I'm not familiar with the specifics of military work but let me offer some insight from the non military code.
This situation may actually involve three codes. First the National Electrical Code which has authority with regards to wiring methods and materials. The NEC identifies three different "air handling" arrangements. 1) "Ducts" 2) "Plenums" and 3) "Other Environmental Air Spaces". The first two Ducts and Plenums generally requires a metallic covering or enclosure of the conductors, there are exceptions for plenum rated cable where entry into the duct or plenum is required to serve a piece of equipment in the airstream. The latter, "Other Environmental Air Spaces" includes the space above a suspended ceiling used for return air. Quite often this is labelled a "plenum" however within the context of the NEC this is incorrect. The NEC specifically permits certain types of speciality cables to be exposed in this area and allows cables to be run through this area unlike ducts or plenums. Red FPLP fire alarm, or blue and yellow CMP communications and data cable are examples. The Mechanical Code however only contains two definitions with regards to air handling and they are 1) "Ducts" and "Plenums". With the context of the mechanical code the space above a suspended ceiling is a plenum. Items that are not regulated by the electrical code fall within the jurisdiction of the mechanical code. Here we will find that materials that do not fall with the Flame Spread (25) and Smoke Index (50) requirements for these spaces are prohibited. PVC piping is an example of a prohibited material within a plenum. The Building Code also provides requirements with regards to combustibles in concealed spaces, fire and draft stopping, etc. The use of a CPVC piping system listed and tested in compliance with the E-84 standard is acceptable pursuant to 2000 IMC 602.2.1. Of course there may be restrictions on its use exposed unless the piping system is protected in accordance with its listing. In this example the sprinklers are resolving an electrical code violation, non rated cable in a plenum. John Drucker Fire Protection Subcode Official (AHJ) New Jersey -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Steve Kowkabany Sent: Thursday, July 12, 2007 12:08 PM To: [email protected] Subject: Non Plenum-Rated Cable in Non-Combustible Ceiling I have an odd situation on a military job I am doing right now where we are adding sprinkler protection to 100,000 sqft of office space in a 3-story building that has been built in three phases over the past 25 years of non-combustible construction. We are planning on using CPVC piping for this application to hopefully make the retrofit less labor intensive. That's all pretty straightforward but the problem arises from the fact that the base communication department has been steadily adding lots of non-plenum rated cable on top of the drop ceiling into a non-combustible return plenum ceiling space above the first and second floors. The space above the ceiling varies in depth from 4-5 feet with 16" deep fire proofed steel joists spaced 3'-9" OC in some areas and 7'-6" OC in other parts. As a result, the military has recognized the life safety risk of this and allows two options per the latest UFC-3-600-1, which are to either replace all of the illegal cable over 5 years (impossible for us) or sprinkler above the ceiling. So we are adding sprinklers above the ceiling. I'm a little confused on a couple of things, and hope to get some guidance from anyone who has run into similar situations: 1) Can you typically still assume the ceiling space is non-combustible and use CPVC piping if there is some non-plenum rated cabling in there? 2) What is the best approach for sprinklering a ceiling space this deep - standard K5.6 brass uprights spaced at a normal light hazard 225 sqft/head? Thank you very much in advance for any thoughts on this, Steve Kowkabany, P.E. Fire Protection Engineer Neptune Fire Protection Engineering LLC 216 Seagate Avenue Unit B Neptune Beach, FL 32266 904-652-4200 Phone 904-212-0868 Fax _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field)
