ANSUL system?

[Guest]

Hello All, could someone please tell me what an ANSUL system is? There will be 5 circuits going into a box containing 9 normally closed contacts. The 5 circuits are 2-3 phase grilles, 1-1 phase rice warmer, 1-1 phase refrigerator drawer, and finally 1-1 phase light. I'm guessing this is a type of emergency shut off system. The ANSUL system shows to be tied into the exhaust/vent hoods. Thanks.

 

[kpepin]

Re: ANSUL system?

an ansul system is a fire suppression system used on cooking equipment

 

[bigjohn67]

Re: ANSUL system?

Ansul is a chemical used to put out grease fires. Code requires that the Gas and all electrical be shut off automatically if the ansul system is "fired"
Located near the ansul bottles is 2 micro switches. One is used to trigger a fire alarm system and the other is used to shut off all electrical that is under the hood.

The easiest way to do this is to run the control circuit thru the microswitch first then to the hood control box. When the ansul cable is pulled, the control circuit will open, shutting off power.

 

[Guest]

Re: ANSUL system?

Thanks for the quick replies. So who usually installs the pull cord, exstinguisher bottles, and the alarms? The co. installing the fire alarm system or the HVAC co. that is installing the hoods? Thanks.
Do the letters "ANSUL" stand for anything?

[ December 19, 2004, 07:52 PM: Message edited by: iaspiretowire ]

 

[ronaldrc]

Re: ANSUL system?

I have wired many small restaurants that use the ANSUL system.

All the ANSUL control heads I ever worked with had double throw limit switches on them giving you a normally open or normally closed contact choice.

Most of the time we set a small load center with a shunt trip main breaker and bring the equipment that has to be shut down fat fryers grilles Etc. from it.

If you don't want to go that route use a contactor large enough for your load and hold the coil energized with the normally closed contacts in your ANSUL system control head.

Ronald

 

[Guest]

Re: ANSUL system?

Originally posted by ronaldrc:
use a contactor large enough for your load and hold the coil energized with the normally closed contacts in your ANSUL system control head.

Ronald

Hi Ronald. Im trying to bid a small commercial job. I have mostlly been doing residential. The only thing Im not understanding is this ANSUL system. The blueprints show that I supply and wire the contactors for the ANSUL system, but the prints dont show anything else. Can I expect another trade on the job to be supplying all the other parts of the ANSUL system such as the control head you mentioned? Thanks.

 

[ronaldrc]

Re: ANSUL system?

Yes that is right in all the jobs I have did.

The only electrical parts that are usually supplied by the ANSUL system are the limit switches to actuate the shut down of the electrical equipment to be shut down.

We always supplied the contactors shunt trip breakers and enclosures for them.

The only part of the ANSUL system the Electrical contractors are usually concerned with are just the limit switches mounted inside the ANSUL control head the control head is usually mounted on top of one of the large Co2 tanks. The conduit for the ANSUL system cables and melt links are furnished and installed by the ANSUL system contractor. The ANSUL system control head with the limit switches are furnished by the ANSUL contractor.Conduit and all the mechanical gear are all furnished by the ANSUL contractor.

I would check with the contractor to be sure.

Ronald

[ December 19, 2004, 09:44 PM: Message edited by: ronaldrc ]

 

[ken987]

Re: ANSUL system?

I've wired one of these systems once, I too was a bit cautious, never seeing this before. However it was?pretty simple and straight forward. The only one I wired was as follows:
The hood came with controls for the two exhaust fans and one makeup air unit(this unit provides fresh make up air while the exhaust fans are on, I belive this is the only fan that will be shut off when the ANSUL system activates).
The ANSUL system was installed by the contractor that installed the hood, they ran everything for their system. The electric end of it is yours. In the ANSUL control box there will be contacts NO and NC and there will be a few of them.. It's your job to use these contacts to control a contactor or shunt trip breakers. In my installation, the hood control box had two terminals one power to supply the contact in the ANSUL box and the other for the return wire from the contact. The other terminals your going to have to use to shut down everything else. Rons ways to shut off the rest would be good.

 

[hurk27]

Re: ANSUL system?

The one's I wired I used a remote panel that fed everything under the hood it was fed by a shunt trip breaker the ANSEL system just triped this breaker. simple

 

[lady sparks lover]

Re: ANSUL system?

