ansul system

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RICK NAPIER

Senior Member
Location
New Jersey
The requirements for lights under the hood are in NEC 410.10(C) and have to be identified for the use. One thing that has not been mentioned is that the hood exhaust is suppose to be automatically activated when the appliances are in use IMC 507.2.1.1
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
One thing that has not been mentioned is that the hood exhaust is suppose to be automatically activated when the appliances are in use IMC 507.2.1.1
Or inversely, the gas can't be turned on until the exhaust system is on, which is what we must do here.

How would you sense gas flow to energize the exhaust fan, unless the appliance has trigger terminals?
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
The most common way is with a heat sensor in the hood.
I've seen wiring diagrams that use them, but I haven't wired any systems where they were used.

The suppression systems use the lead links in the steel wire; when they melt, the microswitches operate.
 

renosteinke

Senior Member
Location
NE Arkansas
The question "Is the system required to turn off the hood lights?" is a good example of the need to READ THE STANDARDS. Doing so will likely make for a much nicer discussion with the fire marshall.

Sad to say, but every 'fire marshall' I've encountered has learned this topic by word of mouth; not one has read, let alone owned, the applicable standard.

As best I can tell, NFPA 96 (Kitchen hoods) is silent on the topic. NFPA 17A, which does address the extinguishing system, makes an indirect reference.

NFPA 17-A, in 5.6.2.2, reads:
All sources of fuel or heat to appliances served by the
common exhaust duct shall be shut down upon actuation of
any protection system in accordance with 4.4.3.

Now, the question arises: are the hood lights "sources of fuel or heat to appliances?" I submit that, strictly speaking, they are not, and thus NOT required to be turned off.

This is not to be confused with "should be." I can understand the desire to shut off the lights; I've seen far too many lights either filled with condensed oils, or covered with a layer of grease. I can see the fire actually originating there - well above the spray of the nozzles.

Now, every 'fire marshall' I have encountered has also been quite surprised to have their understanding of things explored. Being part of the Fire Dept, rather than the Building Dept, they are accustomed to a far more dictatorial culture in their bureaucracy. I'm not even clear on whether they actually adopt any code besides the 'fire code.'

Yet, the lights are 'small potatoes' compared to the issue of make-up air. That issue can become contentious when there is no specific fresh air supplied to the hood.
 
All these responses have covered the main requirements. Every system is different. There are new installs and up-fitting of existing systems. The rules have changed over the years.

New systems can be either self-contained Ansul-type with a pre-wired control box and switches, or can be just fans mounted on ducts, and we have to wire everything together from scratch.

Sometines, there's already one or more shunt-trip breakers, sometimes a whole kitchen panel controlled by a shunt-trip. Often, only the exhaust fan was connected to the micros.

In existing systems, I use contactors; shunt-trips are expensive and require running a cable back to the panel. Contactors are easy, cheap, and can be mounted where needed.

Here's a few pics from a new church kitchen I didn't wire, but I installed the system:

FireChurch1.jpg


FireChurch2.jpg


FireChurch3.jpg


The box contains four contactors. There were four 120v receptacles, so I used two 2p contactors for those. The three cables with the tape (a 12/3 and two 12/2's), are those feeds.

The fan supplies and loads (controlled by two 3p contactors), plus the circuit/light supply, enter and exit the top. From the bottom are the cables to the gas valve and the lights.

The 1/2" flex goes in the wall to the switches, and the 1/2" EMT to the horn-strobe, to the extinguisher box which contains the microswitches, and then on to the gas reset box.

Here's a pic of the wiring diagram:

Fire3.jpg


Both of these circuits were fed by the same supply; I just showed them separated them for ease of tracing. (Big! Sorry.)

Now, under-hood lights must also shut off. Appliances under the hood that must shut down, whether their supply is under the hood or not. Unused receptacles can be blanked off.

We also have to install a horn/strobe unless there's a building alarm system tie-in, and a gas valve w/reset box that must shut down the gas even upon manual exhaust shutdown.

That means every morning starts with turning on the exhaust, pressing the button on the reset box, and then lighting each standing pilot. The owners and cooks HATE this requirement.
Hey larry in my area fort lauderdale, florida your job will fail, That enclosure you are using is a junction box, not allow to install contactor or devices. You will have to use an enclosure with a inner panel
 
Ansul System

Ansul System

In my area (Dade, Broward, Palm Beach County's) the job will fail electrical inspection, Using JB is not allow for devices, will have to use an enclosure with a inner panel
 

nakulak

Senior Member
Hey larry in my area fort lauderdale, florida your job will fail, That enclosure you are using is a junction box, not allow to install contactor or devices. You will have to use an enclosure with a inner panel

what code reference is that ?
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
In my area (Dade, Broward, Palm Beach County's) the job will fail electrical inspection, Using JB is not allow for devices, will have to use an enclosure with a inner panel
How far apart must the inner panel be from the box's rear?

I ask because those boxes do have double back panels.
 
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