VE Option

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Alwayslearningelec

Senior Member
Location
NJ
Occupation
Estimator
Have a job with a lot of large size MI cable. Thinking about requesting a VE to go to EMT and RHH 2 hour wire. We need to do a cost analysis first but I think it would be cheaper. Next we need to write RFI and sell this VE alternative. Anyone familiar with the two scenarios and can offer reason why EMT with RHH 2 hour wire would be a better alternative? Thanks a lot.
 
Having installed MI cable IMO you should ignore that stuff like the plague. EMT is the easiest to install. Not sure if there has been a change in the 2 hour rated conductors but when we used them 15 years ago they were very hard to pull into the EMT due to the not so slick insulation. We've installed nothing but 2 hour rated MC cable in the past 10 years.
 
infinity said:
Having installed MI cable IMO you should ignore that stuff like the plague. EMT is the easiest to install. Not sure if there has been a change in the 2 hour rated conductors but when we used them 15 years ago they were very hard to pull into the EMT due to the not so slick insulation. We've installed nothing but 2 hour rated MC cable in the past 10 years.
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2 hour rated MC cables for permanent install...wow. Thought only pipe and wire for perm. Why was MI so hard to install?

Anyway if someone could help with some pointers as to why the owner should side with emt/ 2 hr rated wire over MI cable that would be great.

What I think is:

1. Quicker to install which will help the schedule.
2. Less risk of damage.
 
I can answer this easily! Go with RHW-2 (not RHH) in Allied EMT per FHIT 25E. MC and MI are hard to pull. MC (both Lifeline - FHIT 50 and Vitalink - FHIT 120) are good and better than MI - FHIT 1850, but harder to install and they need rollers/sheaves. It's also not like normal MC and is very fradgile. Dent or break that copper armor and it needs to be replaced! MI is hard and has lots of "extra" stuff you will need. An EMT install will be 25% less (installed costs) over MC and 50% over MI. But go with RHW-2 not RHH (both are actually made). The RHH is like pulling sandpaper. And make sure you follow the FHIT document from UL. NEC 728 will mandate it and that will override any NEC conflicts. That FHIT is the bible. Don't look at the wire cost either, since you will need brand specific things regardless of the system. Look at a "total" cost or installed cost. That will tell you the real picture. Some of these systems wires are 10% cheaper, but you'll spend 40% more on components which negates the wire savings. If you need any documents on this, let me know.
 
Boingo1972 said:
I can answer this easily! Go with RHW-2 (not RHH) in Allied EMT per FHIT 25E. MC and MI are hard to pull. MC (both Lifeline - FHIT 50 and Vitalink - FHIT 120) are good and better than MI - FHIT 1850, but harder to install and they need rollers/sheaves. It's also not like normal MC and is very fradgile. Dent or break that copper armor and it needs to be replaced! MI is hard and has lots of "extra" stuff you will need. An EMT install will be 25% less (installed costs) over MC and 50% over MI. But go with RHW-2 not RHH (both are actually made). The RHH is like pulling sandpaper. And make sure you follow the FHIT document from UL. NEC 728 will mandate it and that will override any NEC conflicts. That FHIT is the bible. Don't look at the wire cost either, since you will need brand specific things regardless of the system. Look at a "total" cost or installed cost. That will tell you the real picture. Some of these systems wires are 10% cheaper, but you'll spend 40% more on components which negates the wire savings. If you need any documents on this, let me know.
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Thank you very much. So what do you think( besides cost savings) the benefits is to the owner as to why they should choose EMT/RHW over MI cable? I need to sell it.
 
Boingo1972 said:
I can answer this easily! Go with RHW-2 (not RHH) in Allied EMT per FHIT 25E. MC and MI are hard to pull. MC (both Lifeline - FHIT 50 and Vitalink - FHIT 120) are good and better than MI - FHIT 1850, but harder to install and they need rollers/sheaves. It's also not like normal MC and is very fradgile. Dent or break that copper armor and it needs to be replaced! MI is hard and has lots of "extra" stuff you will need. An EMT install will be 25% less (installed costs) over MC and 50% over MI. But go with RHW-2 not RHH (both are actually made). The RHH is like pulling sandpaper. And make sure you follow the FHIT document from UL. NEC 728 will mandate it and that will override any NEC conflicts. That FHIT is the bible. Don't look at the wire cost either, since you will need brand specific things regardless of the system. Look at a "total" cost or installed cost. That will tell you the real picture. Some of these systems wires are 10% cheaper, but you'll spend 40% more on components which negates the wire savings. If you need any documents on this, let me know.
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Not sure RHW-2 can go in EMT. Don't think it is listed for such.
 
