Exhaust Fan Interconnect Electrical

Bubbles

Anyone out there ever hook up an interlock system for a 25' Gas appliances Restaurant Hood/Exhaust Fan with Make-up air out the roof setup? 2 Horse on Make-up air motor, and 1 Hp on each of 2 exhaust fans. 208v 2-pole set-up. We did one several years ago for a paint booth setup in a warehouse and I'm a little rusty. I heard the building/fire dept is going to be tough on this around here just curious as to T&M for the typical set-up? The hood guy said his normal electricians charge him 2,000 around here for doing it. We already have a line run to it. If it's too involved and risky (wrath of fire marshall) I might just pass to guys that go from one to another and have the learning curve already down. ..Thanks..going fishing now...

K2

We just flunked one yesterday because the GFI's behind the equipment under the hood did not shut off with the fire system. We had it set up so all the fans shut off with the systen but now only the make up air has to shut off and any gfi's. Fire guys say it's different in every juristiction and can change from one Marshal to the next. Owners are po'd because they can't open.

Bubbles

bummer. I think here in case of fire. Make-up air has to shut off with all electrical except exhaust fans stay on. Keep me up to date how it goes. I'll use you as my guinea pig.lol...you got any pics and who do you get your relays and such from? How much for you material on just the set-up of system??

TxElectrician

we feed a sub panel - sized according to load- with a shunt trip breaker to feed make up air and all electrical devices, equipment under the hood. The hood contractor provides us with a set of contacts from his fire panel to activate the shunt.

Magnettica

I recently worked on a make up air system for a commercial kitchen but someone else went back and finished it off and installed the relay. I believe you want all vents/ fans/ exhausts to shut down in the event of a fire so that the oxygen does not feed the fire. If someone in-the-know could add to this discussion it would be much appreciated.

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swade

We converted a Bob Evans into a BBQ joint last year. Fire Marshall wanted only make up air and outlets under the hood to shut down when the ansul system engaged. They wanted the exhaust fans to stay on to pull smoke/heat out.

Connection wise it was exactly as TXelectrician said

nap

last several restraunts, in my area;

eveything under the hood must shut down (all equipment and all electrical sources) . Make up air shuts down. Exhaust fan goes to full speed it if is speed controlled, if not, simply remains on.

gas must shut down. Fitter will need to install the emerg valve. Depending on what type it is, Ansul may attach to it or electriciann electrical shut off.

I have had 1 restaraunt where any ansul trip caused action at all the hoods in the kitchen (4 or 5 total hoods) and a couple where only the affected hood was dealt with.

the hood contractor? It has always been Ansul installed switches around here to activate the controls. The hood contractor doesn;t do anything. His stuff is controlled by mine.

Like the others; a panel with a shunt trip feed is the easiest but when it comes to the exhaust, if it is a VFD, second contact in Ansul is an input to the VFD so the ex fan will spin up to full speed.

wirenut1110

All the systems I've done have micro switches in the Ansul system that I use these switches to energize the shunts, a relay to interrupt make-up air and a contactor to "jump" the switch(es) to turn the exhaust fans on. Pretty simple set-up.

nap

that sounds like one of those prepackaged control boxes. Depending on how much power OP has involved, that may be the best way to go.

It all depends on exactly what OP has involved and what is supplied to him I guess.

luckyshadow

Just finished a school and last year completed a commercial kitchen in a prison here in Maryland -

When the ansul is activated...

Fire Alarm must ring alarm
Everything under the hood must shunt off ( electrical and gas)
Make up air must turn off
Exhaust fan must stay on OR turn on if it's off.

This is done by feeding everything under the hood out of a panel that has a shunt trip main breaker OR providing shunt trip breakers for those circuits.

Plus the kitchen equipment provider provides a control panel that controls the hood lights and exhaust fans. The fire alarm is run through the microswitches in the ansul cabinet, and the fire alarm relay for the shunt trip breaker must be next to the panel with the shunt trip breakers ( nfpa 72 rule)

firemike

Pretty much the same here in Michigan: Upon activation os fire suppression system:

An audible and visual anunciator (visible to kitchen employees) must activate.

Gas valve supplying cooking equipment under the hood, make-up air, any general duty plugs under the hood, and all electrical equipment under the hood must shut off, but the exhaust fan must continue to operate. Ther are slight variables from place to place.

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-Mike-

muckusmc

If they are following the IMC in your area you will also need a sensor in the exhaust to operate exhaust/makeup air fans automatically with the switches off - set to 135 degrees
muck

pulpfiction32

We are doing one right now. We have to have all fans and make up on shunt trip breakers. Everything gets hooked up in a large contactor box with 2 swithces on its face for lights and hood The hood guy has been so helpful on this job he has made a pain in the ass into a breeze