904.3.7.1 Carbon dioxide systems.

Carbon dioxide systems, where allowed, shall be provided with the additional safety measures set forth in FC 904.3.7.1.1 through 904.3.7.1.8.

904.3.7.1.1 Egress precautions.

All areas whose atmospheres will be made hazardous by the discharge of carbon dioxide shall be provided with:

   1.   Exit and exit routes that are kept clear at all times.

   2.   Lighting and exit directional signs in accordance with the construction codes, including the Building Code.

   3.   Only outward swinging, self-closing doors at exits, and panic hardware on any such doors that are secured with a locking or latching device.

904.3.7.1.2. Ventilation and other safety equipment.

A carbon dioxide system shall be provided with a fixed emergency forced ventilation system able to clear the area with sufficient capacity to accomplish at least 6 air changes per hour, and such other safety equipment as may be prescribed by the commissioner.

904.3.7.1.3 Detection, activation, alarm and control.

Detection, predischarge alarms and discharge alarms shall be provided within and outside the protected area and such other areas that are made hazardous by a carbon dioxide discharge. Such alarms shall be audible and visible.

904.3.7.1.3.1 Automatic operation.

The carbon dioxide fire extinguishing system shall be activated by an automatic cross-zoned detection system in which activation of a detection device in one zone shall sound a local alarm and transmit an alarm to an approved central station, and activation of a detection device in the cross zone shall initiate the predischarge warning signal and after a time delay, initiate the discharge of carbon dioxide. The predischarge warning signal time delay shall be of sufficient duration to allow for evacuation from the protected area. Distinct alarms shall indicate the activation of a detector in one zone, the activation of a detector in a cross zone (predischarge alarm) and the discharge of carbon dioxide. Such alarms shall be continued until the atmosphere has been returned to normal except that the alarm for the detector in one zone may be discontinued when the alarm for the cross-zoned detector is activated.

   Exceptions:

      1.   A carbon dioxide fire extinguishing system activated solely by manual means may be installed with department approval upon a showing satisfactory to the department of the need for such a system.

      2.   A detection system that is not cross-zoned may be installed with department approval upon a showing satisfactory to the department of the need for such a detection and activation system.

904.3.7.1.3.2 Manual operation.

A manual pull station shall be provided which, upon activation, transmits an alarm to an approved central station, overrides any delay other than the predischarge delay, and causes the carbon dioxide to discharge. Activation of a carbon dioxide fire extinguishing system by means of a manual pull station shall result in a complete predischarge delay sequence prior to system discharge.