zip ties for support?

[stew]

We do some add on circuits for ac units and have done several on manufactured homes. We currently use pvc under the home due to the fact that the inspectors require the nm to be protected under the home. Dont know where that requirement is in the NEC but they want it so they get it. My question has to do with the use of heavy duty zip ties for support of the pvc. The only other way to support is to drill the cross beams to get a tec screw started and of course use a strap. Are zip ties ok to use?

 

[iwire]

Re: zip ties for support?

Originally posted by stew:
We currently use pvc under the home due to the fact that the inspectors require the nm to be protected under the home. Dont know where that requirement is in the NEC but they want it so they get it.

550.15 Wiring Methods and Materials. (H) Under-Chassis Wiring (Exposed to Weather). Where outdoor or under-chassis line-voltage (120 volts, nominal, or higher) wiring is exposed to moisture or physical damage, it shall be protected by rigid metal conduit or intermediate metal conduit. The conductors shall be suitable for wet locations.

Exception: Electrical metallic tubing or rigid nonmetallic conduit shall be permitted where closely routed against frames and equipment enclosures.

Originally posted by stew:
My question has to do with the use of heavy duty zip ties for support of the pvc...... Are zip ties ok to use?

No

352.6 Listing Requirements.
RNC, factory elbows, and associated fittings shall be listed.

Fitting. An accessory such as a locknut, bushing, or other part of a wiring system that is intended primarily to perform a mechanical rather than an electrical function.

Is there a flange you could put a beam clamp on?

 

[stew]

Re: zip ties for support?

so again we go back to the fact that nm is not listed for wet locations and is thus a code violation. Now if this were a stick built home instead of a factory built home then nm is ok in the crawl. Exactly yhe same location but ok for one and not the other????? why???

 

[iwire]

Re: zip ties for support?

Originally posted by stew:
so again we go back to the fact that nm is not listed for wet locations and is thus a code violation. Now if this were a stick built home instead of a factory built home then nm is ok in the crawl. Exactly yhe same location but ok for one and not the other????? why???

I hear you loud and clear and have no idea why the difference.

 

[dillon3c]

Re: zip ties for support?

Originally posted by stew:
[qb] so again we go back to the fact that nm is not listed for wet locations and is thus a code violation. Now if this were a stick built home instead of a factory built home then nm is ok in the crawl. Exactly yhe same location but ok for one and not the other????? why???

Think it could have something to do with the fact of wheel and axle, getting to the location for set-up.And any-type of road,and in lew of all type weather conditions encountered, verses distance that could be traveled?Most of these homes at hit the road,at least twice in their lifespan..(factory to dealer to owner)

At location and final set-up.Hurricaine under-pin is mandatory,but is the underpinning siding skirts around bottom of mobiled/manufactured home.Is this mandatory in every location,and even on private lots,where underside of manufactured home might infact be exposed to the conditions of wet/damp locations.

[ June 18, 2005, 12:32 PM: Message edited by: dillon3c ]

 

[don_resqcapt19]

Re: zip ties for support?

Very few of the commonly used conduit supports are listed for that purpose. I see no reason not to use wire ties to support conduit, if they have adequate strength and are suitable for the location.
Don

 

[iwire]

Re: zip ties for support?

Originally posted by don_resqcapt19:
Very few of the commonly used conduit supports are listed for that purpose. I see no reason not to use wire ties to support conduit, if they have adequate strength and are suitable for the location.
Don

Don I am guessing you do not run much PVC?

All the PVC straps or supports I get are UL listed, which I agree is different than the straps or supports I get for other raceways.

Also if I use standard strut clips, 1 hole clips or 'minins' I will fail inspection here in MA.

None of those supports allow the movement of the PVC required.

Of course tie wraps would allow the movement and personally I think they would work fine.

 

[apauling]

Re: zip ties for support?

bob: support is often provided by resting on some beam or other, don't know of any of those listed for that purpose. By fittings, I don't see optional brackets that are not part of the actual assemblies as "fittings". Requiring strut type fittings for SFD's is a bit much. And if I remember correctly, you were in a pointed discussion where a wire hanger was the "listed" support. I always wondered if the manufacturer listed their wire for that application

For PVC, I don't know where what secures it is listed for SFD's. These are also under Fed regs and it is what they allow and require.

Some jurisdictions have gone bananas over listed NM standoffs and others haven't. Supporting NM at multiple switch locations can be a mess if the jurisdiction parses out (IMO) unintended requirements. The same goes for listed pipe clamps. Zip ties are listed for support of many things, and I, for one, would accept them in that application.

paul

 

[dillon3c]

Re: zip ties for support?

Originally posted by apauling:
[QB] Zip ties are listed for support of many things, and I, for one, would accept them in that application.

I tend to agree with apauling on this..Think it could be better suited for this application.

But on a personal note,when I read this this morning,I went surfing..I could not back this application up,in looking listed/listing as in a approval for the supporting non-metalic conduit.

I gave up....

 

[iwire]

Re: zip ties for support?

Well Paul you are right I have different opinions about the support of steel raceways vs plastic raceways.

You can call it a flip flop, I would call it prudent.

