tyraps as emt support

[mdshunk]

To me, 'securely fanstened in place' means it ain't gonna move. You don't get that with a cable tie, or rebar tie wire.

You also don't get that with many of Caddy's products, which you have not decried. The zip ties are way more secure than this Caddy hanger, for instance:

What about bat wings? They move around a lot too.

 

[crossman]

It has been said a few times already, but the way I read 358.30(B), and considering the pipe runs which are over 3 feet from the boxes, actually putting tie-wraps on the pipes IS gold-plating the job.

 

[ultramegabob]

Is Velcro permitted?

db

I am straying away from conduit for a second, but velcro is often used to secure powerpoles to the floor in commercial spaces, it comes packed with the powerpole...

 

[iwire]

I'm not sure I agree that cable ties ARE permitted.

Thats OK, the inspectors in my area think differently.

Given the absence of any NEC definitions for either 'supported' or 'securely fastened in place', we seem to be forced to adhere to the whims of the inspector.

Have you read the code sections under discussion or are you shooting from the hip?

In many cases conduit only has to be supported, that is done by the truss.

Securing the conduit needs to be done within 3' of the boxes. How it is secured is definitely up to the inspector.

This forum seems to be evenly divided between thinking inspectors are either saints or morons.

Some are either, no different then ECs.

Just because the code doesn't say you can't do it, does not necessarily imply approval.

Actually it does mean that, it is a permissive code.

The code also does not say you can't poke somebody in the eye with a sharp stick.

Outside the scope of the NEC.

To me, 'securely fanstened in place' means it ain't gonna move. You don't get that with a cable tie, or rebar tie wire.

Your right, that is what it means to you.

I think most of this 8-page thread was devoted to admonishing FLEX for speaking his mind.

I don't think you read it with an open mind, like Flex you feel this is crap and we all should stop saying it's OK.

Is Velcro permitted?

It is not prohibited.

 

[barclayd]

What about bat wings? They move around a lot too.

Sure, there are a lot of ways to hang stuff, like from ceiling wires, but where do you draw the line? Would a piece of #12 copper wrapped around once and twisted twice work? #14? A piece of poly pull string? There's got to be a limit somewhere.

Part of me wants to say "The NEC should define 'Securely Fastened in Place'." But that's REALLY scarey.

db

 

[mdshunk]

There's got to be a limit somewhere.

There is, and those of us interested in enhancing our bottom lines constantly explore those limits.

I'm not a psychic, but I think I can safely say you're an employee. No?

 

[iwire]

Part of me wants to say "The NEC should define 'Securely Fastened in Place'." But that's REALLY scarey.

db, the places I have used tie wraps to secure EMT have been in the webs of steel trusses 18' to 45' off the floor even if the tie warp breaks the truss still supports the EMT.

No one is up there to grab the EMT and move it, the only thing that may hit these EMTs are forklifts and in that case tie wrap or a two hole clip nut and bolted to the truss it will not matter the EMT will be damaged.

To me each job gets it's own methods, would I tie wrap EMT on to the wall of a hallway? Heck no.

Will I tie wrap an EMT to a truss 20' above the floor and above a dropped ceiling, yes I might depending on the job.

 

[barclayd]

To iwire
Of course the AHJ can allow cable ties. I'm curious to what else they allow - wire? string? rubber bands? Where do they draw the line, Bob? and what criteria do they use?

Yes, I am familiar with 358, and know the difference between supported and secured - (even though they're not defined.)

You say, here and in other threads, that the NEC is a 'permissive' code - that if it is not prohibited, then it is permitted. Do you have a Code Reference for that? I honestly can't find it.

