Shunt Trip Breakers Commercial Cooking

[Brunz]

I am looking for documentation on the use of shunt trip breakers or other disconnecting means for receptacle power under the hood of a commercial cooking application, where an Asul system is used as the fire supression system. I am told that the chemical used is conductive.

 

[augie47]

Most of the regulations are found in NFPA17A.
In general terms, because of the conductivity of the Ansul fire protection, all electrical under the hood must be disconnected when the system trips.

 

[Brunz]

Ansul Fire Protection

Ansul Fire Protection

Excellent, my next question, is the disconnecting means required to be a shuntrip breaker? Is it permissable to feed the circuits through a contactor and use the normally closed contacts on the Ansul System to control the coil?

 

[Hendrix]

Most of the regulations are found in NFPA17A.
In general terms, because of the conductivity of the Ansul fire protection, all electrical under the hood must be disconnected when the system trips.

Around here, the fan must keep running.

 

[Brunz]

From what I understand only the power serving the equipment under the hood must be disconnected, the lights and fan are not in line to be affected by the chemical used.

 

[RICK NAPIER]

This question keeps popping up. In NFPA 17A article 4.4.3.1 requires "all sources of fuel and electric power that produce heat to all equipment protected by the system shall be shut down." 4.4.3.2 requires "gas appliances not requiring protection but located under the same ventillation equipment shall also be shut down. This means only the cooking equipment protected by the ansul system and other gas appliances need to shut down. The lights and other electric power do not need to shut down if you are using NFPA 17A.

 

[Brunz]

Excellent, my next question, is the disconnecting means required to be a shuntrip breaker? Is it permissable to feed the circuits through a contactor and use the normally closed contacts on the Ansul System to control the coil? Would this be a suitable disconnecting means?

 

[augie47]

Brunz,
I appreciate Rick's post and don't disagree with it in any way. That said, you might want to check with the Fire Marshal, if any, for the area in question.
After reading Rick's post I contacted the FM that has been requiring ALL electrical to shut down and he advises it is a National Fire Code (2006) requirement but I have no documentation to support that.
(He is providing documentation, and if and when he does I will update the post)

 

[Brunz]

I appreciate you following up for me. I am only being asked to shut down equipment power. I am working with an older kitchen and panel. Currently there is no disconnecting means for the equipment power in the event of an alarm on the Ansul system. The panel has no open spaces to fit shunt-trip breakers into it. Would it be legal to use a contactor as a disconnecting means if the coil power is fed through a set of normally closed contacts on the Ansul system in order to avoid using shunt-trip breakers?

 

[Cow]

Would it be legal to use a contactor as a disconnecting means if the coil power is fed through a set of normally closed contacts on the Ansul system in order to avoid using shunt-trip breakers?

I've used a contactor the last 2-3 times. As long as the hood equipment/make up air shuts down when the fire suppression system is activated, is all they care about.

The exhaust fan is left running.

 

[Brunz]

Thank you sir.

Bryan

 

[Brunz]

Thank you Sir

 

[Brunz]

Thank you. It will save me a sub-panel.

 

[220/221]

The ones I have done .....

Everything under the hood off, gas supply off, ex fan on, makeup air off. Ex fan is not under the hood it is remotely located on the roof. All done via contactor/switches.

The one I am doing next week utilizes a 50 amp shunt trip breaker for a slide in gas/electric range.

 

[mcclary's electrical]

The ones I have done .....

Everything under the hood off, gas supply off, ex fan on, makeup air off. Ex fan is not under the hood it is remotely located on the roof. All done via contactor/switches.

The one I am doing next week utilizes a 50 amp shunt trip breaker for a slide in gas/electric range.

It's the same way here, I'm doing one tomorrow that uses a 60 amp, tan handle CH shunt trip.

 

[RICK NAPIER]

Augie,
In the IFC 2006 904.11.2 System interconnection.-"The actuation of the fire extinguishing system shall automatically shut down the fuel or electric power to the cooking equipment. The fuel and electric supply reset shall be manual." Also articles 904.5 Wet-chemical systems and 904.11 Commercial cooking systems direct you back to NFPA 17A. These would not require anything beyond previous stated NFPA 17A requirements.

 

[LarryFine]

Excellent, my next question, is the disconnecting means required to be a shuntrip breaker? Is it permissable to feed the circuits through a contactor and use the normally closed contacts on the Ansul System to control the coil?

I do the wiring for such system upgrades, and unless shunt-trips are already in use, I use contactors as you describe. Never been an issue.

 

[LarryFine]

Around here, the fan must keep running.

Here, the exhaust must turn or stay on, everything else, including make-up air and lights, must shut down.

 

[LarryFine]

Would it be legal to use a contactor as a disconnecting means if the coil power is fed through a set of normally closed contacts on the Ansul system in order to avoid using shunt-trip breakers?

Absolutely.

 

[Brunz]

Larry,
Rick stated that the electric supply reset must be manual.

Augie,
In the IFC 2006 904.11.2 System interconnection.-"The actuation of the fire extinguishing system shall automatically shut down the fuel or electric power to the cooking equipment. The fuel and electric supply reset shall be manual."

If this is the case then with a contactor, as soon as the Ansul system is reset, the power to the coil will be restored, energizing the circuits that were previously disconnected. This would not be a manual reset would it? Am I thinking too much into it?