Limit length for explosion-proof flex conduit

Status
Not open for further replies.
orange_blossom75728

orange_blossom75728

Member
Location
Japan
Hello everyone. I really need your help!! First of all, Id like you to know that I work as an interpreter, so I have few knowledge about electrical thing, and I'm not so good at English. Sorry for that. I appreciate it if you could advise me with using easy words.

Is there the length limits for explosion-proof flex conduits? As far as I checked NEC2014 and NFPA 70, I found the statement about flex metallic conduit (FMC) but I could not find the specified length for explosion-proof type. Where to be installing them is classified as class 1 div1 location in Hangar, also the length of explosion proof flex conduit will be over 3m. Thank you in advance.
 
Technically, there is no explosionproof flexible conduit. It is an explosionproof flexible coupling. They are very expensive. It must be a listed factory manufactured product.

Theoretically, you can have a manufacture make them for any length. However, the standard maximum length is 3 feet. A length of 3 m will be incredibly expensive..
 
> GoldDogger
I missed that part Thank for letting me know. 144in is over 3m. So over 3m explosion proof flexible couplings (conduits) exist with special order. That's good news for me :)
 
My next concern is whether explosion proof flex should comply with NEC or any regulation. As I mentioned, the place is class 1 div 1 location. I'm not sure Japanese manufacturer can provide the products with applying to those regulations.
 
A word of caution. While manufacturing explosionproof flexible couplings is not "high-tech" it does take very specialized processes.
 
Status
Not open for further replies.
Top