// CODE SNIPPET
516.0 Recirculating Systems
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Recirculating systems containing or for use with appliances used in processes producing smoke or grease-laden vapors shall be equipped with components in accordance with the following:
- The clearance requirements of Section 507.4.
- The hood shall comply with the requirements of Section 508.0.
- Grease removal devices shall comply with Section 509.0.
- The air movement requirements of Section 511.2.1 and Section 511.2.2.
- Auxiliary equipment (such as particulate and odor removal devices) shall comply with Section 512.0.
- Fire-extinguishing equipment shall comply with the requirements of Section 513.0.
Exception: Fire-extinguishing equipment in accordance with Section 513.1 and Section 513.5.
- The use and maintenance requirements of Section 514.0.
- The minimum safety requirements of Section 515.0.
- The requirements of Section 516.0. [NFPA 96:13.1]
- Provisions shall be provided for latent heat and excessive moisture acceptable to the Authority Having Jurisdiction.
Gas-fueled or electrically fueled cooking appliances shall be used. Listed gas-fueled equipment designed for use with specific recirculating systems shall have the flue outlets connected in the intended manner. Gas-fueled appliances shall have not less than 18 inches (457 mm) of clearance from the flue outlet to the filter inlet in accordance with Section 509.2.2 through Section 509.2.2.3 and shall be in accordance with the installation requirements of NFPA 54 or NFPA 58. [NFPA 96:13.2.1 — 13.2.3]
Recirculating systems shall be listed with a testing laboratory in accordance with UL 710B or equivalent. [NFPA 96:13.2.4]
Cooking appliances that require protection and that are under a recirculating hood shall be protected by either the integral fire protection system in accordance with UL 710B or Section 513.0. [NFPA 96:13.2.4.2]
A recirculating system shall not use cooking equipment that exceeds that recirculating system's labeled maximum limits for that type of equipment, stated in maximum energy input, maximum cooking temperature, and maximum square area of cooking surface or cubic volume of cooking cavity. [NFPA 96:13.2.6]
The listing label shall show the type(s) of cooking equipment tested and the maximum limits specified in Section 516.2.4. [NFPA 96:13.2.7]
A fire-actuated damper shall be installed at the exhaust outlet of the system. [NFPA 96:13.2.8] The actuation device for the fire damper shall have a maximum temperature rating of 375°F (191°C). [NFPA 96:13.2.10]
The power supply of an electrostatic precipitator (ESP) shall be of the "cold spark," ferroresonant type in which the voltage falls off as the current draw of a short increases. [NFPA 96:13.2.11]
Listing evaluation shall include the following:
- Capture and containment of vapors at published and labeled airflows.
- Grease discharge at the exhaust outlet of the system not to exceed an average of 2.9 E-09 (oz/in3) (5.0 E- 06 kg/m3) of exhausted air sampled from that equipment at maximum amount of product that is capable of being processed over a continuous 8 hour test with the system operating at its minimum listed airflow.
- Listing and labeling of clearance to combustibles from the sides, top, and bottom.
- Electrical connection in the field in accordance with NFPA 70.
- Interlocks on removable components that lie in the path of airflow within the unit to ensure that they are in place during operation of the cooking appliance. [NFPA 96:13.2.12]
The recirculating system shall be provided with interlocks of critical components and operations as indicated in Section 516.3.1 through Section 516.3.3.1 such that, where an interlock is interrupted, the cooking appliance shall not be able to operate. [NFPA 96:13.3.1]
Closure panels encompassing airflow sections shall have interlocks to ensure the panels are in place and fully sealed. [NFPA 96:13.3.2]
Each ESP shall have a sensor to prove its performance is as designed, with no interruption of the power to exceed 2 minutes. [NFPA 96:13.3.4.1]
The sensor shall be a manual reset device or circuit. [NFPA 96:13.3.4.2]
An airflow switch or transducer shall be provided after the last filter component to ensure that a minimum airflow is maintained. The airflow switch or transducer shall open the interlock circuit where the airflow falls 25 percent below the system's normal operating flow or 10 percent below its listed minimum rating, whichever is lower. The airflow switch or transducer shall be a manual reset device or circuit. [NFPA 96:13.3.5.1 — 13.3.5.3]
The location of recirculating systems shall be approved by the Authority Having Jurisdiction. Items to be reviewed in the fire risk assessment shall include, but not be limited to, life safety, combustibility of surroundings, proximity to air vents, and total fuel load. [NFPA 96:13.4]
In addition to the appliance nozzle(s), a recirculating system shall be listed with the fire protection for grease filters, grease filtration, odor filtration units, and ductwork, where applicable. [NFPA 96:13.5.1]
In addition to other fire-extinguishing system activation device, there shall be a fire-extinguishing system activation device installed downstream of an ESP. [NFPA 96:13.5.2]
The requirements of Section 513.6 shall also apply to recirculating system locations. [NFPA 96:13.5.3]
Automatic or manual covers on cooking appliances, especially fryers, shall not interfere with the application of the fire suppression system. [NFPA 96:13.6.1]
Filters shall be cleaned or replaced in accordance with the manufacturer's instructions. [NFPA 96:13.6.2]
ESPs shall be cleaned a minimum of once per week and in accordance with the manufacturer's instructions. [NFPA 96:13.6.3]
Inspection and testing of the total operation and safety interlocks in accordance with the manufacturer's instructions shall be performed by qualified service personnel not less than once every 6 months, or more frequently where required. [NFPA 96:13.6.5]
Fire-extinguishing equipment shall be inspected in accordance with Section 514.2. [NFPA 96:13.6.6]
A signed and dated log of maintenance as performed in accordance with Section 516.6.3 and Section 516.6.4 shall be available on the premises for use by the Authority Having Jurisdiction. [NFPA 96:13.6.7]