The substation building shall include the following fire protection requirements:
a. CO2 extinguishing system be designed in accordance with NFPA 12 as a total flooding system, which shall provide complete coverage throughout the building and beneath the raised floor if applicable.
b. Reference section ( Fire Suppression Systems | CO2 Extinguishing Systems ) for additional design information.
c. Class B:C portable CO2 fire extinguishers shall be provided throughout the building in accordance with NFPA 10, and especially near switchgear equipment.
Fire Alarm & Fire Protection of Substation Building
The substation building shall include the following fire and gas detection requirements:
a. A fire suppression system control panel (FSSCP) shall be located at an accessible location preferably near the main exit. Reference section 7.1 for design information pertaining to the FESCP.
b. The FSSCP shall be a stand-alone panel, which shall communicate with the main FGCP, via the integrated network monitoring the general alarm and trouble contacts in the panel.
c. Smoke detectors shall be installed throughout the building, including beneath the raised floor if applicable.
d. Smoke detector spacing for the building shall not exceed 400 sq. ft. area per detector. Reference NFPA 72 to confirm any additional requirements for reduced spacing that may apply.
e. Smoke detectors are not to be located in the direct stream of the room’s airflow, with a minimum distance of 3’-0” from any supply air diffuser.
f. Duct detectors shall be provided for each HVAC system that exceeds 2000 CFM. Duct mounted smoke detectors with sampling tubes shall be mounted in the supply duct(s) upstream of any branch connections. Duct detectors shall meet the requirements of NFPA 90A for design and installation.
Note: Additional detectors in the return plenum or at the return opening of the HVAC unit may also be required based on criteria in NFPA 90A.
g. Releasing stations shall be located at each exit at a maximum height of 4’-6”.
h. Combination horn/strobe notification device(s) to be mounted in unobstructed location 8’-0” above finished floor. If three (3) or more strobe appliances are located in field of view less than 55’-0” apart, then the strobe circuit shall be synchronized.
i. The general alarm and trouble outputs shall be monitored by an addressable module, which shall be programmed with a peculiar address point for proper identification at the main FGCP. The module(s) shall communicate to the FGCP, via an analog signaling line circuit.
j. Operation of the local CO2 extinguishing system shall be activated by the FSSCP.
k. Reference section 6.1, and section 4 and 5 of the Fire and Gas Detection Standard for additional information pertaining to the CO2 fire alarm and detection circuits.
l. Fire alarm system required for the substation building shall be designed in accordance with NFPA 12 and 72.
m. Two (2) IR combustible gas sensors shall be located at the air intake(s). They shall communicate with the main FGCP, via the integrated network or to the Plant Safety PLC, via 4 – 20 mA signal.
n. Reference section 4 and 5.2 of the Fire and Gas Detection Standard for additional information pertaining to the gas detection circuits.