My first commercial kitchen

[wireperson]

I'm doing the rough in for a comercial kitchen , it's the first time in years that I'm doing it.the part that I'm concern about is the ANSUL system , the prints call for 3 j boxes where the hood area is , circuits are1 for ansul system,1 for shun trip, and 1 for gas valve, I undestand that , when the ANSUL system is on , you should shut off all electrical equipment or outlets under the hood . npw how do I acomplish this? how do I wire the shun trip and gas valve? some help please. Also the prints calls for EMT to be used but there is a note that says that I can use MC , in your experience can I use MC for all the outlets in the kitchen

 

[480sparky]

The gas valve is the plumbers problem..... usually a mechanical system shuts the gas off, but dont' worry about that.

There's a set of contacts in the Ansul system. Run your control voltage through those contacts so when the system discharges, it sends the control voltage to the shunt trip breakers, turning them off.

You'll also need to shut down the make-up air.

 

[chris kennedy]

You will probably only need one conduit to the Ansul control box.

MC is fine, unless local restrictions apply.

 

[celtic]

Have the Ansul guys change the relay from 2 to 4 contacts.....just in case

Last kitchen I did I used 3 contacts....FA, hood[shunt ckts], gas valve. [If I recall correctly ??]

EDIT:
This may come in handy also ~ Open NFPA 96: Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations, 2008 Edition.

 

[aftershock]

Make sure your exhaust fan comes on when the system is engaged
I usually use a switch to the coil of a contactor for the exhaust and also bring in the s/l from the system to the same coil so no matter if the switch is on or not, the exhaust will come on when the system is engaged.

 

[480sparky]

Have the Ansul guys change the relay from 2 to 4 contacts.....just in case

I'm never so fortunate. I get one set of contacts. That's all they bid. So I always figure installing another set of relays to do everything I need it to.

Some chain restaurants will supply a 12x12 j-box prewired with their own design of what needs to happen if the system is set off. Check your specs.

Discharging the Ansul system may also require triggering the fire alarm system, if there is one.

 

[wireperson]

how does thw shutting off the circuits under the hood work ? are they wired normally , from the outlet to the panel?

 

[wireperson]

here is the diagram

 

[480sparky]

Are the breakers that feed them shunt trips?

 

[celtic]

how does thw shutting off the circuits under the hood work ? are they wired normally , from the outlet to the panel?

Are the breakers that feed them shunt trips?

They should be shunts.

The print may not show it...the panel schedules may not even show them [as was the case on the last one I did].

 

[aftershock]

I have never had the pleasure of working a system that has contactors/relays built in. I have only worked with a system with 2 micro switches. 1 NO and 1 NC.

I use a common hot to the micro switches, this same hot will also be my hot for the switch that will control the contactor for the exhaust fan. (keeps from having a backfeed).

I could draw a diagram, but I do my best by being at the job and working my brain from there.

 

[wireperson]

no they Are not

 

[480sparky]

no they Are not

If not, you're going to need a contactor to shut them off.

 

[celtic]

no they Are not

If not, you're going to need a contactor to shut them off.

Is one of the panels, the one that feeds the under the hood items, a MCB shunt?

 

[480sparky]

Is one of the panels, the one that feeds the under the hood items, a MCB shunt?

Certainly a plausabilty....:wink:

 

[aftershock]

Are the breakers that feed them shunt trips?

Call me stupid for asking this, but, does this mean the ungrounded and grounded conductors are controlled by the breaker?

 

[celtic]

Certainly a plausabilty....:wink:

..an expensive one

 

[celtic]

Call me stupid for asking this, but, does this mean the ungrounded and grounded conductors are controlled by the breaker?

Just the ungrounded.
There is no requirement to break all the conductors as you would have with gas station pumps and the like.

 

[480sparky]

Call me stupid for asking this, but, does this mean the ungrounded and grounded conductors are controlled by the breaker?

No a shunt trip uses an external power source to 'trigger' the mechanism, shutting the breaker off. They have either leads or terminals to receive that incoming power, and a coil to trip the breaker off.

As you can see, it uses an extra 'space' for the trip mechanism. So a 1-pole shunt trip needs 2 spaces.... a 3-pole would need 4 spaces. You also need to verify the control voltage matches the coil specs for the breaker (similar to coild voltages for lighting contactors).

And no, I'm not going to call you stupid.

 

[aftershock]

No a shunt trip uses an external power source to 'trigger' the mechanism, shutting the breaker off. They have either leads or terminals to receive that incoming power, and a coil to trip the breaker off.

As you can see, it uses an extra 'space' for the trip mechanism. So a 1-pole shunt trip needs 2 spaces.... a 3-pole would need 4 spaces. You also need to verify the control voltage matches the coil specs for the breaker (similar to coild voltages for lighting contactors).

And no, I'm not going to call you stupid.

So these are used in place of a contactor? Sorry if I seem under educated on these type of breakers, I have only knowledge of using contactors to control electrical.