ssnapier 0 Posted October 15, 2011 I am having a bit of trouble with this, hopefully someone here can shed some light on things. I am bidding on a small project that involves a subway tunnel and they are specifying that I must use "tunnel rated" wire. I have never heard of this particular rating and cannot find any information on it. Is this really a special rating, or would direct burial rated wire work just fine? Share this post Link to post Share on other sites
survtech 0 Posted October 15, 2011 I believe you will need plenum-rated cable. Part of the testing of plenum-rated cable involves running a length of it in a so-called Steiner Tunnel. According to Extron Electronics, "The Steiner Tunnel is a specially constructed fire chamber that positions a group of cables of the same type and about 24 feet in length into a horizontal frame within an air handling plenum. Air rushes into one end of the plenum. Gas burners supply a specific level flame under the cable bundle about 4.5 feet from the end near the air inlet. While the flame is applied for a specified period of time, the length of flame travel along the cable is monitored as well as the amount of smoke produced. At the opposite end of the tunnel, a vent shaft funnels the air and smoke past photoelectric sensors." That said, there may be other requirements for the job. Why not just ask? Share this post Link to post Share on other sites
ssnapier 0 Posted October 17, 2011 That said, there may be other requirements for the job. Why not just ask? I plan to ask, but the meeting is not until late next week. I was trying to get ahead of the curve by getting most of my costs figured out ahead of that meeting. Share this post Link to post Share on other sites
