[CanadianSparky]

Ok so I got thrown into doing this kitchen hood. Not much info given. Basically I have a exhaust fan, make up air, and lights.
Doing research on here I have figured basically everything needs to shut off except the exhaust...which could also depend on local requirements.

Now my question is how exactly are the make up air and exhaust supposed to be controlled? Basically is it just a on/off PB on the wall that enables both units for normal operation? I can figure out the controlling to be inter connected with the fire suppression without much problems I am just actually unsure of the normal operation side of it.....never done one before. Also I have noticed you guys talk about using shunt trip breakers to kill power to make up air, lights etc, but could I just achieve the same results with contactors....or are the shunt trips needed?

 

[erics37]

I've seen it done with shunt trips as well as with contactors. Shunt trips are great for it. You would just run your shunt circuit through the contact in the fire suppression control box and if it triggered, it would trip all the breakers.

Regarding the exhaust fan, typically (as I understand) the exhaust needs to stay on if it's already running, or it needs to turn on if it's NOT running. To achieve that you could put in a contactor controlled by a contact in the fire suppression box and just run a loop parallel to whatever switch turns the fan on normally.

 

[wcord]

Ok so I got thrown into doing this kitchen hood. Not much info given. Basically I have a exhaust fan, make up air, and lights.
Doing research on here I have figured basically everything needs to shut off except the exhaust...which could also depend on local requirements.

Now my question is how exactly are the make up air and exhaust supposed to be controlled? Basically is it just a on/off PB on the wall that enables both units for normal operation? I can figure out the controlling to be inter connected with the fire suppression without much problems I am just actually unsure of the normal operation side of it.....never done one before. Also I have noticed you guys talk about using shunt trip breakers to kill power to make up air, lights etc, but could I just achieve the same results with contactors....or are the shunt trips needed?

The MAU should come with a control panel. You will have to install contactors for the exhaust fans. You will have control wiring from the fire suppression, to the control panel. And the control panel will operate the contactors.
Don't use shunt trips.

 

[farlsincharge]

Here you just need to kill the makeup air. Use a microswitch in the suppression box. Can't have positive pressure in a fire. It is also required to interlock the exhaust fan to the makeup air so it won't run without the exhaust fan.

 

[joe cool]

Microswitch in the ansul panel operates no and nc contacts in the hood panel. Here we have to kill mau and all underhood electric including lights so I run mau and all underhood electrics on a small subpanel backfed with a two pole shunt trip breaker. Saves a buck that way.

 

[CanadianSparky]

Ok so this job is becoming more and more of a headache. The MAU is not in yet but they need the wiring run now to a JB by the location as the ducting is running through a separate tenant space and they can't have the other tenant shut down too long(don't ask).

Is there any control wiring typically needed to go up to the MAU or is it just straight feeds and all the controls are done in the kitchen.

 

[ponyboy]

Ok so this job is becoming more and more of a headache. The MAU is not in yet but they need the wiring run now to a JB by the location as the ducting is running through a separate tenant space and they can't have the other tenant shut down too long(don't ask). Is there any control wiring typically needed to go up to the MAU or is it just straight feeds and all the controls are done in the kitchen.

The MAU and exhaust feeders will probably terminate within a control box located on or near the actual hood. This control box is where your interlocking between the hood, ansul type system, and shunt trip breakers will occur

 

[Stickshaker]

It is also required to interlock the exhaust fan to the makeup air so it won't run without the exhaust fan.

Even after the Ansul is discharged?

 

[Shockdoc]

Most the new installs now just need a constant feed to the control panel, the on/off switch and temp sensor are wiref low voltage in parallel. Anything electric under hood and make up air shuts down during ansul op. What u can do is drag a feed from ex fan leg, make/break at ansul and feed contactor( s) feeding said items.

 

[Hawkrod]

Your in Canada so it may not apply but in the US an updraft hood exhaust has to be mounted with a hinge for NFPA. This means a whip with some slack so the fan can be tilted back for service.

NFPA Fire Code #96: 7.8.2.1
“Rooftop terminations shall be arranged with or provided with the following:
(8) A hinged upblast fan supplied with flexible weatherproof electrical cable and service hold-open retainer to permit inspection and cleaning that is listed for commercial cooking equipment..”
NFPA Fire Code #96: 8.1.1.1
“Approved upblast fans with motors surrounded by the airstream shall be hinged, supplied with flexible weatherproof electrical cable and service hold-open retainers, and listed for this use.

Hawkrod

 

[CanadianSparky]

Most the new installs now just need a constant feed to the control panel, the on/off switch and temp sensor are wiref low voltage in parallel. Anything electric under hood and make up air shuts down during ansul op. What u can do is drag a feed from ex fan leg, make/break at ansul and feed contactor( s) feeding said items.

It is looking like All the controls will be done myself. They seem to have an ansul system with just a set of NO and NC contacts...None of the contacts will be able to handle the loads of any of the equipment.

This is the equipment that was order....Don't ask me why but not my problem
Exhaust fan(120v 20.8fla) :no:
Make up air(specs are kinda up in the air because no one has answers but it is a 208 3ph)
Hood lights
Gas valve (no one has the answer if it is mechanical or electrical)

Now I have never wired up a make-up air unit before and not sure what it comes with control wise as I can't get any specs or info on that either. Basically I have the feeds for exhaust and MAU ran up to where the units will be as we had to have this done because the ducting and wiring runs through another tenants space an they have basically been booted out until the ducting is done.

Do the MAU typically have control wiring running up to the unit or is it all done in the kitchen. I plan on controlling the MAU, lights, valves, and exhaust all through a series or contractors which will be tied into the Ansul system.

 

[Shockdoc]

It is looking like All the controls will be done myself. They seem to have an ansul system with just a set of NO and NC contacts...None of the contacts will be able to handle the loads of any of the equipment.

This is the equipment that was order....Don't ask me why but not my problem
Exhaust fan(120v 20.8fla) :no:
Make up air(specs are kinda up in the air because no one has answers but it is a 208 3ph)
Hood lights
Gas valve (no one has the answer if it is mechanical or electrical)

Now I have never wired up a make-up air unit before and not sure what it comes with control wise as I can't get any specs or info on that either. Basically I have the feeds for exhaust and MAU ran up to where the units will be as we had to have this done because the ducting and wiring runs through another tenants space an they have basically been booted out until the ducting is done.

Do the MAU typically have control wiring running up to the unit or is it all done in the kitchen. I plan on controlling the MAU, lights, valves, and exhaust all through a series or contractors which will be tied into the Ansul system.

All the mua units I ever wired were non heated and straight on/off operation with the exhaust fan. You being in Canada will most likely have a heated system so anticipate control wiring for the heat. On New jobs I planned in the past I sank a pull box next to panel with relay bank inside and make/break feeds going out, switch to control lights, mua and exhaust.

 

[CanadianSparky]

All the mua units I ever wired were non heated and straight on/off operation with the exhaust fan. You being in Canada will most likely have a heated system so anticipate control wiring for the heat. On New jobs I planned in the past I sank a pull box next to panel with relay bank inside and make/break feeds going out, switch to control lights, mua and exhaust.

It will be heated so that is good to know. This is basically what I plan on doing with the feeds but instead of by the panel it will be located next to the ansul system. I believe the MAU has OL incorporated with the unit but the exhaust system will also need OL installed.