Im writing in response to your answer to Mr. Ralph Bouvy in the October 1995 issue. I believe your

I`m writing in response to your answer to Mr. Ralph Bouvy in the October 1995 issue. I believe your response to his question about plenum-rated power cabling is incorrect.

The 1993 National Electrical Code, Article 645-5(d), specifically allows power cables and receptacles associated with data-processing equipment to be located under a raised floor, even where it is used for ventilation. There are some other requirements if you do this. For instance, your computer room must meet the special requirements listed in Article 645-2. Most of the computer rooms that I have been in meet these requirements. Another commonly neglected fact is that power cables in the computer room are not required to be secured in place, which is permitted in Article 645-5(e). It is important to note that the power cables must be listed as part of, or for, electronic computer/data-processing equipment. This is often not the case for facilities that install "homemade" power cables. I encourage everyone with a computer room to read Article 645.

As far as obtaining plenum-rated power cables, there are many manufacturers that offer UL-listed plenum rated power cables. One such company that I use frequently is Computer System Products Inc., located in Minneapolis. This company offers many different configurations of power cables, including circuit breakers, and can be reached at (800) 422-2537.

Steve Riffel

U.S. Department of Veterans` Affairs

Austin, TX