FIRE RATED WIRING What the FT4! Paul Latreille, C.E.T. Ottawa Branch Manager
INTRODUCTION OBC requirements for emergency power OBC requirements for emergency power for fire alarm systems and other building services Requirements for protection of electrical conductors Confusion with fire rating duration: one or two hours FT 1, 4, 6, circuit integrity cables, FAS rated wiring
RELEVANT EXPERIENCE Paul Latreille has provided fire protection and life safety services as designer, project manager and branch manager on over design 500 projects in his 27 year career including : Place De Ville Ottawa s largest office complex Every shopping centre in Ottawa The Peace Tower and Centre Block Headquarters for: Nortel, RCMP, PWGSC, Bank of Canada, CSIS, NRCAN, Canadian Space Agency, Mitel, Newbridge, JDS Uniphase
Emergency Power Requirements 3.2.7.8 Fire alarm systems including those with voice require emergency power supplied from a generator, or batteries or a combination of the two Duration: 24 hours of supervisory power followed by full load power for: o 2 hours for buildings falling under 3.2.6 high buildings
Emergency Power Requirements What is a high building you ask? Group A, D, E or F occupancy over 36m in height (grade to floor level of top storey), Group A, D, E, or F occupancy over 18m in height where the cumulative or total occupant load on or above any storey above grader other than the first storey, divided by 1.8 times the width in meters of all exit stairs at that storey exceeds 300, Containing a group B occupancy in which the floor level of the highest storey of that occupancy exceeds 18 m, Containing a floor area or part of a floor area above the third storey designed or intended for a Group B Division 2 or 3 occupancy, and A Group C building over 18 m
Emergency Power Requirements for Fire Alarm Systems Back to emergency power requirements: o 1 hour for a Group B occupancy that is not within the scope of 3.2.6 o 5 minutes for a building not required to have an annunciator, and o 30 minutes for all other buildings.
Emergency Power Requirements for Building Services 3.2.7.9. An emergency power supply has to be capable of operating under a full load for not less than 2 hours and be provided by an emergency generator for: Elevators serving storeys above the first storey in buildings over 36 m high; All fire fighter s elevators Water supply for fire fighting (fire pumps) if dependent upon electrical power for operation and if under 3.2.6 Fans and other electrical equipment for pressurization systems and exit stair protection Fans for smoke venting
Emergency Power Requirements for Building Services (continued) 30 minutes for water supply for firefighting if dependent upon electrical power for operation and if NOT under 3.2.6 No fire rating of wiring required for standpipe only fire pumps that are located in buildings that are not under 3.2.6
Protection of Electrical Conductors 3.2.7.10 Conductors are required to be protected if they fall under in 3.2.6 and if they serve: Fire alarm systems Emergency equipment identified and required under 3.2.6 (fans for smoke movement, venting fans, exhaust fans, elevators, CACF etc) Fire pumps Mechanical systems related to compartments in hospitals, contained use areas, mezzanines and smoke control Emergency lighting
Protection of Electrical Conductors (continued) 3.2.7.10 (continued) Cables to conform to ULC-S139 Fire Test for the Evaluation of Integrity of Electrical Cables and hose stream application and have a circuit integrity rating of not less than 1 hour. OR Circuit integrity refers to the ability of a power or control cable to maintain voltage and current to the load or the ability of a data and optical fibre cable to maintain error free data transfer and retrieval. (from the new S- 139)
Protection of Electrical Conductors (continued) 3.2.7.10 (continued) Cables to be located in a service space that is separated from the remainer of the building by a fire separation that has a fire resistance rating of not less than 1 hour. OR A service space is a space provided in a building to facilitate or conceal the installation of building service facilities such as chutes, ducts, pipes, shafts or wires. Services spaces shall not contain any combustible material other than the electrical conductors being protected. The fire resistance rating of a service space is never waived even if the building is sprinklered. A service room means a room provided in a building to contain equipment associated with building services.