Originally posted by iaspiretowire:
Hello All, could someone please tell me what an ANSUL system is? There will be 5 circuits going into a box containing 9 normally closed contacts. The 5 circuits are 2-3 phase grilles, 1-1 phase rice warmer, 1-1 phase refrigerator drawer, and finally 1-1 phase light. I'm guessing this is a type of emergency shut off system. The ANSUL system shows to be tied into the exhaust/vent hoods. Thanks.

It's a fire suppression system, for a kitchen. Have those spec'd by the architect all the time. It's very simple, if you don't have the contacts that are wired to the fire alarm system for shutting off the fan, lights, and other system. Other than that, it can be a pain to install.

Some have a mechanical pull station, some have a electrical pull station...


Lady

 

[steve66]

Re: ANSUL system?

Sometimes the mechanical cable runs in a conduit, and the electrical contractor has to provide and install the conduit.

Steve

 

[ronaldrc]

Re: ANSUL system?

On the contrary Lady sparks I even found the install simple.

Steve I have installed exactly four in my life time and I have never installed the conduit for the cable.

The contractor installing the ANSUL always installed that part and pulled and hook his activation cables and melt links.

Ronald

[ December 20, 2004, 03:27 PM: Message edited by: ronaldrc ]

 

[Guest]

Re: ANSUL system?

Originally posted by ken987:
In the ANSUL control box there will be contacts NO and NC and there will be a few of them.

So I will not have to supply any contacts, they will allready be inside the ANSUL control box? I just land the circuits that I want the ANSUL system to shut off at the ANSUL control box? Sounds easy enough.

 

[lady sparks lover]

Re: ANSUL system?

Originally posted by ronaldrc:
On the contrary Lady sparks I even found the install simple.
Ronald

He's better at it then my friends in the field. You should hear the RFI's I get from the field. I personally have never installed one, but I guess from the grapevine they told me it can be a pain doing the low voltage contacts connections.

Hey if it's easy for you, then great...maybe you can come show me and my people.

[ December 20, 2004, 03:45 PM: Message edited by: lady sparks lover ]

 

[ronaldrc]

Re: ANSUL system?

Lady sparks the ones I wired where very simple.

I have wired fire system control panels for fast food places that can be very complex.

I'm sure the larger ANSUL systems can get complex too.

Ronald

[ December 20, 2004, 03:58 PM: Message edited by: ronaldrc ]

 

[bowman]

Re: ANSUL system?

in CA. the electrical connection should be made in a j-box just outside where the microswitches are located(factory leads about 8". In my experince the contractor installing thefire supression system ran the pipe and all other apperateus. we were responsible for electrical too and from to the contactors for the hood and air and shunt etc.......

 

[hurk27]

Re: ANSUL system?

By iaspiretowire: I just land the circuits that I want the ANSUL system to shut off at the ANSUL control box? Sounds easy enough.

Not in most cases as these contacts on the micro switch's in the control box are only rated for 10 amps and I have seen some rated only for 3 amps so in most cases you will have to ether control a contactor or a shunt trip breaker.

 

[sceepe]

Re: ANSUL system?

Careful everyone. I recently heard about an interesting experience on a school final inspection. Inspector went to test the hood and when he initiated the test, the power did not shut off to under hood appliances. After quick checks of wiring and drawings, it was found that the 20A, 1P breaker feeding the shunt trip main breaker for the under hood equipment panel was off. Yep just that one breaker.

Moral of the story, if you use shunt trip breakers for the under hood equipment shutoff required by code, this is not a fail safe design. This is because the shunt trip needs power to activate and open the breaker.

I have begun using a contactor and letting the micro switch open the circuit (instead of closing it) and shut everything down. Another option would be to use a low voltage trip breakers instead of the shunt trip. Either way, when micro switch opens the circuit the under hood appliances loose power.

 

[iwire]

Re: ANSUL system?

sceepe

I like your thinking, and your design practice. I am often bothered by fire alarm drawings that are not drawn in a fail safe manor.

That said I do not believe there is a requirement for the Asul system to be fail safe.

 

[kiloamp7]

Re: ANSUL system?

sceepe, - I agree 100% that using the "dropping out" of a contactor, or the "tripping" or a ckt. bkr. that has an undervoltage trip, is a much better design.

NFPA 96 is the applicable document.
I too, was surprised to hear of designers using shunt trip bkrs. to meet NFPA 96.

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