Flex Conduit for electrical wiring. 2

[TomFitz]

I am looking for a type of electrical flex conduit for wiring a sauna heater. I had galvanized flex conduit originally in place but it deteriorated due to users pouring water containing clorine over the lava rocks.
I am told that there is another type of conduit that would be both impervious to heat as well as chemical corrosion but I don't knww the name of it..
I appreciate any assistance in finding something to solve this problem.

Thanks,
Tom..

 

[resqcapt19]

You could look for some stainless steel flexible conduit.

http://www.flex-tubes.com/stainless-steel-flexible-conduit.html

If it is not too hot (less than 60°C) you could use liquidtight flexible nonmetallic conduit.

http://www.carlon.com/Master Catalog/Carflex_Brochure.pdf

 

[waross]

There should not be any wiring in that area. Try to reposition your wiring when you replace it.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[mcgyvr]

I'm with Bill...
That's just asking for trouble.. Move that wire (and use stainless steel flex or maybe a properly placed stainless sheet as a splash shield).. You KNOW that users will continue to pour water over the rocks...

 

[waross]

But, for the ultimate in a cable able to withstand abuse try "Pyrotenax" from TYCO.

Resistance to Fire with Water Spray 650°C - Category W
A new sample of cable is exposed to flames at 650°C for 15 minutes whilst passing a current at the rated voltage and then the spray is turned on to give exposure to both fire and water for a further 15 minutes. A single survival category is defined in the table below.


650°C for 3 hours W Surpasses

They have short premade cables for wiring gasoline pumps. One of those may suffice.
To paraphrase Hallmark;-
"When you care enough to bend the very best!

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[TomFitz]

Thank you all for your input..
I agree with "waross" that the installation of the power supply wiring under the unit was poor judgement. They should have came into the unit from the side. And yes, people WILL continue to pour water over the unit in spite of large signs posted telling them "do not". I guess you can't fix "stupid".. I will go with Stainless Steel to replace the galvanzed..
Thanks again.....

 

[cranky108]

I don't know if it is still made, but I had some alumuminum flexable conduit. It might work in place of the stainless.

I'm just not sure which would be better in the clorine. I do know alumuminum is good in salt.

 

[resqcapt19]

Note that as of the 2008 edition of the National Electrical Code "flexible metal conduit", no mater what material it is made of is no longer permitted to be used in wet locations 348.12(1). You have to use either liquidtight flexible metal conduit (Article 350) or liquidtight flexible nonmetallic conduit(Article 356) for wet locations.

 

[dpc]

I agree with Bill - this might be a good application for short section of Mineral Insulated (MI) cable. See NEC Article 332.

David Castor

http://www.cvoes.com

 

[dbaird]

Check:

http://www.mtgmoltec.com/

This stuff is used in all kinds of outdoor applications. It is flexible, waterproof, impact/crush resistant and corrosion/sunlight resistant. UL, CSA and IEC approvals.

Good Stuff!!

David Baird

Sr Controls Designer
EET degree.
Journeyman Electrician.

 

[resqcapt19]

David,
It appears that the products in your link are UL "Recognized" and not UL "Listed" products. If this is a project covered by the NEC, the NEC requires the use of Listed raceways.

 

[MacGyverS2000]

A sidenote (and someone feel free to correct me if I'm wrong)... it only has to be listed with a NRTL, not necessarily UL.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[dpc]

If a UL listing exists for that class of product. MI cable is certainly allowed by the NEC. I'm not a Code lawyer - just an engineer.

David Castor

http://www.cvoes.com

 

[resqcapt19]

David,
Not everything is required to be a listed product by the rules in the NEC, but all raceways are. The link you posted is to raceways, and the products in the link are not listed. That would prohibit their use in any installation covered by the NEC. MI and some other cable wiring methods are not required to be a listed product by the NEC.

Dan,
Yes any NRTL is acceptable...I tend to use "UL" as a generic term, much like "crescent" wrench.

 

[dbaird]

Reply to all:
Here is another company that IS UL listed:

http://www.murrplastik.com/pages/conduit.tpl?c=suv

David Baird

Sr Controls Designer
EET degree.
Journeyman Electrician.

 

[resqcapt19]

David,
I only see UL Recognized products on that site. Those products are not the UL listed products that are required by the raceway rules in the NEC. That company does not have a listing for "Flexible Nonmetallic Conduit, Liquid-tight" that could be used per the rules in Article 356. Here is a link to all of the companies that have a UL listing for products that can be used per Article 356.

 

[stevenal]

Rescaps link links indirectly to

http://database.ul.com/cgi-bin/XYV/...n=versionless&parent_id=1073985930&sequence=1

Looks like 60C wet and 105C dry are as high as they go. How hot does it get under there?

 

[dbaird]

resqcapt19

http://www.murrplastik.de/Default.aspx?mid=mp_product_suv2&cid=en&id=2&action=applicationDetails

Note: UL File E148958



David Baird

Sr Controls Designer
EET degree.
Journeyman Electrician.

 

[resqcapt19]

David,
From the UL Guide information for YDRQ2, which is the guide that that UL file number is listed under.

The devices covered under this category are incomplete in certain constructional features or restricted in performance capabilities and are intended for use as components of complete equipment submitted for investigation rather than for direct separate installation in the field. THE FINAL ACCEPTANCE OF THE COMPONENT IS DEPENDENT UPON ITS INSTALLATION AND USE IN COMPLETE EQUIPMENT SUBMITTED TO UNDERWRITERS LABORATORIES INC.

That is not a product that can be field installed under the rules of the NEC. It is a product that can only be used as part of a complete manufacturered assembly.

 

[dpc]

Don,

Please refer to NEC Article 352 regarding MI cable.

MI Cable is a Wiring Method and does not even require a Raceway. It can be run exposed, embedded or concealed.

This stuff has been in use for a very long time.

The Pyrotenax installation manual states the bulk cable is UL LISTED.



David Castor

http://www.cvoes.com