Aren't these motorised dampers specified the fail safe in a way that favors fire mode operation? And secondly as per AS1668.1 all wiring to smoke exhaust systems should be fire rated and be controlled by the FFCP so this should be an issue.
In my experience in the Northeast US, the control of dedicated smoke equipment (that is HVAC equipment that only operates during a fire event, as opposed to post event smoke purge/cleanup, etc. which is typically done by standard environmental AHU's and EF's.) control of dedicated smoke control equipment is done by EITHER the Fire Alarm System OR BMS, but not both. If it is done by BMS, all cabling and comm must be protected by 2-hr rated (Mineral Insulated Cable or standard cable run within a 2-hr rated enclosure).
Thanks for commenting Dennis. Here in Australia, the BMS is not permitted to play any part in the smoke control system, regardless if the cables and power supplies are protected etc. Interesting, good to know.
Is it not standard process for the BMS to mute the fire trip signal during fire testing? I've also seen it quite explicitly stated in both mechanical specs and FERs that the AHU BMS dampers are to have their power run through a fire trip relay. That being said, I've definitely seen what you've shown with relays that have been overridden not only after commissioning, but after annual fire tests. It's quite worrisome.
@@bryceanderson17 there's always somebody dumb enough to outsmart such efforts 🤭 like moving the wire from the N.O. terminal to the COM terminal, directly connected to the hard active... "Hey relax, I'll put it back how it was after lunch"... Often on a Friday before a long weekend 🥳
Hummmmmm l can see how it could happen, but cannot recall seeing that "mimic" clause in a FD. Most FDs monitor the Fire Alarms to precisely to suppress the mismatch alarms. And having the power supply to the dampers downstream of the dampers is commonplace - in my experience. My gripe is commonly seeing fire interface panels in their plastic enclosures located in exposed positions.....ie: they connect to fire rated MCCs from exposed positions. Next gripe, is over time fire service companies sometimes change the fire matrix, especially those that are very complex, making a mockery of the fire engineering. I have seen this often, but yet the Fire Safety certificate is signed.....😮 My top tip for dampers used for smoke control is to have end switches (or similar) so that the BMS can monitor the actual position remotely during fire testing....,.saves time and hassle.
This is gold. ❤️
Aren't these motorised dampers specified the fail safe in a way that favors fire mode operation?
And secondly as per AS1668.1 all wiring to smoke exhaust systems should be fire rated and be controlled by the FFCP so this should be an issue.
In my experience in the Northeast US, the control of dedicated smoke equipment (that is HVAC equipment that only operates during a fire event, as opposed to post event smoke purge/cleanup, etc. which is typically done by standard environmental AHU's and EF's.) control of dedicated smoke control equipment is done by EITHER the Fire Alarm System OR BMS, but not both. If it is done by BMS, all cabling and comm must be protected by 2-hr rated (Mineral Insulated Cable or standard cable run within a 2-hr rated enclosure).
Thanks for commenting Dennis.
Here in Australia, the BMS is not permitted to play any part in the smoke control system, regardless if the cables and power supplies are protected etc.
Interesting, good to know.
Is it not standard process for the BMS to mute the fire trip signal during fire testing?
I've also seen it quite explicitly stated in both mechanical specs and FERs that the AHU BMS dampers are to have their power run through a fire trip relay.
That being said, I've definitely seen what you've shown with relays that have been overridden not only after commissioning, but after annual fire tests. It's quite worrisome.
It is worrying, maybe we shouldn't supply relays with mechanical overrides for life safety relays?
Cheers.
@@bryceanderson17 there's always somebody dumb enough to outsmart such efforts 🤭 like moving the wire from the N.O. terminal to the COM terminal, directly connected to the hard active... "Hey relax, I'll put it back how it was after lunch"... Often on a Friday before a long weekend 🥳
Hummmmmm l can see how it could happen, but cannot recall seeing that "mimic" clause in a FD. Most FDs monitor the Fire Alarms to precisely to suppress the mismatch alarms. And having the power supply to the dampers downstream of the dampers is commonplace - in my experience.
My gripe is commonly seeing fire interface panels in their plastic enclosures located in exposed positions.....ie: they connect to fire rated MCCs from exposed positions.
Next gripe, is over time fire service companies sometimes change the fire matrix, especially those that are very complex, making a mockery of the fire engineering. I have seen this often, but yet the Fire Safety certificate is signed.....😮
My top tip for dampers used for smoke control is to have end switches (or similar) so that the BMS can monitor the actual position remotely during fire testing....,.saves time and hassle.
Every single BMS FD in Victoria Australia has that statement in the FD. Where are you based?
@@bryceanderson17 Sydney.....