Obviously costs is the big one, but....MI takes a lot longer, requires splices (at least on each end) which are failure points, it uses magnezium oxide which is hydroscopic and often fails testing, and you must splice in normal stranded buidling wire to terminate it. That section of normal wire has no fire rating. So if the area you are termining in and using the normal wire, you must ensure that structure holds a 2 hour minimum rating. If it doesn't, well you're going to need to upgrade those structures, which costs a ton! If it does, there is still a risk of the normal wire failing. Also MI is lenght limited due to it's large bend radius. They can only put so much on a reel. Yes they say we can factory splice it, but you still have to meet that bend radius so that's just smoke and mirrors (unless you want a 10 foot tall reel). RHW-2 systems can terminate directly onto the equipment, no splicng or anything and you're protection goes 100% of the way. FHIT 25E uses Lifeline RHW-2 and Allied EMT with Raco set screw couplers/connectors with Wiegmann 3R boxes if needed. Just be carefule with conduit and wire systems, the fill rate is way different and will use larger conduits. I've attached some documents including FHIT 25E and instructions on it.
 

Attachments

  • Prysmian FHIT.25E FHIT Short Package- May 2025.pdf
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don_resqcapt19 said:
I don't understand. What would prohibit RHW-2 from being in any raceway?
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He's using EMT and trying to maintain a 2-hour rating with the combination of the EMT and a 2 hour conductor. Seems like this brand of RHW-2 is 2 hour rated in EMT.

www.radix-wire.com

DuraLife® RHW-2/R90 Power Cables | Radix Wire & Cable

Radix provides high temperature wire, high performance cable at the thinnest possible diameter without sacrificing its performance.
www.radix-wire.com www.radix-wire.com
 
infinity said:
He's using EMT and trying to maintain a 2-hour rating with the combination of the EMT and a 2 hour conductor. Seems like this brand of RHW-2 is 2 hour rated in EMT.

www.radix-wire.com

DuraLife® RHW-2/R90 Power Cables | Radix Wire & Cable

Radix provides high temperature wire, high performance cable at the thinnest possible diameter without sacrificing its performance.
www.radix-wire.com www.radix-wire.com
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Lifeline has been available with EMT since 2001, so not new. The Duralife RHW-2 in EMT is pretty new. Both hold a 2 hour fire resistive rating. A manufactuer can only make suggestions based on their UL test data. Most go and test every 6 weeks or so. If you have an issue on a job, which you will, ask yourself which company can help more and which can't. Trust me on this, a "newer" company doesn't have the test data to fix most problems whereas one who's been making it for decades will. Those fixes (if they don't have the data) can cost more than the entire system and they are expensive! The more experienced manufacturer will always be a safer choice. Not to mention you will need technical support for all of these systems, so getting to an engineer right away (instead of weeks) is important too. Big companies have lots of engineers, but small ones, not so many.
 
Boingo1972 said:
Not to mention you will need technical support for all of these systems, so getting to an engineer right away (instead of weeks) is important too. Big companies have lots of engineers, but small ones, not so many.
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Given what you have listed as your occupation can you tell us what company do you work for or would you rather not say?
 
I'm an electrical engineer who designs cables for manufacturers including fire resistive ones. I help them figure out what components/materials are necessary to be successful with testing at UL so they can achieve a listed system. I started in that field with Draka many many years ago which gave me the knowlege to help others. Since I've worked alongside all ceramifyable silicone cable manufacturers (not MI), I understand each system and their limitations. I also teach classes (for credits) to city/state AHJ's to bring them up to speed on current listings and code requirements which are constantly changing. Been doing this for a long time and I see over and over the same mistakes made, so I promote a best practice method to avoid those costly mistakes regardless of manufacturer.
 
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