# Use of RHW-2 in EMT or other 2 hour fire rated Conductor



## varmit (Apr 19, 2009)

From long ago memory: RHW has a softer, rubbery insulation that creates more friction than THHN when pulled in. It is a larger diameter also.

However, I do not believe that RHW-2 in EMT will give you a code compliant , 2 hour fire rated installation. RHW-2 only has a 90C insulation - the same temperature rating as THHN. Please refer to NEC 695.8.


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## Cow (Jan 16, 2008)

Never used either method.


Was your inspector also the one to suggest RHW-2 in pipe? 



What size conductors are you planning on going with?


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## telsa (May 22, 2015)

RWH is FAT.


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## Southeast Power (Jan 18, 2009)

Cow said:


> Never used either method.
> 
> 
> Was your inspector also the one to suggest RHW-2 in pipe?
> ...


There will be 4x 350s in 3" EMT. It fits


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## Southeast Power (Jan 18, 2009)

varmit said:


> From long ago memory: RHW has a softer, rubbery insulation that creates more friction than THHN when pulled in. It is a larger diameter also.
> 
> However, I do not believe that RHW-2 in EMT will give you a code compliant , 2 hour fire rated installation. RHW-2 only has a 90C insulation - the same temperature rating as THHN. Please refer to NEC 695.8.


The manufacturer claims it has a 2 hour fire rating. 

http://www.ckelectricalsales.com/pdf_files/VitalinkRHWUSMarket37711.pdf

http://s3.amazonaws.com/zanran_storage/tycothermal.com/ContentPages/2529492530.pdf


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## varmit (Apr 19, 2009)

OK, always interested in new things.


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## manchestersparky (Mar 25, 2007)

Southeast Power said:


> We have been asked to install conductors for and existing fire pump.
> The installation as it sits is a 1970s designed electrical system with only normal power feeding it.
> It has to be connected to a generator.
> The inspector suggested MI cable. I have only seen this once in our jurisdiction. It's extremely rare. The more we looked into it, it's been suggested we look into RHW-2 in EMT with steel fittings.
> ...


Article 695.6(2)(3) gives us the option to use a " Listed electrical circuit protective system". 
This "system is in the UL White Book under FHIT
There are more stringent rules to follow then just NEC chapter 3 . There are requirements for additional supports then the NEC requires, Type of conduit, type of fittings, what the conduit can be supported too. Its not just a case of using steel fittings and RHW


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## Wirenuting (Sep 12, 2010)

MI is good stuff. 
But it sure looks tempting to a plumber a few years down the road.


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