# commercial ventahood



## erics37 (May 7, 2009)

For the fire suppression system, everything under the hood needs to shut off (that's what the shunt trip breakers are for). If there is a gas line then the solenoid valve will need to close.

Exhaust fan will need to turn on (or stay on if it's already running), and make-up air will need to shut off. You can accomplish all that with relays and/or contactors.

The idea is to remove as much of the fire triangle as possible. Electrical arcs, flammable gas, fresh oxygen, etc. and also to vent smoke and stuff out so it doesn't collect inside.


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## darren79 (Dec 20, 2011)

erics37 said:


> For the fire suppression system, everything under the hood needs to shut off (that's what the shunt trip breakers are for). If there is a gas line then the solenoid valve will need to close.
> 
> Exhaust fan will need to turn on (or stay on if it's already running), and make-up air will need to shut off. You can accomplish all that with relays and/or contactors.
> 
> The idea is to remove as much of the fire triangle as possible. Electrical arcs, flammable gas, fresh oxygen, etc. and also to vent smoke and stuff out so it doesn't collect inside.



This will need to be tied into the fire alarm as well if there is one in the building.


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## D-Bo (Apr 15, 2012)

depending on job specs you could end up with a supplied control box that has all the relaying done for you. power in power out and done. don't forget the lights


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## zen (Jun 15, 2009)

thanks for the info...the kitchen equip was all used so there was no box on it that was pre wired..i fed power to the fire supp. to the normally closed side and then fed power back to the panel from the the normally open side..when it trips it feeds back to the panel to trigger the shunt trip breakers..putting all the kitchen equipment on shunt trips except the exhaust fan...inspector came yesterday ,,got our green tag and walked out with a good check,,it was easier than i thought it would be ..thanks for the help


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