ANSUL system?

[hurk27]

Re: ANSUL system?

By Kiloamp7: For us electrical folks, it is easier if the fuel source to the appliances under the "grease hood" are natural gas.

Why is that?
Even if the fuel is natural gas all the electrical under the hood still has to be shut down. And most Ansel systems will have a mechanical cable that shuts down the gas.

 

[iwire]

Re: ANSUL system?

Originally posted by hurk27:

By Kiloamp7: For us electrical folks, it is easier if the fuel source to the appliances under the "grease hood" are natural gas.

Why is that?
Even if the fuel is natural gas all the electrical under the hood still has to be shut down. And most Ansel systems will have a mechanical cable that shuts down the gas.

It's easer and cheaper to shutdown one or two 20 amp branch circuits than to kill a few 50 to 100 amp feeders for fryers, ovens roasters, etc.

[ December 23, 2004, 05:20 AM: Message edited by: iwire ]

 

[dnbob]

Re: ANSUL system?

The last restauarant I did, every breaker under the hoods was a shunt trip type. We just ran a switch loop from the panelboard branch breakers to the ansul n.o. contact. We have also used contacters and held the coil closed with the n.c. contact, or as others have said use a sub-panel with a shut trip main and put all of the necessary loads though that. If you are doing the fire alarm system, you will also be responsible to wire to one of the contacts for the ansul system.

 

[hurk27]

Re: ANSUL system?

Ok Bob you got me there.
Ok now I'm tired, too much thinkinggggg.

 

[George Stolz]

Re: ANSUL system?

Fresh out of high school I was a manager at Wendy's. I was on the team of managers that opened a new store, complete with all the whistles and bells. Instead of the normal electric kitchen equipment, the whole place was gas. When we finally opened for business, we got a walkthrough of the store and it's features. One impressive feature was the Emergency Stop Button for the entire kitchen area. If there was ever a problem, hit that button to kill the entire kitchen, problem solved. There was even a valve that shut off the gas.

Circumstances worked against me, and a series of events compounded one slow evening, when I decided to pull the chili stove and clean behind it. I reached back, unplugged the quick-release gas supply hose and was rewarded by an ear-piercing shriek which sent me startled, tripping over the grill. By the time I got my bearings, the miss-installed quick release valve vented enough gas to ignite from the pilot of the fryer beside it, resulting in a very impressive bonfire behind an expensive piece of equipment!

Oh yeah! The emergency stop button! I jumped over, hit the big red button, and was rewarded with the quiet click of the clocks on the fryers shutting off. Unfortunately, the emergency shut-off valve for the gas was never hooked into the E-stop. Oops.

When the fire was extinguished, my friend hopped behind the chili stove, gas line in hand, hand over the end, and asked in a suprisingly collected tone, "Where does this go?"

[ December 26, 2004, 06:28 PM: Message edited by: georgestolz ]

 

[kiloamp7]

Re: ANSUL system?

Believe you will find that NFPA 96 requires that the fuel source for the appliance be shut off. In addition, the supply fan must shut off & the fire alarm system must be notified.

A simple 120V. recept. under the grease hood, that is simply there for the, say, timer or clock that is built-in to the gas fueled appliance, does not have to shut off.

Sure, if the appliance is electrically "fueled" , like an electric griddle, then its electrical "fuel" supply must be shut off.

This is what NFPA 96 states.

I understand that some installations are sometime subject to "whims" of the AHJ.
I understand that sometimes design considerations enter in to the best set-up for that particular facility, & how that facility is operated & staffed.

 

[iggy2]

Re: ANSUL system?

There are a lot of things that are easy to miss here...

The gas to gas fired appliances must be shut down too.
A trip must report to the fire alarm system, if there is one. If there is no FA system, a local audible or visual alarm is req'd.
Control power to appliances does not have to be shut down. Only fuel (gas) and heat producing electric power need be shut down, like the gas on a convection oven, but not the 120 volt control circuit to the oven.
The hood supply/exhaust fans may have to be shut down; or supply shut off and exhaust go to max. It's up to the local inspector.
Some appliances (like fryers) come with contactors built in for shut down. But they have to be spec'd that way.
Supply/exhaust fan motors are often 2 speed, or wired through VFDs. If 2 speed, depending on type of motor winding, 6 pole disconnects are required - very expensive.
The Ansul control panel needs 120 VAC.
Lights inside the hood must be approved for the purpose. Usually vaportights.
Take a look at NFPA 96 for more info.

 

[renosteinke]

Re: ANSUL system?

Ansul is the name of a company that makes fire extinguishers, etc. They have a very good fire school in Wisconsin. For all I know, the company was named after its' founder.
Most areas have specialty contractors who maintain range hoods, and the extinguishing systems.