RNC raceways have a nasty habit of looking like junk in no time at all if not installed properly.

Other than a few fire jobs I have never seen the same problems with steel raceways.

 

[apauling]

Re: zip ties for support?

this is under a mobile home, under fed regs, not visible to any but the committed. I think that the zips would probably be more secure than toggled to sheetrock, which is a code compliant install. I can not find anything that specifically allows or disallows (IMO).

hope the original poster is helped, paul

 

[iwire]

Re: zip ties for support?

Originally posted by apauling:
this is under a mobile home, under fed regs, not visible to any but the committed.

Mobile home or not, addded installations fall under the NEC not the Feds.

 

[apauling]

Re: zip ties for support?

it looks like 352.30 allows any type of support as long as it meets the criteria listed in 352.30 which does NOT require listed devices for support. The devices need to follow 3 parameters; distance, expansion, and secure, and no stated requirements for listing except for the conduit assembly itself.

go figure

paul :roll:

 

[don_resqcapt19]

Re: zip ties for support?

Bob,
You're correct. I don't run much PVC and when I do, I use it in the only use that I think that it is suitable for...underground, usually concrete encased. You do make a good point about the supports for PVC, in that they must permit the movement caused by thermal expansion and contraction. However, we have the same rule in the other raceway articles requiring the use of listed fittings, and few of the commonly used securing or supporting devices are listed for the purpose.
Don

 

[stew]

Re: zip ties for support?

I think the responders seem to be a bit confused as to the actual structure involved here. Thes are manufactured homes some very largs at 300 or more sq ft. They have no means of movement when sited. there are no axles involved except for the original set up. the use usaully 4 long concrete pads and put support beams at sveral location on the longitudinal axis the outside of the footprint sits on a typically 36 inch high concrete block foundation not unlike an older home which may have been refoundationed.These homes are exactly like a stick built stucture with the exception that they are not built on the ground but moved to the foundation. I do not see how thes fall under any of the requirements for "mobile" homes unles mayby the state of wash has something in the wac or another set of regs. Gotta check because i want to be totally up to speed on this. Also can anyone tell me what type of wire is used within nm ? And im with the majority im going to use heavy ties until i get called and then maybe we have a long discussion with the inspector about whats listed for the use and whats not. Thanks for your many fine inputs.

[ June 19, 2005, 01:11 AM: Message edited by: stew ]

 

[iwire]

Re: zip ties for support?

Originally posted by don_resqcapt19:
I don't run much PVC and when I do, I use it in the only use that I think that it is suitable for...underground,

Don I could not agree more.

Unfortunately once in a while I am forced to use it exposed, when this happens I use Sch 80 exclusively and support the heck out of it.

 

[dillon3c]

Re: zip ties for support?

Originally posted by stew:
Thes are manufactured homes some very largs at 300 or more sq ft. They have no means of movement -when sited.there are no axles involved except for the original set up .- the use (usaully) 4 long concrete pads and put support beams at sveral location on the longitudinal axis the outside of the footprint sits on a typically 36 inch high concrete block foundation not unlike an older home which may have been refoundationed.These homes are exactly like a stick built stucture -with the exception that they are not buillt on the ground but moved to the foundation.- I do not see how thes fall under any of the requirements for -"mobile"homes- unles mayby the state of wash has something in the wac or another set of regs.

Sort of sounds..Transported by highway/interstate as structure, by means of its own wheel & axle to me..
-And I'm sure these are very fine structures indeed sir..But I cut-paste your own descriptions for reply to your posting.And to the regards, of why wiring methods "may" be so differant, between these two dwelling .I do see similarities..*in your posting..

[ June 19, 2005, 07:22 AM: Message edited by: dillon3c ]

 

[iwire]

Re: zip ties for support?

Originally posted by stew:
I think the responders seem to be a bit confused as to the actual structure involved here. Thes are manufactured homes some very largs at 300 or more sq ft. They have no means of movement when sited. there are no axles involved except for the original set up.

Originally posted by stew:
I do not see how thes fall under any of the requirements for "mobile" homes unles mayby the state of wash has something in the wac or another set of regs.

Stew according to the NEC what you described is a "Manufactured Home" and falls under article 550.

Article 550.2 Definitions.

Manufactured Home. A structure, transportable in one or more sections, that is 25 m (8 body ft) or more in width or 12 m (40 body ft) or more in length in the traveling mode or, when erected on site, is 30 m2 (320 ft2) or more; which is built on a chassis and designed to be used as a dwelling, with or without a permanent foundation, when connected to the required utilities, including the plumbing, heating, air conditioning, and electrical systems contained therein. Calculations used to determine the number of square meters (square feet) in a structure will be based on the structure?s exterior dimensions, measured at the largest horizontal projections when erected on site. These dimensions include all expandable rooms, cabinets, and other projections containing interior space, but do not include inside bay windows.
For the purpose of this Code and unless otherwise indicated, the term mobile home includes manufactured homes.

Good luck with your tie wraps it may fly where you are it would not here.

 

[stew]

Re: zip ties for support?

Thanks for pointing that out i wire i guees if i would have looked i would have seen that as well. Thanks again and I have a large supply of 3/8 wide tie wraps too!!