I don't think I would call it 'crap', more like 'marginal quality', but then I'm much more eloquent than FLEX.

db

 

[nakulak]

Since the ahj has the ultimate say (assuming no court dates are involved), it is at some point up to the inspectors to dispense with contractors who lack common sense or try to skate on thin ice. It is clearly the intent (and conspicously stated) of the code to NOT be a design manual. Its clear that part of the reason for that is that it is so hard to simply write a working code for what it intends to cover. So at some point either the engineer on record (by virtue of the specifications for the job), the architect, the electrical contractor, or the inspector must decide what will work and what won't. Hopefully the electrical contractor, being a responsible master and tradesman, will determine a suitable attachment method prior to or during installation of the product, or if necessary obtain the information necessary from a reliable source, or consult with the professionals on the job, or even the ahj.

What is a suitable attachment method and what is not will continue to change from year to year, and from jurisdiction to jurisdiction, and with new technologies that evolve. So it is a common sense approach to electrical installations to forego the notion that every nut, bolt and wire must be specified by the code, and imshio its a good thing.

 

[iwire]

To iwire
Of course the AHJ can allow cable ties. I'm curious to what else they allow - wire? string? rubber bands? Where do they draw the line, Bob? and what criteria do they use?

They draw the line where it makes sense for the job at hand.

How I have secure a conduit on the wall of high school gym is much different then how I have to secure a conduits up in the trusses 30' above.

One is without question going to be subject to damage and the other will sit up on the truss collecting dust.

Yes, I am familiar with 358, and know the difference between supported and secured - (even though they're not defined.)

Here is an earlier post by Rob, do you happen to have a handbook?

Although it's not code, the authors of the NECH would agree that they are indeed framing members. This is supported by exhibit 344.2 for RMC which references 344.30(B)(4) and has the exact same verbiage as support for EMT, 358.80(B)

You say, here and in other threads, that the NEC is a 'permissive' code - that if it is not prohibited, then it is permitted. Do you have a Code Reference for that? I honestly can't find it

.

Think about that, there is no other way it can work.

I don't think I would call it 'crap', more like 'marginal quality', but then I'm much more eloquent than FLEX.

I have done it and I would call low / poor quality. But again for cheap customers I have no problem with that.

Keep in mind this is primarily a code forum, we discuss what the code really says and does not say. By doing that we all learn the actual requirements. IMO it is just as important to know the code minimums as to knowing how to do top quality work.

 

[barclayd]

There is, and those of us interested in enhancing our bottom lines constantly explore those limits.

I'm not a psychic, but I think I can safely say you're an employee. No?

Actually, I'm a highly respected (I made that up) Engineer. The bottom line thing is somewhat related to (dare I say it) VALUE ENGINEERING. (ouch).
I look for ways to cut costs, too. I prefer Heavy Duty safety switches, but would I allow General Duty. uhhhh I guess so.

Would I allow cable ties 20 feet up? I don't think so. I have never specifically designed to allow using the bar-joist V's to support conduits - and I've never realized I would have to prohibit it. (if I was in Massachusetts) (which I'm not)

db

 

[barclayd]

Hey, I gotta go - I have an appiontment with my therapist.
The only reason I joined this discussion was to make senior member.
Just did it.
See you all tomorrow.

db

 

[roger]

Would I allow cable ties 20 feet up? I don't think so. I have never specifically designed to allow using the bar-joist V's to support conduits - and I've never realized I would have to prohibit it. (if I was in Massachusetts) (which I'm not)

db

Well, you'd have to specifically prohibit it in your specs in NC too.

I have a question though, why is it that you being a pencil pusher (not meaning that in a derogatory way) would not accept experienced installers using this method of securing EMT? The installers have no monetary gain in this argument, just hands on experience in installing EMT.


Roger

 

[barclayd]

Well, you'd have to specifically prohibit it in your specs in NC too.

I have a question though, why is it that you being a pencil pusher (not meaning that in a derogatory way) would not accept experienced installers using this method of securing EMT? The installers have no monetary gain in this argument, just hands on experience in installing EMT.


