Kitchen hood shunt trip

[cppoly]

Anyone know where I can find the requirements for shunt trip electrical equipment under kitchen hoods?

 

[gadfly56]

Anyone know where I can find the requirements for shunt trip electrical equipment under kitchen hoods?

These will be in your building code, fire code, and mechanical code. Also, NFPA-17A if you are dealing with a UL300 wet chemical suppression system. If you are in NYC, try the fire department's Range Hood Unit.

 

[fmtjfw]

NFPA 1 Fire Code

NFPA 1 Fire Code

[2009] 50.4.6.1 Upon activation of any fire-extinguishing system for a cooking operation, all sources of fuel and electrical power that produce heat to all equipment requiring protection by that system shall automatically shut off.

There is more but that is the basic principal. You trip the power and close the gas cutoff valve (often electrically).

 

[gadfly56]

[2009] 50.4.6.1 Upon activation of any fire-extinguishing system for a cooking operation, all sources of fuel and electrical power that produce heat to all equipment requiring protection by that system shall automatically shut off.

There is more but that is the basic principal. You trip the power and close the gas cutoff valve (often electrically).

That's one place to look, but adoption of NFPA 1 seems rather rare. And what you cited is basically word-for-word out of NFPA 17A. The building and mechanical codes usually go further, requiring that ANY electrical equipment under the hood be turned off, not only that to "covered appliances". Hood lights, convenience outlets, etc, not just the electronic controller for the gas-fired fryer.

 

[cppoly]

The way that's worded, does that mean only cooking equipment with a fire extinguishing equipment needs to be shut down automatically?

Cooking equipment without fire extinguishing equipment does not require an automatic shut down?

Is the only cooking equipment requiring fire extinguishing equipment hoods?

 

[fmtjfw]

That's one place to look, but adoption of NFPA 1 seems rather rare. And what you cited is basically word-for-word out of NFPA 17A. The building and mechanical codes usually go further, requiring that ANY electrical equipment under the hood be turned off, not only that to "covered appliances". Hood lights, convenience outlets, etc, not just the electronic controller for the gas-fired fryer.

Here in WV NFPA 1 is adopted as part of the state fire code. I happen to have a copy from when I took training on it.

NFPA 1 Adopted statewide in 20 states. MI MD WV HI WI KY RI LA FL CT VT NH MA ...
IFC Fire Code "Used or adopted in 42 states or parts thereof, DC, NYC, Guam & PR"

There was an attempt to come up with one fire code involving NFPA and regional building code groups for 2000. It fell apart for several reasons:
1) each group wanted to protect its publishing revenue base.
2) the regional building code groups took input only from code officials. NFPA more open process.
3) the regional groups looked at it as a building code.
4) IBC? sued NFPA for using "International" in standards names.

 

[fmtjfw]

The way that's worded, does that mean only cooking equipment with a fire extinguishing equipment needs to be shut down automatically?

Cooking equipment without fire extinguishing equipment does not require an automatic shut down?

Is the only cooking equipment requiring fire extinguishing equipment hoods?

Assuming the hood has fire extinguishing system (Sprinkers, ANSUL system ...) anything under under the hood is to be shut down.

I am familiar with ANSUL systems which have a switch that indicates operation of the extinguisher.

Here that would trigger several things:

1) send an alarm to the fire alarm system of the building, initiate evacuation; low voltage supervised circuit like alarm pull station
2) force the exhaust hood fan to RUN even if turned off manually; vent smoke
3) force any incoming air fan to STOP even if turned on manually; don't add combustion air.
4) trip the gas valve for appliances under the hood.
5) trip electrical power under the hood, typically shunt trip a main breaker feeding a subpanel for equipment under the hood.
6) the overload relays of the exhaust fan may be overridden, causing the fan to run to failure, if necessary (like a fire pump).
7) not turn off all lighting in kitchen; may rely on emergency lighting.

This often takes careful design so that things "fail-safe" on broken control wires.

 

[iwire]

Assuming the hood has fire extinguishing system (Sprinkers, ANSUL system ...) anything under under the hood is to be shut down.

Now wait a moment and go back and read what you posted above.

It does not support the statement that 'everything must shut down'.

Under the code section you posted only the sources of fuel and electricity that produce heat must be shut down.

 

[fmtjfw]

Now wait a moment and go back and read what you posted above.

It does not support the statement that 'everything must shut down'.

Under the code section you posted only the sources of fuel and electricity that produce heat must be shut down.

I first posted the code that I would apply for the OP's first question.

He then asked another question, and I told him what I would do. Note: no code references.

What the code states (which is a minimum) and what I would implement are two different things. Same with fail safe and supervising control circuits.
There is probably other stuff in NFPA 72 about the interconnect with the Fire Alarm system and somewhere else about the exhaust fan. I didn't bother to look around for the added quotes. [I'd already been told that NFPA 1 was not adopted in a lot of states.] He (or you) can talk to your code officials about what code applies or what they want.

What I posted was the checklist items we used when we had an ANSUL or sprinkler system in a commercial kitchen hood.

Fire Marshal appeared happy when we implemented the checklist. He's happy, I'm happy.

What applies in your state or town may be something different.

 

[steve66]

NFPA 96 - Standard for ventilation control and fire protection of commercial cooking operations would probably have more specific requirements.

I believe it says you have to remove power to "heat producing appliances" under the hood.

 

[gadfly56]

NFPA 96 - Standard for ventilation control and fire protection of commercial cooking operations would probably have more specific requirements.

I believe it says you have to remove power to "heat producing appliances" under the hood.

Yes, under NFPA 1, NFPA 17A, and NFPA 96 you would have to shutdown the gas to the fryer, but not the rice cooker. Under the 2009 IBC, it would be everything under the hood.

 

[cppoly]

Is equipment shutdown required if there are no hoods?

 

[gadfly56]

Is equipment shutdown required if there are no hoods?

Umm, I'll start by saying "no", but then I wonder what would trigger a shutdown anyway if there isn't a UL300 system for the appliances?