Sapphire and Hvac Shutdown

[cb1151]

I have a situation where the owner wants to change the sequence of operation so that the hvac shuts down via EPO upon discharge.

I do not feel like this is possible due to the time sapphire is discharged within (10 seconds I believe). The crac units could potentially recirculate air as the sapphire discharges, until the crac has stopped churning 100%.

Anyone have any input on this? Code references, past experience? Anything?

 

[cdafd]

delay the discharge till hvac shut down???

cannot give you standard section to support delay

 

[cb1151]

yes, they want to add a delay basically for the discharge but they are not wording it that way. Smoke and mirrors basically.

As far as I know, delays are for evacuation, not shutdowns.

 

[cdafd]

Suggest call maker, and ask for tech support.

They sometimes have heard alot of the questions we ask, and can give guidance, and may be part of thier install instructions.

We are looking at a fm 200 system and there is a 45 second built in delay which at the same time also sends a signal to shut down the hvac.

what kind of detection are they proposing???

 

[DM2]

You need to have a read through NFPA 2001 (but you probably knew that). You'll find that the shutdown of a HVAC system isn't required and provided it recirculates the fire suppression agent, it may actually be a good thing. The concern would be if the HVAC unit is the one that caused the fire.

NFPA 2001 doesn't specify a time period for which the equipment has to be shutdown. The delay posted by CDAFD is a viable option.

You may also want to have a consult with NFPA 75, section 8.4 "Standard for the protection of Information Technology Equipment", and NFPA 76 "Standard for the fire protection of Telecommunications Facilities" if you facility falls into either of these two categories.


Regards,
Dan Marr

"Real world Knowledge isn't dropped from a parachute in the sky but rather acquired in tiny increments from a variety of sources including panic and curiosity."

 

[cb1151]

It turned out that the EPO couldn't even do what they wanted to do.

NFPA 2001 says equipment should be shut down but if it can't be then gives another option (forget off the top of my bald head).

The end result was the hvac shuts down before the time delay. The time delay is 20 seconds. Crac unit shuts down 100% in 8 seconds.