clean agent system delay

[cda]

anyone know if there is a maximumn time delay allowed, once that detection has said dump?????????????

nfpa 2001 does not appear to have a max delay

 

[Coug Dad]

4.3.5.6  Time Delays.

4.3.5.6.1* For clean agent extinguishing systems, a pre-discharge alarm and time delay, sufficient to allow personnel evacuation prior to discharge, shall be provided. For hazard areas subject to fast growth fires, where the provision of a time delay would seriously increase the threat to life and property, a time delay shall be permitted to be eliminated.

4.3.5.6.2  Time delays shall be used only for personnel evacuation or to prepare the hazard area for discharge.

4.3.5.6.3  Time delays shall not be used as a means of confirming operation of a detection device before automatic actuation occurs

The delay is allowed to be long enough only to allow occupant evacuation from the space.

 

[cda]

""or to prepare the hazard area for discharge."""

The room we are looking at has motorized louvers, that are open to the outside.

It takes about 90 seconds for them to close, once two smokes are activated, and louvers cannot be speeded up.

They cannot close on first alarm.

So now when two detectors lock in, the thirty second clock starts, before the system dumps.

So was wondering if the delay can be bumped to 90 seconds ????

 

[globe trekker]

cda,

While researching your question, I came across some engineered systems

that were set for 30 secs. & some 60 secs.

I believe that each application is going to be different, with different

parameters to consider, ..custom designed to each installation.

.

 

[cda]

They are looking into if they can even program it past thirty seconds

 

[Coug Dad]

If it takes 90 second to prepare for discharge, that would be acceptable per NFPA. If it were my protected space, I would look for a way to speed that up to get protection quicker on the high value equipment. As an AHJ you would probably have to accept it.

 

[globe trekker]

Once you get past the 30 sec. range, involvement of the fire itself will

become a greater obstacle.

Tyco, Kidde & Ansul were the manufacturers that I looked at.

.

 

[cda]

Thank you....