Protection of Electrical Conductors (continued) 3.2.7.10 (continued) Electrical conductors associated with mechanical equipment are to conform to the following: Cables to conform to ULC-S139 Fire Test for the Evaluation of Integrity of Electrical Cables and hose application and have a circuit integrity rating of not less than 2 hours. OR Cables to be located in a service space that is separated from the remained of the building by a fire separation that has a fire resistance rating of not less than 2 hours.
Other Solutions for Protecting Cabling? Conduit encased in concrete (protection of conventional wiring). In these types of systems, 2 inches of concrete is considered adequate for 1-hour fire resistance. Approximately 4 inches of concrete is required to protect conductors for 2 hours. These systems are very cost effective if proper coverage can be achieved throughout the entire circuit. However it is easier to fire rate conduits up to 1 1/2 inches. It is harder to guarantee 2 to 4 inches. Also, non fire-rated junction and pull boxes compromise the system
What Fire Alarm Wiring Do You Have to Protect? If a fire alarm transponder or annunciator located in one fire compartment is connected to a central processing unit or another transponder located in a different fire compartment, the electrical conductors connecting them shall be protected for 1 hour.
What Fire Alarm Wiring Do You Have to Protect? 3.2.7.10(7): Fire alarm system branch circuits within a storey that connect transponders and individual devices need not conform to sentence 2 (ie. 1 hour rating). APPENDIX NOTE:. A level of protection is required for those conductors protecting the major elements of the fire alarm system. 3.2.7.10(7) permits the protection of electrical conductors to be waived for portions connecting a transponder or fault isolation device to the fire alarm input devices ( fire detectors, manual stations etc) or a voice communication transponder to a fire alarm audible signaling device, provided all circuits or portions of the circuits are contained within the same storey
What Fire Alarm Wiring Do You Have to Protect? Did you read that right? What does that mean? This is a critical interpretation. Hardwired systems require all wiring in the riser to be fire rated. Distributed systems would require all wiring between control units stacked vertically to be fire rated and all circuits that supply multiple floors to be likewise fire rated. Signaling circuits (a strobe circuit for example) that serves multiple floors will now be required to be fire rated.
What Fire Alarm Wiring Do You Have to Protect?.
So, one or two hour rated cable? This is an easy one to answer. Its got to be 2 hours. Anyone know why? Pentair (Pyrotenax) only make a 2 hour rated cable. Pentair is the ONLY manufacturer in the world that has a ULC listing for circuit integrity and a fire rating of 2 hours.
Circuit Integrity and Fire Rated Cables an update ULC de-listed all previous CI cables including mineral insulated cables (2012) Pentair re-tested their cables to the revised ULC standard and ULC re-listed their cables as fire rated cables and circuit integrity cables. (2013) NO OTHER CABLES AT ALL ARE ULC LISTED. PERIOD. Draka Life Line - Only UL listed and only for horizontal installation (2014) and only for one specific manufacturers EMT type conduit Radix CI Only UL listed and vertical restrictions of max 28 ft. (2014) RSCC Only UL listed and 480 Volts Max.(2014)
Circuit Integrity vs FT rated cable This is circuit integrity fire rated cables:
Circuit Integrity vs FT rated cable This is FT rated and FAS cables:
FT Ratings and FAS Type Cables An FT rated cable is not rated or tested to endure fire for any duration. It is simply tested to determine its smoke development classification (how much smoke it will produce) and its flame spread rating (how quickly flame will spread along the cable) Can get only FT-1, FT-4, and FT-6 rated cables. An FAS rated cable is one classified and specifically designed for fire alarm and voice communication use and stands for Fire Alarm Signal (FAS). FAS is a cable type. FT is a smoke development and flame propagation rating system An FAS type cable will be FT rated.
FT Ratings Explained FT1 Vertical Flame Test per C.S.A. C22.2 No. 0.3-92 Para 4.11.1 A finished cable shall not propagate a flame or continue to burn for more than one (1) minute after five (5) fifteen (15) second applications of the test flame. There is an interval of fifteen (15) seconds between flame applications. The flame test shall be performed in accordance with Para 4.11.1 of Canadian Standards Association (CSA) Standard C22.2 No. 0.3. In addition, if more than 25% of the indicator flag is burned, the test cable fails. FT1 Cables can be used in Combustible buildings.
