CI Cable: An Issue of Safety

I read the article "Circuit Security," (Sept. 2001, p. 55), along with the letter that this piece on circuit integrity (CI) cable elicited in the December 2001 issue. I took interest in the subsequent response by author Dean Wilson that he is "not aware of any notable fire occurring where propagation of smoke through the conduit played a significant role in the physical damage or threat to life." On the subject of CI cable creating flammable smoke when it ceramifies, I offer the following comment: While it is true that over the years there has been some awareness of the general issue of smoke migration through conduit as stated, we believe it is now a more critical life-safety issue. Out of the 30 types listed in Electrical Circuit Protective Systems, only these "ceramifiable insulated" cables result in flammable gases being channeled directly into emergency equipment enclosures, and the volume of smoke and gas produced is very large, creating a hazardous environment. We contend that where life-safety circuits are involved, hazards, such as smoke migration, should not be introduced in any system that might result in an emergency.

Barry O'Connell, P.E., Commercial Marketing Director Pyrotenax Cable Ltd., Trenton, Ontario