# Commercial Hood Electrical Wiring



## electricpotential (Jan 19, 2013)

Hi Guys,

I am going to wire up one commercial Hood, need to know please! how i can wire this up, and how things are connected, I mean fresh air makeup unit and Range hood And fire suppression system. How these things interlocked normally.
I will be very thank full for kind support.

Thanks
Electric Potential


----------



## Bbsound (Dec 16, 2011)

Obviously you need to check local codes, but around here the following needs to happen:
When the fire suppression system is activated the exhaust fan has to come on even if it is currently in the off condition. 
The make up air has to shut off. 
The air handling unit that serves the area has to shut off. 
All power under the hood has to be killed, including the lights. 
The gas valve has to shutoff and have a manual reset button. 
The fire alarm system has to go into alarm for the building.


----------



## cal1947 (Nov 14, 2009)

*cal1947*



Bbsound said:


> Obviously you need to check local codes, but around here the following needs to happen:
> When the fire suppression system is activated the exhaust fan has to come on even if it is currently in the off condition.
> The make up air has to shut off.
> The air handling unit that serves the area has to shut off.
> ...


 the co. installing the eq. sends the panels with with relays in them and the breakers for outlets and hood lights we have them on shunt trip


----------



## electricpotential (Jan 19, 2013)

cal1947 said:


> the co. installing the eq. sends the panels with with relays in them and the breakers for outlets and hood lights we have them on shunt trip


Can you please elaborate little more, 

Thanks


----------



## aftershockews (Dec 22, 2012)

You will be fine. I am thinking that the new hoods may have most if not all of what you need built in them, I could be wrong. If you know how to read schematics you should do just fine.
First fire suppression system I did I had to make up my own contact box and use the micro switch from the system to control the electrical under the hood. And I was left to do this without any help other than being told what electrical had to be shut down when a fire occurred.


----------



## wcord (Jan 23, 2011)

Your fresh air makeup unit and hood will come with a control panel or some sorts. 
Depending on the manufacturer, you may have power to each unit, with controls from each unit to the control panel.
You will also have a shutdown control from the fire alarm panel to either the fresh air makeup, or the control panel.
You probably will have a fire alarm initiating zone which will monitor the fire suppression system.
As pointed out previously, this should be in the schematics.


----------



## Celtic (Nov 19, 2007)

Everything under the hood goes OFF when fire suppression gets activated ~ not just those items attached to the hood.
The lights on the hood go off, the gas solenoid closes, all electric to stove, range, fryers, etc everything under the hood goes dark.


----------



## 220/221 (Sep 25, 2007)

The systems I've done recently are pretty simple.

At the Ansul bottle, there is a mechanism that, when the fire cable is pulled, triggers a set of contacts. 

There are a couple NO's and a couple NC's rated for about 10 amps.

Exhaust needs to turn on/stay on so you wire it from the line side of the switch, thru the NO's. When the system is triggered, the EF will turn on/stay on

Make up air, lights, electric fryers and gas valves need to shut off so they go thru the NC's. When the system is triggered, they will turn off.

The last one I did had a gas valve that didn't require electrical connection. It had a mechanical shut off, hooked into the cable pull system.


----------



## Dash Dingo (Mar 3, 2012)

I'll be doing exactly what your going in a couple of weeks. I got word that there will be a temperature sensor on the hood, so that if they forget to turn the exhaust on it will automatically turn it on. This sensor is low voltage I'm told, so I ran a 18/4 back to a contactor box. I'm not to sure how I'm going to make that work yet.? You might want to ask about that. The kitchen I'm doing is all Sheetrock, so once it's finished I'm effed. 

Also, you might have a summer/ winter controls for your make up air unit. I roughed in a 1" conduit for that.


----------



## GEORGE D (Apr 2, 2009)

This is one I'm recently hooking up, unfortunately don't have pictures of the actual control box, just a fuzzy pic of door diagram.


----------



## Celtic (Nov 19, 2007)

GEORGE D said:


> This is one I'm recently hooking up, unfortunately don't have pictures of the actual control box, just a fuzzy pic of door diagram.


What brand/model #, etc?


----------



## GEORGE D (Apr 2, 2009)

Not sure, I'll be back there Wednesday, I'll try to remember to look and take more pics.


----------



## electricpotential (Jan 19, 2013)

GEORGE D said:


> Not sure, I'll be back there Wednesday, I'll try to remember to look and take more pics.


Hi Bro,
Did you got a chance to take pictures?


----------



## bobelectric (Feb 24, 2007)

Does anyone have ideas on how to balance make-up air to exhaust air so you don't remove the a/c or heat from the building?


----------



## GEORGE D (Apr 2, 2009)

electricpotential said:


> Hi Bro,
> Did you got a chance to take pictures?


No, sorry my schedule changed and haven't been there at all this week, I will def be there one day this week and take some.


----------



## Dash Dingo (Mar 3, 2012)

bobelectric said:


> Does anyone have ideas on how to balance make-up air to exhaust air so you don't remove the a/c or heat from the building?


That's what the thermostat is for. The make up air will replace the exhausted air with either heat or ac.


----------



## Wirenuting (Sep 12, 2010)

bobelectric said:


> Does anyone have ideas on how to balance make-up air to exhaust air so you don't remove the a/c or heat from the building?


Depends on the system. 
If your unit has modulating outside air dampers, start at 25% and hope that the exhaust hasn't been changed since instal. 
To balance the system you need to do the math. Or at least have a volometer to start with.


----------



## Rollie73 (Sep 19, 2010)

bobelectric said:


> Does anyone have ideas on how to balance make-up air to exhaust air so you don't remove the a/c or heat from the building?


Yeah....let an air balancing tech with the proper equipment handle it.


----------



## 220/221 (Sep 25, 2007)

bobelectric said:


> Does anyone have ideas on how to balance make-up air to exhaust air so you don't remove the a/c or heat from the building?


I would imagine it's as simple as X CFM out = X CFM in.

There is no question that you are going to remove A/C and heat and I would assume there are different stratagies for different climates.

In AZ, 99% of the systems are a simple evaporative coolers, sized the same as the exhaust CFM. It has to wreak havoc on the buildings AC system in the heat of summer, but that's the way it's done. I did install a refrigeration style make up air on a Cracker Barrel a couple years ago. That can't be cheap to operate.

In freezing cold climates, I assume they have to pump in heated air during the winter months.


----------

