Burrito Q: Fastening of EMT

[cowboyjwc]

The picture from the handbook references IMC, not EMT. So it is non-compliant. So far the minority is correct....:grin:

Whew, at least I didn't have to point that out.:grin:

 

[mxslick]

In the handbook, it refers you back from the EMT article. Nice try.

So much for the handbook being a valid reference then...:grin:

Clear as mud!!

 

[George Stolz]

So much for the handbook being a valid reference then...:grin:

Clear as mud!!

Feel better?

 

[charlie b]

As I see it, the fact that if you try to apply "A" and "B" together it makes B entirely moot is proof that A & B are not to be used together.

I don't think "B" is saying that you only have to securely fasten near the boxes. Rather, "B" is saying that allowing the EMT to rest on the bottom of the holes in the wood is adequate to carry the weight. In addition, however, you still have to keep the EMT from moving around. You do that by using a clamp every 10 feet, no matter how many boards the EMT penetrates within that 10 feet. The clamp need not support the weight (i.e., it can be over the top of the EMT), but it does have to keep it from moving.

 

[mxslick]

Feel better?

Is that Handbook commentary or Code?

Isn't handbook commentary non-enforceable, and therefore not something that can trump a more restrictive Code article? :grin:

Maybe the burrito should be split. :grin:

 

[George Stolz]

Is that Handbook commentary or Code?

Isn't handbook commentary non-enforceable, and therefore not something that can trump a more restrictive Code article?

I'd say you've hit the nail on the head (and thus it is not code compliant until the section is fixed), but I'd hate to spoil folks' belief that I believe everything Bob says. It would probably cause an uproar on more than a couple forums.

 

[mxslick]

I'd say you've hit the nail on the head (and thus it is not code compliant until the section is fixed), but I'd hate to spoil folks' belief that I believe everything Bob says. It would probably cause an uproar on more than a couple forums.

Darn, now I've spoiled the outcome of the thread..maybe we should close it now. :grin:

LOL since when did anyone believe that you believe everything Bob says? :grin:

But I do love hearing out all the differing opinions on topics here, it is always educational and often quite fun.

 

[iwire]

I don't think "B" is saying that you only have to securely fasten near the boxes. Rather, "B" is saying that allowing the EMT to rest on the bottom of the holes in the wood is adequate to carry the weight. In addition, however, you still have to keep the EMT from moving around

Nope. :grin:

Consider this from the 2005 ROP.

8-133 Log #343 NEC-P08
(358-30(B))

Final Action: Reject

Submitter: Glenn W. Zieseniss Crown Point, IN

Recommendation:

Revise text to read:
(B) Horizontal runs of EMT supported by openings which horizontal opening is not larger than 3 times the nominal inside diameter of the raceway through framing members at intervals not exceeding 3 m (10 ft) and securely fastened within 900 mm (3 ft) of termination points shall be permitted.

Substantiation:

Some openings may be more than 10 feet in width. I have seen several installations where the raceways looked like snakes between termination points in the roof trusses. The 3 times the nominal ID of the raceway of the opening in the framing members would constrain the raceway to an appearance as required by NEC 110.12 (1st sentence). Workers installing other items or equipment can easily deflect the raceway either purposely or accidentally while doing their work. Painters or persons installing advertisements may disturb the electrical raceway position. The 3 times the nominal ID would allow some minor deflections of the raceway if the framing member openings are not in a straight line.

Panel Meeting Action: Reject

Panel Statement:

Refer to the panel action and statement on Proposal 8-17.

Number Eligible to Vote: 14

Ballot Results: Affirmative: 13

Ballot Not Returned: 1 Cox

IMO that clearly shows the CMP is aware that conduits laying on trusses do not have to be fastened every 10' and they see no real issue with it.


This is what the CMP says in 8-17

Panel Statement:
Insufficient technical substantiation has been provided to support the change.

 

[iwire]

Darn, now I've spoiled the outcome of the thread..maybe we should close it now.

I would not count on that. :grin:

since when did anyone believe that you believe everything Bob says? :grin:

You should believe. :grin:

 

[iwire]

And as I mentioned in my post above, the handbook calls out IMC, NOT EMT

I don't care about the handbook but the rules are the same.

so I would still say no way is this compliant.

You will have to take it up with the CMP.

 

[iwire]

Geez, I know times are tough, but would you really want to do an install like that ?

I did not see the 'how would acrwc10 like to see it done' option on the pole.

 

[cschmid]

wow I voted non compliant as it has no lateral support so it is not securely fastened in place..but all the code sections have been listed..teach me to vote before reading whole thing..wait I would still vote no..

 

[George Stolz]

IMO that clearly shows the CMP is aware that conduits laying on trusses do not have to be fastened every 10' and they see no real issue with it.

