Type I Hoods

[RJJ]

when a type I hood with suppression is activated besides the gas shut off just what electrical connections need to be disconnect. Just where in the Nec or NFPA would this be covered. As of late we have had various discussion regarding this issue. I believe the electrical outlets associated with any appliances also need to be disconnected. Your thoughts!

 

[cda]

Anything under the hood

Will have to find a reference

Not sure what IFC says but should have somewhat similar language

 

[RJJ]

The discussion is related to receptacles associated with appliances!

 

[cda]

If the appliance or outlet is under the hood or supplies an appliance under the hood, I have always seen it shut down

I have heard arguments about it

Check what IFC says and will research what nfpa and IFC says

 

[fireguy]

I have the electrician shut down power to all receptacles under the hood and the intake air. The fire system is tested and listed to operate and control the fire with the exhaust fan on or off. My personal preferance to is to have the exhaust fan on to vent the combusion gases and heat out of hte building. The exhaust fan also helps move the suppression chemical through the plenum and duct.

 

[Francis Vineyard]

2006 IBC; is this what you are looking for;

[F] 904.3.3 System interlocking. Automatic equipment interlocks with fuel shutoffs, ventilation controls, door closers, window shutters, conveyor openings, smoke and heat vents and other features necessary for proper operation of the fire-extinguishing system shall be provided as required by the design and installation standard utilized for the hazard.

[F] 904.11.2 System interconnection. The actuation of the fire suppression system shall automatically shut down the fuel or electrical power supply to the cooking equipment. The fuel and electrical supply reset shall be manual.

Though we’ve been enforcing both fuel and electrical appliances under hood automatically shut down and no one has contest it, the code says “or” not “and”.

 

[Mac]

My understanding has been that the 'electrical power' referred to means supplies to any electrical powered cooking equipment that is under the hood, which includes cord-connected countertop appliances too.

Not sure about receptacles not in use though.....

 

[RJJ]

Frances: Thanks for the sections. We have enforced the shut down of everything in the past and still do. The question came from one of my electrical inspectors after an inspection that did not have all electrical shut off. At the time I was out of the office and did not have access to my code books. The inspection was failed pending chapter and verse. The electrical inspector only inspect per NEC. My position was fail it and when I get into the office I will find the sections. Corrections had been made on Friday before I was able to react.

 

[cda]

also for future ref

NFPA 17 A 2002

4.4.3 Shutoff Devices.

4.4.3.1 On activation of any cooking equipment fire-extinguishing system, all sources of fuel and electric power that produce heat to all equipment protected by the system shall be shut down.

4.4.3.2 Gas appliances not requiring protection but located under the same ventilation equipment shall also be shut off.

4.4.3.3 Steam supplied from an external source shall not be required to be shut down.

4.4.3.4 Solid fuel cooking operations shall not be required to shut down.

4.4.3.5 Exhaust fans and dampers are not required to be shut down on system actuation as the systems have been tested under both zero- and high-velocity flow conditions.

4.4.3.6 If the expellant gas is used to pneumatically operate these devices, the gas shall be taken prior to its entry into the wet chemical tank.

4.4.3.7 Shutoff devices shall require manual resetting prior to fuel or power being restored.