to type everything in the teeny tiny box, it gets confusing. After posting and rereading, I decided the add everything starting with the BTW near the end of the post.
Sorry, I honestly didn’t expect the post to go on… and on… and on. It just kinda’ snowballed, hey it is winter here in the great state of OHIO. [Linked Image]
Quote
Do you really think any one will buy all of these NFPA documents?
I guess I was trying to make a point by including all of the document titles. I would expect an Electrical Engineer or other “design professional” to research the appropriate document. Since many (but not all) of people that visit this site are Electrical Contractors, I would expect that if you are doing design work… then yes… I would expect you to get the document… review it… apply it. If you are only working off of someone else’s specs or prints… heck, let them pay for the documents and the time doing the research.
Quote
Even if you're a member and can access them free...
Sorry, but, just being a member doesn’t get you “free” access to the standards.
However, members do get “free” access to the on-line version of the NEC. [Linked Image]

Edited to correct two code errors.

[This message has been edited by safetygem (edited 01-29-2005).]

Joined: Jan 2004
Posts: 615
J
Member
Quote
Do you really think any one will buy all of these NFPA documents?
Even if you're a member and can access them free, who but an attorney (with their support staff) would try to research every standard you provided?
I simply ask that answers be practical and somewhat (I know this can be relevant)concise

After reading such a fine response from safteygem, I was a bit surprised to see that response, let alone from a moderator. Maybe it was meant differently.

I think the point that was well made is that the EE is considering alot more things that just the NEC when he/she specifies something, and that's why they are a critical part of the process. Makes me glad I don't have to research it, and now I know the extent to which I am relieved.

Joined: Jan 2005
Posts: 316
L
Member
Thanks for the great responses as to the oxygen question ! I have talked with the owners of the building ( state of maryland prison system ) , the general contractor, and am awaiting a reply from AHJ, and we are going with the engineers thought and if it needs correcting it will be on his time.
Safetygem - the room is in a new building at a maximum security female prison, it is located off a corridor the seperates medical/dental and security.
As to flex (FMC) into transformers - can't find anything about this in NEC so I'm keeping it the way I feel is best ( AHJ has approved this method )

Joined: May 2002
Posts: 1,716
R
Member
Jps, I think you may indeed have taken it wrong.

But since we're here let me ask you this, would you take the time (I know you said you're glad you don't have to) to research all these standards for one specific item? [Linked Image]

Now for my comment to the engineers request.

If he had not specifically called out for a method in his spec and only mentioned "Per the NEC and all applicable codes" in the opening of his spec, I would ask for a change order to provide anything above and beyond them.

Now, if this oxygen storage area has been deemed as a non classified room by an Architect under an AIA design, and the engineer based his design around it, all is probably fine.

I don't know about Luckyshadow's location, but in my area plan review would have questioned it also.

Roger



[This message has been edited by Roger (edited 01-30-2005).]

Joined: Jan 2005
Posts: 5,445
Likes: 2
Cat Servant
Member
Lucky,
You may truly be "lucky" as to the transformer question.
I also learned, and as a habit also, to connect transtormers to conduit with some form of "flex." This was clearly taugh to me, when I was an apprentice, as a "trade practice," and not a code requirement.
Yet I have noticed, on the last few transformers I've installed, that the instructions referred to loosening some internal bolts...seems that the coils are mounted on rubber pads, that are compressed for shipment! So the flex is probably redundant.

It is that transformer comment of the engineer's that helped me decide that he has NO trade experience, is out of his depth, and needs to be reined in. I just don't believe the engineer is qualified! (Having three years, including time at one of the "premier" schools, I know all too well that engineers, including "electrical engineers," graduate without having the slightest educations in matters electrical!)
Not to denigrate engineers, but their trade is quite different that that of an electrician (just as a 'mechanical engineer' doesn't learn squat about fixing cars).

Joined: Jan 2004
Posts: 615
J
Member
No Rodger, I wouldn’t take the time nor would I think it was part of my job description as an electrician. Had I thought that was what he was suggesting by the post, I suppose I too would have felt the response was impractical. I appreciate the list, however, as an example of the breadth and depth of issues involved in just determining how to properly classify an area. As an EC, even though I may have a slight edge on the EE in NEC, it’s a little humbling to see how much I don’t know about the given situation. There is a lot more to consider than just NEC, and now I know how much more.

Joined: Jun 2003
Posts: 1,143
D
Member
FYI, many public libraries and most Fire Departments have current copies of the various NFPA codes, and (the FD's at least) will be happy to let you review them during "business hours" ie 0800-1900.

Just my $0.02

Joined: Feb 2004
Posts: 494
M
Member
Hi,
I think he may be confusing that Grounding bushings are required on concentric/eccentric knockouts when used on a SERVICE.

I will have to dig up the article but I know a lot of inspectors who will not pass an inspection for this.

Look at 250.92 (B) last paragraphs.

I will see if I can find the reference in Stallcups Designing Electrical systems and the code...I know I saw that somewhere.

As far as the oxygen question, just consider this...how many places is oxygen bottles used? HUNDREDS IF NOT THOUSANDS. They are in bedrooms, cars, planes, trains, submarines, etc. Are there any classified equipment installed there?

Anytime this situation comes up just get up with the engineer with a code book in your hand. Say to him...” I was looking in my code book to see if I could find the reference you were making and was not able to find it...would you mind showing me where it is or getting me the article so I will know for future reference?"...

As far as flex to a transformer...that is first year apprentice stuff. Flex is used to feed small transformers for a couple reasons, one is to makes it easier to connect, disconnect, replace etc. I am not so sure I buy into the vibration theory. The transformer itself will be constructed of regular nuts and bolts for the most part.

Hard piping in a transformer is okay when you’re talking a big transformer but for a small one flex is the only way to go. If flex was not legal for connecting motors and transformers anymore it would have been heard like a shot around the world! Just think of the millions of connections that are already out there!

Just my 2 cents worth of bytes.

Regards

Greg

Common sense prevails a lot of times, not to knock any of the other responses.

There are specific ways to determine a classified location and NFPA 30 is a good place to start.

Regards

Greg


[This message has been edited by mustangelectric (edited 02-05-2005).]

Joined: Feb 2002
Posts: 375
G
Member
luckyshadow ---

Oxygen is one of the most dangerous substances about.

Self-exstinguishing materials will burn or explode in just several pounds of additional oxygen pressure.

It is not my project so I will let you do what you wish.

Page 2 of 3 1 2 3

Link Copied to Clipboard
Powered by UBB.threads™ PHP Forum Software 7.7.5