# fire suppression system for restaurant



## william sparky (Jan 30, 2010)

i am doing the wiring for a restaurant that has a AMREX system installed.this system has one n.o. and one n.c. switch. The only electric under the hood are the hood lights and a 14 kw fryer. There is a 3 h.p. exhaust fan and a 2 h.p. supply air fan.Voltage is 120/208 3 phase. I need to shut down supply air,hood lights, and fryer and have exhaust fan running when the fire suppression system is activated. Exhaust fan has to come on even if is turned off. Fans are 3 phase and fryer is single phase.I am planning to install a 80 amp shunt trip breaker for fryer and two contactors for the fans.I am not sure how to get this to work with only one n.o. and n.c. micro switch in the AMREX system.Any ideas or diagrams would be appreciated.


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## McClary’s Electrical (Feb 21, 2009)

Use that one n.o. to feed an 11 pin octal base relay.


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## NacBooster29 (Oct 25, 2010)

You may depending on location have to shut off a gas line under the hood also. Also don't put line voltage through the contacts.


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## seabee41 (Dec 21, 2010)

Couldn't you interlock the fan contactors with a third one for the make up air?


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## Amish Electrician (Jan 2, 2010)

"Exhaust fan has to come on even if it is turned off."

Not according to the NFPA code. Might be a job spec. GET THE CODE. Read it. Have it ready at inspection.


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## Awg-Dawg (Jan 23, 2007)

Amish Electrician said:


> "Exhaust fan has to come on even if it is turned off."
> 
> Not according to the NFPA code. Might be a job spec. GET THE CODE. Read it. Have it ready at inspection.


 Comments from NFPA 96-08 Standard for ventilation control and fire protection of commercial cooking operations: 
8.2.3 Exhaust Fan Operation. 
8.2.3.1 A hood exhaust fan(s) shall continue to operate after 
the extinguishing system has been activated unless fan shutdown 
is required by a listed component of the ventilation system 
or by the design of the extinguishing system. 
8.2.3.2 The hood exhaust fan shall not be required to start 
upon activation of the extinguishing system if the exhaust fan 
and all cooking equipment served by the fan have previously 
been shut down. 

Of course this is just a standard and needs to be enforced by the Local AHJ. 
Typical wet chemical system design is: exhaust stays on after discharge, preferably, it would have the ability to automatically turn on from the off position in the event a fryer is accidentally left on overnight and auto ignites. Makeup air always goes down, especially if its connected to the hood, along with power to all appliances.

 (Not my words. I lifted this from the net.)


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## william sparky (Jan 30, 2010)

*fire suppression system*

i guess that you mean n.c. contac to relay


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## McClary’s Electrical (Feb 21, 2009)

william sparky said:


> i guess that you mean n.c. contac to relay


 
NC keeps the coil energized all time. You'll have a much longer lasting system if you use the NO


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## Awg-Dawg (Jan 23, 2007)

william sparky said:


> .Any ideas or diagrams would be appreciated.


 

See if this is any help.

http://www.greenheck.com/media/pdf/kitchen/Wiring_WaterwashArrg.pdf


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## leland (Dec 28, 2007)

Awg-Dawg said:


> See if this is any help.
> 
> http://www.greenheck.com/media/pdf/kitchen/Wiring_WaterwashArrg.pdf




http://www.firesecurity.gr/Pdf/kp_manual.pdf


1 N/c-1 N/o= 1 common.

You will provide the control ckt. 

best bet is a shunt breaker or a contactor. AHJ will make the call on exhaust shut down. Any MAKE UP air MUST shut down.


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