 

[kpepin]

Re: ANSUL system?

Originally posted by kiloamp7:
Believe you will find that NFPA 96 requires that the fuel source for the appliance be shut off. In addition, the supply fan must shut off & the fire alarm system must be notified.

A simple 120V. recept. under the grease hood, that is simply there for the, say, timer or clock that is built-in to the gas fueled appliance, does not have to shut off.

Sure, if the appliance is electrically "fueled" , like an electric griddle, then its electrical "fuel" supply must be shut off.

This is what NFPA 96 states.

I understand that some installations are sometime subject to "whims" of the AHJ.
I understand that sometimes design considerations enter in to the best set-up for that particular facility, & how that facility is operated & staffed.

I just had to do some work on an ansul system and the fire marshall told me we had to shut off the supply fan but keep the exhaust running. He also said that was what the code said. I didn't argue because it was just a matter of adding 2 contact into the control circuit. I find it interesting to read that it must shut off the supply and not mention the exhaust. The way the controls were drawn on my prints showed the supply fan contactor being turned on by the exhaust fan contactor with no interconnection to the ansul system at all. Everything works the way the fire marshall want it to work, the school can make french fries, and everybody is happy now.

 

[kiloamp7]

Re: ANSUL system?

Yes, exh. fan is supposed to keep running.
It sounds like the prints you had were not correct. It is unfortunate that too often, that is the case.

 

[iwire]

Re: ANSUL system?

Originally posted by kiloamp7:
Yes, exh. fan is supposed to keep running.

I have wired quite a few Ansul systems I do not recall that any of them left the Ex fan running.

 

[George Stolz]

Re: ANSUL system?

Around my neck of the woods it's common to kill the make-up air and leave the exaust running, from what I heard it's to clear the room of oxygen and smoke, or something along those lines.

Alas, I haven't had the pleasure yet, just going from what I hear...

 

[don_resqcapt19]

Re: ANSUL system?

One some fire supression systems the exhaust fan is kept running for two reasons. First to carry the supression agent up the exhaust duct and second to vent the heat and smoke vertically, because if it can't go up, it goes horizonatal and spreads the fire.
Don

 

[luke warmwater]

Re: ANSUL system?

The last Ansul brand system that I did was pre-wired for the exhaust to maintain power.

 

[iwire]

Re: ANSUL system?

You guys got me wondering if I remember correctly.

Bob

 

[luke warmwater]

Re: ANSUL system?

HERE is a thread on an Ansul system. It has the specs of the last one that I did. You might have to scroll down a few posts.

 

[bigjohn67]

Re: ANSUL system?

We wire these on a weekly basis. The ansul contractor runs all conduit for activation.
Since we usually are contracted to also pull the fire alarm system, we wire this also.

The simplest way is to require the Hood Supplier, such as Captive Aire, to provide their control panel. It's prewired and gives you 2 dry points to operate shunt trip breakers or other means of disconnect.

 

[toddpdm]

Re: ANSUL system?

Hello, I ended up at this website after a search engine listing. I am an Ansul System installer/inspector. I registered just to reply to this thread. As an installer I run into electrical/plumbing questions or problems on a weekly basis. Hopefully I can be of some help.
1) All remote pull stations, detection lines (brackets holding fusible links), bottles, nozzles and piping will be installed by the Ansul installer.
2) The Ansul installer will supply 1-3 (in rare cases 4) micro switches. The micro switches can handle up to 21 amps. The top pin is common-the second pin is normally open-the third pin is normally closed. If the system is cocked (which is the way it should be left by the installer for wiring purposes) the switches will be open.
3)Exhaust fans must remain on when the ansul system is activated.
4)Make-up air must shut down when the ansul system is activated.
5)Electrical equipment that is located under the hood must be shunted.
6)5-10% of jobs use an electrical gas shut of valve that must also be activated when system is tripped.
Wiring all of these devices together through relays, etc. is way out of my field, but others have made good suggestions in this thread.
I hope this helps.

 

[davedottcom]

Re: ANSUL system?

Originally posted by iwire:
I have wired quite a few Ansul systems I do not recall that any of them left the Ex fan running.

They definately should stay running and in fact the one I hooked up (using that very control panel that I showed you in my last post) actually bypassed the "Stop" control for the exhaust fan when it was activated.
In other words, in the event of a fire, no one could shut off the exhaust fan even if they tried! It's a nice little feature just in case the "Chef" thinks he doing the right thing buy shutting it down.

 

[davedottcom]

Re: ANSUL system?

Whoaaaaa, what happened?!?! :roll:

I thought I was replying to another thread!!!

This one was from like....um...January!

That's it for me tonight... I need some sleep!