Fan Shunt Trip

[Wires277]

Hello guys,

I would like to know if any knows of code that requires air circulators in a commercial building (14,000 CFM) to be on a shunt trip. I know it applies to roof top kitchen hoods but could not find anything in NEC or NFPA for air circulators.

Thanks

 

[mopowr steve]

I can't remember what code it might be but after so many cfm in commercial buildings it may be required to shut the fans down during a fire. So somehow the fans need connected with shunt trip breakers that are controlled by fire alarm or smoke detection systems.

 

[GoldDigger]

Some types of occupancy (e.g. assemblys) require fan shutdown in case of fire or smoke detection.
If the building does not require a central fire detection and protection system, it would be interesting to figure out what should trigger the shunt trip.


Tapatalk!

 

[Wires277]

This is a large building open floor warehouse with 84 fans at 14,00 CFM each total of 1.176.000 CFM. The HVAC systems and other machine in building are on a shunt trip with the fire alarm system, Im sure their should be a requirement for them to be on a shunt just not able to find anything on it.

 

[iwire]

There is no code that requires them to be on a 'shunt trip'.

There are fire codes that require HVAC units that move more than 2000 CFM to shut down during smoke conditions.

How you shut them down is a design choice but we don't use shunt trip breakers we simply break the control circuit with either a smoke detector or a fire alarm relay.

If you use shunt trips not only are you spending more money the units will not restart when the fire panel is reset. You would have to manually reset each breaker.

 

[Wires277]

Thanks Guys......

 

[iggy2]

Look at NFPA 90A and/or 90B for shutdown requirements - assuming they are adopted in your jurisdiction. But many model codes also mimic what 90A/B say.

 

[kwired]

There is no code that requires them to be on a 'shunt trip'.

There are fire codes that require HVAC units that move more than 2000 CFM to shut down during smoke conditions.

How you shut them down is a design choice but we don't use shunt trip breakers we simply break the control circuit with either a smoke detector or a fire alarm relay.

If you use shunt trips not only are you spending more money the units will not restart when the fire panel is reset. You would have to manually reset each breaker.

And in buildings where they have "fire drills" this would mean manually resetting all of them every time there is a drill - or for other testing of the alarm system. If you interrupt control circuits resetting the alarm system restores those controls as well.