Roger

I learned a long time ago (my first Code book was 1978) that there is more than one way to do just about anything. My background has primarily been in high-tech manufacturing. The emphasis there is reliability - downtime can cost millions per hour.

The Code allows emt to be supported by framing members - bar joists. Some inspectors allow cable ties for securely fastening in place. Some do not. Do some inspectors allow emt to be run diagonally across the framing members to save a couple of 90's? I hope not, but probably. Where is the line?

I think most of the tool toters (not meaning that in a derogatory way) affiliated with this site have enough common sense to provide safe, operational, and Code-compliant electrical systems.

There are a lot of gray areas that allow marginally qualified people to 'test the waters'. That, I think, is where the danger lies, not in our legitimate differences of opinion.

db

 

[Pierre C Belarge]

I

The Code allows emt to be supported by framing members - bar joists. Some inspectors allow cable ties for securely fastening in place. Some do not. Do some inspectors allow emt to be run diagonally across the framing members to save a couple of 90's? I hope not, but probably. Where is the line?

db

It is my understanding that bar joists are designed to withstand the forces applied to them in certain ways.

Such as the bottom chord of the joist is not to have additional loads supported by them (such as A/C units, raceways, etc...), unless they have been designed specifically for that purpose.

 

[iwire]

I Do some inspectors allow emt to be run diagonally across the framing members to save a couple of 90's? I hope not, but probably.

They better allow it, it is not prohibited by the NEC.

The purpose of the NEC is safety, not how the job looks. That is your job to provide specifications.

Where is the line?

For an NEC inspection ideally the line is drawn at safety hazards.

That, I think, is where the danger lies, not in our legitimate differences of opinion.

So far we have talked about tie wraps securing EMT on joists and diagonal pipe runs.

Where is the danger?

 

[cschmid]

I believe the only danger is using them in area that would cause the material of the zip tie (cable ties) to deteriorate at an accelerated rate..

 

[roger]

I learned a long time ago (my first Code book was 1978) that there is more than one way to do just about anything. My background has primarily been in high-tech manufacturing. The emphasis there is reliability - downtime can cost millions per hour.

And that has something to do with using cable ties for securing EMT?

The Code allows emt to be supported by framing members - bar joists.

Yes it does.

Some inspectors allow cable ties for securely fastening in place. Some do not.

And what article and section would you think those not allowing it could use to tag it?

Do some inspectors allow emt to be run diagonally across the framing members to save a couple of 90's?

That is not up to an inspector, he may not like it but there is nothing wrong with it.

I hope not, but probably. Where is the line?

Well the inspector can only enforce the codes that are in place.

I think most of the tool toters (not meaning that in a derogatory way) affiliated with this site have enough common sense to provide safe, operational, and Code-compliant electrical systems.

I agree and nothing you have brought up is unsafe or a code violation even if installed by those not affiliated with this site.

There are a lot of gray areas that allow marginally qualified people to 'test the waters'.

As well as those that are extremely qualified

That, I think, is where the danger lies, not in our legitimate differences of opinion.

db

I think the qualified tradesmen and inspectors will come together to keep most dangers at bay and this is even if the EMT is supported with cable ties and run diagonally across joists and framing members.

Roger

 

[R Bob]

It is my understanding that bar joists are designed to withstand the forces applied to them in certain ways.

Such as the bottom chord of the joist is not to have additional loads supported by them (such as A/C units, raceways, etc...), unless they have been designed specifically for that purpose.

Interesting point! I have been on many projects where the specs explicitly prohibit supporting any load from the bottom chord, struts and webs of the bar joists. They do allow support from the top chord or the deck above. Some of the documents elaborate by requiring concentrated loads of certain weights be seperately engineered and detailed. If the specs don't address the issue, how do you know?

 

[roger]

They do allow support from the top chord or the deck above.

Once you are under the 2008 NEC, (if not already) you would have to be aware of the requirements of 300.4(E) and being on the top cord would probably cause a violation of this article section.

Roger