FT Ratings Explained FT4 Vertical Flame Test Cables in Cable Trays per C.S.A. C22.2 No. 0.3-92 Para 4.11.4 The FT4 Vertical Flame Test Cables in Cable Trays is similar to the UL-1685 Vertical Tray Flame Test, but is more severe. The FT4 test has its burner mounted at 20 from the horizontal with the burner ports facing up. The UL-1685 Vertical Tray has its burner at 0 from the horizontal. The FT4 samples must be larger than 13mm (.512 ) in diameter. If not, then the cable samples are grouped in units of at least three (3) to obtain a grouped overall diameter of 13mm. The UL-1581 Vertical Tray does not distinguish on cable size. The FT4 has a maximum char height of 1.5 m (59 ) measured from the lower edge of the burner face. The UL- 1685 has a flame height allowable up to approximately 78 measured from the burner. FT4 Cables can be used in Non-Combustible building
FT Ratings Explained FT6 Horizontal Flame & Smoke Test per C.S.A. C22.2 No. 0.3-92 Appendix B Products passing the FT6 Horizontal Flame and Smoke Test are designated FT6 in the column where the trade number appears. This test is for cables which must pass a Horizontal Flame and Smoke Test in accordance with ANSI/NFPA Standard 262-1985 (UL-910). The maximum flame spread shall be 1.50 meters (4.92 ft.). The smoke density shall be 0.5 at peak optical density and 0.15 at maximum average optical density.
Combustible/Non-Combustible Construction Combustible Construction Means that type of construction that does not meet the requirement for noncombustible construction. Combustible means that a material fails to meet the acceptance criteria of CAN/ULC S114, (Standard Method of test for determination of non-combustibility in Building Materials) (ref: NBC Part 1 Section 1.1.3.2). Noncombustible Construction Means that type of construction in which a degree of fire safety is attained by the use of noncombustible materials for structural members and other building assemblies. Non-Combustible means that a material meets the acceptance criteria of CAN/ULC S114, (Standard Method of test for determination of noncombustibility in Building Materials) (ref: NBC Part 1.1.3.2).
When are FT Rated Cables required? 3.1.4. Combustible Construction and 3.1.4.3 Wires and Cables 3.1.5. Noncombustible Construction, 3.1.5.18 Wires and Cables, 3.1.5.21 Wires in Computer Room Floors, 3.6.4.3 Plenum Requirements FT1 rated cables are permitted in buildings of combustible construction and in computer room sub-floors but NOT in ceiling plenums. Alternative (combustible construction only): located in totally enclosed non-combustible raceway, concealed spaces in walls or concrete slabs
When are FT Rated Cables required? FT4 rated cables are permitted in non-combustible construction, anywhere in the building including computer room subfloors. Alternatives (combustible and non-combustible): Located in totally enclosed noncombustible raceway, concealed spaces in walls, concrete slabs, or 1 hour fire separated service room FT-6 rated cables are permitted in combustible and non-combustible construction and can be used in concealed spaces between the ceiling and the floor or the ceiling and the roof used as a plenum.. Alternatives (combustible and non-combustible): FT4 for single conductor electrical wire and cables. Located in totally enclosed noncombustible raceway.
But... FT classified cables are but one of the permitted classifications of cables. Alternatives are: FT1 Alternatives: FT4, FT6, MPP and CMP (plenum rated cables), MPR, CMR, MPG, CMP, MP, CM, CMX, CMH FT4 Alternatives: FT6, MP, CMP (plenum rated cable), MPR, CMR, MPG, CMG FT6 Alternatives: MPP, CMP (plenum rated cable Check with you local AHJ ad refer to the Ontario Electrical Safety Code (table 19)
Summary Emergency power requirements do not dictate cable circuit integrity ratings (1 hour versus 2 hours) Only one cable is ULC listed for circuit integrity and it only comes in a 2 hour rating An FT rating is required for cables in a building but this has nothing to do with circuit integrity or fire rating of cables There are alternatives to FT ratings Caution is to be used if you choose to build a non-combustible enclosure (but please don t do it)
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