You could read that into it, or you could also surmise that they took issue with the specific dimensions the proposer specified.

 

[iwire]

You could read that into it, or you could also surmise that they took issue with the specific dimensions the proposer specified.

Huh?

If it was securely fastened it could not move regardless of the dimensions.

You absolutely do not have to apply A when B applies.

 

[Smart $]

I'm with Charlie - the "and" needs to be an "or" for the text to make sense.

It surely does not...

A is there for when the EMT is not run through framing members. That is why the AND is there too... because a single run of EMT between termination points could be both through framing members AND not.

 

[jusme123]

I see it the same way.

how are you getting past 358.30 ( 'AND' being the key word)

 

[roger]

So, when does the poll close George?

Roger

 

[George Stolz]

You could read that into it, or you could also surmise that they took issue with the specific dimensions the proposer specified.

Huh?

If it was securely fastened it could not move regardless of the dimensions.

You know, since the CMP didn't get struck by lightning when they wrote their response, they must have read the proposal in detail, examined it from several perspectives, discussed it at length, and chose their words with extreme care. Or, they didn't like the idea of opening a can of worms, so they issued their boilerplate response when a proposal doesn't give them a warm fuzzy feeling when they read it.

It's a leap to assume they gave the proposal a passing thought when "lack of technical specification" or "successfully for years" is issued in response. I've seen proposals where they just completely didn't understand the concept being questioned by the proposal - entirely.

So to point to that response as proof that...

You absolutely do not have to apply A when B applies.

Is a weak argument, IMO.

The problem is (A).

358.30(A) Securely Fastened. EMT shall be securely fastened in place at least every 3 m (10 ft). In addition, each EMT run between termination points shall be securely fastened within 900 mm (3 ft) of each outlet box, junction box, device box, cabinet, conduit body, or other tubing termination.
Exception No. 1: Fastening of unbroken lengths shall be permitted to be increased to a distance of 1.5 m (5 ft) where structural members do not readily permit fastening within 900 mm (3 ft).
Exception No. 2: For concealed work in finished buildings or prefinished wall panels where such securing is impracticable, unbroken lengths (without coupling) of EMT shall be permitted to be fished.
Exception No. 3: Horizontal runs of EMT supported by openings through framing members at intervals not greater than 3 m (10 ft) and securely fastened within 900 mm (3 ft) of termination points shall be permitted.

Whoops, I lied, that third exception doesn't exist. Therefore, (A) requires us to fasten a conduit every ten feet. Holes in 2x4's, web joists, or what have you have no bearing on this section.

I'm not saying that's what they intend, but the words aren't arranged correctly for what they seem to intend, IMO.

It surely does not...

And please...don't call me Shirley.

A is there for when the EMT is not run through framing members. That is why the AND is there too... because a single run of EMT between termination points could be both through framing members AND not.

You're saying that if the word were changed to "or" then we'd no longer have any direction as to how to install a conduit that happens to cover both instances in the same run?

So, when does the poll close George?

Probably breaktime tomorrow morning.

 

[Smart $]

...

You're saying that if the word were changed to "or" then we'd no longer have any direction as to how to install a conduit that happens to cover both instances in the same run?

...

No, I'm not saying that (openly ). All I"m saying is the use of and is grammatically proper if portions of a single run can be installed per "A" and "B", but not the same portion.

I agree rewriting "B" as an exception to "A" would be more concise if the intent is to support per "A" or "B".

 

[iwire]

You know, since the CMP didn't get struck by lightning when they wrote their response, they must have read the proposal in detail, examined it from several perspectives, discussed it at length, and chose their words with extreme care. Or, they didn't like the idea of opening a can of worms, so they issued their boilerplate response when a proposal doesn't give them a warm fuzzy feeling when they read it.

It's a leap to assume they gave the proposal a passing thought when "lack of technical specification" or "successfully for years" is issued in response. I've seen proposals where they just completely didn't understand the concept being questioned by the proposal - entirely.

George as witty as that was, :roll: the CMP is clearly acknowledging that under section B we do not have to secure the EMT.

You absolutely do not have to apply A when B applies.

Is a weak argument, IMO.

I will give you that,:grin: but the CMP statement is not.

Here is something from Mike Holt.

Q 3. When EMT is installed within metal studs and it is not resting on the bottom of the opening, is additional support required?

A 3. Horizontal runs of EMT is considered supported by openings through framing members where securely fastened within 3 ft of termination points [358.30(B)]. The key word here is "supported". If the raceway is not resting on the framing member, then it is not supported. This does not mean that the conduit must rest on every framing member. As long as it is resting on one framing member every 10' and it is securely fastened within 3' of the tubing termination points, the installation complies with the NEC.

http://www.mikeholt.com/mojonewsarchive/NECQ-HTML/HTML/NEC-Questions-013~20040709.php